UNITED STATES DEPARTMENT OF COMMERCE • John T. Connor, Secretary NATIONAL BUREAU OF STANDARDS • A. V. Astin, Director

Dimensional Metrology

Subject-Classified With Abstracts

Through 1964

Including linear, angular, and geometrical measurement

and in-process control of size and form, but generally not

including gages, gaging, and inspection as to limits of size.

Compiled by Irvin H. Fullmer

National Bureau of Standards Miscellaneous Publication 265

Issued August 1, 1966

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C., 20402

Price ?3
Abstract

This bibliography covers two of the three principal divisions of dimensional metrology, namely (1) linear, angular, and geometrical measurements of solid bodies, and (2) in- process control of sizes. The remaining division is gages, gaging, and inspection as to specified limits of size. There are about 3,600 references classified under main subject headings in 12 sections, which are further subdivided into 102 subsections covering. 100

subjects. The 12 main subjects are (1) general metrology, physical and dimensional; (2) length and diameter measurements by interferometry ; (3) length and diameter measure- ments by mechanical methods: (4) calibration of line standards of length, including tapes; (5) dimensional measuring instrument design features; (6) angle measurement;

(7) measurements of deviations from geometrical regularity; (8) measurement of profile; (9) measurement of screw threads; (10) measurement of gears; (11) measurement of thickness of thin films; and (12) measurement and production techniques for accurate

in-process control of size and form. The references in each subsection are arranged chronologically and a brief abstract of each is given with few exceptions. The bibliography is an

attempt to organize and make more readily available the extensive existing knowledge

in the field covered.

Library of Congress Catalog Card No. 64-62750
Foreword

In the manufacture of modern machines and instruments, an indispensable requirement is the control of the dimensions of parts to within specified tol- erances. Such control makes possible the interchangeability of parts produced

in different localities; it also is essential to the proper functioning and relia- bility of the final assembly. Various methods are used to achieve dimensional control. They include

(1) control by the production machine or process; (2) application of statis- tical methods of quality control, which involve measurement of samples of parts taken at intervals; and (3) the gaging of in-process or finished parts by means of fixed or indicating gages. All such methods of control require that measurements of the gages or product be made. Thus the underlying basis of such control is the selection and application of measuring techniques whose

accuracy is compatible with the gage or product tolerances. This bibliography has been compiled to facilitate the application of exist- ing knowledge regarding measuring methods and equipment. In particular,

it is designed to further the development of a series of American Standards by

Sectional Commitee B89 on Dimensional Metrology, organized under the pro- cedure of the American Standards Association and sponsored by The American Society of Mechanical Engineers. Although the literature of dimensional metrology is extensive in the areas of gaging methods and gages, the present

publication, consisting of about 3,600 references, is mostly limited to dimensional measurement that yields numerical results. A. V. Astin, Director.

Preface

The arrangement of this bibliography was de- termined by the nature of the subject matter

treated. A strictly chronological arrangement of

all entries -would have required an extensive subject index, which was considered economically impracticable for such a broad subject, Instead, the

entries are grouped into sections according to the

principal subject treated in each case, and a brief

abstract of each entry is given. There are 12 major sections, which are further

subdivided into 102 subsections covering 100 subjects. Within each subsection, the references are arranged chronologically, so that a reading of the

successive abstracts will yield a fairly comprehensive picture of the historical development of each

subject. There is some, but not extensive, cross- referencing. The order of the sections has only slight rela- tion to their importance. The first section is general and therefore introductory. The section on interferometry is placed next because the in- ternational standard of length is now a wavelength

of light from a krypton 86 lamp. From the point

of view of historical development, section 4 might

have been the second section, followed by section 3. The compiler has not indicated in detail the

sources of the abstracts, of which he prepared

about 25 percent. He gratefully offers the follow- ing acknowledgments with respect to assistance and sources

To the Engineering Index, Inc., New York, for about 50 percent of the references and abstracts which were copied, by permission, directly from

the numerous volumes of the Engineering Index. To Physics Abstracts, London, as the source of about 25 percent of the abstracts. To Dr. Lewis V. Judson, Physicist, NBS (now

retired), who had compiled lists of early refer- ences which are embodied in section 4 and subsection 6.4. To Dr. Werner F. Vogel, Engineering Advisor, NBS (Professor Emeritus of Engineering Mechanics, Wayne State University, Detroit), for

suggestions relative to arrangement and content, particularly with reference to sections 9 and 10. To Dr. Erwin G. Loewen, Bausch and Lomb,

Inc., who furnished a list of references not other- wise available to the compiler. To the secretarial staff of the Engineering Metrology Section, NBS, who over many years pre- pared an extensive card file on this and other

subjects of interest to the Section, and for typing and duplicating services.

v
How To Use This Book

// you are looking for references on a particular topic: First consult the

table of contents and find the subsection that covers your topic. (If the topic

is a broad one or is not well defined, it may take more than one subsection to cover it adequately.) Then turn to the page number indicated, where you

will find the references of that subsection listed in the order of their dates of

publication. // you are looking for publications by a particular author: First consult the author index at the back of the book, where all publications included in this bibliography are listed under the author's name, by subsection number and

year of publication. You can then find the references you need by consulting

the page numbers given. If there are a great many publications by a single author, you may be able

to select those most likely to interest you on the basis of their subsection numbers (which indicate the topics) and years of publication. A considerable number (a minority) of the papers listed herein are in

a file at the Engineering Meteorology Section, NBS, which is keyed to this publication. When articles are not otherwise available to the reader this file may be consulted. Advance arrangement to do so is desirable. Also, authors

are invited to send reprints for inclusion in this file. Further hints on the use of the book may be obtained by reading the

preface. Also, note the list of abbreviations that follows.

vi
Bibliographic Abbreviations

AAAS American Association for the Advance- ment of Science Abh Abhandlung(en)

Acad academie, academy AGMA American Gear Manufacturers Association. Agric agricultural AIEE American Institute of Electrical Engineers Akad Akademie, akademii Am American An anales Analyt analytical Angew angewandte Ann annales Annu annuaire AOA American Ordnance Association App applied Arch architectural ASA American Standards Association ASHRAE American Society of Heating, Refrigerating, and Air Conditioning Engineers ASME The American Society of Mechanical Engineers Assn association ASTM American Society for Testing and

Materials ASTME American Society of Tool and Manufacturing Engineers

Astron astronomical, astronomische

Astrophys astrophysical, astrophysics

Austral Australian Automat automation

Ber Berichte BIPM International Bureau of Weights and

Measures

Bldg building

Brit British Bros brothers BS British Standard

Bui bulletin Bur bureau

Can Canadian

Cer ceramic Chem chemical, chemistry Chun Chimie, chimique

Cir circular Civ civil Co company

Conf conference

Constr constructional Corp corporation CP circular pitch CR comptes rendus Dept department DIN German Engineering Standard

Div division Dokl doklady DP diametral pitch Ed edition

Elec electric, electrical Elecn electrician Eng engineering (British Periodical)

Engr(s) engineer(s) (British Periodical) Exper experimental

Fiz fizika, fiziki

FoKoMa Fertigungstechnisches Forschungs- und

Konstruktions-Kolloquium WerkzeugMaschinen und Betriebswissenschaft Fortschr Fortschritte Found foundation Gaz gazette GB Great Britain Gen general, generale Geol geological Geophys geophysics, geophysical Ges Gesellschaft GOST Russian All-Union State Standard Gov government Handb handbook Handl Handlungen Hogsk hogskolans IEEE Institute of Electrical and Electronic Engineers

Ilium illuminating IMS Industrial Mathematics Society Inc incorporated Indus industrial, industrielle, industries Ing Ingenieur

Inst(s) institut, institute (s) Instn institution Instrum(s) instrument(s) InstrumKde Instrumentenkunde

Int international IRE Institute of Radio Engineers ISA Instrument Society of America ISO International Organization for Standardization Izmer Tekh izmeritel'naya tekhnika

Izv izvestiya J journal K kungliga

Lab(s) laboratory(ies) Ltd limited Mach machinist Machy machinery Mag magazine Mar marine Math mathematical

Matl(s) material (s) Meas measurement Mech mechanical Mem memoirs, memoires Memo memorandum

Met metallurgical, metallurgy Mfg manufacturing

Mfr(s) manufacturers) Mgmt management

Mil military Min mining Misc miscellaneous Mitt Mitteilungen Mod modern Monogr monograph Mun municipal Nachr Nachrichten NASA National Aeronautics and Space Administration Nat national Naut nautical NBS National Bureau of Standards NPL National Physical Laboratory, Great

Britain

vii
Opt optical, optische, optique PA pressure angle PERA Production Engineering Research Association of Great Britian

Phil philosophical Phys physical, physics, physik, physique

Prac practice, practical Prec precision Proc proceedings Prod product, production Progr progress Pt part PTB Physikalisch-Technische-Bundesanstalt Pub public Publ publication Q quarterly Rec record Rech recherche Refs references Refrig refrigerating, refrigeration Rep(s) report (s) Res research Rev(s) review (s), revue Roy royal, royale Ry railway S south SAE Society of Automotive Engineers, Inc. Schweiz schweizerische

Sci scientific, scientifique, science

Sec section Ser series Sipbldg shipbuilding

Shipbldr(s) shipbuilder^) Shipg shipping Soc soci6te\ society Spektrosk spektroskopiya Stand standard (s) Supp supplement, supplemento

Syst system Tech technical, technische Technol technology, technological Techn(s) technique(s) Teen technica Tekh tekhnicheskoi Tekn tekniska Telecomm telecommunications Theor theorique Tidskr tidskrift Trans transactions Trav travaux Univ university VDI Verein Deutscher Ingenieure Vent ventilating, ventilation Verh Verhandlungen

Wiss wissenschaftliche Wld world

Zeit Zeitschrift Zh zhurnal Ztg Zeitung

vill
CONTENTS

Page Foreword i iii Preface v How to use this book vi Bibliographic abbreviations vii Section 1. General metrology, physical and dimensional 1 1.1. General physical metrology 1*

1.2. General dimensional metrology 6

1.2.1. General 6*

1.2.2. Units of length and angle 10*

1.2.3. Measurements in two- and three- dimensional coordinates 13

1.2.4. Surveying methods applied to large mechanical structures 15*

1.3. Precision, accuracy, uncertainty 17

1.3.1. General 17*

1.3.2. Instrumental errors 19*

1.3.3. Statistical or mathematical treat- ments 22

1.3.4. Personal equation 26

1.4. Temperature effects and measurement 28

1.5. Deformation, deflection, and wear 31*

1.6. Vibration isolation and control 34

1.7. Effects of surface state and texture '_ 36

Section 2. Length and diameter measurements by

interferometry 41

2.1. Interferometry, general 41

2.2. Interferometry theory 44

2.2.1. General 44

2.2.2. Method of coincidences.- 48*

2.2.3. Aperture correction 50

2.2.4. Refractive index of air 52

2.2.5. Phase change at reflection 53

2.3. Wavelength standards and light sources 56

2.3.1. General 56*

2.3.2. Cadmium 59

2.3.3. Krypton . 61

2.3.4. Mercury 63

2.3.5. Helium 65

2.3.6. Atomic beam 65

2.3.7. Lasers 66

2.4. Length and diameter measurements 68

2.4.1. General 68*

2.4.2. Fringe count interferometers and

dilatometers 72*

2.4.3. Fabry-Perot interferometers 78

2.4.4. Interference comparators 81*

2.4.5. Measurement of long lengths 84*

2.4.6. Measurement of line standards 86*

2.5. Metrological gratings 87

Section 3. Length and diameter measurements by

mechanical methods 91

3.1. Contact length standards 91

3.2. End measuring rods and measurement of long lengths 94*

3.3. External diameters 97*

3.4. Internal diameters. ..' 101*

3.5. Measuring machines and bench micrometers. 103*

3.6. Manual measuring tools 108

3.6.1. General 108

3.6.2. Micrometers 110

3.6.3. Vernier instruments 114

3.6.4. Dial and test indicators 114

Pag* Section 4. Calibration of line standards of length, including tapes 117

4.1. Line standards, general 117*

4.2. Calibration of subintervals 120

4.3. Calibration of tapes 122*

4.4. Measuring microscopes and line comparators 123

Section 5. Dimensional measuring instrument design features 129

5.1. Measuring instruments, design principles.. 129

5.2. Amplification 131

5.2.1. General 131

5.2.2. Electrical 132*

5.2.3. Mechanical 138

5.2.4. Optical 139*

5.2.5. Pneumatic 141

5.3. Dials and pointers 143

5.4. Optical features 143

5.5. Pivots 146

5.6. Slides, stands, and tables 146

5.7. Springs and suspensions 148

Section 6. Angle measurement 153

6.1. Angle measurements, general 153

6.2. Alinement, straightness, and autocollimators 157

6.3. Angle gage blocks and polygons 162

6.4. Calibration of graduated circles, dividing

heads, and protractors 164

6.5. Angle measurement by interferometry 167*

6.6. Sine bars, plates, and fixtures 169

6.7. Spirit levels 170

6.8. Tapers 172 Section 7. Measurements of deviations from geometrical regularity 175

7.1. Planeness measurement 175*

7.2. Parallelism measurement 180*

7.3. Straightness and surface topography 181

7.4. Roundness and concentricity measurement. 185 Section 8. Measurement of profiles 189

8.1. Measurement of radius or profile by mechanical methods 189

8.2. Contour measurement by optical projection. 193

8.3. Measurement of involute contours 196

Section 9. Measurement of screw threads 197

9.1. General I 97

9.2. Lead measurement 202

9.3. Wire and ball measurements of screw threads and other helicoidal features 205*

9.4. Tables for ball, pin, or wire measurements. 212

Section 10. Measurement of gears 213*

10.1. Gear metrology, general 213

10.1.1. Standards and nomenclature 213

10.1.2. Textbooks and handboo s dealing partially with measuring methods 215

10.1.3. Numerical tables 217

10.1.4. Technical papers on gear measure- ment, general 222

10.2. Spur and helical gears 228

10.2.1. Involute form measurement. ... 228

10.2.2. Master gears; composite deviation testing 230

ix
Page Section 10. Measurement of gears—Continued

10.2. Spur and helical gears—Continued

10.2.3. Lead measurements 232

10.2.4. Pin and ball measurements of spur

gears and spur splines 232

10.2.5. Tooth index position measure- ment 234

10.2.6. Tooth thickness, pitch, and span measurement 234

10.3. Bevel, hypoid, spiroid, and worm gears or

drives 238

Section 11. Measurement of thickness of thin films. 241

11.1. Interferometric methods 241

11.2. Polarimetric methods (ellipsometry) 247*

11.3. Miscellaneous methods 249

*One or more additional references relating to this subject •<

Page Section 12. Measurement and production techniques

for accurate in-process control of size and form 257

12.1. General 257* | 12.2. Machine tools 259

12.3. Automatic control 262

12.4. Grinding 265

12.5. Lapping 266 ! 12.6. Manufacture of precision measuring tools and components 268

12.6.1. General 268

12.6.2. Scales and gratings 270*

12.6.3. Worms and power screws, includ- ing lead screws 271 | 12.6.4. Screw thread gages 273

' 12.6.5. Other gages 274 Author index 277

given in the Addendum at the end of the section.

X
Section 1. General Metrology, Physical and Dimensional

CONTENTS

Page

1.1. General physical metrology 1 1.2. General dimensional metrology 6

1.2.1. General 6

1.2.2. Units of length and angle ; 10

1.2.3. Measurements in two- and three-dimensional coordinates 13

1.2.4. Surveying methods applied to large mechanical structures 15

1.3. Precision, accuracy, uncertainty 17

1.3.1. General 17

1.3.2. Instrumental errors 19

1.3.3. Statistical or mathematical treatments 22

1.3.4. Personal equation 26

1.4. Temperature effects and measurement 28

1.5. Deformation, deflection, and wear 31

1.6. Vibration isolation and control 34

1.7. Effects of surface state and texture 36 Addendum to Section 1 39 1.1. General Physical Metrology

The Progress of Science as Exemplified in the Art of Weighing and Measuring, PROF. Wm. HARKNESS, U.S. Naval Observatory. Presidential address before the Phil- osophical Society of Washington, 1887. Smithsonian Report, 1888, or Bui of the Phil Soc of Washington

vlO 1887 p 39-86 67 refs. Historical paper dealing partly with length standards. The Theory of Measurement, A deF. PALMER. McGrawHill Book Co. 1912 248 p. Chapters 1-7 deal with the

general principles that underlie all measurements, nature and distribution of errors, and most probable result ; 8-12, precision of measurements; 13, methods of physical

research. The Theory of Measurements, L. TUTTLE. Jefferson Laboratory of Physics, Philadelphia. 1916 303 p. Some

chapter heading are: Angles and circular functions, sig- nificant figures, coordinates in three dimensions, accuracy,

j the principle of coincidence, measurements and errors, indirect measurements, systematic and constant errors. Republished in expanded form, 1925, Tuttle and Satterly. Mensuration for Marine and Mechanical Engineers, J. W. ANGLES. Longmans, Green and Co. London 1919

162 p. Collection of formulas and tables ; elements of trigonometry; lengths, taper, speed; areas of rectilinear

figures; areas of circle and ellipse; surfaces, volumles, weights; surface and volume of cylinder, displacement;

I the cone and sphere ; similar figures, Simpson's rule

weights of machinery. Metrology in the Industries, Proc Phys Soc of London

Meeting of Mar 28, 1919 29 p 3 figs. A general discussion initiated by Sir R. T. GlazebroOk. The International Bureau of Weights and Measures, J. BOYER. Sci Am Monthly v3 n2 Feb 1921 p 105-9 7

illus. An interview with Charles Edouard Guillaume,

director. Bibliography for Measuring Instruments, with Special Reference to Instruments and Methods of Metrology used

in Mechanical Engineering, F. J. SCHLINK. J Opt Soc Am and Rev Sci Instrum v9 Sept 1924 p 309-21. Bibliography classified under the following heads: 1. General

material, theoretical or basic, on physical and mechanical instruments. 2. Measurement and production of small linear and angular displacements and distances.

3. Theory and measurement of vibration ; measurement of speeds and time intervals. 4. Frictional and other types

of hysteresis and their relation to instrument design and

testing ; accuracy, sensitivity and variance. 5. Dynamometers, measurement of force (except weighing scales), torque, and accelerations. 6. Measurement and control

of temperature and humidity. 7. Weighing scales. 8. Pressure gages, manometers, and aneroid barometers.

9. Engine indicators. 10. Properties and design of springs.

11. Miscellaneous instruments. History of the Standard Weights and Measures of the United States, L. A. FISCHER. NBS Misc Publ n64 1925

34 p. Paper contains a series of photographs of important

standards, both ancient and modern.

Metorology, W. BLOCK. Eng Progr, v6 Sept 1925 p 283-5

4 figs. Its definition, significance, and fields of appli- cation

Precision Measurements, G. BERNDT. Eng Progr v6

Sept 1925 p 289-91 4 figs. Their significance and utility in engineering; examples taken from machine construction and instrument making, illustrating great savings achieved by applying precision measuring. Measurement and Calculation, N. R. CAMPBELL. Long- mans, Green and Co., Ltd. 1928 293 p. Chapter headings

are: the laws of measurement, number, numerical laws, derived measurement, classification of magnitudes, stand- ards and factors, errors of measurement, errors of numerical mws, calculation, and argument from dimensions. Experimental Mechanical Engineering, 1, Engineering

Instruments. H. DIEDERICHS AND W. C. ANDRAE.

1930 John Wiley & Sons, Inc. 1082 p. illus. diagrs., charts,

tables. Rewritten text based upon Carpenter and Diederich's "Experimental Engineering," for students and practicing engineers; construction, calibration, and use of instruments for measuring length, etc,; methods in use
described, theory explained and commercial forms of in- struments presented. Eng. Soc. Library, N.Y. ATM Archiv fiir Technisches Messen, R. OLDENBOURG

Lieferungen 4-12 Nov-June 1932 Munich and Berlin, 222 p. illus. diagrs. charts tables. Compendium of measuring

instruments and methods intending to cover, in 5 vols., whole field of technical measurements ; parts are issued monthly, but may be bought singly ; each contains concise

2 to 4-page reviews of dozen instruments or methods, accompanied by references to sources from which account was compiled. Eng. Soc. Library, N.Y.

Introduction a l'Etude de la Metrologie Industrielle, P. NICOLAU. Mecanique v20 n269 Nov-Dec 1936 p 235-45. Introduction to study of industrial measurements ; bio- graphical report and cross-sectional view of technique employed in mechanical engineering. Pruefen und Messen als Voraussetzung technischen Fortschritts, C. RAMSAUER. VDI Zeit v80 n48 Nov 28 1936

p 1429-32. Testing and measurements as prerequisites of technique in engineering progress; author points to role which precision measurements play in modern engineering, and discusses various fields of application in mechanical engineering, aviation, welding, electrical engineering and in factories. Limits of Measurability. W. GERLACH. VDI Zeit v81 Jan 2 1937 p 2-7. The author presents a general review

of the importance of precision in measurement and outlines the methods by which the limits of measurability have been extended. Examples are given of the application of physical laws to this end, e.g., the application of the theory of interference colours to the determination

of thickness. Atomic physics and the quantum theory have extended the attainable limits. The reaction of the measured quantity on the measuring device often imposes

a limit on direct measurements. The influence of the Brownian movement is discussed and illustrated in rela- tion to the measurement of very small amounts of energy

;

and the measurement of atomic magnitudes is discussed. Tolerances and Their Effect on Physical Measurements,

C. DARWIN. Light and Lighting v37 n6 June 1944 p 86

;

Engrs' Digest (Am Ed) vl nil Oct 1944 p 616-8. Author

emphasizes that tolerances has become respectable part, not only of engineering practice, but also of fundamental

science; among examples cited are manufacture of machine for weighing bullets, theory of sound, and optical measurements ; Uncertainty Principle as limitation to tolerances in nature. From address before Illuminating Engineering Soc. Effect of Tolerances on Measurements, C. DARWIN.

Metal Progr v47 n5 May 1945 p 941-6. Discussion of examples showing allowable tolerances, limitations and

physical measurements, including importance of subject

of errors and tolerances in relation to foundations of

physics. Metrologie Generale (Grandeurs et Unites), M. DENISPAPIN, J. VALLOT. Dunod, Paris, 1946 428 p plates I-XLVI tables diagrs. charts. Discussion of measure- ment in general, international system of weights and

measures, and symbols and equations of fundamental sys- tems of measurement ; methods of measurement and units described for fields of geometry, geography, mechanics, angular measure, stresses, electricity and magnetism, heat and radiant energy, optics and time as well as for every- day use. Eng. Soc. Library, N.Y. A Discussion of Units and Standards, Staff of NPL. Proc. Royal Soc A vl86 21 Mar 1946 p 149-217 6 figs refs. A

discussion of 10 types of physical standards. Symposium on Metrology, J. C. EVANS, Eng vl61 n4189 Apr 26 1946 p 401-2; Nature (London) vl57 n3991 Apr 27

1946 p 538-40. Review of symposium held at Royal Society, of short papers dealing with principal units and

standards of scientific measurement, read by Director, D. Darwin, and members of staff of National Physical Laboratory. Training In Inspection and Gaging In Mechanical Engineering, R. L. GEER. Instrum vl9 nl2 Dec 1946 p 726-8. Need in mechanical engineering curriculum of study of precision measuring techniques; origin and development

of course in measuring instruments for Sibley School of Mechanical Engineering, Cornell Univ. is discussed : pro- gram of lesson topics of course is outlined in detail. Fundamental Concepts of the Technique of Measurement.

J. HARTMANN, Rev Sci Paris v85 Apr 1 1947 p 323-4 in French. The idea of measurement as a production, anal- ogous to an industrial production, of which the product

is an image in figures of the property measured, is de- veloped. The terms, uncertainty (incertitude), error

(faute). tolerance, in relation to the production, and in- determinacy, falsification, in relation to the product, are

clearly defined. The relationships between these are ex- plained and illustrated by examples. It is shown that the uncertainty of production is manifested by the indetermi- nacy of the product, i.e. by oscillatory deviations from

a mean value, whereas the error of production is manifested by the falsification of the product, i.e. by a unilat- eral deviation. Limit of Sensitivity, J. L. VAN SOEST, J. L. BOR- DEWIJK. Tijdschrift van het Nederlandsch Radiogenootschap vl2 May 1947 p 113-23 in Dutch. A general

discussion of sensitivity of measurement and restrictions on the accuracy of measuring instruments and scale readings. Metrologie, son Origine, son Evolution, A. C. PRULIERE.

Microtecnic vl n3 June 1947 p 126-32 ( English translation

in separate section p 54-7). Origin and development of metrology ; data on metric system and length standards

;

review of work done in field of metrology in United States, England, France, Germany and Switzerland. Bibliog- raphy.

Precision Measurement Methods and Formulas, J. JOHNSON. Pitman Publ Corp, New York and London, 1948

181 p diagrs tables, Bridging gap between "school" mathematics and practical application theory, book presents

actual problems and their solutions ; overall theory behind

solution is shown ; solutions are for greater part based on

setups requiring simplest of instruments; no special

ability other than knowing how to use trigonometric

tables is necessary. Eng. Soc. Library, N.Y. Some Applications of Electronics in Metrology, E. J. B. WILLEY. Sci Progr v36 Jan 1948 p 55-65 4 figs 18 refs. A short review article. Electrical gages, surface meters,

vibration and acceleration meters, strain gages and ultra- sonic thickness meters and flaw detectors are touched on. Instruments, Physics, and Physicists, G. F. GARDNER.

Gen Elec Rev v51 nlO Oct 1948 p 11-3. Good measuring

instrument is essentially conveniently arranged physics experiment that can be repeated at will within specified accuracy limits; historical examples of instrument de- velopment or invention are given. Messung und Darstellung physikalisch-technlscher Groessen, W. SPAETH. VDI Zeit v91 nl8 Sept 15 1949 p

471-5. Measurement and presentation of physicaltechnical quantities ; relation between two coordinates

;

practical examples include time and reciprocal of time, hardness and softness, stability limit of rivets, frictional phenomena, coefficient of expansion and melting point, and applications in Bessemer converter. Bibliography. 2
Coup d'Oeil sur la Situation de la Metrologie Industrielle dans le Monde, M. CHALVET. Rev. Gen de Mecanique

v34 nl3 Jan 1950 p 18-25. Outline of world status of in- dustrial metrology; historical background; types of measuring apparatus; gages, comparators, interferometers, etc; illustrations. Xeue optische Messgeraete fuer Werkstueck- und Werkstoffpruefungen, A. METZ. VDI Zeit v92 nl3 May 1 1950 p. 323-31. New optical measuring instruments for

testing of workpieces and materials ; different types of microscopes. Atomic Definition of Primary Standards, R. D. HUNTOON, U. FANO. Nature (London) vl66 n4213 July 29

1950 p 167-8. In view of limits to accuracy with which

one can compare any physical quantity with primary

standards, possibility of selecting other quantities to serve in place of present primary standards, such as im- mutable properties of atoms or molecules with which

other physical quantities can be readily and accurately compared, is considered ; set of working definitions consistent with latest values of atomic constants are atomic

meter, second, ampere, Newton, Coloumb, and kilogram. Handbook of Measurement and Control, M. F. BEHAR,

editor. The Instrum Publ Co. Pittsburgh 1951 291 p. Classisification ; measurables, effects and methods ; static measuring properties ; the response ; the prime relay. Changes of State Caused by the Process of Measurement,

G. LUDERS. Ann Phys Leipzig. v8 n5-8 1951 p 322-9 in German. A treatment by v. Neumann (Mathematische Grundlagen der Quantenmechanik, 1932) is critically dis- cussed and an alternative treatment introduced, which

permits of a fuller discussion of the concept of the compatibility of measurements.

Units and Standards of Measurement Employed at the National Physical Laboratory. I. Length, Mass, Time;

Volume, Density and Specific Gravity, Force and Pressure, Dep of Sci and Indus Res. London, H.M. Sta- tionery Office 1951 12 p. This pamphlet describes the standards of the three fundamental units of measurement, and definitions of them are given in the inter- national Metric and British Imperial Systems. The

derived units are also described, and the values of the

standards and bases of measurement employed in work

involving these units are given. The absolute value of the acceleration due to gravity at the Laboratory is included. Recent Developments and Techniques in the Maintenance

of Standards, London, H. M. Stationery Office 1952 100

p. Proceedings of a symposium held at the N P L on

21st and 22nd May 1951. Reported in Nature (London)

vl68 Oct 6 3 951 p 594-7. Fluctuation Theory in Physical Measurements, C. W. Mc- COMBIE. Rep Progr Phys vl6 1953 p 266-320. An at- tempt is made to give a coherent, elementary account of the ways in which fluctuation theory has been applied to some of the simpler types of physical measurement. Uncertainties in measurements involving suspended systems

are discussed on the basis of simple correlation function arguments, and consideration is given to the methods of measurement appropriate when there are various practical limitations on the parameters of the suspended sys- tem. There follows an elementary development of the mathematical and physical considerations usually employed in treating fluctuations in linear measuring in- struments : reaiarKs on the status of the random force method as applied to equilibrium systems are included. The circumstances under which there is an absolute limit

to the attainable accuracy are discussed. It is shown

that, in the case of measurements with a suspended sys- tem, feedback may enable these limits to be attained with

a convenient measurement procedure. An account is given

of various approaches to the calculation of the limits of accuracy in measurements with radiation detectors. Finally some elementary results are established concerning the optimum characteristics of an instrument used to follow a varying signal in the presence of noise. 78 refs. Instrument Engineering. v2: Methods for Associating Mathematical Solutions with Common Forms, C. S. DRAPER, W. McKAY, S. LEES. McGraw-Hill Book Co., New York, 1st ed. 1953. 827 p. Continuing presentation of generalized method of- attack on problems of measurement and control, volume reviews mathematical background and illustrates procedures by actual derivation of quantitative results. Eng. Soc. Library, N.Y. Metrology and the Classification of Measuring Apparatus,

A. MOLES. Ann Telecomm v8 July 1953 p 250-3 In French. The precise function of measuring apparatus as transducers of information is recalled and discussed. The

distinction between recording and measuring is emphasized, and the information obtained by Fourier and similar analyses of records is briefly discussed. It is shown that

the field of measuring apparatus is limited and in the

physical domain is defined by three factors, the scales of frequency /max//min, amplitude Am^x/A m m, and precision us. By means of a three-dimensional diagram [diagramme

d'equarissage] with coordinates log A, log f, and vs the various instruments are classified according to their particular technical field and usefulness. Pratical Calibration Adjustments for Apparatus Which

Obeys a Theoretical Law Imperfectly, J. W. HEAD, Elec- tronics Eng v25 Dec 1953 p 499-501. Various empirical methods of adjustment are considered. The nature of the adjustment achieved is fully explained. The object throughout has been to obtain easily a calibration curve which is sufficiently smooth and sufficiently near the ob- served values to satisfy practical requirements, rather than to find the unique curve which satisfies a least- squares or other mathematical criterion of goodness of fit. Concepts in Measurement, D. J. MONTGOMERY. J ISA

vl nil Nov 1954 p 51-3. Analysis of some of concepts in physical measurement illustrating modern work in phi- losophy of science and its applicability to problems in in- strumentation ; example of measurement of temperature by means of mercury thermometer, and of measurement of average cross-section area of non-uniform filament by means of vibroscope. The Language of Instrument Calibration and Performance, K. M. GREENLAND. J Sci Instrum v33 n7

July 1956 p 249-54. A critical discussion is presented of the terms used in describing the establishment, of instru- ment scales and the performance of measuring instru- ments. Examination of a number of vocabularies and of unrecorded usage shows that many of the important terms have more than one meaning. Arguments are put forward

in support of certain unique definitions consistent, wherever possible, with the original sense of the words. The

discussion takes as a basis the new definitive glossary compiled by the British Standards Institution (B.S. 2643:

1955). Some Principles of Measurement and Control, J. F. COALES. J Sci Instrum v33 nl2 Dec 1956 p 457-64. Measurements can be divided into two broad classes: those which only have to be observed and recorded and

those which are used to control sources of power in order

to change some quantity such as position, speed, temperature or pressure. In both cases the principles are the same : there are certain limitations from which all measuring instruments suffer, e.g. they all disturb the physical system on which the measurements are being made and

they all have inertia and damping to some degree. Also, no measuring instrument is completely stable and all exhibit unwanted fluctuations if the sensitivity is in- creased to the limit of usefulness. These limitations are

3
discussed together with the principles underlying the design of measuring systems to reduce their effect to a minimum. The simple theory of linear control systems

is developed, and it is shown that the only real difference between measuring systems and control systems lies in the magnitude of the power required at the output. Negative feedback in a closed-loop system is shown to be the equivalent of the restoring force in an open-loop system.

Precise Measurements of the Density of Mercury at 20°

O. I. Absolute Displacement Method, A. H. COOK, N. W.

B. STONE. Phil Trans A v250 Nov 28 1957 p 279-323. The densities of four samples of mercury at 20° C were measured by finding the mass of mercury displaced by an

accurately formed cube of known volume that just sinks

in mercury. The cube is of tungsten carbide and was

lapped to such an accurate form and good surface finish that the standard deviation of the volume of mercury dis- placed, as calculated from optical interference measure- ments of the dimensions of the cube, is 0.15 parts per

million. The weight of mercury displaced had an uncertainty of 0.28 ppm but the uncertainty of the density at 20° O is increased by errors of temperature measurement and the effects of residual grease films on the cube to up

to 1 ppm. The mean density at 20° G and 1 atm pressure

of four samples of mercury from different sources is 13.545 892 g/cm3

, the range of the four values being 1.1 ppm. The corresponding value at 0° C is 13.595 086 g/cm3

. The

purification, chemical analysis and determination of the

isotopic constitution of the samples are carefully dis- cussed. Optics in Metrology, P. MOLLET. Pergamon Press 1960 436 p. Colloquia of the Int. Commission for Optics, 6-9 May 1958. A compendium of 59 papers in three languages. Bases of Measurement, H. BARRELL. Instn Prod Engrs

J v37 nl Jan 1958 p 3-18 (discussion) 19-35; Mass Prod

v33 nl2 Dec 1957 p 59-65, 120. How standards are compared ; comparing end standards by contact measurement

in measuring machines; comparison of primary standards

of mass ; defining standard of time or frequency ; 1, 200- ton compression machine being used for calibrating 135- ton load standard by buildup from three 50-ton standards.

Classification and Nomenclature for Standards of Measurement, A. G. McNISH, NBS. IRE Trans on In- strumentation v7 n3 and 4 Dec 1958 p 371-8. Definitions

of units and standards, classification of standards, orders

in the prototype category, orders in other categories, nomenclature for other laboratories. Measurement : Definitions and Theories, C. W. CHURCHMAN, P. RATOOSH. John Wiley & Sons, Inc. 274 p. New York. 1959. I. Some meanings of Measurement.

II. Some theories of Measurement. III. Some problems

<n the physical sciences. IV. Some problems in the social sciences. Length and Time in the Problem Range of the Physi- kalisch-Technischen Bundesanstalt ( PTB )

, U. STILLE.

Z angew Phys vll n8 Aug 1959 p 316-23 in German. A

review in which the units, standards and methods of measurement of length and time, with particular refer- ence to the practice at the PTB, are briefly surveyed. Some 150 references. Algebra of Microscopic Measurement, J. SCHWINGER.

Nat Acad Sci Proc v45 nlO Oct 1959 p 1542-53. Fundamental mathematical structure of quantum mechanics is considered from viewpoint of natural evolvement as symbolic expression of physical laws governing microscopic realm ; measurement theory based on concept of

interaction between system of interest and measurement

apparatus that can be made arbitrarily small, so that measurement disturbs no property of system ; representation of physical quantities by numbers identifies properties with nondisturbing measurement results; calculation methods.

Precision Measurement and Calibration. NBS Handb j 77 Supt. of Documents, Government Printing Office, Washington, D.C. 1961. A compilation by SHERMAN

F. BOOTH, of 150 selected papers previously published by I the staff of NBS. Issued in three volumes:

I. Electricity and Electronics, 840 p.

II. Heat and Mechanics, 965 p. III. Optics, Metrology, and Radiation, 1036 p. Special Report on Measurement Standards. ISA J v8 i n2 Feb 1961 p 38-74. Measurement Gap, O. L. LINE- 1 BRINK, 38: Why Are Better Standards Needed, T. K. j| GLENNAN, A. T. WATERMAN, A. B. KINZEL, H. F. 1 YORK, H. W. RUSSELL, A. V. ASTIN, 39-41 ; Measure- ment Standards in Science and Industry, G. A. HALL Jr, ; 42-4 ; NBS—Source of American Standards, W. A. WILD- J HACK, 45-50; Traceability—Instrument Pedigree; S. C. RICHARDSON, 51-3; Evaluating Measurement Stand- ! ards, B. AXMAN, 54-7 ; Recommended Environments for Standards Labs, ISA Measurement Standards Task Force

58-62 ; Refining Measurements by Capacitance Techniques, 3 F. K. HARRIS, R. D. CUTKOSKY, 63-6; Education for Metrology, G. A. HALL JR, 67-8 ; Role of ISA in Meas- urement Standards, O. L. LINEBRINK, 69-70; Bibliog- raphy on Measurement Standards, 71-4. Prise Automatique de l'lnformation, J. GOUZIL. Auto- matisme v6 nil, 12 Nov 1961 p 437-^4, Dec p 495-9, v7

n6, 7-8 June 1962 p 219-27, July-Aug p 275-82. Auto- matic obtaining of information ; automatic measuring j instruments and measuring principles ; continuous or analog indicating devices for measuring instruments ; applications to teletypes and facsimile, weighing etc. Main Trends in the Development of Measurement Techniques, V. O. ARUTYUNOV. Meas Techns 1961 n5 Dec

1961 p 241-5. Translated from Izmer Tekh n5 p 1-5 May

1961. Discusses problems of diversity, accuracy, measuring range, dynamic measurements, special conditions, i;

. operational inspection in production, and reliability. Sleeping Giant of Sciences Awakens. Indus Quality Control vl8 n6 Dec 1961 p 15-7. Efforts made to overcome

serious shortcomings in attaining extreme accuracies with

respect to measurements, standards or calibrations ; pro- gram of U.S. Bureau of Standards to meet situation by i enlarging and strengthening its own calibration services i program, by encouraging industry and developing greater t cooperation between government and industry ; efforts made by military branches ; work done by Center for I Measurement Science, operated by School of Engineering, George Washington Univ. Washington, DC.

Instrumentation for Engineering Measurement, R. H. CERNI, L. E. FOSTER, John Wiley & Sons, Inc. New : York, 1962 456 p. Contents: Measurements of physical systems ; transducers and primary sensors ; amplifiers and

j signal conditioning ; data indication and recording

;

telemetry and data transmission ; data handling and proc- essing ; data instrumentation system. Experimentation : an Introduction to Measurement Theory j and Experiment Design, D. C. BAIRD. Prentice-Hall,

Inc. 1962 198p 20 refs. Contents : The nature of measure- ! ment ; the propagation of uncertainties ; the nature of ex- perimenting; experiment planning; experiment evaluation ; the scientific report ; laboratory practice ; appendix. Experimentation and Measurement, W. J. YOUDEN,

NBS. Nat Sci Teachers Assn, Washington, 1962 127 p. Introduction, the plan of the book ; why we need measure- ments ; measurements in experimentation ; typical collec- n tions of measurements; mathematics of measurement;

instruments for making measurements; experiment with

weighing machines; selection of items for measurement; measurement of thread strength. 4
United States Air Force Calibration Program, W. L. HORTON. ISA Trans vl nl Jan 1962 p 81-94 7 figs 4 tables 7

refs. Outlines in detail USAF calibration program, in- cluding its mission assignment, organizational location in the Air Force, concept of operation, calibration procedures, location of laboratories, activities supported, facilities and environments personnel and training, measure- ment areas and accuracies, program monitoring, deter- mination of requirements, future objectives, and general

discussion of calibration philosophy. Making Meaningful Measurements, P. K. WINTER. Gen

Motors Eng J v9 n2 Second Quarter 1962 p 20-5. Nature

of process called measurement, and means whereby working hypotheses are tested and retested, and on basis of which next step in investigation is planned ; various examples relating to chemical analysis are given ; evaluation of measurement results ; precision and accuracy

defined. Fundamentals of Measuring Practice, DIN 1319 Jan

1962 15 p. Deutschen Normenausschusses, Berlin.

States basic principles governing the use of measuring

instruments and fundamentals of errors arising in measuring practice. High Speed Instrument for Quantitative Mapping, D. R. GREEN. Rev Sci Instrum v33 nlO Oct 1962 p 1079-81. Instrument for mapping magnitude of variables, such as temperature, vibrational amplitude, radiation, height, etc. at different positions on surface is described ; values of variable are recorded as broken line segments on 2-dimensional map; visible density of map is greater within

regions of greater line length so the qualitative picture

is obtained at glance; instrument was designed for application to heat transfer testing of nuclear fuel elements

method may have many other applications. Appraisal of Current Measurement Personnel and Effect upon Quality of Measurement, C. D. FERRIS. ISA

Proc Preprint 44.4.62 for meeting Oct 15-18 1962 6 p. Appraisal of competencies and deficiencies of personnel and resultant effect upon measurement quality as re- vealed by regular course work and special programs pre- sented at Center for Measurement Science; particular areas of concern are lack of realization of physical limi- tations of equipment and technology, statistical treatment

of data, and setting of confidence limits. How We'll Measure Tomorrow, Steel Dec 31 1962. What's ahead in measurements? New combinations of present techniques. For example, ultrasonics and eddy

currents in one tool enable operators to determine case

depth, hardness, tensile strength, micro-structure, and

density of parts in process without stopping the line. (The technique is expected to become a real help to those looking for ways to automatically control a process with a computer.) Finer, closer, more reliable dimensional measurements. The newest machine parts within

millionths of an inch on a production instead of a

laboratory basis. (It was formerly considered a labora- tory technique. ) Significance : More accurate and re- liable parts than ever before. New rays—neutrons, elec- trons, and lasers—offer new ways to tell how good struc- tures are inside, improving the reliability with which

inspectors can evaluate the quality of the parts. Defining the Concept of Measurement, G. I. KAVA- LEROV, I. Ya. KAVERKIN, S. S. SOKOLOV, N. A. SHOST'IN. Meas Techns 1962 n8 Feb 1963 p 621-5 13

refs. Translated from Izmer Tekh n8 p 1-3 Aug 1962. Compares several definitions of the concept of measure- ment and concludes with the following definition of measurement: Measurement is an operation consisting

of comparing experimentally a given quantity with a cer- tain value of that quantity adopted as a unit of comparison, performing the required logical and computing

operations and presenting the result in a numerical form

with an indication of its accuracy. Measurement-Agreement Audits—Method for Increasing

Confidence in Measurements. P. M. RIVOT, IEEE Int Convention Rec v 11 pt 5 (Aerospace & Navigational Electronics, etc) 1963 p 264-9. Causes for measurement in- compatibility and some measurement-agreement-audit

techniques for increasing confidence in compatibility of measurements ; measurement agreement audit can be con- sidered system for checkiug and having necessary adjust- ments made in accuracy of calibrations, measurements, and

tests by submitting appropriate samples or measurement

devices for calibration, measurement, or test. Fundamentals of Measurement, A. G. McNISH. Electro- Technology v71 n5 May 1963 p 112-28. Historical devel- opment of measurement systems and standards ; conceptual basis of measurement ; techniques of measurement,

including aspects of precision and accuracy, are de- scribed ; basic quantities of mass, time and temperature, and other physical quantities, including electrical quantities are examined, and impact of contemporary technology on measurement concepts and techniques. 6 refs. Mechanical Measurements—Basic Tool of Precision Engineering, C. L. SAPPET, E. D. KNAB. Bell Laboratories Rec v41 n5 May 1963 p 187-91. Requirements and methods

for precision measurements in Bell Laboratories Mechanical Testing Laboratory at Whippany, N.J. ; metrological techniques for testing physical properties of materials, accuracy of gears and bearings, strains and stresses in structures, effects of irradiation, and other precision measurements. Reproduction of Rapid Processes by Means of Linear Recording Systems, V. G. VASIL'EV. Meas Techns 1963 nl Aug 1963 p 7-13 5 figs. Translated from Izmer Tekh nl

p 6-9 Jan 1963. Develops a method of deciphering oscil- lograms to find the real nature of a phenomenon when solv- ing problems of measurement and automatic control technology. Proceedings of the 1962 Standards Labortory Conference. NBS Misc Publ 248 Aug 16 1963 254 p. Contains 31 papers and panel discussions presented at sessions dealing with

National Bureau of Standards service to industry, error analysis of measurement systems, National Conference of Standards Laboratories business and information, cor- porate measurement standards programs, measurement

agreement comparisons among standardizing laboratories, training of measurement personnel, calibration recycle analysis and work load control, NCSL relations to and

cooperation with technical societies, and recommended

practice for standards laboratories. Principles of Measurement, L. FINKELSTEIN. Soc In- strum Techn Trans vl5 n3 Sept 1963 p 181-9. Underlying

philosophy of measurement is surviving from point of view of instrument and control technology ; definition of measurement, its relation to qualitative concepts, classi- cal and modern views of processes, and scales of measure- ment are discussed ; uses of measurement analyzed ; na- ture of measuring instruments is examined. Les Etalons de Mesures Physiques, J. TERRIEN. Soc des Ingenieurs Civils de France—Mem vll6 nil Nov 1963 p

17-32. (Standards of Physical Measurement.) Particular

aspects of standards for measuring physical quantities are reviewed ; modern standards of length, mass, time, force, pressure, temperature, as well as standard measurements

for photometric and ionizing radiations are discussed. Quantity of Information for a Uniformly Distributed Measured Variable and Error, V. I. RABINOVICH, M. P. TSAPENKO. Meas Techn 1963 n6 Nov 1963 p 455-60 3

figs 4 refs. Translated from Izmer Tekh n6 p 1-5 June
1963. Describes a technique which may be applied for comparing measuring instruments as well as in certain cases for determining the quality of measuring processes. International System of Units—Resolution nl2, NASATech Translation F—200 Feb 1964 3 p. Resolution 12 of Eleventh General Conference on Weights and Measures

adopted standards based on 6 basic units called Inter- national System of Units ( SI) ; units established are meter

for length, kilogram for mass, second for time, ampere for

electric current, degree Kelvin for thermodynamic temperature, and candle for light intensity ; nomenclature and

abbreviations are established, and derived units included. Translation from 0. R. des Seances de la Conference

Generate des Poids et Mesures, Paris, Oct 11-20 1960. Metrology, H. BARREL, Encyclopedia Britannica, 1965

Ed. vl5 p 310-4. Outlines the scope and organisation of

metrology, defines units and standards of measurement and their functions in the process of measurement ; dis- cusses random and systematic errors of measurement;

provides a table of the accuracies currently attainable in some of the more basic operations of metrology ; and gives detailed descriptions of the standards of length and mass

and how they are maintained.

Scientific Metrology on the International Plane and the Bureau International des Poids et Mesures, J. TERRIEN.

Metrologia vl nl Jan 1965 p 15-26. Subjects discussed are : Convention du Metre and related organizations ; past

activities of the Bureau ; length measurement ; mass meas- urement; temperature measurement; electrical measure- ments ; photometric measurements ; time and frequency measurement; ionizing radiation measurement; the SI, International System of Units ; and Conclusion.

1.2. General Dimensional Metrology

1.2.1. General

Miscellaneous Papers on Mechanical Subjects, J. WHIT- WORTH. Longman, Brown, Green, Longmans, and

Roberts, London. 1858 183 p. Contains the following papers : On Plane Metallic Surfaces or True Planes, p 2-19, read at the meeting of the British Association in Glasgow

1840; On a Uniform System of Screw Threads, p 23-36, read at the Institution of Civil Engineers in 1841 ; Presi- dential Address delivered to the Institution of Mechanical

Engineers, Glasgow, 1856 p 41-53 ; On Standard Decimal Measures of Length, p 57-69, read at the meeting of the

Institution of Mechanical Engineers, Manchester, 1857

;

Rifled Fire-Arms, p. 73-84 5 figs ; New York Industrial Exhibition in 1853, special rept p 87-177. Laboratory Physics, D. C. MILLER. Ginn & Co. Boston

1903 403 p. Contains descriptions of exercises in making

length and angle measurements, including the following

:

Length with the calipers ; length and radius of curvature with the spherometer; constant of a micrometer microscope; length with the (line) comparator; length with the dividing engine; (graduation of) circular arc with the dividing engine ; errors of a graduated scale by Gay-Lussac's method ; errors of a graduated scale by precision methods ; length with the optical micrometer ; constants

of a level with the level trier ; areas with the planimeter

;

angular distance with the sextant ; small lengths with the

interferometer; plane and plane-parallel surfaces by optical methods ; angle of a crystal by the reflecting goni- ometer ; and angle of a prism with the spectrometer. Measurements of Length and Area, including Thermal

Expansion. NBS Cir n2 4th ed May 1 1912. A general

description of the tests made by the Bureau involving the

precise measurement of length and area. Length Standards and Measurements, L. A. FISCHER,

NBS. J Washington Acad Sci v5 n5 Mar 4 1915 p. 145-59. Presidential address before the Phil Soc of Washington

on Jan 16, 1915. Reviews history of various length standards and discusses accuracies of measurement.

Stretched Wire Apparatus for Measuring Thermal Expansions, A. W. GRAY. Chem and Met Eng v21 nl3 Nov

26-Dec 3 1919 7 p 6 figs refs. Discusses difficulties in making reliable measurements, stretched wire method for measuring linear displacements, accuracy and range of the method, detailed description of simple stretched wire

dilaitometer, preparation of specimens for testing, sources

of error, concrete illustration of an expansive determination, variations of the instrument. A Dictionary of Applied Physics Edited by Sir R. GLAZE- BROOK. MacMillan & Co. London in 5 vols. v3 1923

Meteorology, Metrology, and Measuring Apparatus. Contains articles on surveying tapes and wires; design of

scientific instruments ; comparators ; line standards of ; length ; gages ; metrology, micrometers, and many others. Gage Inspection Methods F. R. DANIELS. Machy (NY)

v28 May 1923 p 702-5 8 figs. Discusses wear of inspection

j standards, uses of measuring machines, use of lead measuring machine, inspection of taper plug gages, application

of the sine bar fixture, bench centers with dividing head. Precision Measuring Instruments Used in Gage Inspection,

G. K. BURGESS, Army Ordnance, v4 May-June 1924 p I

! 375-80 8 figs. Deals with such apparatus as is applied in measurement of dimensions of gages and tools used in manufacture of machine parts, artillery ammunition, etc. Fine Measurement, J. E. SEARS. Machy (London) v24 \

[ May 15, 29 and June 5 1924 p 209-12, 266-71, and 299-303 j 22 figs. Deals with precision measurement in its relation

j to mechanical work ; methods by which control of standard

gages is effected in laboratory; recent development in methods of precision measurement. See also : Prazisions- , Liingenmessungen (Precision Length Measurements), J. E. SEARS. Zeits fur Feinmechanik und Prazision v33 nl9 ' J 1925 p 209-13, n20 p 222-5, n21 p 235-8 11 figs in German.

Optics as Applied to Measuring, O. EPPENSTEIN. Eng "I 1 Progr v6 Sept 1925 p 293-301 23 figs. Applications in con-

' struction of apparatus and machines ; notes on magnifying glass; optical dividing head; measuring microscope; 'I projection apparatus; thread-measuring comparator;

micrometer; optimeter; measuring machine; measuring

by light interference. Precision Machines and Instruments for the Measurement ; - of Length, G. K. BURGESS, NBS. Paper No. 335, Proc. ) [

! World Engineering Congress, Tokio, 1928 v5 58 illus. For

abstract see p 39. Gauges and Fine Measurements, F. H. ROLT. Edited by

R. T. GLAZEBROOK. 2v London, MacMillan. 1929 723

p. Reviewed in Times Trade and Eng Supp v25 n597 Dee 14 1929 p 311. Book is directed specially to measure- J S ments of length of which practical use is made in engi- neering manufacture and tests, and two volumes deal re- | spectively with standards of length, measuring machines and comparators, and with limit gages, measuring inj struments, and general methods of measurement. Measurement of Length, W. BLOCK. Instrum v3 Aug i 1930 p 501-10 7 figs. Continuation of Chapter 6 on meas- urement of length ; measuring screws and their practical application ; test indicators ; dial gages ; special measuring apparatus.

6
Messgeraete und Verfahren fuer den Austauschbau, G. BERXDT. VDI Zeit v76 Mar 5 1932 p 241-7. Measuring

instruments and methods for production of interchangeable parts ; gages, mechanical and optical feelers, micrometers, measuring machines and comparators, measuring

of angles and degree of tapering, dividing heads, etc.

screw-thread measuring equipment ; measurement of gear

teeth. Arehiv fuer Teehnisches Messen, R. OLDENBOURG.

Lieferungen 15-18 Sept-Dec 1932. Berlin and Munich.

Illus diagrs charts tables. Arehiv fuer Teehnisches Messen is encyclopedia of technical measuring instruments and methods being published serially in loose-leaf form

articles are well-illustrated practical descriptions, usually with bibliographies and are signed ; all classes of measure- ments included. Eng Soc Library, N.T. Fundamentals of Mechanical Dimensional Control, I. H. FULLMER. Mech Eng v57 nl2 Dec 1935 p 772-80. Correlation of fundamental principles of mechanical precision, tolerances, precision in production of parts, gaging and measuring physical dimensions. Bibliography.

Application of Optics to Engineering Measurements, F. H. ROLT. Eng vl44 n3734 Aug 6 1937 p 162-6. Few of more important types of optical instruments now on market described and illustrated, including measuring

microscopes, projection machines, optical levers, angle measuring instruments, and autocollimators for testing

straightness. Lecture delivered at Conference of Optical Devices in Research and Industry held by Inst, of Physics. Engineering Measurements. H. W. BOWEN. Junior

Instn Engrs J v49 pt2 Nov 1938 p 61-79. Standard of measurement ; interferometry ; measurement of flatness, industrial standards; measuring machines; screw gage and thread measurements.

Die praktische Bedeutung einer zuverlaessigen Messung,

H. TOERNEBOHM. Sehweizer Arehiv v5 nil Nov 1939

p 309-25. Practical significance of reliable measurement,

with special regard to errors in design of workpieces and

their influence on measurement results ; inspection of macrogeometric design errors by means of measuring in- struments; discussion of fits and tolerances and their measurement, thread and linear measurements, gages, etc. Der Abbesche Grundsatz fuer Laengenmessungen, R. LEH- MANN. Werkstattstechnik und Werksleiter v34 n5 Mar

1 1940 p 73-5. Application of fundamental rule of Abb6

to longitudinal measurement; use of rule in workshop

practice is shown on basis of examples. Using Checking Gauges. Can Machy v51 nl2 Dec 1940

p 125-9. New standards of accuracy highlight importance

of proper use and controlled accuracy of thousands of measuring and master instruments ; data on standards of

length, wavelengths of different colors of light; stand

gages, comparing end standards, and comparators. Based

on a lecture given by PROF. H. GRAYSON, Univ of Toronto.

Begriffe und Benennungen in der Messtechnik, G. BERXDT. Werkzeugmaschine v45 n9 Mar 6 1941 p 227-

32. Conceptions and terminology of measurement tech- nique; dimension measurement, gages, sorting, gaging, comparing, difference between measurement and testing. Messen in der Werkstatt (Measurement in the Workshop), K. KRESS. Carl Hanser Verlag, Munich 1942 96

p 118 figs. Contents : Concepts of measuring and testing

problems and build-up of work-room ; influence of workpiece errors on tolerances and fits ; influence production accuracy and workmanship ; influence of work-piece errors on measurement results and their measurement ; measuring force and deformations ; influence of temperature

differences ; end standards ; properties of measuring equip- ment and methods. Fine Workmanship Fine Weapons, F. L. STEVENS. Can Machy v54 nl2 Dec 1943 p 426, 428-9. Discussion of in- struments being used in Britain to secure greater accu- racy ; autocollimator, section projector, vertical measuring

machine, balloon theodolites, interferometer, and lenses

of improved design are discussed. Dispositif Automatique de Mesure et de Controle, Pratique

des Industries Mecaniques v28 nl Apr 1945 p 9-12. Auto- matic measuring and controlling apparatus for various purposes described and illustrated ; discussion of mechanical and electrical transmission of measurements;

application of special devices, such as bolometer which works by means of photoelectric cell for checking diameter

of drill holes, and of device applicable only for measure- ment of cylindrical bodies. Bibliography.

Essentials of Metrology, C. H. KLAWE. Prenco Aircraft Manuals, T.D. Bui n2 May 1945 39 p 48 figs 23 refs. General remarks, standards room, accuracy of measurement,

units and standards of measurement, precision blocks, optical instruments for absolute measurements, measuring

machines, comparators and indicators, micrometers,

vernier calipers, measurement of angles, measuring screw

threads, measurement of surface rectitude, small tools for measuring purposes. German Measuring Instruments Reflect High Degree of Precision. Am Mach v89 nl8 Aug 30 1945 p 99, 102. Flexibility in German tooling provided through application of high quality gage blocks, vernier calipers, quality control

in operating department instead of relying on specialized

jigs and fixtures or transfer of working tolerances to snap, plug and ring gages ; design and operation of variety

of German precision measuring instruments discussed.

Sir Joseph Whitworth, A Pioneer of Mechanical Engineering, F. C. LEA. Longmans, Green and Co., London, 1946

31 p 16 figs. A brief account of some of the work of SIR JOSEPH WHITWORTH (1803-87). Among the subjects discussed are: the true metal plane surface; importance

of precise measurement, and the measuring machine

standard gauges ; and screw threads. Quelques Applications de l'Optique a. la Metrologie des Longueurs ( Some Applications of Optics to the Metrology

of Length), A. MOTTU. Microtecnic vl nl 2 Feb 1947 p

27-31, Apr p 71-6 (English translation in separate sec- tions p 8-10 and 28-30). Some applications of optics to metrology ; historical background and development of standards of length ; Fizeau's method for comparing end

standards with line standard ; line standards and their comparison ; characteristics of measuring machines ; de- sign and operation of jig borer cited as example of im- portance of optics in precision measurement.

Engineering Metrology. K. J. HUME. MacDonald and

Co. Ltd. London 1950 293 p. Contents : Basic principles

standards of measurement ; standardisation ; manufacture

of gauges; optical projectors and microscopes; linear measurement ; angular measurement ; circular division ; straightness, flatness and squareness; alignment testing; screw threads ; screw thread measurement ; surface

finish ; gauge and instrument design ; miscellaneous measurements. Messwerkzeuge Werkstattmessungen (Measuring equip- ment, workshop measurements), H. KORWIEN. Fach- buchverlag Gmbh, Leipzig. A. Ziemsen Verlag, Wittenberg. 1950(?) 248 p"335 figs. The study of this book

places the plant specialist in the position safely to decide which kind of measurement is best and most economical

in the production of single work pieces. After a theoretical introduction in the fundamentals of measurement and economical production (measuring system, standards,

771-846 O—66 2
fits, tolerances, ISO system, etc.) there are set forth systematically the construction, operation, and manage- ment of the variety of measuring instruments and machines. All occurring cases of measurement (length, angle, threads, gears, surface texture, etc.) are treated, from the simplest to most precise. National Research Laboratories—Gauge and Associated Measurements, Work of Metrology Section, R. H. FIELD.

Can Machy v62 nl, 2 Jan 1951 p 69-74, Feb p 101-4 119. Jan : Present situation in Canada regarding standards of length and mass ; length standards for shop use, and in- struments used for gage measurements ; angle measurement. Feb : Equipment for measurement of plugs and

tapers; optical projectors used for measurement, thread gage measurement, devices for measuring hobs and sur- face plates ; measurement of surface finish studied ; photo- graphs. Kontrolle im Austauschbau, Lehre oder anzeigendes Gerat

(Control in interchangeable manufacture, gages or indi- cating instruments). G. BERNDT. Wiss Zeit der Techn

Hochschule Dresden v2 n4/5 1952-3 p 639-50 16 figs 8

refs. Precision Measurement In Metal Working Industry. Prepared by Dept. of Education of International Business Machines Corp. Syracuse Univ Press, Syracuse, N.Y.

revised 1952 365 p. Manual for use in Factory Training Program of IBM Corp ; deals with instruments and gages among which are ; plug, ring and snap gages, micrometers and verniers, angle-measuring instruments, comparators,

optical instruments, hardness testers, and nondestructive

testing methods. Eng Soc Library N.Y. Previous edi- tion published in 1944. Metrologie DAtelier (Workshop Metrology), L. COMPAIN. Editions Eyrolles, Paris, 1952 261 p 91 figs bibliog- raphy. Chapter headings are : generalities, units, standards, direct measuring instruments ; comparators ; inter- changeability and the use of limit gages ; verification of screw threads ; verification of gears ; applications of geo- metric verification to parts and assemblies. Development of Engineering Metrology, F. H. ROLT.

Engr vl93 n5018-5019 Mar 28 1952 p 448-50, Apr 4 p

480-3; Machy Market n2701-2702 Aug 22 1952 p 25-7, Aug 29 p 27-8. Development of tools and instruments

for measurement ; gages and measuring instruments in Great Britain in 1900 ; measurement of standard gages by

optical interference methods ; early machines for measuring screw gages ; comparators ; work at National Physical Laboratory ; developments by Zeiss and Societe Genevoise d'Instruments de Physique; testing flatness and

straightness ; metrology and machine tools ; measurement

of surface finish and gears ; illustrations. Niektore Radzieckie Narzedria Miernicz do Warsztato- wych Pomiarow Dlugosci i Katox, A. TOMASZEWSKI.

Przelad Mechaniczny vll nlO Oct 1952 p 389-91. Soviet instruments for measuring angles and lengths in machine

shops and principles of interference meter of Uverski, design measuring projector of Safronov and Moskalev and angle plates of Kushnikov ; diagrams. Pomiary Na Optimetrze Poziomym Produkcji Radzieckiej,

L. LOWCZYNSKI. Mechanik v25 nil Nov 1952 p 492-5. Measurements by means of horizontal optical meter manufactured in Soviet Union ; instrument used for precise measurements in metal industry ; principle of measuring

;

structural elements of instruments ; external and internal measurements ; accuracy of measurements ; diagrams. The Science of Precision Measurement. The DoAll Co., Des Plaines, 111., revised 1953 258 p. History and develop- ment ; on clearances and tolerances ; gage blocks ; the micro-step gaging system ; angle measurement by the use of

sine bars and sine plates; measurement with light waves;

measurement with electrical and mechanical comparators

;

thread and gear inspection by the wire method ; mobile in- spection ; statistical systems of dimensional quality

control. Taschenbuch der Laiigenmesstechnik fur Konstruction, Werkstatt, Messraum, und Kontrolle (Handbook of length measurement technique for construction, workshop, meas- urement room, and control), P. LEINWEBER in cooperation with G. BERNDT and O. KIENZLE. SpringerVerlag, Berlin 1954 806 p 790 figs 39 tables. An exceptionally comprehensive review of measuring means and

methods under the following general headings : Fundamentals ; standards and measuring equipment for general purposes; gages; treatment, care, and surveillance; simple measuring problems ; composite measuring problems

;

special work areas ; organization of measuring systems

;

and tables. Engineering Inspection, Measurement and Testing, H. C. TOWN, R. COLEBOURNE. Odhains Press Ltd. London

1956. Contents : The function of the inspection depart- ment ; standardization ; principles of precision measure- ment; standards of length, linear measurement; comparators and measuring machines; multidimension in- spection machines ; measurement during machining—

automatic sizing; workshop inspection methods and cal- culations ; angular measurements ; testing straightness and flatness; screw thread measurement; surface finish measurement.

Practical Metrology, vI-IV, K. J. HUME, G. H. SHARP.

McDonald and Co. Ltd., London, 1956-1962. Presents 43 experiments in measurement of gages, etc. Les Appareils d'Optomecanique, M. PAUL. Rev Gen

Meeanique v39 n82 Oct 1955 p 343-50, v40 n85 Jan 1956

p 29-34. Application of optical instruments to industrial measurement and control. Oct 1955 : Optical control of alignment ; comparators ; profile projectors. Jan

1956 : Application for control of machines. Modern Measurement Methods, V. W. STANLEY. Mass

Prod v32 n2 Feb 1956 p 88-94, 98. Method for producing

three-dimensional airfoil models using relatively simple equipment; use of autocollimator for measurement of small changes of rotation or angle; straightness or flat- ness measurement, circular and bore measurement; applications of pneumatic or air gaging ; interferometry for length standards ; optical technique using plane trans- mission diffraction gratings. Messkniffe und Messhilfen (Measuring Artifices and

Auxiliaries), R. LEHMAN. Feingerateteehnik v5 nlO

Oct 1956 p 463-70 18 figs 8 refs. Contents: (1) general

principles of measurement ; ( 2 ) small scales and the measuring microscope ; (3) simple dividing head ; (4) co- ordinate measurement of hole locations; (5) measure- ment of small parts with hand measuring tools. Dis- cusses use of available measuring means when special measuring equipment is not available. Engineering Precision Measurements, A. W. JUDGE.

Chapman and Hall, Ltd., London, (3d ed) 1957 447 p 445

figs refs. Contents : Linear measurement, instruments and indicators; micrometers, verniers and measuring

machines ; engineering fits, gauges and methods ; slip gauges and their uses ; screw thread measurements

;

internal measurements ; measurement of angles ; comparators; other optical measurement methods; measure- ment of straightness, flatness and alignment; inter- ferometry methods; miscellaneous methods and

appliances ; surface finish ; automatic gauging and worksizing ; appendices. Precision Instruments for Engineering, E. R. ALLAN.

Design v29 June 1957 6 p 14 figs. Describes British pre- cision equipment used in engineering industry. Dis- 8
cusses desirable improvements in design standards and

styling. The Measurement of Thickness, G. KEINATH. NBS Cir n585 1958 79 p. Methods for measurement of thickness are treated in seven groups (mechanical, chemical, electrical, magnetic, optical, x-ray and radioactive) according

to physical operating principles. Ranges, accuracies, ad- vantages and limitations are discussed. A bibliography

of references, a list of suppliers and an index of gauges, methods, applications and trade names 'covered are ap- pended. 220 refs. The Transfer of Basic Length Standards into Industry,

E. G. LOEWEN. Presented at Section M AAAS Annual

Meeting, Dec 30 1958. Discusses screws, scales, electrical

scales, gage blocks, direct measuring interferometers. Some Fundamentals of Modern Dimensional Metrology,

I. H. FULLMER. ASTME v60 n240 1960 13 p 11 figs 17

refs. Discusses recent developments in attaining ex- tremely high precision and accuracy in the measurements

of lengths and the dimensions of master gages. Precision Measurement and Gaging Techniques, W. GROHE. Chem Publ. Co., N.Y. 1960 222 p. 116 figs 21

refs. Among 15 chapters contains chapters on comparators, gage blocks, interferometric measurements.

Metrology and Gauging, S. A. J. PARSONS. MacDonald

and Evans, Ltd. London 1960 2d ed 27 chapters 286 p 209

figs. The following subjects are treated: Fundamental

length standards ; light waves as length standards ; working standards ; principles of interchangeability ; design of

gages, gaging screw threads ; manufacture of gages

testing limit gages ; measuring equipment and mechanical measuring devices ; optical principles and measuring de- vices ; electrical devices ; pneumatic measuring devices

circular division ; screw thread measurement ; measure- ment of gears ; measurement of surface texture ; straightness, flatness, and alignment testing; miscellany; appendices. Metrologie Industrielle (Industrial Metrology), E. BO- DART, R. MOSSOUX, Univ of Liege 1961. Contents:

Introduction; dimensional control; gages; instruments and accessories for measurement ; control of gages ; meas- urement of angles ; screw threads ; surface state ; verifica- tion of gears ; exercises. Cours de Mdtrologie (Course in Metrology), E. BODART,

Univ of Liege, 1961 247 p. Contents : Introduction ; defini- tion and realization of units ; precision amplification, accu- racy ; length standards ; interference measurements ; measuring techniques and instruments ; gages, dimensioning, and tolerances ; measurement of angles ; measurement of inaccessible elements ; screw threads ; gears ; surface state. Gomz (State optico-mechanical plant) Instruments for

linear and angle measurements, N. F. DELYUNOV, E. I. ROZENBERG. Meas Techn 1961 n4 Nov 1961 p 264-9

8 figs 4 refs. Translated from Izmer Tekh. n4 p 5-9 Apr

1961. Describes universal measuring microscopes, opti- meters and comparators, cathetometers. Also, in recent years several instruments for special application have been made, such as the MIV-1 and MIV-2 machines for measuring the parameters of guide screws 2000 mm long, optical contactless micrometers type OBM-2 for measuring thick- ness up to 50 mm by a countless method, an instrument

type PGVK for checking shaft screws, and a number of other precision measuring instruments. Engineering Dimensional Metrology, L. MILLER. Ed- ward Arnold Publ Ltd Lond 1962 290 p 184 figs refs. Contents: The true plane; definition and measurement

of surface texture; instruments for measuring surface

finish and roundness; standards of length; the calibra- tion of working standards by interferometry ; same by

direct comparison in series ; development of limit systems

metrology of angles ; metrology of screw threads ; metrology of gear teeth ; measuring machines.

Opportunities Presented to British Industry by Recent Developments in Engineering Dimensional Metrology, J. LOXHAM. Machy (London) vlOO n2581 May 2 1962 p 1015-22. Handmade vs mass-produced products ; exist- ing manufacturing arrangements; conditions necessary

for ideal arrangement ; economics of high precision manufacture; why present period is very suitable for intro- ducing "ideal arrangement" ; management requirements. Measuring in Millionths. C. W. KENNEDY. Machy

(N.Y.) v68 nlO, 12 June 1962 p 128-37, Aug. p 118-27, v69 n3 Nov p 131-9. Recommendations of ways and means

to improve and modernize daily routines. June. Gaging

equipment ; effects of environment ; errors due to vibration; combating dirt, metallurgical effects; phenomenon

of penetration ; gaging pressure ; deflection. Aug. Study

of inspection problems such as looseness, wear, and im- proper manipulation; gaging errors introduced by de- ceptive geometry of lobing. Nov. Effective procedures

for calibrating master gage blocks ; interferometry, and

use of laboratory and modern compact types of inter- ferometers. Die Weiterentwicklung der Prazisionslangenmessteehnik,

ihre Anwendung in Fertigung, Kontrolle und Messraum, im Blickwinkel der Automatisierungsbestrebungen und

der Kaderfrage (The further development of the pre- cision length measuring technique; its application in

finishing, control, and measuring room, in the angle of view of the automation endeavor and the framework question), G. MEISTER. Feingeratetechnik vl2 n5 1963 p

212-24 19 figs 74 refs. A comprehensive review of the

state of the art of applying the micron, the arc second, and

electronics to the control of machines and automatic measurement. Also presents a look toward the future. Length and Mass Calibration at National Bureau of Standards, T. R. YOUNG NBS Misc Publ 248 1963 p 9-13. Sur- vey is presented of present length and mass measurement

capability, developments underway, and plans for future work ; particular reference is made to present and future accuracy capabilities and requirements. Case Histories of Methods to Achieve Cost Reduction Through Optical Tooling. A. W. YOUNG. ASTME

Creative Mfg Seminars-Tech Paper SP63-120 Feb 1963

7 p. Eleven examples are described dealing with align- ment of machine tools, checking out rotational error of rotary tables, transfer of angular measurement in shops, use of telescope and clinometer mounted in one fixture,

etc. Checked Your Gage Blocks Lately, H. EASTMAN. Am

Mach/Metalworking Mfg vl07 n5 Mar 4 1963 p 56-8. Recommendations on how to conform with government

contracts which require adequate gage surveillance pro- grams, with special emphasis on "pedigree" of measure- ment standards ; calibration laboratories ; importance of measuring technique and what should be done to mini- mize uncertainties ; preparing blocks ; checking flatness ; temperature stabilization ; light contact pressure of comparator recommended ; blocks of different materials

equipment maintenance.

Differential Measuring Mechanisms, A. 1. SOLOV'EV.

Meas Techn 1962 nl2 July 1963 p 1007-11 3 figs 3 refs. Translated from Izmer Tekh nl2 p 19-22 Dec 1962. Article demonstrates the measuring facilities provided by

kinematic double-contact measuring (differential) mechanisms, their structural and kinematic unity, and

their degeneration into parallelogram devices which constitute a double tangential mechanism. The reason for the elimination of the effect of the component's run-out on the measurement results in differential mechanisms

9
has been demonstrated analytically. Formulas have been

suggested for determining the displacement of the in- dicator stem in terms of the depth of machining and the geometrical parameters of the mechanisms.

Geometrical and Physical Limitations in Metrology, J. 0. MOODY. Int Prod Eng Res Conf Proc Sept 9-12 1963 p 567-73. Published by ASME. Refinements in metrol- ogy are explored from point of view of engineers in metal working industry; measurement of flatness, parallelism,

straightness, roundness, and surface finish ; measurement

of elastic and permanent compression, deflection, and sur- face deformation; problems arising from effects of temperature and of heat transfer on objects being measured, and on measuring machines or references. Machine Tool Optics, K. RAENTSCH. Int Prod Eng Res

Conf Proc Sept 9-12 1963 p 625-33. Published by ASME.

Review of all current possibilities of applying linear optical measuring devices to machine tools, principles of which apply to measuring instruments as well ; special

stress is placed on adherence to Abbe Comparator principle, with methods outlined of how to simulate ad- herence with special optical techniques, in order to achieve more compact designs. Geometrical and Physical Limitations in Metrology, J. C. MOODY. Tool and Mfg Eng Oct 1963 p 69-74. Fundamental concepts, geometrical features, physical properties, temperature and heat. Why, When, Where, How and What of Measurements, D.

E. WENDELN. ASME-Paper 63-WA-256 for meeting Nov 17-22 1963 5 p. Proper time and place to measure

are emphasized to gain maximum benefit from measure- ments taken ; small part with 0.040+0.001 diam hole is used as example and engineering approach to four dif- ferent methods of inspections are explained ; current meas- urement problems are discussed and areas requiring research and development work are pointed out. Metrology, P. MARTIN. Bui n!314 1964 of the Soc Genevoise d'Instruments de Physique, 22 figs. Reviews history

of metric and yard systems. Discusses contemporary

industrial metrology and describes role played by SIP in the progress of metrology. Fundamentals of Dimensional Metrology, Wilkie Brothers

Foundation, T. BUSOH. Delmar Publ, Inc. New York

1964 428 p. A text about technique. Discusses reasons

for, language of, and systems of measurement ; measuring

instruments, standards, and comparators; reference planes ; and angle measurement. DIG, a Long-Travel Ultraprecise Absolute Reading Digital Linear Measuring Instrument. Bansch and Lomb,

Rochester, N.Y. 1964 8 p 4 figs. DIG, produced by General Measurements Research Inc., is a long-travel (40 in. single

scale) digital measuring instrument giving absolute measurements in microns, ten-thousandths in. or 50 microinches. Three basic elements are : a precisely calibrated

glass scale, an optical/electronic reading head, and an

electronic readout console. The reading head and scale may be attached to any set of guided machine elements Whose relative position is to be measured or controlled. Measurements are made by digitally interpolating in- tervals between reflective scale graduations, spaced one mm or 0.050 in. apart. A unique coarse encoder identifies the scale graduations by scanning an adjacent decimal- coded track. Automatisierung in der Laneenmesstechnik (Automation

in Length Metrology), W. ECKERKUNST. Veb Verlag

Technik, Berlin 1964 320p 311 figs 82 refs. Deals with in- dicating gages and pickups in mechanized and automated

testing and sorting equipment ; mechanized testing and

sorting equipment for testing stationary workpieees ; auto- matic testing and sorting, including (1) supply line, metering arrangements, measuring arrangments, data accumulators, and derivation systems, and (2) executed constructions of automated testing and sorting ; problems of testing moving workpieees including (1) determination of form

deviations and (2) examples of mechanized and automated

testing equipment for out-of-roundness and form ; testing

in the machine and realized constructions ; automation of the evaluation pickup for statistical quality control ; profit- ableness of mechanized and automated testing equipment.

Precision Length Measuring Instruments of Japan '63, T. NAKADA, President, Editorial Committee. The 30th Anniversary Issue of the Japan Society of Precision Engineering, Tokyo, Apr 1964 137 p. Part I on precision measuring instruments for length includes abstracts from

Japanese Industrial Standards and catalog displays of gage blocks, vernier calipers, micrometers, interference comparators, measuring machines, and gages. Part II on

precision measuring instruments for angle and applied system includes abstracts from Japanese Industrial Stand- ards and catalog displays of precision flats, levels, dividing

heads, toolnraker's microscope, projectors, autocollimators, gear measuring instruments, interferometers, air gages, electronic comparators, auto sizers and sorters, etc.

1.2.2. Units of Length and Angle

Standard Decimal Measures of Length, J. WHITWORTH.

Publ. in Miscellaneous Papers on Mechanical Subjects, J. WHITWORTH. Longman, Brown, Green, Longmans, and

Roberts, London, 1858. Paper read at meeting of the

Institution of Mechanical Engineers, Manchester 1857 p

57-69. Advocates use of decimal system of measures,

replacing fractions such as eighths, sixteenths, and thirty- seconds of an inch. Weights and Measures of the United States, T. C. MEN- DENHALL. Tech Q Dec 1892 p 312-19 ; Eng News Nov 9

1893 p 378. Gives history of the yard and pound, and the growth and adoption of the metric system as the inter- national system of weights and measures.

Industrial Length Measures (La Loi des Longueurs Industrielles), F. BAYLE. Tech Mod vl5 Mar 1, 15 and Apr 1 1923 p 129-34, 165-9, and 209-11 7 figs. Necessity

for standardization ; principles of standardization ; units

of length; national and international law for length measure ; advantages of a universal length measure. A Fundamental Basis for Measurements of Length, H. W. BEARCE. NBS Sci Papers n535 Sept 22 1926 p 395-408. Relations between yards and meters, inches and milli- meters ; definition of meter in terms of light waves ; ac- ceptance of simple relation ; points out that official action by United States defining yard and meter in terms of light waves, and adopting relation 1 in.=25.4 mm as exact, would not only give offlcial sanction to simple and con- venient relation already widely used in United States and Great Britain, but would tend to bring about its universal adoption ; change would never be felt except in cases of extreme accuracy such as manufacture and test- ing of precision end standards and graduated linear

scales. La Conversion des Unites Anglaises de Mesures Combiners

et de Temperatures en Unites Metriques (Conversion of British units into metric), E. KLAPPER. Genie Civ v94

nl9 Mav 11 1929 p 459-61 ; English abstract in Engineering vl28 n3327 Oct 18 1929 p 490. Synopsis of principal combined units which writer has been able to compile from study of British and American as well as continental

publications ; symbols used in table are those which have

been standardized for scientific purposes in different countries. The Conversion of Combined Metric units into British

units. Eng vl29 Jan 23 1930 p 20. Reference is made to 10
article by E. KLAPPER published in Oct 18 1929 issue of

this journal, covering table of factors for converting

quantities expressed in British or American units ; as table contained a number of errors it is reprinted in full with

certain additions ; every care has been taken in checking

rhis table as it now appears, and it is believed to be enrirely reliable. Definition of Inch, H. W. BEARCE. Mech Eng v54 nlO

Oct 1932 p 689-91. Recent proposals for defining inch

present basis of United States inch; relation of United

States to British inch ; proposal to establish value, 1 inch

equals 25.4 mm, as standard industrial practice. Standard Inch-Millimeter Conversion Factor for Industrial Use, C. E. JOHANSSON. Indus Standardization v4

nl Jan 1933 p 1-4. Practical significance in industrial

practice of use of standard conversion ratio 25.4. Angle Converters and Meter. H. MAURER. Zeit fuer Instrumkde v55 Nov 1935 p 448-56. Disadvantages of various systems of angular measurements, e.g., in terms

of radians, degrees, minutes, seconds, etc., are briefly re- ferred to. the application of such systems in military and

naval science being, interalia referred to. The advantages

of a system in which 2 * radians divided into 6.000 units are pointed out. The term "set" (derived from sechs and

tausend) is suggested for the new unit. Devices for in- terconversion of the various scales are described and their use exemplified. Why Metric System?, A. BLACK. Aero Digest v54 nl

Jan 1947 p. 151, 207. It is stated that arguments in favor

of metric system are old and fallacious and that switch

to metric dimensions would cause chaos ; author suggests

discarding foot, yard and mile and substituting multiples

of inch; prefixes of metric system could be used; thus, 1000 inches would become "kiloinch" and 1,000,000 inches would become "meginch." Les Bases Fundamentales de Nos Unites de Mesure, A. PICCORD. Microtecnic vl nl Feb 1947 p 14-9. (English

translation in separate section p 1-4). Fundamental

bases of our units of measurement ; historical review of theory and development of centimeter, gram and second

as measurements of length, mass and time and standards from which they are reproduced. Fundamental Considerations Regarding Use of Relative Magnitudes. J. W. HORTON. IRE Proc v40 n4 Apr 1952

p 440-4. Advantages of expressing quantities as relative magnitudes, as demonstrated by convenience of decibel

with relative magnitudes, changes in quantities may be

expressed as ratios, which combine by multiplication

there are two number systems, conforming concurrently

to decimal system by which relative magnitudes may be

evaluated; use of "logit" (1001

) as basic number relating these systems. On the Dimensions of Angles, O. REEB. Optik vll n2

1954 p 75-94 in German. The author suggests that in addition to the basic units of mass, length and time, angle should be considered as fundamental. Tables are given showing the dimensions of properties used in photometry and rotational dynamics, in terms of the system based on

four fundamental units. Measurements and Calculations in Physics. Fundamentals of the Introduction of Physical Quantities and the

Definition of Units (Messen und Rechnen in der Physik. Grundlagen der Grosseneinftihrung und Einheitenfestle- gung). U. STILLE. Braunschweig: Friedr. Vieweg and

Son 1955 viii+416 p in German. A detailed systematic

classification and explanation of the concepts and rela- tions between physical quantities, units and dimensions

in use in physics, together with a description of the vari- ous standards and constants and their measurement.

Section 1 deals with the general theoretical background,

including the recent treatment of Fleischman; section 2-5 respectively with mechanics, heat and thermal radiation, electricity and magnetism, acoustics and light; sec- tion 6 with the numerical data and other details of the standards and constants; and section 7 presents in 35

tables a summary of the units, dimensions, definitions and

numerical values of the quantities discussed in the previ- ous sections. The recommendations and resolutions of international and other bodies regarding units and stand- ards are quoted in the original and include those up to the end of 1954, while the approximately 1000 literature references include work up to the middle of 1954. An

important reference and source book giving both the pres- ent agreed values and nomenclature and also previous de- velopments and changes. Dimensions of a Solid Angle, O. REEB. Optik vl2 n4 1955 p 196-9 in German. Reasons are given for assign- ing to solid angles a dimension which is independent of the dimensions of other quantities, not excluding the dimension of a plane angle. Conversion of Inch and Metric Sizes on Engineering Drawings. L. W. NICKOLS. Eng vl99 n5174 Mar 25 1955 p 409-11 ; Engr vl79 n4653 Apr 1 1955 p 409-11. Factors involved in converting British system of linear measurement on engineering drawing to metric, and con- versely ; logical and simple scheme for interconversion

described. Communication from NPL.

The Decilit: a New Name for the Logarithmic Unit of Relative Magnitudes, V. V. L. RAO AND S. LAKSHMI- NARAYANAN. Letter in J Acoust Soc Am v27 n2 p

376-8 Mar 1955. The standard magnitude ratio of 10° 1 is accepted as a useful device for the specification of

relative magnitudes. The significance of such a standard- magnitude ratio when considered as the basis of a unit

is discussed. The name decilit is suggested. Units and Systems of Weights and Measures, L. V. JUDSON. NBS Cir n570 May 21 1956 29 p. Data on origin, development, and present status of units and standards, together with general information about metric system, and usage of standards of length, mass, time, and

capacity in United States and in Great Britain ; tables of weights and measures. The Standard of Length and the Standard of Time, A. PERARD. Nature (London) vl77 May 5 1956 p 850-1. Comments on the article by Clemence and mentions that Olemence mistakenly confused the micron with the ang- strom as the length which is subject to experimental

determination. The meter as defined in terms of wavelength, using the wavelength of the red Cd line as 0.643 846 96XlO~6m, is strictly equal to the meter defined by means of the Pt-Ir prototype and thus though the stand- ard is changed the unit of length is not. The Units of Time and Length, L. ESSEN. Nature

(London) vl80 July 20 1957 p 137-8. The constancy of the velocity of light is regarded as an essential feature

of any system using a wavelength standard of length. An

ideal system would define units of length and time in terms of the wavelength and frequency of radiation from

a given source, but in practice the Cs line could be used

for standard frequency and a suitable light-source for standard wavelength. Consideration is given to the time system in which interval is based on the atomic unit and

epoch on astronomical measurements.

Origin of Foot-Measure, C. ST. C. DAVISON. Engr vl84 n4778 Oct 4 1957 p 418-21. Historical development of measures of length since Tower of Babel, as illustrated by

display at Science Museum and underlined by educational

Oispxay ojJl nistory of measurement standards set up by

General Motors Corp at their Indiana plant. 11
Secular Changes of the Units and Constants of Physics, A. H. COOK. Nature (London) vl80 Nov 30 1957 p 1194-

5. It is argued that absolute changes in physical quantities are indetectable experimentally and that only changes in ratios of quantities are measurable. The

bearing of this argument on the choice of basic units is discussed and it is pointed out that secular changes in non-dimensional ratios do have physical significance. What Will New International Inch Mean to U.S. Metal- Working? Am Mach vl03 n4, 6 Feb 23 1959 p 89-93, Mar 23 p 137-8. Various opinions presented. Atomic Standards of Length and Time, H. BARRELL

and L. ESSEN. Sci Progr v47 Apr 1959 p 209-29. Comprehensive review. 31 references. The Basis of our Measuring System, A. G. McNISH, NBS.

Proc IRE v47 n5 May 1959 p 636-^3 10 refs. Present

units and standards, from prototypes to electricity stand- ards ; physical constants as standards. Length and Time in the Problem Range of the Physikalisch-Technischen Bundesanstalt PTB, U. STILLE Z angew Phys vll n8 Aug 1959 p 316-23 in German. A re- view in which the units, standards and methods of meas- urement of length and time, with particular reference to the practice at the PTB, are briefly surveyed. Some 150

references. Units of Weight and Measure (United States Customary and Metric) : Definitions and Tables of Equivalents, L. V. JUDSON. NBS Misc Publ n233 62 p 1960. The units

of length, area, volume, capacity, and mass in the United

States are defined. Tables of interrelation and tables of equivalents for these units in the metric system and in the

U.S. customary system are given. All values in the text and in the tables have been revised to be in accord with

the Federal Register announcement of July 1 1959, an announcement entitled "Refinement of values for the Yard

and Pound" in accordance with an agreement among the

directors of National Standards Laboratories of English- speaking nations to obtain uniformity in precise measure- ments involving the yard and the pound. The long tables were all recomputed on an automatic computer and

printer. This is" a revision of Misc Publ n214 1955. Search for a Fundamental Length in Microscopic Physics, W. A. McKINLEY. Am J Phys v28 n2 Feb 1960 pl29-34. This paper reviews some of the attempts to introduce into microscopic physics a constant of fundamental length. These theories aim to restrict the notion of localizability in the domain 10"" cm or smaller in an effort to remove

the well-known divergences which arise in modern field theory. The Change in the Definition of the Meter and Other Important Decisions of the International Conference for Weights and Measures, J. STULLA-GOTZ. Acta Phys

Austriaca vl4 n3-4 1961 p 317-23 in German. A brief record of the reasons for the adoption of the orange-yel- low emission line of krypton-86 as the light source for the definition of the meter in terms of light waves. A

summary of the new International Unit System is also

given. The New Standard for the Meter, L. E. HOWLETT. Can

J Phys v39 n4 Apr 1961 p 639-641. On 14 October 1960 at the 11th International Conference on Weights and Measures, the physical prototype for the International Meter,

a platinum iridium bar bearing two fine lines, which since 1889 has preserved the world's basic unit of length, was

relegated to the position of an honoured scientific museum

piece by the adoption of the following resolution to base

henceforth the International Meter on a wavelength of

light : "The meter is the length equal to 1650 763.73 wavelengths in vacuum of the radiation corresponding to the

transition between the levels 2pw and 5d5 of the atom of I krypton 86." Decimal System, Yes—Metric System, No, B. L. WEINER. j Civ Eng (N.Y.) v31 n6 June 1961 p. 58-9. Author advo- J

cates changeover to some decimal system in order to elimi- ! nate manhour losses inherent in use of non-decimal quantities, but opposes adoption of metric system, because he j considers units thereof artificial and impractical ; he rec- | ommends keeping present unit values of English system

unchanged, but to express their divisions and multiplications by decimal numbers. On Relation Between Old and New Definition of Inter- national Metre, K. H. HART, K. M. BAIRD. Can J Phys

v39 n6 June 1961 p. 781-7. In October 1960, Eleventh

General Conference of Weights and Measures adopted

as new definition of International Meter 1,650,763.73 wavelengths in vacuum of unperturbed .606/t line of Kr86;

measurements, in terms of new definition, on four copies

of meter which were well known in terms of former Inter- » national Meter prototype are reported. On The Definition of the Metre in Terms of a Light 1 Wavelength, E. ENGELHARD, R. VIEWEG. Z angew ; Phys (Germany) vl3 nl2 Dec 1961 p 580-96 In German. \ A general survey of the subject. A description is given

of the 86 Krypton discharge tubes and the specified operat- ing conditions which minimize the minor sources of error 1 for the new monochromatic light standard. Conversion Factors and Tables, Brit Stand Instn—BS 1 350 pt2 1962 293 p. Tables of equivalent values of quantities expressed in different units, and summary tables of principal conversion factors from ptl ; they apply in metrology, mechanics, and heat. Meter, H. BARRELL. Contemporary Phys v3 n6 Aug

1962 p 415-34. History of establishment of meter ; meas- 1 urement of arc of meridian and its accuracy ; international i prototype meter and its recalibration ; light waves as standards of length; isotope sources of monochromatic

light ; history of optical meter ; definition of meter unani- mously adopted by 11th Gen Conference of Weights and

Measures ; Engelhard hot cathode krypton-discharge lamp [. recommended by Conference. 36 refs. How to Adapt Metric System, J. B. BAKER. Iron Age

vl90 n9 Aug 30 1962 p 121-3. Five considerations for ex- 3 ploring possibility of converting to metric system are dis- cussed including management's attitude, drawing, tool, machines and materials. Millionths or Microns, Which Measuring System, D. B. DALLAS. Tool & Mfg Engr v49 n4 Oct 1962 p 75-8. Reasons for change in measurement practice and argu- ments against conversion are discussed ; important prob- lems of unavoidable long conversion period and high cost

of conversion are considered. Unit of Length, J. TERRIEN. Zeit Instrumkde (Ger- many) v70 nil Nov 1962 p 271-8 in German. The de- t velopment of the international unit of length, the meter,

is reported, beginning with the origin of the Metric Sys- i tern in France during the French Revolution, the creation | of the meter unit of length derived from a particular - dimension of the earth, leading to the French "Metre des i Archives" in the form of an end-standard, further on to the International Prototype Meter in the form of a line- a standard and finally to the new meter definition using a wave-length of the radiation emitted by atoms of the krypton nuclide Kr88 given in 1960 by the Eleventh General Conference of Weights and Measures. The measuring

techniques and the scientific problems connected with the various forms of the meter, especially the physical founda- ! tion of the new wavelength definition of the meter and the important part played by the International Bureau of Weights and Measures during the development of the meter 12
is taken into closer consideration. Further possibilities in

trie near future are discussed. Translation available at NBS Library. Vew Definition of the Meter, B. A. VOLKOVA. Meas

Techns 1962 n8 Feb 1963 p 626-30 1 fig 8 refs. Translated from Izmer Tekh n8 p 5-8 Aug 1962. Describes in a popular manner the essence of the new definition of the meter,

its significance, and the possibility it provides for a further raising of the accuracy of linear measurements. The International Committee on Weights and Measures. Nature (London) vl97 Mar 16 1963 p 1055-6. Describes

the October 1962 meetings of the committee which were

held in Paris. Proposals were made which, when formally

r.dopted, will result in improved or extended bases for length and temperature. Included were 12 new secondary —avelength standards of length based on lines of Kr66

, Hg195 and CdU4

. There were six proposals to modify the Inter- national Practical Temperature Scale: (1) incorporate the

Tse (He4) and the Tas (He3

) scales in the International

Scale; (2) define the equilibrium boiling points of hydrogen and oxygen to be 20.267 °K and 90.17 °K ; (3) in- corporate a Pt resistance scale between the hydrogen and

oxygen points ; (4) eliminate the sulphur point (444.6 °C) and replace with the zinc point (419.505 °C) as modified

in following section; (5) change the values of the zinc

i419.505 °C), silver (960.8 °C) and gold (1063 °C) points by about +0.07, +1.1 and +1.5 degrees respectively; (6) replace the standard thermocouple on the scale with the Pt resistance thermometer. The International Committee also adopted two new prefixes for denoting sub- multiples of units. They are : femto, 10"15

, symbol "f", and atto, 10"18

, symbol "a". Integration of British and Metric Systems, M. MATEOS,

ASME-Paper 63-PROD-24 for meeting May 7-9 1963 4 p. Study of possibilities of complete change to metric system ; author proposes adjustment of British system to cushion

shock of transition to metric system and shows that conversion from proposed metrified British system to metric

can be done easily. United Kingdom Standards of Yard in Terms of Metre,

P. H. BIGG, P. ANDERTOX. Brit J App Phys vl5 n3 Mar

1964 p 291-300. Intercomparisons of United Kingdom yard

standards (formerly known as imperial standard yard and

its parliamentary copies) and their determination in terms

of international meters ; by Weight and Measures Act

1963 yard unit is equal to 0.9144 wagelength meter.

1.2.3. Measurements in Two- and Three- Dimensional Coordinates

See also subsection 4.4. Micrometer for Photographic Plate Measurement, A. WOLFER. Zeit InstrumKde v27 Oct. 1907 p 297-301. Description of a new micrometer made by Toepfer, of Potsdam, for measuring rectangular coordinates on photo- graphic plates. Herbert Microscopic Measuring Machine. Am Mach. v53

July 22 1920 p 187. The machine has a table capable of

12-in. longitudinal movement by accurate amounts by

insertion and removal of hardened steel measuring rods between flat contact pieces. The table carries a pair of

centers, one of which can be adjusted crosswise to enable

accurate alignment of work. A microscope fitted with two

crosshairs, one rotating with the outside tube and the

other rotating with the eyepiece, is mounted on a com- pound slide controlled by micrometer screws. The outer

tube of the microscope has a dial reading to half degrees and the eyepiece has a vernier reading to one minute

of arc. A light projector is fixed to the machine and will project parallel rays of light through a lens upon a mirror and past the work.

Wickman Universal Gage Measuring Machine, Am. Mach.

v53 Dec 2 1920 p 1068a. This machine gives comparator

readings of diameters and pitches to an accuracy of 0.00001 in., and, it is said, has proved capable of obtain- ing comparator measurements of length and diameters to an accuracy of 0.000005 in. Magnification is carried out bv

a combination of mechanical and optical means ; a mechanical magnification of 60 to 1 is magnified approxi- mately 40 times by means of light, resulting in a magnification of 4,000 to 1, which eliminates the personal ele- ment. Capacity : Length gages up to 12 in. ; major, core and effective diameter measurements of screw plug gages up to 6 in. diameter; pitch of screw plug gages up to 4

in. diameter. Measuring by Optical Means. Machy (N.T.) v32 May

1926 p 695-7 6 figs. Applications of two optical instru- ments, developed by Bausch and Lomb Optical Co., Rochester, N.T., intended for use in shop, tool-room and inspection department ; one is a direct-reading thickness measure

for accurate measurement to 0.0001 in. ; other is tool- maker's microscope, applicable in connection with screw

threads, gages, small jigs and other parts, consisting

essentially of a base on which is mounted a work-table

that may be moved longitudinally and transversely be- neath a vertical microscope by means of micrometer screws which actuate separate slides. The microscope is adjust- able on a post that is fastened to the rear of the base. Angular measurements can also be made by means of graduated collars and rotatable cross lines in the focal plane of the eye-piece. A Two-Coordinate Measuring Machine. Am Mach v69 Nov 1 1928 p 706-7 ; Instrum vl S'ept 1923 p 419-20 1 fig. Measuring machines made by Soeiete Genevoise d'lnstru- ments de Physique of Geneva, Switzerland is designed to measure in two coordinates at same time ; in one direc- tion measurements of 16 in. (400 mm.) are possible; in other direction measurements of 4 in. (100 mm.) can be made. The object to be measured is placed on a table which moves in one direction on V and flat ways under

the action of a precision micrometer screw which causes motion of the table through 16 in. The microscope is carried on a slide by which it is moved across the table by

a similar micrometer screw through a range of 4 in. See

also Am Mach v73 Dec 4 1930 p 900. Compound Measuring and Gauging Table. Machy (Lon- don) v36 Aug 1930 p 697-8. Compound table developed by

Alig and Baumgartel having traverses of 22 and 28 in. Screws are provided for approximate setting. Settings are made with end standards and a sensitive dial gage. Soeiete Genevoise Universal Two-Coordinate Measuring

Machine. Am Mach v73 Dec 4 1930 p 900. This twocoordinate measuring machine is intended for general use

in inspection departments of industrial plants. Provision

is made for testing thread gages, micrometer screws, worms and taps for pitch, angle of profile, and diameter by means of an optical method. A heavy cast-iron bed

supports the two slides which move at right angles. The

longitudinal slide has a travel of 16 in. It has an opening to permit illumination from below. Pieces to be measured are not clamped to this slide, but to one of three interchangeable fixtures. A transverse carriage serves to carry the sighting microscope for measurements in the other coordinate. The front part of the transverse car- riage has a vertical slide on which the tool holder can be adjusted in height. The minimum free distance between

the T-slotted table and the tool holder is 3 in., the maxi- mum 6% in., while the distance from the table to the trans- verse carriage is 21 %2 in. A 6-in. circular table is fur- nished extra. Single Element Verniers Reading Two to Three Dimensions, R. E. LEWIS. Rev. Sci Instrum v21 p 647-9 July

1950. See abstract under 3.6.3. 13
An Investigation of the Errors of Co-ordinate Machines

Using Light Beams, R. PUTSCHBACH. Zeit angew Phys

v3 n9 1951 p 329-32 in German. The Saladin co-ordinate generating machine using the reflection of a light beam

from two orthogonal plane mirrors, is shown to suffer from asymmetrical pin-cushion distortion arising from the variation of the optical path length on rotation of either

of the mirrors. An additional reflection from a cylindri- cal mirror between the two plane mirrors renders the dis- tortion symmetrical, so that it can be corrected by simple

optical methods. The Coordinate Setting Machine, as sponsored by the U.S. Air Force, Published by Fairchild Aircraft Division, Hagerstown, Md., Apr 1952. Contents : Introduction ; its back- ground ; establishing the collimation line ; setting the machine to dimensions ; setting a typical fitting ; the universal positioner ; optical rectangle ; conclusion ; specifications. Universal Measuring Machine for Three-dimensional Forms. Machy (London) v86 n2220 June 3 1955 p 1207-9. New machine introduced by Precision Grinding, Ltd, Surrey, based on machine designed during war for inspection

of three-dimensional cams ; with modifications it is now

employed as universal measuring machine ; measuring head and various arrangements for measuring cams, gears, threads, length and gap gages, etc. Les Appareils d'Optomecanique, M. PAUL. Rev Gen

de Mecanique v39 n82 Oct 1955 p 343-50, v40 n85 Jan 1956 p 29-34. Application of optical instruments to industrial measurement and control. Oct 1955: Optical control of alignments ; comparators ; profile projectors. Jan 1956 : Application for control of machines. Toolmaker's Microscope Measures Without Contact, W. P. CHRISTOPH. Am Mach vl02 n3 Feb 10 1958 p 116-8. Three-dimensional microscope described provides for di- rect measurement of three coordinates in mutually per- pendicular system without contacting object ; third dimension obtained from indication on scale of vertical measuring screw ; problems to be handled with instrument are

those which present serious measuring difficulties; more

convenient and quicker measurements possible; optical features. Photoelectric Indicator for Precision Setting in Co-ordi- nate Measurements [on Photographic Plates], E. DJURLE AND G. GRAN. J Sci Instrum v35 n8 Aug 1958 p 304-

5. The indicator presents the intensity in the line or point

to be measured as mirror images on an oscilloscope and

uses the traces as coincidence marks. Measurements can

be made in two co-ordinate directions with a standard

deviation of 0.3/i or better for the setting on a line or point. On the Positioning of a Point Using RI, S.-Y. HORI, Y. OKAMOTO, H. UTUMI, N. MORITA. Report of the Central Inspection Institute of Weights and Measures, Japan,

v8 n3 report 19, 1959 in Japanese. It is the purpose of

this report to describe a method for positioning a point in an opaque material by the utilization of RI. The position of a point which is in an opacity or intercepted by an opaque material has been obtained by the intensity of radi- ation and the absorption coefficient of radiation ; a new in- strument is contrived which is able to carry out the posi- tioning of a point only by a single scanning basing upon the

triangle surveying method. Studying errors crept into

this method, this instrument is proved to have a good

accuracy generally less than about 30ft. The authors

think that, as this method is applicable to the radiation thickness meter and general tracer experiments, will be

also usable for the study of flow phenomena in a metal

constitution and circulatory system of living body. New Instrument for Three-Dimensional Inspection, A. G. JONES. Inst Prod Engrs J v38 n8 Aug 1959 p 455-8.

Instrument enables measurements of accuracy of 10"4 in. : without correction, on curved or flat surfaces ; it consists : of low powered microscope fitted with cross graticule in J

i focal plane and illuminating system mounted on a jig ill borer; unit has been used successfully for three years in >

measurement of wind tunnel models and many general engineering metrology problems ; diagrams and graphical

data. The Moore Universal Measuring Machine. Moore Special Tool Co. 1960. Provides a combination of rectilinear t and angular positioning with electronic indicator or microscope supported on an accurate, rotatable spindle. '') Position Transducer Using a Divided Circle and Coded

Scale, I. R. YOUNG. J Sci Instrum v37 n4 Apr 1960 p

125-7. A small transducer is described in which a coded : scale is used to distinguish the lines on a divided circle. j

i This unit is intended as a positional reference in a large i : data-collecting system. The circle and code are both -

i detected photoelectrically, through using very different

cells and lamps. In order to keep the instrument diameter I 3 small, the coded scale is made in drum form. A Semi-Automatic Apparatus for Evaluating Stereoscopic i Cloud Chamber Photographs, T. HOLTWIJK. Nederlands

Tidjschrift voor Natuurkunde v26 n5 May 1960 p 150-2 in Dutch. A stereo-viewing system is described for deter- mining the position coordinates of cloud-chamber tracks from stereophotographs. The two stereoplates are pro- jected on to a screen. The Z-coordinate of a given point ; : on the track is determined by superimposing the two r i images and the X- and Y-coordinates determined by mov- i

II ing a positioning mark on to the point. The position co- i) a ordinates are converted to an electric signal which in I, $ turn is fed into a "Zebra" computer. The equipment has

been used in conjunction with a 5 MeV betatron.

i Accumulating Digitizer System, T. H. FIELDS, R. W. FINDLEY. Rev Sci Instrum v31 nl2 Dec 1960 p 1312-7. Si System for digital measurement and automatic recording ; of linear or angular position ; adding-substracting scaler is } j, used to accumulate pulses generated by digitizing element ;

t K performance of system, as used for coordinate measure- || K ments on bubble chamber photographs.

1 Pi Apparatus for Automatic Treatment of Photographs Ob- A tained From Bubble Chambers. E. M. ANDREJEV, P. j j{ HIRSL, G. M. KADIKOV, R. POSE, M. I. POPOV, V. V. P Si SMIRNOV, N. S. TOLSTOJ, I. A. ZARUBIN. Nuclear '! If Instrum and Methods (Netherland) vll n2 May 1961 p 297-306. A description is given of an automatic ap- ' "i paratus for coordinate method application to photographs 'j »' taken from bubble chambers. The accuracy of the coJ I ordinate measurements on the film is 2—4 microns. Track- j i( ing velocity (over the film) reaches 3 mm/sec. The co- ordinate readings are punched on perforated tape, and L TM they are ready to be put into electronic computers for

? ^ further mathematical treatment. Numerical Control Opens New Horizons in Inspection ? * Practice, H. W. BREDIN, Machy (N.Y.) v67 n9 May 1961 [

j, p 124-7; Machy (London) v99 n2545 Aug 23 1961 p 413- i

. 14. Recently developed universal measuring machines I j, equipped with numerical control provide rapid and auto- matic means of checking most complicated components; f h design and operation of 8-axis measuring machine devel- k

i

1 oped by Pratt and Whitney Co. West Hartford, Conn; K digital read-out of inspection results ; inspection data used j hi! for design purposes.

i in New Developments in Coordinate Measurements, T. S. i, GLADILINA. Meas Techns 1961 n3 Nov 1961 p 178-82 7 : ,s figs 1 ref. Translated from Izmer Tekh n3 p 4-7 Mar 1961. I ;il Describes the development of a coordinate measuring j „ microscope MKI intended for accurate and productive , § 14
measurements of coordinates in miniature details, as

well as for the measurement of distances and angles. The maximum lengths measured by the MKI in two mutually perpendicular directions are 100X100 mm, the microscope graduations for measuring length amount to lp and for angles to 10 sec. ; the error in length measurements

amounts to 2". Inspection of Gauging Dimensions Involving Linear and

Angular Measurements, J. C. EVANS, C. O. TAYLERSON.

G. B. Nat Phys Laboratory—Notes on App Sci n27 1962 p 1-42. Publication serves as practical guide to inspectors concerned with examination of position gages and related work involving simultaneous linear and angular measure- ment i measuring block described may provide convenient means of inspecting other types of precision work.

Inspection Time Slashed on Parts Adaptable to Coordi- nate Measuring Techniques, C. H. WICK. Machy (N.Y.) v69 n2 Oct 1962 p 107-9. Inspection time was reduced

by about 80% (on applicable parts) and quality control

greatly improved be means of Sheffield-Ferranti coordi- nate measuring machine at Plymouth ( Mich ) Div of Burroughs Corp; hole and surface locations can be quickly and accurately measured on this machine, with dimensions of both X and Y coordinates being displayed simultaneously on direct readout panel ; lengthy and

laborious bench checks with gage blocks, surface plates, and height gages are no longer required. Inspecting True Position Tolerances for Round Holes,

J. V. LIGGETT. Assembly & Fastener Eng v5 nlO Oct

1962 p 32-5. Simplified inspection method is outlined and shortcuts which can be adopted in operations are indi- cated; relating location to hole size; converting coordi- nates to radial measure ; establishing datum point ; ex- ample showing drawing of part to be inspected, and

inspection report form which gives necessary calculations. New Three-Coordinate Universal Measuring Machine. Bui 1312GB Societe Genevoise d'Instruments de Physique, Geneva 1963 4 p 4 figs. Uses standard steel scales with

readings on micrometer projection screens. Measuring

range is 16X8X8 in. Numerous accessories are listed. Picomm Coordinate Measuring Machine. Bui. D82 Pratt and Whitney Co., Inc. 1963 6 p. Measures the relationship

of points, holes, and surfaces to an accuracy of 0.001 in. Gives decimal readout of X and Y coordinates and may

be operated with a printer. Calibration of Precision Coordinate Comparator, G. H. ROSENFIELD. Photogrammetric Eng v29 nl Jan 1963 p

161-73. Procedures for calibrating screw-type, precision coordinate comparator; errors to be calibrated are periodic screw-error, scale-error and secular screw-error, curvature and weave of ways, and nonperpendicularity

of axes; periodic error is calibrated using 2 mm scale graduated into 0.1 mm increments; calibration model is formed by least squares sine wave fit ; scale-error and

secular screw-error are calibrated using 240 mm calibrated

scale graduated into 1 mm increments ; calibration model

is formed by least squares polynomial fit and harmonic

analysis; work done in connection with RCA Ballistic Camera Review Project. Look at Optical Tooling, D. J. FAIRFIELD. Machine & Tool Blue Book v58 n6 June 1963 p 84-91. Discussion

of processes utilized by optical tooling including autocollimation, auto-reflection, planizing, plumbing and level- ing; examples of optics employed on machine tools in order to achieve required standards of precision to keep chuck jaws on lathe parallel to axis of rotation, to align ways and bed, etc; checking out of rotational error in rotary tables' alignment and positioning of huge and

and intricate welding fixtures; optical tooling used for checking machined workpieces.

X-Y-Z Measurement. Prod Technol vl n8 Nov. 1963 p

312-3. Three-dimensional inspection machine, introduced by Ferranti Ltd, is designed for rapid inspection of high

precision parts, without loss of accuracy in measurement, and incurring strain on part of operator using machine;

layout of machine is similar to that of vertical milling machine ; tee-slotted table carries workpiece and is mounted on coordinate (x-axis and y-axis) slides and

probe unit moves on vertical (z-axis) slideways on front of machine column ; measuring capacity is 10 in. on all 3 axes ; at temperature of 68 F, accuracy of plus or minus

0.0002 in. is obtainable in x-y plane and plus or minus

0.0003 in. in combination with z-axis. New Higher-Accuracy Three-Axis Measuring Machine. The Sheffielder vlO nl 1964. Workpiece can be measured

in X, Y, and Z planes in a simple progressive action without resetting. Applies moire gratings with photocell read- ing heads and digital readout to 0.0001 in. New Production Equipment. Ferranti 3-Dimensional Measuring Machine, G. W. MASON, A. J. BARKER.

Machy (London) vl04 n2668 Jan 1 1964 p 37-8 1 fig. Machine is based on the Ferranti co-ordinate inspection machine but incorporates a vertically-adjustable, counter- balanced measuring head. Movements are measured by

individual moire diffraction gratings and photoelectric scanners. 1.2.4. Surveying Methods Applied to Large Mechanical Structures

Surveying Instruments Enter Shop, P. KISSAN. Civ Eng

(N.Y.) vl9 nil Nov 1949 p 27-9. Surveying instruments have important assets which are lacking in shop measuring equipment ; they can easily provide accuracy of 1/1000-in. at 20 ft; for shop conditions, usual field proce- dures must be modified and new methods developed ; prob- lem is outlined and suggestions for its solution are offered ; technique was developed to provide precision in large parts such as jigs built to very small tolerances, used in production of interchangeable parts. Maximum Likelihood Estimates of Position Derived from Measurements performed by Hyperbolic Instruments. E. LUKACS. J Res NBS v47 Sept 1951 p 197-201. Certain

electronic surveying instruments—referred to as hyperbolic instruments—determine the difference between the

distances from fixed stations to a moving object. Data

obtained from a single observation yield one relation be- tween the three coordinates of the moving object and

restrict it to a hyperboloid of revolution. To locate a

position in space, observations are taken, more than three equations for the three coordinates are obtained. In

general these equations will not be compatible ; it is then

a statistical problem to find an estimate for the unknown

position. In this paper maximum likelihood estimates are obtained for positions in space derived from such

hyperbolic data. A Laboratory Method for Determining the Angles Sub- tended by Distant Objects, K. GROSSFIELD. J Opt Soc Am v42 Oct 1952 p 754-5. A method is described for the determination of the small angle subtended by a distant

object. Rays from the object are passed through a bi- prism, thus causing an interference pattern. If the object

is considered as two separate sources, then by altering the position of the biprism the interference pattern caused by one of these sources may reinforce or blur the inter- ference pattern caused by the other. A relation similar

to that of a two-slit stellar interferometer has been derived and tested by experiment. Hence the angle subtended by the object can be evaluated. The Precise Establishment of Long Co-ordinates in Factories. O. S. READING. U.S. Coast and Geodetic Survey. Paper n30 Symposium on Engineering Dimensional Me15
trology, NPL Oct 1953 p 485-93 4 figs. Describes system

using rays of light, avoiding well known causes of re- fraction, and sensitive levels. Recent developments greatly facilitate the precise establishment of long coordinates. An Interferometric Method of Distance Measurement;

Frequency Modulation Radar, G. BROUSSAUD. Rev Opt

v35 nil Nov 1956 p 593-603 in French. The equations governing the measurement of distance by optical inter- ference methods are developed to include distance measure- ment by f.m. radar. This latter method differs from opti- cal techniques not only in the wavelength employed but

in the kind of problem which it solves. Electro-Optical Distance Measuring, A. BJERHAMMAR. K Tekn Hogsk Handl nl51 1960 101 p. A report on the examination of the reliability of a quartz crystal of BT

cut used as an electro-optical light modulator at frequency

4 Mc/s. A theoretical analysis is made and at proper adjustment the fundamental frequency is obtained with- out distortion of even harmonics. Odd harmonics give no errors in a suitable phase discriminator. A 70%

modulation is obtainable. Zero point drift of the instru- ment is studied. At a distance of 102 cm the standard

deviation of a single measurement is ±1.1 cm. The in- strument, described in detail, is called a Terrameter.

Practical operating ranges are 50 m to 5 km. Total power

consumption is 5.5W. Theory of modulation is studied in

detail. 120 oscillograms are reproduced. An Electro-Optical Device for Measuring Distance, A. BJERHAMMAR. J Geophys Res. v65 n2 p 412-7 Feb

1960. A light beam is modulated at 4 Mc/s by passage through a piezoelectric quartz crystal between polarizers. The beam is transmitted over the distance to be measured

and returned to a photocell. The output from the latter, together with a signal from the oscillator, is fed into a phase-sensitive superheterodyne circuit. The arrange- ment is suitable for distance from 50 m to 5 km. At 1 km the standard deviation of a single measurement was

found to be ±11 mm.

Physical Principles of the Electro-Optical Determination

of Distances, A. KAROLUS. J Geophys Res v63 n2 Feb

1960 p 394-403. The principles of distance meters based on the methods of Fizeau and Karolus for the measure- ment of the velocity of light are discussed. The dis- cussion is concerned primarily with the quantitative eval- uation of the systematic errors in the methods of modulating light and of light and phase measurement. It is concluded that detailed study is necessary to develop a meter sufficiently accurately for geodetic applications. Increased Accuracy of Measurement by Means of Tape

Measures, B. E. KOSTICH. Meas Techn 1959 n4 May 1960 p 249-51 2 figs 3 refs. Translated from Izmer Tekh n4 Apr 1959 p 7. Discusses accuracy of measurement in applying tapes in heavy engineering. Application of an Optical Inner Base Range Finder in a Factory Arrangement for Checking Dimensions of up

to 25 m, B. E. KOSTICH. Meas Techn 1959 n6 June 1960

p 413-5 2 figs 4 refs. Translated from Izmer Tekh n6 June

1959 p 19. The application of instruments and length measurement methods used in surveying for the dimension

control in heavy machine construction has aroused much

interest. The TsIZM measuring device is based on the

optical system of a range finder with a variable parallax

angle, which secures an accuracy greater than that of the variable base method. Simultaneous Adjustment of Angular and Distance Measurements, F. F. CEELY, JR. J Geophys Res v65 n9 Sept

1960 p 2845-8. The development and use of electronic distance-measuring instruments has posed the problem

that many of our triangulation networks have become a mixture of triangulation, trilateration, and traverse, especially in the areas where control is needed for the inter- state highway program. A method of adjusting triangulation, trilateration, and traverse simultaneously is pre- sented in this paper. The formulae, methods, and tech- niques were devised in an attempt to make an adjustment

that gives a satisfactory solution with minimum distor- tion to both angular and distance measurements. A pres- entation of several approaches to the problem is made

with emphasis given to the application of these methods

to an intermediate-sized electronic computer.

Distance Measurement by Means of a Light Ray Modulated at a Microwave frequency, K. D. FROOME, R. H. BRADSELL. J Sci Instrum v38 nl2 Dec 1961 p 458-62. Describes an experimental equipment (known as the "NPL Microwave Mekometer") using elliptical polarization modulation of a light beam at 9400 Mc/s and intended

for the accurate measurement of distances of the order

of 50 m. The beam is returned from a distant reflector to the modulator at which the ellipticity is either increased

or cancelled. A knowledge of the speed of light and the modulation frequency serves for derivation of the modulation wavelength ; the distance from reflector to modulator is then obtained in terms of the number of modulation

wavelengths in it. Optical Tooling for Precise Manufacture and Alignment,

P. KISSAM. McGraw-Hill Book Co. Inc. 1962 272p. Subjects covered include the optical-tooling method and pro- cedures, optical principles, optical instruments and their

tests and adjustments. Optical tooling is a system of measurement and alinement utilized for the precise control

of large sizes. The fundamental accuracy of optical tool- ing depends on the use of the telescopic sight, the use of gravity as a reference direction and the application of many special optical devices, generally of the same nature

as very precise surveying instruments.

Effect of Chromatic Aberrations on the Sighting Accuracy

of Geodetic Telescopes, K. E. NIGGE. Zeit InstrumKde

(Germany) v71 n3 Mar 1963 p 67-72 in German. By

means of two theodolites with lens-system telescopes and

two with mirror-lens telescopes, the problem of achromatism of the surveying type of telescopes was studied ex- perimentally. The main consideration was how the accu- racy of sighting with triangulation theodolites is influ- enced by parallax due to inexact focusing caused by in- sufficient correction of the chromatic aberrations. An Alignment Interferometer, J. B. SAUNDERS. Appl

Optics (USA) v2 n5 May 1963 p 541-2. An interferometer

is illustrated which permits very accurate alignments of points along a straight line several miles long. An error

of 1/10 of a fringe spacing corresponds to less than 0.4 mm for a distance of 1.6 km with a wavelength of light 5600 A and a 25 cm diameter mirror on the interferometer. Ample illumination is obtainable with zirconium arc lamps. Keeping Abreast of Instrumentation Development, A. E. BUSCH. Surveying & Mapping v23 n2 June 1963 p 275-

82. Industrial surveying instruments are considered which utililze fundamental principles of alignment, and

angle or distance measuring, but which have been refined, automated and applied to various types of problems, in- cluding missile tracking, fire control and even contour

analysis of parabolic surfaces ; alignment telescope, jig transit, visual and electronic autocollimators, and special radar alignment telescope used in Nike missile tracking

system, are described ; work to produce new types of cine- theodolite is reported ; importance of use of survey equip- ment by qualified operators is emphasized. The NPL Mekometer, R. H. BRADSELL. Trans Soc Instrum Techn Nov 13 1963 5 p 2 figs 7 refs. Describes an electronic device for the measurement of distances of the order of 50 meters to an accuracy of about 0.05 mm.

Applies the method of coincidences to several different 16
modulation frequencies of light which is elliptical polari- zation-modulated by a crystal of ammonium dihydrogen

phosphate subjected to a microwave field. Optical Tooling for Profit, L. HURTT. Naval Engrs J

v76 n3 June 1964 p 461-5. Optical tooling is adaptation

of surveyors methods and instruments to manufacturing

tasks ; instruments include jig transit, precision level, right-angle devices, optical micrometer, optical tooling

scale and tapes, and these are defined ; application of "Master Planes Procedure", which is establishment of master horizontal and vertical reference planes, is ex- plained ; diagrams show examples of optical tooling as

applied in marine industry.

1.3. Precision, Accuracy, Uncertainty

1.3.1. General

Discussion of the Precision of Measurements, S. W. HOL- MAN. Technol Q vl n 2, 3, 4 1887. Notes of a brief lec- ture course on the laws governing the precision of measurements, with application of the methods of least squares. Die Sicherung richtigen Langenmasses unter besonderer

Beriicksichtigung der Endmassnormale ( Accuracy in EndStandards of Length), H. STADTHAGEN. Zeit VDI v55

Sept 9 1911 p 1525- 9. The reasons for the uncertainty in the use of these standards are discussed ; and suggestions are submitted for the removal or mitigation of the errors. Elements of the Precision of Measurements and Graphical

Methods, H. M. GOODWIN. McGraw-Hill Book Co., N.Y.

1913 104 p. Precision discussion of direct measurements

deviation and precision measurements ; weights and

weighted mean ; criterion for rejecting observations ; computation rules and significant figures ; precision discussion

of indirect measurements. Measurement and Errors in Manufacturing, G. S. RADFORD. Mgmt Eng vl n5 Nov 1921 8 p 2 figs. Discusses

evolution of measuring, selection of characteristic qualities, selection of standard samples, measurement by comparison with a scale, the measuring instrument, measure- ment and accuracy, precision in measurement, theory of

errors, cure for errors. Uber die Grenze der physikalischen Messgenauigkeit (The

Limits of Accuracy in Physical Measurement), W. BLOCK. Zeit Instrumkde v44 Aug 1924 p 366-70. A concise summary of the limits of accuracy of measurement of physical quantities based on the fundamental units of time, mass and length. It is shown that almost theoretical ac curacy can be obtained in the case of mass and length

units. Paper furnishes a useful collection of details con- cerning limits of accuracy in physical measurement of standard units. Maximum accuracy of length and mass

measurements equals 5X10"7 and 5X10"8

. Einige Bemerkungen zur Fehlerrechnung bei technischen Messungen (A few Remarks Regarding Estimation of Errors in Technical Measurements), G. BERNDT, Zeit Fein- mech und Prazision, v3 July 5 1925 p 139-41. Correction of Data for Errors of Measurement, W. A. SHEWHART. Bell System Tech J v5 Jan 1926 p 11-26

6 figs. Discusses error corrections of data taken to show

quality of a particular lot, or taken periodically to detect

significant changes in quality of product, or taken to relate observed deviations in quality of product to some particular cause. Erreurs de Mesures; Erreurs et Tolerances de Fabrication des Calibres; Interchangeability des Pieces Filetees (Errors of Measurement ; Errors and Tolerances of Manufacture of Gages; Interchangeability of Threaded Parts),

L. FRAICHET. Services Techniques de LAeronautique

Bui Technique n61 Sept 1929 38 p 8 figs (in French), Chapter 1 deals with measurement of angles such as those

of a trapezoidal gage, measurement of small angular dif- ferences, taper gages, and squares. Chapter 2 gives the mathematical relationships of errors in measurement of

pitch diameter, pitch, and flank angle by means of wires

of any thread angle. Chapter 3 deals with standardization of threads and interchangeability of threaded parts. Tiber die Dezimalgleichung beim Ablesen von Skalen ( Dec- imal Equation Reading of Scales), H. BAECKSTROEM.

Zeit fur Instrumkde v50 Nov Dec 1930 p 609-24 665-79 36

figs. Nov : Subjective division of scale interval symmetry

of subjective interval at various locations of division ; cal- culation of corrections ; series of experiments by Gross- mann ; calculation of average error. Dec : Calculation of average error from complete series of observations ; in- fluence of number of observations on decimal frequency, and of nonuniform division on exactness ; test results. Bibliography. Die physikalisch-theoretischen Grenzen der Messbarkeit, W. GERLACH. VDI Zeit v81 nl Jan 2 1937 p 2-7. Physical theoretical limits of possibilities of measurements

author shows how in light of modern developments in measuring technique, limits of measurements are only determined by developments in physics and discusses pres- ent day possibilities under headings : small energy, meas- urement of atomic values, etc. Fehlertheorie und Ausgleichrechnung und Ihre Anwendung auf betriebsmassige Langenmessungen (Error theory and compensation calculation and their application to op- erational length measurements). H. SCHMIDT. Werkstattstechnik und Werksleiter v36 n23/24 Dec 1942 p 2-4

1 fig 5 refs. Experimental Data and "Sufficient" Accuracy, H. A. HUGHES. Nature (London) vl58 July 6 1946 p 29. The Fundamental Problems of Experimental Physics,

J. HOUGH. Am J Phys vl9 Dec 1951 p 489-99. An ele- mentary treatment of the nature of an experiment is given

in order to demonstrate the various factors which must

be considered in planning an experiment. Particular at- tention has been paid to the factors on which the accuracy

of the final result depends ; and it has been found desirable

to introduce two new quantities, the reading and experi- mental limits, which give a measure of the maximum ac- curacy of a measurement and an experiment, respectively, obtainable with the particular apparatus. On Absolute Measurement, E. DORSEY, C. EISENHART.

Sci Monthly v77 n2 Aug 1953 p 103-9. Theory of errors, averaging, quaesitum, definitive value, dubiety, procedure,

report, miscellaneous. Engineering Dimensional Metrology—Proc of Symposium

held at NPL, Oct 21-24 1953 2 v. Her Majesty's Stationery

Office, London, 1955 689 p. Collection of 40 papers cover- ing measurement problems relating to workshop inspection, pneumatic gaging, machine tools, gear measurement, small

scale and large scale metrology, surface finish, and related

subjects. Das Genauigkeitswese in der technischen Normung (The

Essentials of Accuracy in Technical Standardization),

J. ICKERT. Springer Verlag 1955 99 p 51 figs 67 refs. Investigates the general principles of accuracy in relation- ship to technical standardization. General bases of ac- curate gaging and uncertainties in standards. 17
How to Appraise Accuracy in Measurement, W. J. DARMODY. Am Mach vlOO n22 Oct 22 1956 p 130-2, 48 pointers to help evaluate workpiece, measuring or gaging instrument, reference standard, environment of measurement, and human element in measurement. Measurement Error Detection and Correction. W. J. HILL, Tool Engr v42 n6 June 1959 p 73-8. Inspection problems encountered when material supplied by outside sources must meet rigid requirements of components in control system ; approach to inspection of gyro bearings was to determine repeatability of shop and supplier measuring equipment, average difference in measurement be- tween them, and correction factor. Ueber die Messunsicherheit beim Messen von Durchmessern Ueber 500 mm im Grossmaschinenbau, L. WIZENEZ.

Werkstattstechnik v49 n6 June 1959 p 323-9. Inaccuracies

in measurement of diameters of over 500 mm in construction of heavy machinery ; attempt made to determine sys- tematic measuring errors according to their size and im- portance ; factors discussed which influence measurement

of large diameters, such as temperature, gravity, measuring force, etc. Propagation of Error in a Chain of Standards, A. G. McNISH, J. M. CAMERON. IRE Trans vI-9 n2 Sept

1960 p 101-4 2 figs. Discusses the concept of traceability

in standards and how errors are propagated in a chain

of standards. Experimental examples are given. Investigation into Accuracy of Industrial Measurement

of Sizes between 0.2 Inch and 5 Inches, P. W. HARRISON.

Instn Mech Engrs-Proc, vl75 n3 1961 p 211-34. Report

of study by NPL on behalf of Brit Standards Instn, con- cerned with Int Organization for Standardization revi- sion of system of limits and fits which will include en- larged section on measuring instruments ; work pieces were circulated to 40 firms whose measurements were compared with those made at NPL; comparisons are made

with earlier work on sizes 4-80 in. Systematic Errors in Standards of Measurement, W. J. YOUDEN, NBS. AOA Meeting, Feb 1961 6 p 1 fig. Investigation into the Accuracy of Industrial Measure- ment of Sizes between 0.02 in. and 5 in., P. W. HARRISON.

Inst Mech Engrs, 1961 15 p 7 figs 5 refs. Work-pieces were

circulated to forty firms whose measurements were compared with those made at NPL. The algebraic mean

error of these measurements at different diameters, al- though having a distinctive pattern, was small in rela- tion to the spread of individual errors about this mean.

Errors on external measurements were less than those on internal measurements, and the report discusses this and other characteristics in relation to the techniques of measurements used. Some optimism is apparent in the estimates of accuracy made by the participating firms. The results of this investigation are linked with those

of an earlier investigation covering the size range 4 to 80 in. An Analysis of Measurement Errors as Applied to Cali- brations, J. R. MILLER III. Calibration Center, AOMC,

Redstone Arsenal, 3 p 3 refs. Deals with: (1) bounds

to be placed upon the uncertainly of a reported value.

(2) propagation of errors in a chain of standardization or measurement laboratories. How to Handle Errors in Measurements, R. P. BENEDICT. Prod Eng v32 n41 Nov 13 1961 p 93-5. Three

questions discussed are finding best way to report uncertainties, how error in measurement will be propa- gated into result, and how uncertain results may be con- verted into meaningful test interpretation ; examples given and precautions recommended. Measurement Problems in Physical Experiments, J. P. KOHN. Instrumentation vl5 n4 1962 p 10-13. Definitions of accuracy, precision and sensitivity; problems in selecting instruments according to these characteristics ;

j examples of pressure measurements and studies of solid state materials and corrosion rates of metals. On Realistic Measurement of Precision and Accuracy, A C. EISENHART, NBS. ISA-Nat Aero-Space Instrumentation Symposium 8th-Proc 1962 p 75-83. Nature and j objectives of measurement ; measurement as production

process ; correction and adjustment of measurements ; law

of large numbers and mathematical formulation of bias and precision of measurement process ; variations of pro- cedure, apparatus, observers, and environmental conditions allowable in "repeated" applications. 21 refs. Basic Principles and Accuracy of Measurement in Relation to ISO System of Limits and Fits, L. W. NICKOLS,

NPL, Paper n3, Nat Conf on the Accuracy of Industrial Measurement of Length and Diameter, Apr 17-18 1962

22 p 10 figs 4 refs. Discusses interpretation of limits of f size, error of a measuring instrument, relation between

the inaccuracy of the measuring process and the safety margin, effect of errors of form of the workpieces, in- fluence of workshop conditions on accuracy of measure- ment including the effect of temperature and the influence of the workpiece on inaccuracy of measurement.

Industrial Needs as Reflected by NPL Investigations on Accuracy of Measurement, P. W. HARRISON. Machy

(London) vlOO n2585 May 30 1962 p 1237-42. Reference made to 2 extended investigations carried out by NPL to 'establish accuracy of measurement of size currently achieved in British industrial firms ; method used was

to select appropriately shaped workpieces having internal and external diameters from 0.02 in. up to 80 in. ; parts were measured first at NPL under optimum conditions, and then by private firms ; summary given on manner in j which results were examined ; conclusions drawn.

Basic Principles and Accuracy of Measurement in Relation

to ISO System of Limits and Fits, L. W. NICKOLS.

Machy (London) v 101 n2594 Aug 1 1962 p 235-41. Dis- cussion of some problems which are being faced in prep- aration of Part 2 of new ISO system and possible ways of overcoming them ; system now in course of preparation,

will give recommendations for dimensional inspection concerned with principles of gaging, design of gages, measuring instruments, and accuracy of measurement; , interpretations of limits of size ; relation between inaccu- j racy of measuring process and safety margin ; effect of , errors of form of workpieces.

Realistic Estimates of Errors in Measurements, W. J. YOUDEN. ISA-Proc Preprint 44.5.62 for meeting Oct \ 15-18 1962 4 p. It is emphasized that concept of error

in measurement has meaning only in terms of use to which measurement is put ; method for experimental esti- mate of realistic errors is given together with some ef- ficient methods of tracking down most important sources

of error. Accuracy Analysis of Measurements, W. J. DARMODY. , ASME-Paper 62-WA-280 for meeting Nov 25-30 1962 p 5. Total or system concept of measurement is useful approach to constructive analysis of measuring accuracy

;

elements useful as guides in analyzing measurement ac- curacy are considered as follows—standard, workpiece, , instrument, person, environment. The Accuracy of Industrial Measurement of Length and ! Diameter. Proc Conf nl4 NPL Apr 17-8 1962 Her Majesty's Stationery Office, London, 1963 437 p illus. Twelve

papers with discussions. Uncertainties in Calibration, W. J. YOUDEN. IRE Trans

Insbrum (USA), vl-ll n3-4 Dec 1962 p 133-8. Presents j some methods for making comparisons between standards and items undergoing calibration. These methods may be i IS
used in a variety of measurements. The purpose is to ac- cumulate data that provide objective estimates of the

precision and that are also useful in detecting sources of systematic errors. This purpose is achieved by using some

standard statistical designs in the scheduling of the work

program. The problems of stating the uncertainty and

of combining the uncertainties in a chain of calibrations are discussed. Error Analysis in Metrology. D. B. SCHNEIDER. Misc

Publ 248 1963 p 93-102. Analytical method developed at Boeing Primary Standards Laboratory is presented that

recognizes and combines quantitative values for systematic and random component errors which significantly influ- ence measurement results ; included in method is tech- nique for determining confidence interval of uncertainty

example of application of technique is illustrated by cali- bration of optical pyrometer. Measurement Errors—Identification, Detection, Evaluation and Expression, A. J. PLOURDE. NBS Misc Publ

248 1963 p 103-9. Definition is given of measurement uncertainty and methods for evaluation of uncertainty are recommended ; paper is based on concepts developed at Metrology Dept of Bureau of Naval Weapons, Pomona,

Calif. Measurement-Agreement Audits—Method for Increasing

Confidence in Measurements, P. M. RIVOT. IEEE Int Convention Rec vll pt5 (Aerospace & Navigational Electronics, etc) 1963 p 264-9. Causes for measurement in- compatibility and some measurment-agreement-audit tech- niques for increasing confidence in compatibility of measurements; measurement agreement audit can be considered system for checking and having necessary ad- justments made in accuracy of calibrations, measurements, and tests by submitting appropriate samples or measure- ment devices for calibration, meaurement, or test. Correlation of Certain Basic Terms in the Field of Measurements, A. B. SHAEVICH. Meas Techns 1962 nlO June

1963 p 805-7 4 refs. Discussion by N. Y. Krupp p 807. Translated from Izmer Tekh nlO p 1-2 Oct 1962. Dis- cusses meanings of terms such as precision, accuracy, and reproducibility. Determining the Precision of Tolerance-Limited Controlling and Measuring Devices, B. A. VIGMAN, B. B. DUNAEV. Meas Techns 1963 nl Aug 1963 p 16-9 4 figs 2

refs. Translated from Izmer Tekh nl p 11-^ Jan 1963. Develops an analytical-graphical probability method which

provides a single-valued determination of the precision re- quired for a tolerance controlling and measuring device

for a given set of parameters. Geometrical and Physical Limitations in Metrology, J. C. MOODY. Int Prod Eng Res Conf Proc Sept 9-12 1963

p 567-73. Published by ASME. Refinements in metrology

are explored from point of view of engineers in metal working industry; measurement of flatness, parallelism,

straightness, roundness, and surface finish ; measurement

of elastic and permanent compression, deflection, and

surface deformation; problems arising from effects of temperature and of heat transfer on objects being measured, and on measuring machines or references. Natural Boundaries in Metrology, L. W. NICKOLS, P. W. HARRISON. Int Prod Eng Res Conf Proc Sept 9-12 1963

p 574-84. Published by ASME. More practicable ap- proach than development of completely new techniques

of measurement, which must necessarily be few in number, is seen to be improvement of accuracy of existing measuring techniques by carefully analyzing sources of

error and taking necessary action to minimize errors;

influence of errors is discussed that arise from standard, measuring equipment, process of comparison used, variations in ambient temperature and personal errors of

inspector ; ways are discussed in which some of these

errors can be counteracted. 18 refs. Variation in Contact Error Between Repeatedly Wrung

Surfaces, E. G. THWAITE, R. T. LESLIE. Brit J App

Phys vl4 Oct 1963 p 711-3 1 fig 4 refs. A controlled ex- periment is described for determining the variability of contact error between highly flat steel surfaces when

repeatedly "wrung" together; this led to an estimated standard deviation of 0.292 x 10~6 in. for the distribution of the contact error and an "on the average" tolerance limit about the mean at the 90% level of ±0.52 xlO"6 in. A

linear increase of length with serial order of wringing of approximately 0.08X10"6 in. per wringing was observed and

has been attributed to a progressive formation of asperities on the surfaces. Neuere Untersuchungen fiber Messunsicherheit (Recent Experiments Regarding Measurement Uncertainty), P. LEINWEBER. Werkstattstechnik v54 n5 1964 p 230-6 2

figs 5 refs. Measuring results on indicating length meassuring instruments were reported in earlier publications, and proposals were developed for definitions of the con- cept "measurement uncertainty" and for characteristic numerical values for the accuracy of measuring instru- ments. Here these proposals are discussed on the basis' of further measurements, and objections raised against them are treated. Measurement Error Propagation, J. R. MILLER III. Instruments & Control Systems v37 n6 June 1964 p 133-

4. Propagation of error in chain of measurements is dis- cussed; procedure is described for determining error in- troduced by standards and instruments used ; procedure

eliminates need for any predetermined accuracy ratios

(10:1, 5:1, 4:1, etc) but requires scrutiny of each component of system to determine which part of error is sys- tematic, and which part random.

Uncertainties in Measurement, R. P. BENEDICT.

Electro-Technology v74 n4 Oct 1964 p 51-3. Simple rules for determining maximum certainty of result which is re- lated to one or more measured independent variables ; ex- perimental uncertainties; application of method to practical example dealing with measurement of pressure using

fluid meter. Guaranteeing a Measurement and Gage Selection Guide, W. B. McCALLUM. ASME Paper 65-Prod-2 for presentation at the Metals/Production Eng Conf June 9-11 1965 5p refs. Discusses the major variables encountered in a measuring system and establishes a technique of numerically evaluating their total effect in relation to an ac- curacy ratio between the measuring instrumentation and

the product tolerance at a specific confidence level. By

applying this technique more than 100 measuring devices have been evaluated. Some of the results are tabulated

for instruments used by certain people under specific conditions. 1.3.2. Instrumental Errors

Variance of Measuring Instruments and its Relation to Accuracy and Sensitivity, F. J. SCHLINK. J. Washington Acad Sci v8 June 19 1918; NBS Sci Paper n328 p 741-64

7 figs. The terms accuracy, sensitiveness, and variance

are quantitatively defined. Discusses types of variance, means for reducing variance, and relation of variance to useful sensitivity. Genauigkeiten der Messzeuge (Accuracies of Measuring

Tools), R. P. SCHRODER. Der Bebrieb v4 n9 Feb 11 1922 p 269-74 in German. Definition of the concept of accuracy. Dependability of accuracies. End measures. Primary standards. Comparison standards. Testing

standards. Working standards. DIN 168. Standards of production. 19
Genauigkeitsanspriiehe an Mikrometer und Ftihlhebel (Ac- curacy Claims Regarding Micrometers and Indicators),

G. BERNDT. Iter Betrieb v4 n9 Feb 11 1922 p 280-4 13

refs. Micrometers : Relation of measurement and read- ing accuracy of screw micrometers; progressive and pe- riodic thread errors ; deviation from planeness and parallelism of the measuring surfaces ; fluctuations of the measuring pressure ; bending open ; errors of adjustment ; in- fluence of temperature ; measuring accuracy ; use with measuring machines. Indicators : Good definition of the

short lever arm or combintaion of mechanical and optical amplification ; influence of measuring pressure ; multiple

levers (dial gages). Recent Developments in the Art of Fine Measurement,

J. E. SEARS. Eng vl21 June 4 1926 p 652-4 8 figs. Recent

experience shows that it is not possible to get agreement

of interpretation between different observers of lines better than 0.00001 in., and this accuracy could be sur- passed at present by material end standards with ends

furnished optically flat and parallel, and by natural standard based upon wave-lengths of light ; author refers

to advance made in this direction ; interference methods of measurement ; triode valves applied to measurement of small displacements ; measurement of internal diameters. Genauigkeit von Messgeraeten, G. KEINATH. Archiv

fuer Techn Messen v4 n46 Apr 1935 (J 021-1) p T54 2p. Precision of measuring instruments ; analysis of concept of accuracy ; accuracy requirements and guarantee ; differ- ence between accuracy in reading of instruments and as

applied to measurements; practical tolerances. Bibliog- raphy. Errors in Measurement of an Object by the Microscope,

F. EHRENHAFT. CR Acad Sci v204 Jan 4 1937 p 40-1. Two particles identical in substance and size are separately measured visually or photographically in the field of

a microscope. The particles are then moved together till they touch. The diametrical measurement at right angles

to the line joining their centers gives a check oh the first measurement ; the difference between this and that along

the line of their centers gives the correction to be applied

to the measurement of single particles. Accuracy of Measuring Instruments, G. H. BARKER.

Power and Works Engr v33 n381 Mar 1938 p 110-5. Dis- cussion on accuracy of means of measurement, its deter- mination and proof and accuracy with which measure- ments are made; intrinsic and practical accuracy and

true values ; expression of "limits of error" ; percentage and absolute errors; practical accuracy of fluid flow meters ; accuracy tests against measured true values. Die Angabe der Genauigkeit bei Langenmessgeraten (The

Specification of Accuracy in Length-measuring Devices), H. SCHMIDT. Werkstattsteehnik/Der Betrieb v37/22 nlO 1943 p 375-6 6 refs. English translation available. Accuracy and Geometry of Precision, E. W. PENNINGTON. Tool and Die J v 9 n8, 10, 11, Nov 1943 p 90-2, Jan 1944 p 99-101, Feb p 102-3, vlO n2 May 1944 p 90-2. Nov 1943: Discussion of requirements of accuracy of (1) position or adjustment, (2) size, and (3) form, and fulfil- ment of these requirements through flat surface plate. Jan 1944 : Illustrated description of Whitworth's method

of making or originating true flat surfaces and straight

edges. Feb : Commentary on important combinations of

flat surfaces or straight edges, i.e., angles. May : Methods

outlined for producing true and self proving 30, 45 and

60° angles. La Metrologie dans l'lndustrie Moderne, W. RUGGABER.

Rev Universelle des Mines v4 n2 Feb 1948 p 176-85. Metrology in modern industry ; importance of precision measurement and errors due to instruments, discussed

;

temperature and elastic deformation ; instruments made

by Societe Genevoise d' Instruments de Physique, includ- ing microscope and profile projectors, described and

illustrated. Physical Limits of Some Measuring Processes, A. MOTTU.

Microtecnic v3 n2, 3 Mar-Apr 1949 p 85-90, May-June

p 98-111. Measurement of line standards; inherent er- rors of microscope and means for minimizing them ; errors inherent to scale ruling ; choice of magnification power

;

comparison of line standards ; factors influencing measuring accuracy ; photoelectric process ; profile projectors

;

surface quality measurement using Schmaltz's method,

interference microscope, and "Talysurf" surface meter. Errors of Second-Order Measuring Instruments, E. T. BENEDIKT. Rev Sci Instrum v20 April 1949 p 229-33. The various types of error which affect the result of a measurement performed by an instrument behaving as a second-order linear instrument are defined. The theoretical systematic error is shown to be caused by the (dynamical) lag with which the instrument responds to the

signal. If the damping is high, this type of error is oc the rate of change of the signal. The accidental error

resulting from input noise and accidental changes of the instrument constants is considered. It is shown that all these effects can be represented by an effective input noise. A formula for the mean square error in the indication

of the instrument is given in terms of the correlation function of the above effective noise. Related theoretical questions on random functions are also discussed. Notes on the Care and Use of Electrical Instruments, F. D. WEAVER, Instrum v23 nl2 Dec 1950 4 p 5 refs. Pre- cautions that should be observed by users of electrical instruments to enable them to achieve greater accuracy

in measurement and to extend the useful life. Sources

of error. Measurement Errors—Classification and Interpretation,

J. C. BOONSHAFT. ASME Paper n53—A-219 for meeting Nov 29-Dec 4 1953 6 p. Classification and appearance

of errors contributing to uncertainty of measurement with

industrial indicating and recording instruments; design

details and measurement situations which affect them

;

special reference made to mechanical pneumatic trans- mission and receiver devices; relationships and typical

figures are given to show technique of evaluating precision, or internal consistency. Some Present Day Trends in Engineering Metrology, C. O. TAYLERSON. Instn Prod Engrs J v33 n4 Apr 1954 p 233-9. Progress at National Physical Laboratory, in development of precision instruments for measurements of kind required in machining, toolmaking, etc; optical measurement aids ; microscopes and screw checking de- vices ; autocollimating telescope ; angle gage blocks ; pneu- matic gaging; examples of dynamic metrology. Standard Calibration Methods for Measuring Instru- ments, J. A. HARRINGTON. ISA J vl n7 July 1954 p 24-7. Importance of accurate dimensional control in industrial measurement and methods necessary to maintain precision ; standard inch and its relationship to meter ; use of light waves ; some common errors of meas- urement and how to overcome them in different kinds of gages ; problems in measurement of surface roughness. Instrumental Drift, W. J. YOUDEN. Sci vl20 n3121 Oct

22 1954 p 627-31. Drift is usually explored by making

series of repeated measurements on same object ; problem

discussed of how operator can "forget" previous readings

so that subsequent readings will not be influenced by

earlier ones ; comparison of actual and calculated drift

;

application of statistical methods in checking instrument

performance.

Scale and Reading Errors of Electrical Indicators, F. D. WEAVER. Instrum & Automat v27 nil Nov 1954 20
p 1812-^. Errors limit accuracy of even best electrical indicating instrument to about 0.1% ; sources of errors are analyzed, and National Bureau of Standards calibration methods presented. Ten-Millionth of an Inch, I. C. GARDNER, NBS. Ord- nance v39 n210 May-June 1955 pp 896-901 12 figs. Analyses sources of error for measurements to 10"7 in. Messfehler bei optischen Messgeraten (Measuring Errors

with Optical Measuring Apparatus), L. MEYDING.

Feinwerktechnik v62 n9 Sept 1958 p 319-22 7 figs 4 refs in German. As with other measuring instruments, optical instruments also have certain errors. If one would mini- mize measurement errors the limitations of the measuring

instrument must be known. This work considers the

limitations and the sources of errors. How to Conquer Gaging Errors, C. W. KENNEDY. Iron Age vl82 nl7 Oct 23 1958 p 70-2. Nine pitfalls of precision gaging are wear, dirt, looseness, pressure, deflection, temperature, vibration, geometry, and approximation ; detection of faults ; their causes and remedies. Measuring of Contact Gaps by the Absolute Interference Method, I. T. UVERSKII. Meas Techns 1958 n3 Nov

1959 p 304-6 2 figs. Translated from Izmer Tekh n3 MayJune 1958 p 46. Describes investigation of accidental and

systematic errors introduced by the measuring contacts

of length measuring instruments operating on the contact

principle. Analysis of the Results of Checking Gauges and Instru- ments, E. F. DOLINSKII. Meas Techns 1958 n3 Nov 1959 p 273-82 1 ref. Translated from Izmer Tekh n3 MayJune 1958 p 22. The general problem of analyzing re- sults of checking gauges and instruments can be divided according to the number of check "points" and the type

of prevailing errors into the following categories : checking constant-value gauges ; checking sets of gauges and

instruments with constant systematic errors only ; checking instruments with random errors only ; checking in- struments with systematic and random errors, which is the general case. Deals with large scale testing of mass

produced measures and measuring instruments when the aggregate of both the tested and reference measures and

measuring instruments is sufficiently large. Methods of

calculations, however, are applicable to small groups of reference measures and instruments, using the discrete

distribution of probable error densities which corresponds

to the given number of instruments and their errors. This

is only possible if the errors of the available measures

are determined with sufficient accuracy by more accurate methods than those normally used in checking these measures. Instrument Uncertainties, L. P. ENTIN. Control Eng

v6 nl2 Dec 1959 p 95-8, v7 n2 Feb 1960 p 75-8. General

aspects of instrument uncertainties of zero, such as those depending on manufacturing misalignment, ambient temperature variations and hysteresis ; total zero uncertainty

uncertainties of scale factor and instantaneous slope, as

related to specifying linearity, tolerance, excitation, and

resolution. New Limits of Accuracy, L. POLK. Machy (N.Y.) v66 n7 Mar 1960 p 128-9, 188. Aspects of precision and

accuracy as they affect national capability, in manufacture

and measurement, to "zero in" on target in space or on market objective in expanding programs of new product development; seventh decimal accuracy on 4 in. gage

block; measurement of internal diameters; from laboratory accuracy to machining tolerances. Evaluating Error of Measurement of Attribute Gages,

G. E. SORBER, Western Elec Engr v4 n3 July 1960 p 26-31. Method for evaluation of errors in "go-no-go" gages is'

based on application of mathematical Probit Method tech- nique originally developed in biological sciences. A Method of Determining Variance in the Presence of a Linear Systematic Error. A. YU GIDEL'. Meas Techns

1959 nl2 Sept 1960 p 928-31 2 figs. Translated from Izmer Tekh nl2 Dec 1959 p 6. The determination of the vari- ance of a series of measuring instrument readings is possible not only with constant external conditions but also

in the presence of a systematic error. The method here developed provides the determination of the variance of instrument readings in the presence of a systematic pro- gressive linear error. Influence of Measuring Force, Stylus Radius, and Surface

Finish on Accuracy of Measurement of Work-Pieces by Comparator, L. W. NICKOLS, T. R. J. OAKLEY. Instn Mech Engrs Proc vl75 n3 1961 p 195-210, 223-34. In- formation was required to enable recommendations on en- gineers' measuring instruments ; sizes of work pieces were measured using stylii of different radii under successively increased measuring forces ; sizes at any one point were

influenced mainly by alterations in measuring force ; sur- face texture of work piece had greater effect than stylus radius on size variations. Source of Measurement Error in Instrumentation Systems,

R. CERNI. ISA-Proc. Preprint 19-LA-61 for meeting

Sept 11-15 1961 7 p. Errors due to equipment, interference, installation, response, and operation of complex

measuring instruments and systems ; generalized methods

for their elimination or minimization. Observation Accuracy in Relation to the British Standards

Institution's Draft Recommendation for Industrial Instru- ment Scale Design, J. SPENCER. Brit J App Phys vl2 nl2 Dec 1961 p 712-14. The correct specification of industrial instrument observation and experimental results are

presented for two examples of scale design from the Brit- ish Standards Institution draft recommendations. These

results show that the design performance (95% of all scale value for a scale commencing at zero) is achieved providing that observers have a minimum of practice and are allowed a maximum of two seconds observation time under

adequate illumination. Error Bands, A. A. ZUEHLKE. Instrum & Control Sys- tems v35 n4 Apr 1962 p 132-3. "Errorband" concept, rep- resenting upper and lower limits of deviation from zero

error for defining instrument performance without oner- ous testing and calculations of many individual errors in- volved ; example of potentiometer transducer. Sources of Instrument Error, R. CERNI. ISA J v9 n6 June 1962 p 29-32. Measurement inaccuracies due to equipment, interference, installation, or dynamic response

errors. Interchangeable Errors in Instrument System, G. M. AN- DERSON. AIEE Trans v81 ptl (Communication & Electronics) n61 July 1962 p 191-2. Relation of interchangeable error to deviations, from nominal or standard values,

of parameters of system components, to make possible control of total error by means of suitable tolerance limi- tation on component parameters ; analysis developed for two-component system comprising transmitter and indi- cator can be easily extended to include systems comprising three or more components. Paper 59-156.

Classification of Measuring Devices by Their Accuracy,

A. I. KARTASHEV, D. L. ORSHANSKII. Meas Techn

1962 n6 Dec 1962 p 447-51 2 figs. Translated from Izmer Tekh n6 p 1-A June 1962. The category characterizes the degree to which a measure of measuring instrument ap- proaches its maximum attainable accuracy with the existing technique for measuring the given physical value. The class of accuracy indicates the tolerated and actually attainable limiting measurement error.

I
Determining the Error of an Automatic Measuring, Testing, and Sorting Machine, I. B. GERTSBAKH. Meas

Techn 1962 n7 Feb 1963 p 533-7 2 figs. Translated from

Izmer Tekh n7 July 1962 p 1-4. Develops theory and

method for determining the mean-square error, c, of the measuring unit in an automatic testing and sorting machine when it is being checked under workshop conditions. This is based on the knowledge of the amount of components which are allocated to the same group in consecutive sorting. Utilizing the Error Compensation Phenomenon for Raising

the Precision of Measuring Information Systems, N. A. CHEKHONADSKII. Meas Techn 1963 nl Aug 1963 p 3-7

4 figs 5 refs. Translated from Izmer Tekh nl p 3-6 Jan

1963. Some of the errors produced by random external disturbances in links of a measuring information system

can be compensated by suitably selecting certain characteristics of these links, thus greatly raising the accuracy

of the system. The use of special transducers, which

respond to the external effects and feed signals corresponding to these effects to the main channel of the measuring

information system, raises considerably the precision of such systems under operational conditions. Condition and Tasks of Metrology in the Field of Linear and Angular Measurements. L. K. KAYAK. Meas Techns

1963 nil Apr 1964 p 893-7 2 figs 4 refs. Translated from

Izmer Tekhn nil p 1-5 Nov 1963. Discusses raising the

precision in measuring standards of length ; raising accu- racy in reproducing the meter on reference installations

;

reducing the error in the methods of transferring the

values of unit lengths to reference and working measures and instruments ; problems of the automation of linear measurements ; angular measurements ; dilatometry. Neuere Untersuchungen ueber Messunsicherheit (Recent

investigations on uncertainty in measurements), P. LEIN- WEBER, Werkstattstechnik v54 n5 May 1964 p 230-6, Measuring uncertainty (MU) of measuring device comprises accidental and undetermined systematic defects, and is numerically expressed by plus or minus MU = plus

or minus 2 s where s is standard deviation established by

statistical methods ; further proposals for definition of term "measuring uncertainty" are discussed on hand of measurements carried out, and of objections raised by

various workers. Measurement Error Propagation, J. R. MILLER, III. In- strum & Control Systems v37 n6 June 1964 p 133-4. Propagation of error in chain of measurements is discussed

;

procedure is described for determining error introduced by

standards and instruments used ; procedure eliminates need for any predetermined accuracy ratios (10: 1, 5:1,

4 : 1, etc) but requires scrutiny of each component of system to determine which part of error is systematic, and

which part random.

1.3.3. Statistical or Mathematical Treatments

Adjustment of Observations, N. CAMPBELL. Phil Mag

v6 n39 Feb 1920 p 177-94. Develops zero sum method

of adjustment, said to be much simpler and more con- venient practically than the conventional method of least squares and equally valid. Theory of Errors and Least Squares, H. JEFFREYS. Roy

Soc Proc vl38 Oct 1 1932 p 48-55. It is shown that in the absence of previous knowledge of the probable degree

of precision of a set of observations, the probability of a value of h, the precision constant, lying within the range dh is dh/h. This result, applied to the theory of least squares, indicates that when the number of observations

is small, the probability of error is more widely dis- tributed than is given by the usual formula.

Mechanical Adjustment of Observations by Least Squares,

B. GERMANSKY. Zeit fur Techn Phys vl4 n9 1933 p

370-2. The observed points are plotted on graph paper, and pins stuck into the paper at points simply related to these. Rubber bands parallel to the Y-axis are stretched, one over each pin, and passing over a metal rod which

automatically takes up the position of the best straight

line to represent the observations. Method of Least Squares, A. S. EDDINGTON. Phys

Soc Proc v45 Mar 1 1933 p 271-87. Furnishes a concise treatment of combination of observations. Messfehler und ihre Zusammensetzung, A. KONEJUNG.

Zeit des Bayerischen Revisions-Vereins v37 nl8 Sept 30 1933 p 175-8. Errors in measurements and their analysis ; errors in products and quotients ; increase in accuracy by calculation of average values. On the Statistical Theory of Errors, W. E. DEMING,

R. T. BIRGE. Rev Mod Phys v6 July 1934 p 119-61. Reprinted with additional notes 1937 15 figs 47 refs. Theory of Errors, H. KAISER. Zeit fur Techn Phys vl7 n7 1936 p 219-26. The theory of errors of observation is worked out on the basis of probability theory. Richtige Summen und Mittelwertbildung, HUBER.

Waerme v59 n41 Oct 10 1936 p 668. Summation and

averaging examples given of how error may be intro- duced by incorrect application of experimental or test data in determination of mean or summation values. Abbreviated Method and Suggested Cheap Mechanical

Device for Calculating Standard Deviations of Observations, J. L. SPENCER-SMITH, H. A. C. TODD. Textile

Inst J v28 n2 Feb 1937 p T21-6. Rapid graphic method

of calculating deviation of set of observations, by means

of Galton's "ogive" curve, applicable in measurements

on textiles, etc ; comparison of results with root mean

square standard deviation ; probable error of method is 3.5% ; application of method as integrator for routine

testing machines. Bibliography. Les Erreurs Accidentelles de Mesure et d'Observation,

P. SAGASPE. Arts et Metiers n202 July 1937 p 158-66. Theoretical mathematical treatise on accidential errors in measurements and observation of instrument indicators. Application of Theory of Measurements to Certain Engineering Problems, L. E. WOODMAN. Missouri Univ

School of Mines and Met Tech Series Bui vl5 nil June

1942 41 p. Per cent of deviation; percent of error; weighted mean ; precision measures ; notation in powers

of ten ; significant figures ; graphical representation of errors; results; variation of functions; propagation of errors ; adjustment of observations by method of least squares. Fehlertheorie und Ausgleichrechnung und ihre Anwendung auf betriebsmassige Langenmessungen (Error theory and compensation calculation and their application to operational length measurments ) , H. SCHMIDT. Werkstattstechnik und Werksleiter v36 n23/24 Dec 1942 4 p

5 refs. On the Postulate of the Arithmetic Mean, M. BOLDRINI. Comment Pont Acad Sci vlO nl 1946 pl-4. In

Italian. Discusses the circumstances under which the arithmetic mean of a set of observations can be taken as

a valid representative of the set. Improvement of Precision by Repeated Measurements.

Application to analytical Control Methods^ J. MANDEL.

Indus Eng Chem (Analyt Ed) vl8 May 1946 p 208-^. This article critically examines replication of measure- ments as a means of increasing precision. Formulae are provided for evaluating such improvement of precision 22
in any given case and for computing confidence limits in routine analysis. Linear "Curves of Best Fit," A. E. W. AUSTEN, H. PELZER. Nature (London) vl57 May 25 1946 p 693-4. Discusses the procedure for finding the best estimate of the

relation ic=Pv when both w and v are subject to normal

errors. The solution given is of wide application. Linear "Curves of Best Fit" and Regression Lines, D. V. LINDLEY. Nature (London) vl58 Aug 24 1946 p 272-3. Austen and Pelzer's solution is not new. It is important

to distinguish between the above lines ; the former esti- mate the constant of proportionality between true values, the latter provide the best estimate of a true value from

observed values. On the Representation of an Experimental Law by an

Approximate Law and a Curve of Deviation, P. C.R. VER- NOTTE. Acad Sci Paris v223 Dec 23 1946 p 1105-7. In

French. A discussion of the treatment of errors in the

values of quantities determined by experiment. It is shown how the curve of deviation allows the experimental

values to be regularized. Over-Estimation of Probable Errors, R. T. LESLIE. Nature (London) vl60 Nov 29 1947 p 751-2. The usual for- mula for the combination of probable errors is invalid when the observed quantities are subject only to errors in reading scales, which are therefore limited in size. Alter- native formulae are worked out for this case. Graphisches Verfahren zum Ausgleich wiederholter Messungen, W. LEDE. VDI Zeit v90 n3 Mar 1948 p 89-90. Graphic method for averaging of repeated measurements

method described can be used without numerical calculations ; it makes use of transparent triangular scale, shown

in drawing.

Separation of Errors by Calculus of Probabilities, J. MEURERS. Zeit angew Math. Mech v28 p 183-6 June

1948. In German. A method of separating the errors of two different measuring methods applied to the same object of measurement, when the effect of the errors of either method on the results is unknown. The Numbers of Observations Needed in Experiments

Leading to a *-Test of Significance of a Mean or the

Difference of Two Means, G. P. SILLITTO. Res ( London

)

vl Aug 1948 p 520-5. The numbers of observations needed

in experiments requiring statistical methods for their in- terpretation depend on the risks which can be tolerated

of reaching two distinct kinds of erroneous conclusions. For the frequently occurring experiments involving simple comparisons of the mean of a sample with a standard

value or with the mean of another sample, tables are presented showing the numbers of observations needed in relation to the tolerable risks of the two kinds of error, the

precision of the experimental work, and the magnitude

of the difference which the experiment is required to

detect, if it exists. The use of these tables is illustrated by examples. The Foundation of the Calculus of Observations and the Method of Least Squares, J. M. TIENSTRA. Bui Geodesique nlO Oct 1948 p 289-306. In English. An attempt

to provide a new basis, free from "metaphysical conceptions" and resting on "physical facts and sharply formulated hypotheses about properties of series of observations." Distribution of Range-Finding Errors, J. H. CALDWELL,

K. H. SPRING. Letter in Nature (London) v 166 Nov 25

1950 p 906-7. The frequency distribution of error ex- pressed as y=range error/ (true range) 2 is found from

trials to depart from the normal form and to show signifi- cant skewness. This skewness is shown to arise from

the approximation use, which implies that equal range

errors will arise from equal angular errors of opposite

sign. After making allowance for this, the distribution

is found to be symmetrical although still not normal.

Statistical Analysis of Errors in Point Gauge Measurements, G. D. RANSFORD. Houille Blanche v6 n4 July- Aug 1951 p 518-24. Method is applicable when no stand- ard measuring equipment is available; sources of error include calibrated scale length due to temperature changes ; application of "analysis of variance" to solution

of problem; readings taken with 5 similar point gages on 6 different water levels at rest, show that maximum

probable error is plus or minus '0.2 mm. (In French and

English). The Reliabilitv of Measured Values—Fundamental Concepts, C. EISENHART. NBS Rept n 1600 15 Apr 1952 43 p 3 figs. Discusses : inter-relations of bias, precision and

accuracy ; comparison of an accurate biased procedure with an inaccurate biased procedure ; evolution of a reallife direct-measurement process. Calculation of Accuracy of Results of Graphical Square

Intercomparisons, P. M. GILET, G. S. WATSON. Austral J Phys v6 June 1953 p 155-70. Graphical squares of two

types are used for calculating the results of interconipari- sions of standards of length, mass and other quantities, and the results of calibration of scales. By means of graphical squares, estimates of the true values or "im- proved" values are obtained from observations. From the

differences between the improved and observed values, the

residuals, a measure of the accuracy of intercomparison, may be obtained. In this paper expressions are derived which enable the calculation from the residuals, of ac- curacies of observed values, of improved values and of various quantities derived from the improved values. The "Best" Straight Line Among the Points, R. H. BACON. Am J Phys v21 Sept 1953 p 428-46. The familiar method

of fitting a straight line to a set of experimentally observed

points by use of least squares is reviewed, and variations

of it briefly discussed. Then methods, apparently not so familiar to many physicists, for estimating the adequacy

of the fit thus obtained, and for comparing the results of several such experiments, are explained. A few of the

principles of mathematical statistics underlying these methods are given in the appendix.

Sets of Three Measurements, W. J. YOUDEN. Sci Monthly v77 n3 Sept 1953 p 143-7 4 refs. Discusses the signifi- cance of differences between two or more measurements

in relation to uncertainty. Units for Measuring Variations in Measurements, W. J. YOUDEN. Metal Progr v64 n3 Sept 1953 p 91-6, 96B. Three units for measuring variation among measurements

include range of observation, average deviation and stand- ard deviation ; their computation ; number of measure- ments needed ; examples given showing how to make use of information about variation exhibited by group of nu- merical quantities ; statistical table for appraising variability is presented. Rejection of Outlying Observations, F. PROSCHAN. Am

J Phys v21 Oct 1953 p 520-5. Makes available to the

physicist two of the modern statistical tests for possible rejection of outlying observations. These two methods

have been selected because they apply in a majority of the actually occurring situations and because they are so easy to use. Investigation of Errors of Observation, R. T. LESLIE. App Statistics v3 n2 June 1954 p 112-5, supp plate. Statistical theory of errors is often applied to measuring

precision of observations of physical quantities without due consideration being given to question of independence

of errors from various sources ; features of apparatus

designed to investigate this problem as it affects observa771-846 O—66 3
tions made with optical instruments incorporating ref- erence lines, graticules, etc. Sensitivity—Criterion for Comparison of Methods of Test.

J. MANDEL, R. D. STIEHLER. J Res NBS v53 n3 Sept

1954 (RP2527) p 155-9. Single criterion is presented by which relative merit of methods of test can be evaluated ; main advantage of new criterion, referred to as sensitivity, is that it takes into account, not only reproducibility of testing procedure, but also its ability to detect small deviations in characteristic to be measured ; appli- cability to chemical analysis, etc. Tables of Error Function and Its Derivative. NBS App

Math Ser n41 Oct 22 1954 302 p. Improved tables of error

function, or probability integral to 15 decimal places for values of argument x from 0.0000 to 1.0000, and from,

1.000 to 5.946 and over at intervals of 0.0001 and 0.001 respectively ; applicability of tables to problems in refraction, conduction of heat, and other fields of physics, to variety of problems in theory of probability and mathematical statistics. Practical Application of Uncertainty Calculations to Measured Data, L. W. THRASHER, R. C. BINDER. ASME

Paper n55—A-205 for meeting Nov 13-18 1955 5 p. To

assess reliability of measurements, it is desirable to clas- sify two types of measurements : multiple sample and sin- gle sample ; case for single sample has not been established

;

it is proposed that tester estimate his error, uncertainty

interval, and give odds that error would be less than

uncertainty interval if measurement were repeated many

times ; numerical example. A Theory of Certainty. II Application to Metrology, M. C. CAMARGO. Anales de la Real Sociedad Espanola de

Pisica y Quimica v52 (A) nl-2 Jan-Feb 1956 p 43-58. In

Spanish. A mathematical discussion of theory of errors on the postulate that errors above a certain size are impossible (not very improbable, as on the Gaussian treat- ment ) . A formula is obtained which gives the probability that the true value lies between any two given limits. The

size of the graduations of the measuring instrument is taken into account. An expression is also obtained which

serves as a numerical measure of the departure from

the Gaussian distribution.

Statistical Approach to Spatial Measurement, A. M. RUSSELL. Am J Phys v24 n8 Nov 1956 p 562-7. A

method of determining length is described which reduces

the measurement to a counting operation. The same

technique is then applied to the measurement of flat areas and sections of the surface of a sphere. The limits of error are discussed and in particular the dependence of the error upon shape and the choice of a lattice is observed in the measurement of flat areas. Some possible applications are suggested. Limit of Usefulness of Repeated Measurements, R. I. YANUS. Fiz Metallov i Metallovedenie v4 n2 1957 p

369-74 in Russian. It is shown that Gogoberidze and

Kirillov's opinion, that repeated measurement of a particular quantity by the same instrument can reduce the probable random error of the measurement only to the

error in reading the indication of the instrument, is valid only for those trivial cases in which the numerical results

of all measurements are equal. Korekcja Przypadkowych Uchybow Pomiarowych na Zasadzie Ciaglosci Przez Przestawianie Zmiennych, M. MAZUR, M. KRUSZYNSKI. Archiwun Elektrotechniki v6 n3 1957 p 461-72. Correction of casual measuring er- rors ; method of transposition of variables, which permits

correction of casual errors without increasing amount of measuring points ; applicability of method in cases where

curve graphs have to be drawn on base of small amount

of measuring points.

Theory of Error, Y. BEERS, New York Univ. Addison- Wesley Publ. Co. Inc. 66 p 4 illus, paperbound. 2d Ed 1957. Presents the basic principles of the theory of error and

illustrates them by direct application to actual laboratory experiments. In preparing the revised edition major at- tention was devoted to the sections on definition of a stand- ard deviation, rejection of data, the standard deviation

in an average value, and best fit of a straight line. Al- though intended primarily for students in advanced under- graduate physics laboratory courses, the book is adaptable to a wide variety of uses. Contents: Introduction.

Definitions. Classification of errors. Random error of a measured quantity. Propagation of error. Special topics

in the adjustment of data. The statistical errors of nuclear physics. Examples. References. On the Quantization of the Measured Quantity in the

Static Measurement, M. MORIMURA. Report of the Central Inspection Institute of Weights and Measures, Japan,

v7 n2 report 15 1958 in Japanese. As the measuring sys- tem has various sources of error, the measured value

obtained from it is necessarily quantized. The "quantum"

of the measured value in the static measurement by the

linear system with the scale-pointer display corresponds

to the "scale unit" defined by D. M. Mackay. As the measured quantity has the probability distribution, it is more desirable to use the concept of average scale unit weighted by the distribution than to apply directly the

scale unit in Mackay's sense. Under some reasonable as- sumption for physical system, the equation for the average

scale unit was formulated. On the other hand, the optimal way to maintain the given precision is to minimize the

labor necessary to do it, and the optimal condition was

derived. For the case of two simple examples, that is, for the S -distribution and uniform distribution in the measured quantity, the above conditions are calculated and shown graphically. On the Statistical-Graphical Evaluation of Results of Measurments, W. EHRENBURG. Zeit angew Phys

v9 n3 Mar 1958 p 147-51 in German. This paper de- scribes the use of graphs of cumulative distribution functions plotted on probability (normal law) graph paper, with special reference to (1) estimation of standard deviation, (2) dissection into two, or more, normal dis- tributions, and (3) finding normalizing transformations. There is also a theoretical discussion of methods of esti mating probabilities. Engineering Statistics, A. H. BOWKER, G. J. LIEBER- MAN. Prentice-Hall Inc. 1959 585 p illus. Contents: Histograms and empirical distributions ; other probability

distribution ; significance tests ; tests of the hypothesis about a single parameter; tests of hypothesis about two

parameters ; estimation ; analysis of variance ; analysis of enumeration data ; statistical quality control and con

trol charts ; sampling inspection. Die Messunsicherheit und ihre Bedeutung fuer Masstol- eranz und Fertigungstoleranz, R. NOCH. Werkstattstechnik v49 nl Apr 1959 p 195-9. Uncertainties of measurement and their importance to dimensional and

machining tolerances; statistical analysis of measure- ments shows why tolerances indicated by designer cannot

be fully utilized in production ; it is claimed that improved measuring techniques are economically justified, especially for costly workpieces. A Method of Calculating the Experimental Error with a View to its Elimination, P. VERNOTTE. CR Acad Sci (Paris) v248 n21 May 25 1959 p 2968-9 in French. If the physical quantity sought is a linear function of the measured data the experimental error can be expressed as a

series of functions with periods 2, 3, 4. . . . See CR Acad

Sci (Paris) v245 nl8 Oct 28 1957 p 1521-2. These functions can be eliminated by summing the data two at a time, three at a time, etc. The result obtained then lies between

a definite maximum and minimum. As an example the 24
method is applied to some preliminary measurements of

g by the free fall in vacuo method made at the Pavilion de

Breteuil. Utilization of the Theory of Random Functions in Metrology, N. A. CHEKHONADSKII, Meas Techns 1958 n2 Aug 1959 p 121-6 2 figs 2 refs. Translated from Izmer Tekh

n2 Mar-Apr 1958 p 3. A problem in the field of metrology

is examined in the solution of which the methods devel- oped by the theory of random functions can be successfully

used. Article derives a general expression for the result- ant error of a measuring system.

Statistical Analysis of Measurement Data. Special Report. ISA J v6 n9 Sept 1959 p 74-84. Two companion

papers dealing with problems of "data indigestion" in some

branches of engineering, such as in aeronautic research and flight data acquisition ; Less Data—More Information.

B. J. DUBBIN, 74-9; discussion of transducers statisti- cally analyzing measurement signals and transmitting

only their information content ; How to Make PowerSpectral Density Analyses of Measurement Signals, A. R. SOFFEL, 80-4; practical example of how to extract in- formation from random electrical signals. A Graphic Method of Determining the Statistical Mean

and Mean-Square Deviations, D. V. ALIAB'EV. Meas

Techns 1958 n3 Nov 1959 p 282-4 1 fig. Translated from

Izmer Tekh 1958 n3 May-June 1958 p 28. The similarity

of formulas for determining the statistical mean and the

center of gravity of a homogeneous body permits one to

use, in working out observation results, the well-known

graphical methods applied for determining the center of

gravity. The graphic method of determining the statistical mean and the mean-square deviation is speedier than

the analytical method and prevents any gross errors oc- curring. Determination of the Measurement Error of Linear Di- mensions due to Misalignment, G.S. SIMKIN, Meas Techns

1958 n4 Dec 1959 p 399-^03 4 figs 2 refs. Translated from

Izmer Tekh n4 July-Aug 1958 p 15. In measurements

carried out on a comparator or a horizontal optical comparator a misalignment of the part being measured with

respect to the line of measurement is always possible. The

errors, due to misalignment can become especially large when, in measuring long lengths, such relatively inaccurate instruments as end-measuring rods, slide gages, etc., are used. Article considers a law of the distribution of

errors due to misalignment which is interesting in itself, and also gives some equations for the determination of the

size of this error occurring in various length measurements. On the Quality Evaluation of Methods for Checking Measurements Instruments, I. V. DUNIN-BARKOVSKII, A. N. KARPASHETA, Meas Techns 1958 n6 Mar 1960 p 616-24

3 figs. 1 ref. Translated from Izmer Tekh n6 Nov-Dec

1958 p 6. As is known, the basic task of the testing and

checking of measurement instruments, is that of verifying

certain given properties of the latter and, primarily, their accuracy. On the basis of the state of contemporary statistical mathematics, it is possible to formulate and scientifically substantiate objective criteria for the reliability of methods of checking measuring instruments. A Variant Least-Squares Method of Solution of a System

of Observation Equations. J. L. STEARN, H. RICH- ARDSON. J Geophys Res v65 n4 Apr 1960 p 1308-9. A

simple method for dropping an observation in the calculation of least-squares estimators of parameters. Some Problems Connected with the Application of Ran- dom Functions in Metrological Practice, G. S. SIMKIN.

Meas Techns 1959 n4 May 1960 p 241-5 1 fig 7 refs. Translated from Izmer Tekh n4 Apr 1959 p 1. Discusses determination of errors of glass scales, clock-type indicators, and micrometers. In a number of cases the use of random functions in estimating the accuracy of means of measurement enables one to obtain a better estimate of

their accuracy. Random functions may be used with great advantage to study the stability of the process of manufacture of measuring instruments. Evaluation of Circular Components by the Harmonic Analysis Method, M. S. MIRKIN. Meas Techns 1959 nl2 Sept

1960 p 946-52 7 figs 2 refs. Translated from Izmer Tekh

nl2 Dec 1959 p 19. In many instances of machining error

analysis, it is important to establish from the total meas- ured error the value and direction of its components in

all the points of a machined surface. Since the machining process is periodic and consists of a complete cycle, the variation of the error of a circular cross section detail is a function of the angle of rotation. Analysis of various

periodic processes is usually carried out by their expansion into trigonometrical series of the Fourier type. The

analysis of the error by means of such a function has not

only a nominal value, but it reveals the sources of the sep- arate components of the total error, thus reflecting the ac- tual nature of their origin. Thus, the error expressed by

the first term represents eccentricity ; the remaining terms

represent the deviations of the cross-sectional shape from

a circle. Measurement Accuracy as Weighting Factor in Statistical Treatment of Data, D. M. ASPINWALL, J. R. REY.

ISA-Proc Preprint 66-NT60 for meeting Sept 26-30 1960

6 p. Possibilities of improving usefulness of measurement

instrument by considering effect of measurement accuracy on estimated mean and variance of measured quantity

use of maximum likelihood theory to extract full information from set of data with different degrees of accuracy.

Probability and Experimental Errors in Science, an Ele- mentary Survey, L. G. PARRATT. John Wiley & Sons,

Inc. N.Y. 1961 255 p. Chapter Headings : Early develop- ments : Ideal games. Direct measurements : simple statistics. Statistics of measurements in functional relationships. Normal probability distribution. Poisson probability distribution. On Realistic Measurement of Precision and Accuracy, C. EISENHART. ISA-Nat Aero-Space Instrumentation Symposium 8th-Proc 1962 p 75-83. Nature and objectives of measurement ; measurement as production process ; cor- rection and adjustment of measurement; law of large numbers and mathematical formulation of bias and precision of measurement process ; variations of procedure, apparatus, observers, and environmental conditions al- lowable in "repeated" applications. 21 refs. How to Analyze Statistical Instrumentation Errors, P. F. HOWDEN. Electronic Equipment Eng vlO n6 June 1962 p

68-9. Statistical approach is presented for estimating instrumentation errors that occur within instrument,

that are injected at input, or which occur at output. Estimating Experimental Errors, H. WEISS. Machine

Design v34 nl3 June 7 1962 p 154-7. Basic mathematical

descriptions of types of errors in experiments, tolerances, and measurements ; algebraic methods for adding, subtracting, multiplying, and dividing values for which error must be stated ; example given concerns determining area

tolerance obtained in manufacture of rectangular metal

plate to length of 2 plus or minus 0.001 in., and width of 3 plus or minus 0.002 in. Normal Law of Measurement Error Distribution, G. S. SIMKIN. Meas Techns 1962 n4 Sept 1962 p 271-2. Translated from Izmer Tekh n4 p 3 Apr 1962. Actual distri- bution law is often unknown and it is important to deter- mine what it is. Realistic Estimates of Error, W. J. YOUDEN. ISA -J v9 nlO Oct 1962 p 57-8. Discussion of some common mis-
understandings that may arise when comparing measure- ments ; weakness of duplicates ; comparative and absolute values; method of estimating error. Intercomparisons of Laboratory Test Results, J. MANDEL. ISA-Proc Preprint 44.3.62 for meeting Oct 15-18

1962 5 p. Representation of measurement process in terms

of statistical model taking account of experimental er- rors in measurements ; use of model for characterization

of precision, both within and between laboratories, is illustrated. Realistic Estimates of Errors in Measurements, W. J. YOUDEN. ISA-Proc Preprint 44.5.62 for meeting Oct

15-18 1962 4 p. It is emphasized that concept of error

in measurement has meaning only in terms of use to which measurement is put; method for experimental estimate

of realistic errors is given together with some efficient methods of tracking down most important sources of

error. Uncertainties in Calibration, W. J. YOUDEN. IRE Trans

Instrum vl-ll n 3-4 Dec 1962 p 133-8. Presents some

methods for making comparisons between standards and

items undergoing calibration. These methods may be used in a variety of measurements. The purpose is to accumulate data that provide objective estimates of the

precision, and that are also useful in detecting sources

of systematic errors. This purpose is achieved by using some standard statistical designs in the scheduling of the work program. The problems of stating the uncertainty and of combining the uncertainties in a chain of calibra- tions are discussed. Error Analysis in a General Physics Laboratory, W. B. PACKARD, G. G. WOOTAN. Am J Phys v31 nl Jan

1963 p 62-3. Suggests that the error in a function of measurement (s) may be measured in terms of maximum

error, without introducing considerations of probability. The "Maximum error" for a direct set of measurements

is estimated as the maximum absolute deviation from the arithmetic mean. It is pointed out that care must be taken

in deriving maximum errors of derived quantities. Thus

if the maximum error in S is s, the extreme measured

values of P=S+S-' are not (S—s) -HS+s)"1 and S+s-f ( S—s) '. Unfortunately the authors state that the

limits are S—s+(S—s)"1 and S+s+(S+a)"\ which is not

true if 0<S—s<KB+s.

System-Error Analysis, L. COCHIN, R. ISAKOWER.

Prod Eng v34 n3 Feb 4 1963 p 61-5. Method is described

for determining contribution each component adds to

total error of measuring or indicating system ; evaluation

of total system error, done in tabular form as in table presented, permits immediate identification of troublesome

areas in system.

Realistic Evaluation of Precision and Accuracy of Instru- ment Calibration Systems, C. EISENHART. NBS J Res Eng & Instrumentation v67C n2 Apr-June 1963 p 161-87. Calibration of instruments and standards is refined form

of measurement; measurement operation cannot be re- garded as constituting measurement process unless statistical stability of type known as state of statistical control has been attained ; "allowable variations" must

be of sufficient scope to bracket circumstances likely to be met in practice ; indication on precision must be based on

appropriate random sampling of this likely range of cir- cumstances. 80 refs. Statistical Fluctuations and Errors in Measurements, M. DUQUESNE. Microtecnic vl7 n4 Aug 1963 p 142-50. Dis- cussion on origin and limit of validity of principal dis- tribution laws applied to study of characteristics of measuring instruments and exploitation of results obtainable, particularly in measurements of radioactivity.

Experimental Statistics, M. G. NATRELLA. NBS Handb

91 Aug 1 1963, Supt. of Documents, U.S. Gov't Printing Office. In 5 sections : 1 basic concepts and analysis of meas- urement data ; 2 analysis of enumerative and classificatory data ; 3 planning and analysis of comparative experi- ments ; 4 special topics ; 5 tables. Precision Limit Obtainable in Automatic Statistical Treat- ment of Repeated Measurements Results, P. V. NOVITSKII, Meas Techn 1963 n5 Nov 1963 p 365-71 3 figs 11 refs. Translated from Izmer Tekh n5 p 1-6 May 1963. The

labor spent on eliminating random errors is 20-200 times

greater than that spent on eliminating systematic errors. Present achievements in the field of computers and cybernetics open up wide prospects for the automation of measurements and for incorporating automatic computers

in measuring equipment, thus sharply increasing the possible number of obtained and processed measurement re- sults and raising in a new manner the available means

for improving the precision of measuring instruments. The Meaning of "Least" in Least Squares. C. EISEN- HART, NBS. J. Washington Acad Sci v54 n2 Feb 1964 p 24-33 28 refs. The method of least squares as a valuable

tool in applied science stems in part from the algebraic and arithmetical advantages of "least sum of squared

residuals" and in part from estimates of "least mean

squared error" in the important case when the end results are linear functions of the basic observations—a unique

property. Graphico-Analytical Determination of the Mean-Square

Systematic Error in Discrete Measurements, I. M. SHENBROT. Meas Techn 1963 n8 Feb 1964 p 638-43 5 figs 7

refs. Translated from Izmer Tekh n8 p 6-10 Aug 1963. Presents a convenient graphico-analytical method of de- termining the quadratic mean error from a correlation function B(t) graph for several types of discrete measurements.

1.3.4. Personal Equation

Sehen und Messen (Sight and Measurement), HANS

SCHULZ. Zeit der Duetschen Gesellschaft fur Mechanik und Optik Mar 15 1920 p 25-28; Zeit Techn Physik vl n6-7 1920 p 116-121, 129-37. A careful, partly mathematical treatment of the effect of the eye on the accuracy

of measurements. The cases considered are length measurements, photometric comparisons, interference measurements, and microscopic measurements. The limit of accuracy depends even more, in some cases, on the nature

of the eye than on the limitations of the apparatus employed. The limit of accuracy attainable in interference work is put at 0.05/t and in microscopic measurement

at 0.6//. Personality in the Estimation of Tenths, S. ALBRECHT.

Astron J v33 nl3 Dec 11 1920 p 103-12 45 figs. The subject

is treated under three headings : Part 1 deals with per- sonal scale obtained from observations made in connection with the regular program of circle observation, i.e., esti- mations of tenths on the telescope and circle micrometers and on thermometer scales; in part 2, estimations made

on specially drawn scales are discussed ; and part 3 contains supplementary remarks. Note on Estimation of Tenths, P. KIRKPATRICK. Phys Rev vl9 May 1922 p 545. Shows systematic error occurs with a group of observers in the process of estimating

tenths of the interval between two parallel lines. Physiological Limits to the Accuracy of Visual Observation and Measurement, H. HARTRIDGE. Phil Mag 6th

ser v46 July 1923 p 49-79. Definition of the limits to 26
accuracy considered ; acuity of the eye for grating and

double star test objects and for contours; coincidence,

interpolation, and contact methods of measurement ; measurements of depth and distance ; comparison methods of brightness and color measurement.

Psychologische Einflusse bed Toleranzmessungen und

Grosszahl-Auswertungen ( Psychological Influences with

Tolerance Measurements and Large-Number Evaluations), K. DAEYES, K. SCHIMZ. Stahl und Eisen v50

1930 p 1467-9 2 figs 6 refs. In measuring product from a

manufacturer by a user over a period of years this investi- gation showed an increasing tendency for a worker's measurements to deteriorate from relatively exact measurements to estimated values. This shows up first as a

neglect of values 1 and 9 and later 4, 6, and 7. Wave

patterns of frequency curves made up from groups have

their source in the inequality of even and odd numbers in the range of 0 to 4 and 5 to 9. Estimation of Tenths on a Scale, H. BACKSTROM. Arkiv

f Mat Astron och Fysik (Stockholm) v23A n21 1933 p 1--43. An investigation of the systematic errors oc- curring in the decimal estimation of the readings of

scales. Inspector's Errors in Quality Control, J. M. JURAN. Mech

Eng v57 nlO Oct 1935 p 643-4. Quality is measured by human inspector ; it is therefore of considerable im- portance to consider manner in which fallibility of in- spection can arise ; inspectors' errors divided into : errors

in reading measuring instruments, errors in judgment, and in recording. Precision Measurements with the Micrometer Eyepiece, H. RUHLE. Zeit fur InstrumKde v58 Sept 1938 p 355-74. The author is concerned with the errors which arise in

setting the cross-wire of a micrometer onto the edge of a luminous object, due to contrast effects in the eye. In the experiments the luminous "object" consisted of the image

of an illminated aperture, formed by a telescope objective. The actual size of the image was determined by calculation and compared with the apparent size given by the micrometer settings. The variations of the error with

object brightness and exit pupil size were determined. The results are interpreted, taking into account the contrast sensitivity of the eye and the "grain" of the retina. Personal Equation of Men and Machines, J. R. PARKS.

Tool Engr vl9 n3 Oct 1947 p 43-5. Statistical method of obtaining and expressing individual precision of production machines (and setups) of same class, duty, capacity and manufacture ; use of standard deviation "S" as measure of personal equation ; example of data and calculations

involved. On Estimation of Tenths, J. VOLGER. App Sci Res vAl

n3 1948 p 215-8. Test made to check possibility of esti- mating to one-tenth of scale unit, position of pointer on

scale of given instrument; results obtained using 100

artificial scales and 55 observers. Errors in Scale Estimation, A. J. BIRCH, D. K. C. Mac- DONALD. Res (London ) vl Mar 1948 p 287-8 2 figs 1 ref. A histogram of the frequency of observations at each 0.1 of a scale interval shows a crowding effect about the scale

lines. Two probable causes are discussed. Discussion by

E. Eastwood Sept 1948 p 575-6 2 fig 2 refs. A histogram shows tendency to exaggerate the mid-interval points as

well as the scale divisions. Some Variables Influencing Vernier Acuity. I. Illumination and Exposure Time. II. Wave-length of Illumination, K. E. BAKER. J Opt Soc Am v39 July 1949 p 567-76.

Functions relating vernier acuity, or coincidence acuity

to illumination have been obtained for 2 different exposure

times and at 3 regions of the visible spectrum. An ap- paratus providing the necessary stimulus controls has been

described in detail and the procedure is fully explained. An Optical Illusion Affecting Instrument Cross-Wires,

S. TOLANSKY. Lab Prac v9 n9 Sept 1960 p 635-7. A

description is given of an optical illusion which confuses

the estimate of colinearity when inclined lines cross a broad image. The nature of the illusion is examined and

found to depend on (a) angle of inclination of the crossing

lines and (b) the width of the object. The way in which

this illusion might affect cross-wire settings is considered.

Realistic Estimates of Error, W. J. YOUDEN, NBS. ISAJ v9 nlO Oct 1962 p 57-8. Discussion of some common

misunderstandings that may arise when comparing meas- urements; weakness of duplicates; comparative and ab- solute values ; method of estimating error. Measurement Uncertainty, D. B. SCHNEIDER. ISAProc Preprint 44.1.62 for meeting Oct 15-18 1962 4 p. Largest element of uncertainty in assignment of limit of error is shown to be ignorance of individual performing

analysis concerning error ; method is presented for squeez- ing down on error until certainty is reached that limit of error just barely contains error. Appraisal of Current Measurement Personnel and Effect upon Quality of Measurement, C. D. FERRIS. ISA-Proc

Preprint 44.4.62 for meeting Oct 15-18 1962 6 p. Appraisal

of competencies and deficiencies of personnel and re- sultant effect upon measurement quality as revealed by

regular course work and special programs presented at Center for Measurement Science; particular areas of concern are lack of realization of physical limitations of equipment and technology, statistical treatment of data, and setting of confidence limits. Visual Factors in Size Measurement by Microscopy, W.

N. CHARMAN. Optica Acta (Int) vlO n2 Apr 1963 p

129-39. In estimating the size of an isolated object by

visual observation of its image as formed by a microscope

objective, the characteristics of the eye as well as the physical light intensity distribution in the image must be taken into account. Experiments are described in which

the visual sizes of circular objects of known size are measured as a function of the instrumental magnification, the

retinal illumination and the adaptation of the eye, these

results being discussed in relation to the corresponding

diffraction images and the properties of the eye. Investigation of an Observer's Error in Estimating by Eye

Fractions of a Scale Graduation, I. D. FAINERMAN.

Meas Techns 1963 nlO Mar 1964 p 832-^ 4 figs 5 refs. Translated from Izmer Tekhn nlO p 21-3 Oct 1963. The comparison of the observer's readings and the reading errors on linear and curved scales shows, as was to be expected, that the greatest accuracy is attained for a scale spacing

fraction of 0.5 ; moreover, the reading accuracy of the cir- cular scale is smaller than that of the linear scale. Tests have shown that in determining the observer's error of reading measuring instrument scales it is necessary to dis- tinguish and account separately for the "individual scale of readings" and the "individual scale of rounded-off readings." The scale spacing fraction of 0.5 has the largest frequency when the effect of xounding-off is eliminated. Certain individual reading errors are larger on a circular

scale than on a linear scale. The observer's individual er- ror is accounted for as a normal systematic error. Further exhaustive investigation of this error is envisaged. In particular, it is advisable to continue the search for new scale designs in order to raise the accuracy of reading and reduce the Observer's individual errors.

->1
1.4. Temperature Effects and Measurement

Temperature Variations of Cast-Iron Divided Circles, F. GOPEL. Zeit fur Instnimkde v32 Feb 1912 p 33-43, Communication from the Physikal Techn. Reiehsanstalt. Method for determining accurately the variations of scale divisions with different temperatures is described and il- lustrated, with tables showing actual results. On the Choice of a Uniform Temperature for the Calibration of Measuring Instruments (Sur le Choix d'un Degre

Uniforme de Temperature pour l'Etalonnage des Instru- ments de Mesure) , C. COCHET. Rev Gen de l'Electricite, v4 Nov 16 1918 p 740-2. Report of Commission de Normalisation des Ingenieurs des Arts et Metiers de Boulognesur-Seine, recommending adoption of 0 deg. cent, as

standard. Der Einfluss der Temperature auf die Langenmessungen

(The Influence of Temperature on Length Measurements),

G. BERNDT. Der Betrieb v4 nl Oct 8 1921 p 1-8 7 figs in German. By experiments the time was determined which

is necessary for equalization of temperature of different measuring tools with that of the environment when set on

iron plate and in air. For the future the theory of the experiment will be established on the basis of simplifying assumptions and therefrom the determining coefficient of the external heat conduction for the heat exchange as well as the heat transition number. Temperature of Adjustment of Industrial Gages ( La Temperature d'Adjustage des Calibres Industriels), A. PER- ARD. Genie Civ v90 June 25 1927 p 621-4 3 figs. Plea

to German Industrial Standards Committee to readopt ad- justment of 0 deg. instead of 20 deg. cent. ; discusses requisite precision for industrial gages and necessity for stand- ardization of temperature of adjustment. Temperature Adjustment of Length Standards (La Temperature d'Adjustage des Etalons Industriels, des verifica- teurs et des pieces mecaniques), L. GRAUX. Genie Civ

v91 Sept 10 1927 p 250-2. Discusses adjustment on basis

of standard meter at 0 deg. or at 4-20 deg. cent. Temperature of Standardization of Industrial Gages (La Temperature de Definition des Calibres Industriels), C. E. GUILLAUME. Rev Gen de l'Electricite v23 Jan 14 1928 p 73-6. Object of article is to emphasize importance of decision made by German Commission fixing 20 deg. cent, as temperature of standardization ; after stating necessity

of unification of temperature in all countries and difficul- ties which have arisen, author gives some reasons which

have moved him in stating troublesome effect German de- cision can have on desired unification. Concerning Standardization Temperature of Industrial Gages (A Propos de la Temperature de Definition des

Calibres Industriels), A. PERARD. Rev Gen de l'Electricite v23 Jan 28 1928 p 169-70. Discussion of reasons

for not considering temperature of 20 deg. cent, as temperature for standardization rather than 0 deg. cent. ; takes

into account coefficient of expansion. Temperature of Definition of End Standards, G. K. BURGESS, Director NBS. Letter to Members of International Committee on Standard Temperature for End Gages. June 20 1928. Presents results of survey of U.S. National

organizations and manufacturers of tools and gages. Unanimously in favor of 20° C for reasons stated. Temperature of Adjustment for Industrial Standards of Length. (Ed.) Mach (London) v33 Feb 7 1929 p 596. Discusses changing British practice from 62° to 68°. Temperature Control Gives True Leadscrews, F. SCHOEFFLER. Am Mach v87 nl7 Aug 19 1943 p 90-2.

Influence of temperature change on work and machine is particularly important when chasing accurate leadscrews

;

article discusses development and use of special precision

lathe, installed with Zeiss measuring equipment in con- stant temperature room, for chasing leadscrews. Thermometric Scales and Expansion Coefficients, J. M. T. VIDAL. CR Acad Sci (Paris) v233 p 469-71 Aug 6 1951

in French. The scales of two thermometers, which depend

on the expansion of different substances, are shown to form a projective series and the law of expansion relative

to a thermometer is deduced. Some experimental data quoted from the literature is given in support of the re- sults. Contribution a la Metropole Industrielle des Longueurs,

P. GRAND. Rev Gen Mecanique v36 n41, 42, 45 May 1952 p 135-40, June p 167-70, Sept p 293-6. Contribution to industrial measurements of length, with reference to parts

of large dimension ; influence of ambient temperature in workshops ; permissible deviation between temperature of gage and object being measured; measurement of steel parts with steel and wooden gages, and light alloy parts with steel, light alloy and wooden gages ; diagrams. Errors in Temperature Measurement Due to the Construction and Situation of Thermometers, F. LIENEWEG.

Archiv Tech Messen nl96 (Ref V 2165-2) p 107-10 May

1952 in German. Errors due to the lag of the thermometer and the surrounding medium, and, for the resistance thermometer, the heating error, are considered. By ex- pressing the various heat exchanges in terms of equivalent thermal conductivities, and by using the values, obtained

experimentally, of the errors of a thermometer in the two

media, still air and stationary water, it is shown that the

errors for any medium can be expressed simply. Graphical representations to assist calculations in any practical case are given. A Recording Device for Surface Temperature Measurements, N. SASAKI, A. KAMADA. Rev Sci Instrum 23 June 1952 261-3. By means of a small heating coil, the temperature of a thermocouple junction is made to oscil- late regularly between two temperatures Tt and T2 . Simul- taneously the junction makes about one contact every two

seconds with the surface being measured. A short-period galvanometer in the thermocouple circuit produces on a moving photographic film a serrated sine curve whose ser- rations vanish once for every half-oscillation at a point that corresponds to the surface temperature Ta, provided T3 lies between Tx and T2. This mode of measurement

minimizes disturbances due to air currents. Alternatively, use of a thermocouple with two adjacent junctions

is proposed. A simple but accurate portable thermostat

for maintaining reference junctions at temperatures some- what higher than room temperature is also described. Temperature Measurement in Engineering, vl, H. D. BAKER, E. A. RYDER, N. H. BAKER. John Wiley &

Sons, Inc., N.Y. 1953 179 p. First of two-volume work is primarily concerned with thermocouple techniques and in- cludes chapters on fundamentals, basic information neces- sary for design of temperature measuring apparatus, and

specific designs for measuring internal temperatures and

temperature gradients in solid bodies. Eng Soc Library, N.Y. Measurements with Small Resistance Thermometers for Industrial and Laboratory Purposes, O. WINKLER. Arch Tech Messen Issue 205 Ref v212-2 Feb 1953 p 31-2. In German. A note describing small resistance thermometers and their associated measuring bridges. The resistance

at 0°C is 500. Over the range 0-50°C the scale is linear

to about 4%.
Preparation and Use of Cells for Realization of Triple

Point of Water, C. R. BARBER, R. HANDLEY, E. F. HERINGTON. Brit J App Phys v5 nl Jan 1954 p 41-4. General Conference of Weights and Measures in Oct 1948

passed resolution that zero of International Temperature

Scale should be denned as temperature 0.0100 "C below

that of triple point of water ; technique used at Teddingron. England for preparing cells for realization of triple point of water is described; results obtained over ex- tended period. Thermistors vs Thermocouples For Temperature Measurements, R. P. BENEDICT. Elec Mfg v54 n2 Aug 1954 p

120-5. Critical evaluation of thermoelectric properties

of old and well known thermocouple and newer thermistor ; parallel calibration tests show greater sensitivity, higher stability, and shorter thermal time lag for thermistor.

Electrical Parasites Hamper Temperature Measurement,

D. J. PEARSE. Steel Processing v41 nl Jan 1955 p 22-3,

52. Accuracy of measurement affected by parasitic currents induced into thermoelectric circuit; potential dangerous sources of alternating current such as electric machinery, power lines, heating elements, etc, and their elimination : a-c stray pick-up filter circuit at instrument

thermocouple junctions will by-pass stray currents and

reduce their effect to negligible proportions.

Influence de la Temperature sur l'Etalonnage des Jauges,

P. GRAND. Rev Gen de Mecanique v39 n74 79, 83, 84 Feb

1955 p 39-45, July p 247-54, Nov p 395-^00, Dec p 445-50, v40 n86. 88 Feb 1956 p 81-7, Apr p 159-64. Influence of temperature on calibration of gages; environmental

temperature in measuring shop ; temperature of materials

subjected to different environments ; calibration on measuring machine ; comparator calibration ; errors of calibration due to temperature variations. Thermistor Electric Thermometer, R. W. WOODS. Sci vl21 March 4 1955 p 337-8. Continuous measurements

of rectal, subcutaneous, and skin-surface temperatures

of mice were made with thermistors in bridge circuits. Nineteen such circuits were connected to a bank rotary

switch so that any temperature could be selected and

measured on a valve voltmeter. The range was 0-50 °C and the sensitivity about 1%.

Response of Temperature Measuring Elements to Thermal

Transients, J. A. CLARK. ASME Paper n55—SA-18 for meeting June 19-23 1955 19 p. Study concerned with

requirements of modern automatic control and regulation which demand increased speed of response from all measuring and recording instruments ; review of available data

on behavior of instruments sensing and controlling temperature, during any temperature change i.e., transient

period. Bibliography.

Effect of Unstable Thermal Conditions during the Testing of Long Gage Blocks, J. C. MOODY. Metrology of Gage Blocks, NBS Cir 581 Nov 7 1957 p 67-70 1 fig. Supt.

of Docs., Gov't Printing Office, Washington, D.C. On the

basis of a series of tests a technique for the testing of long blocks was established. A Thermal Enclosure for a Microscope, A. BONETTI,

A. E. SICHIROLLO. "Particle Photography" Conf, Montreal, 1958 p 354-6 in French. To reduce the considerable

fluctuations in the position of the image seen in microscopes with fluid drives, produced by thermal gradients, an isothermal enclosure was designed. In particular the construction of such a unit for the Koristka MS-2 microscope is described and the position stability of the image

discussed.

Effect of Temperature Conditions and Coefficients of Thermal Expansion on Accurate Gaging, N. F. KANS.

Indus Quality Control vl5 n3 Sept 1958 p 22-7. Article

is limited to problems encountered using indicator gages with separate gage masters ; most methods of accurately determining piece size at 68 F fall into one of two cate- gories ; no gage reading compensation required and gage

reading compensation required ; types of problems oc- curring in industry ; recommendations made ; series of examples illustrate effects of temperature variation on

materials. A Method of Maintaining Temperature Control over a Wide Range, H. L. ALLSOPP, D. F. GIBBS. J Sci Instrum v35 nil Nov 1958 p 395-7. It is sometimes desir- able to control the temperature in an apparatus without having to use a bath of stirred liquid as a means of maintaining thermal equilibrium. The apparatus described is applicable to such cases, thermal equilibrium being maintained by a stream of gas that is brought to the required temperature in a heat exchanger. The system is effective

in the range from —150° to 200 °C, and the temperature

stability varies from about ±1 °C in the range from 20°

to 200 °C, to ±5 °C, below —110 °C. New Standards of Resistance and Temperature Measurement, P. H. HUNTER. Western Elec Engr v3 nl Jan

1959 p 2-8. Techniques employed at Western Electric's North Carolina Works Standards Laboratory to establish and maintain reproducible standards of great accuracy

multichannel data recording; development of precise oil bath temperature control ; resistance fixed points ; data

processing. On Maintaining an Object at a Uniform Temperature, C. M. CARMICHAEL. A. D. MISENER. Can J Phys v37 n7

July 1959 p 890-3. The apparatus consisted of a sealed 18 in. long, 6 in. dia. steel chamber with heating coils wound on its outer surface. A 12 in. copper cylinder of 4 in. dia., supported inside the steel chamber, acted as a uniform temperature enclosure and objects of various shapes and thermal conductivities were suspended on

nylon threads inside the enclosure. A pressure of 10"2 mm

Hg was maintained in the apparatus to eliminate convection. Two types of measurement were made (within range 20° to 100 °C) to investigate the equilibrium tem- perature over the surface of an object in relation to the temperature over the enclosure surface. In the first, the copper enclosure was maintained at uniform temperature

(to within about 0.003 °C) and the temperature of the

object showed a standard deviation of about 0.002 °C. There was considerable drift. In the second, a temperature gradient was set up along the length of chamber,

enclosure and object, of up to 2 °C. There was approxi- mately a 10-fold reduction in gradient from chamber to enclosure to object. Investigations of the Influence of Temperature Variations on the Readings of a Comparator with Large Mechanical

Magnification, R. NOCH, H. HUHN. Zeit InstrumKde,

v67 nil Nov 1959 p 285-8 in German. Mechanical comparators with high magnification for linear measurements

can alter their readings due to the influence of small changes of temperature. The paper deals with the in- fluence of a slight heat source, for example an operator

or a lamp, on comparators with the graduation of 0.0001 mm.

Surface Temperature Measurement, W. K. MOEN. In- strums & Control Systems v33 nl Jan 1960 p 70-3. Magnitudes and sources of error sometimes encountered during measurement of surface temperatures; effects of convection; changes in thermocouple design and in selection of wire size needed for measurement of higher surface temperatures in laboratory testing. How Temperature Affects the Measurement of Aluminum,

J. C. MOODY. Tool Engr v44 n2 Feb 1960 p 68 4 figs. Describes experiments devised and conducted in seven major manufacturing plants to demonstrate thermal ef- 29
fects, leading to better appreciation of the relationship between temperature and dimensional control. Comments on Various Temperature Combinations, I. H. FULLMER, NBS. 1960 4 p. Gives historical background

of three standard temperatures ; discusses importance of knowing coefficient of thermal expansion accurately, and

discusses proposed change to 23 °C. (Not published.) Automatic Precise Recording of Temperature, G. S. ROSS,

H. D. DIXON. J Res NBS Eng & Instrumentation v64C

n4 Oet-Dec 1960 p 271-5. Apparatus is described which

automatically and continuously records small temperature

changes, and which comprises platinum resistance ther- mometer, modified G-2 Mueller Wheatstone bridge, d-c amplifier, and potentiometric, strip-chart recorder ; high

stability of system obviates need for frequent zero checking; instrument is most useful when maximum temperature range is 1° ; similar arrangement using different equipment is also described. Empirical Determination of Thermocouple Characteristics, R. P. BENEDICT, H. F. ASHBY. ASME Paper 61—

WA-19 1961 17 p. A systematic approach leading to a unique empirical determination of individual thermocouple characteristics is described. This is based on the

application of four premises whose formulation is justified by the results. Typical thermocouple calibration data

are analyzed, and the most probable results are presented. Improved tables of thermocouple reference values are

given. Bibliography of Temperature Measurement January 1953

to June 1960, C. HALPERN, R. J. MOFFAT. NBS Monogr

n27 Apr 6 1961 13 p. More than 500 literature citations to

field of temperature measurement are presented ; refer- ences were collected from scientific and technical litera- ture and government reports; compilation is divided into number of categories based on type of instrument used

;

some references to calibration of instruments and to sci- entific theories, on which temperature measurement is based, are also presented.

Celsius versus Centigrade : The Nomenclature of the Temperature Scale of Science, H. F. STIMSON. Sci (USA)

vl36 Apr 20 1962 p 254-5. The temperature scale known

to U.S. scientists as centigrade was, in many countries, called Celsius after the inventor. In 1948 the 9th General Conference on Weights and Measures, representing the 33 nations that subscribed to the Treaty of the Meter, adopted the name Celsius as standard. For a variety

of reasons the name did not become popular in the U.S. At the 11th General Conference in 1960 the scale was

redefined so that the lower fixed point became the triple point of water with value 0.01 °C; thus making the adjective centigrade incorrect. The name Celsius is correct and its use by U.S. scientists would help to make the nomenclature of temperature uniform in all countries. Precision Temperature Measuring Equipment, J. J. HUNTER. J Brit Instn Radio Engrs v24 n3 Sept 1962 p 251-9. Describes the development of a resistance ther- mometer of high accuracy together with its associated bridge circuit. The thermometer is of the dual-element

type in which two coils of metal having different temperature coefficients of resistance are incorporated in the sensing head. The change in the resistance ratio of the two coils gives a unique indication of temperature. The

bridge circuit developed for use with the thermometer

employs the transformer ratio arm method which allows

highly accurate and stable ratios to be produced. A modified potentiometer recorder automatically balances the bridge and provides direct read-out. A further refine- ment is the addition of a shaft digitizer which gives a record for the temperature in a form suitable for auto- matic data logging. The whole apparatus is stable and

robust and can be used in industrial applications.

Surface Temperature of Thin Sheets and Filaments, J. M. ; BENSON, R. HORNE. Instrums & Control Systems v35 nlO Oct 1962 p 115-17. Instrument and method of measuring temperature of surfaces with thermocouple probe that

is directly heated by electric power supply so that null type reading is obtained with no heat flow to or from J surface ; temperatures of running threads were measured

j to accuracies of order of % C ; special form of probe is

j suited to measuring temperature of moving threadline

of nylon and similar textile material. Bibliography of Temperature Measurement July 1960 to December 1962, C. HALPERN. NBS Monogr 27 supp 1 1963 14 p. About 700 references are presented, col- I lected from scientific and technical journals and reports I on investigations sponsored or conducted by various gov- ernmental agencies; English, German, and French journals, and translations in English of Russian journals are

covered, as well as more commonly used abstract journals. Temperature Error in Equipment for Measuring Large

Dimensions, I. P. VAGANOV. Meas Techns 1962 n8 Feb j 1963 p 644-6 1 fig 1 ref. Translated from Izmer Tekh n8 i p20-2 Aug 1962. For the purpose of determining the

j error due to the variations during measurement in the temperature of the measured object and measuring equip- ment the changes in the actual length of measuring devices due to oscillations in the air temperature of the testing premises and the effect of the heat in the operator's hands

transmitted to the measuring equipment during measure- ments were determined experimentally. Direct Relative Humidity Indication from Dry and Wet

Bulb Temperatures, P. NORDON, N. W. BAINBRIDGE.

J Sci Instrum ( GB ) v40 n3 Mar 1963 p 136. By means of a simple thermistor network, the electrical output of a dry and wet differential thermocouple psychrometer can

be converted to indicate relative humidity directly, obviat- ing the need for an independent measurment of the dry

junction temperature. It is shown that such a network is capable of indicating relative humidity to ±2% of humidity over an approximate ambient temperature range of 56 to 98 °F and a relative humidity range of 30 to 100%. j Mechanical Design of Large Solar Telescope, H. HWANG, ' S. SACHS. ASHRAE J v5 n4 Apr 1963 p 35-46. Account

of cooling problems and their solutions in design of struc- fi ture to house solar telescope at Kitt Peak, Ariz ; thermal

analysis to determine feasibility of controlling temperature of exterior skin of telescope, and methods and feasibility of controlling thermal conditions within building

enclosure, so as to minimize or eliminate thermal currents I in optical path ; cooling load computation and solution of

' boundary conditions. Thermography-New Data Source, Principles and Applications. Automatic Control vl8 n5 June 1963 p 22-3, 57. 1 Infrared thermograph is described that makes precise, noncontact temperature surveys that do not alter tern1 peratures being measured ; it is applicable in determining temperature distribution in machines, electronic equip- ment and chemical and processing equipment. Recording Small Temperature Changes, D. H. NALLE.

jj Meas & Control v2 n9 Sept 1963 p 363-7. Principles of

( platinum resistance temperature measuring elements are

explained, used in conjunction with high-speed oscillo- graph for recording plant temperature variations as small ( as 0.01 °F. Measuring Temperature, L. G. RUBIN. Int Sci and

Technol n25 Jan 1964 p 74-88 6 figs. Although tempera- 1 ture is one of the primary quantities, along with length, mass, and time, it is more subtle conceptually and much

more difficult to define. Article discusses the multiplicity i of temperature scales—thermodynamic scales, practical i temperature scales, and others. 30
Determination of Temperature Corrections for The Dimensions of Machine Details, M. G. BOGUSLAVSKII. Meas

Techns 1963 nlO Mar 1964 p 829-32 2 figs 3 refs Translated from Izmer Tekh nlO p 19-21 Oct 1963. A semiconductor thermometer with a special transducer is described which

is convenient for measuring the temperature of flat, spherical, and fashioned outer and inner surfaces. The special transducer provides temperature measurements lasting not more than 10 sec. The error in measuring temperature

does not exceed ±0.3°. The technique for determining

corrections of temperature deviations from the normal of the article and the measuring instrument by means of a semiconductor thermometer and special graphs raises the accuracy of measurement and productivity in manufacturing precision articles on metal-working machines, and re- duces the percentage of rejects due to inaccurate measurements.

Effect of Temperature on Errors of Instruments in the Course of Measurements. N. N. MARKOV, G. B. KAINER, P. A. SATSERDOTOV. Meas Techns 1963 nil Apr 1964 p 888-902 2 figs 1 ref. Translated from Izmer Tekhn nil p 5-9 Nov 1963. An investigation was con- ducted which shows that in computing temperature errors

for hand-operated instruments it is necessary to take into account the deformations of components which produce

the largest measurement errors. The design formulas recommended in the literature for determining temperature deformations cannot be used for practical purposes, because it is virtually impossible to determine the temperature which affects the deformations, and linear ex- pansion coefficients are seldom known. In all measure- ments temperature oscillations were observed within the range of a few degrees even in a single instrument. A Dilatometer for Measurement of Dimensional Changes

in Metals Due to Irradiation, K. ISEBECK. Zeit Angew

Phys (Germany) vl7 n7 Oct 14 1964 p 497-504 in German. The metal specimen is coupled mechanically to a parallel plate condenser so that changes in length alter the condenser gap and unbalance an a.c. bridge. Relative length changes of 10"8 can be detected and specimen temperatures

held constant to better than 0.01 °C between —20 and

100° C. Effects of alpha particle irradiation on pure gold

at various temperatures and subsequent relaxation have

been measured using the method. Thermal Effects in Dimensional Metrology, J. B. BRYAN,

W. B. BREWER, E. R. McCLURE, J. W. PEARSON. ASME 65-PROD-13, Metals Engineering and Production

Conference, June 9-11 1965 25 p 15 figs 12 refs. A Lawrence Radiation Laboratory investigation shows that in the field of close-tolerance work, thermal effect is the

largest single source of error, large enough to make cor- rective action necessary if modern measurement systems and machine tools are to attain their potential accuracies. A simple, quantitative, semi-experimental method of ther- mal-error evaluation is developed. A relatively simple

device to monitor the thermal environment and automatically effect error compensation is proposed. Includes

glossary of terms, drift-check procedure, and method for determining frequency response of a measuring system. Calibration and Use of Liquid-in-Glass Thermometers, J. F. SWINDELLS NBS Monogr n90 1965 pl-23. This monograph, which supersedes Circular 600, contains information of general interest to both manufacturers and users

of liquid-in-glass thermometers, as well as those who wish

to calibrate thermometers or submit them to the National Bureau of Standards for calibration. Instructions are provided for applicants requesting calibration services, and the techniques and equipment used in the calibration procedures are described. Important elements of ther- mometer design are discussed, and factors affecting the use

of common types of liquid-in-glass thermometers are in- cluded together with tables of tolerances and reasonably

attainable accuracies. The calculation of corrections for the temperature of the emergent stem is given in detail for various types of thermometers and conditions of use.

1.5. Deformation, Deflection, and Wear

Miscellaneous Papers, H. HERTZ. Translated by D. E. Jones and G. H. Schott. 1896. Contains translations of two papers on ball bearings. The best theoretical data

available "on the contact of elastic solids", p 146-62; and

"on the contact of rigid elastic solids and on hardness", pp 163-183.

Ball Bearings for Optional Loading (Kugellager fur

beliebige Belastungen ) , R. STRIBECK. Zeit VDI v45 Jan

19, 26 1901 p 73-9 118-25 25 figs. (1) . The precedent conditions at point of pressure. (2). Experiments relative

to the pressing together of hardened steel balls and plates.

(3). Loading with the entry of the elastic limit in its relation to ball diameter. (4). The equation for the

permissible loading. (5). The frictional work of ball bearings. (6). Experiments with ball bearings.

Steel Ball Bearings. Eng v71 Apr 12 1901 p 463. An

illustrated account of the investigations of R. Stribeck, on behalf of the German Arms and Ammunition Works

of Berlin. An important contribution to the solution of

difficult mechanical problems. Based on Hertz's theoretical work and carried out experimentally. Numerous

graphs and tables. (French translation in Revue de M6-

canique, April 1901.) Application of Elastic Solids to Metrology, C. CHREE.

Phil Mag Nov-Dec 1901 p 532-58 594-616 ; Proc Phys Soc

vl8 1901-3. p 1-57 7 figs. Fundamental equations ; sus- pended and supported solids; pressure of surrounding medium ; solid surrounded by varying medium, aeolotropic

solids, cylinder suspended from the rim; solid cylinder

or prism with axis vertical-complete solution ; flask containing liquid, hollow cylinder containing or surrounded

by liquid ; spherical shell containing and surrounded by

liquid ; cylinder under pressure a quadratic function of Z

general properties, influence of cavities, gravitation, etc.

standards of length; applications of Bernoulli-Euler method ; bar under additional weight ; numerical appli- cations to standards of length; application to deflexion- bars of magnetometers ; concluding remarks.

Test Methods for Hardened Steel with Reference to Spherical Form ( Prufverfahren fur geharteten Stahl unter

Beriicksightigung der Kugelform), R. STRIBECK. Zeit VDI v51 Sept 14 1907 p 1445- 51 9 figs. Results of Tests. Elastic and permanent deformations. (1) Pressure ex- periments. (2) Bending experiments. The Elastic Indentation of Steel Balls under Pressure,

C. A. BRIGGS, W. C. CHAPIN, H. G. HEIL, NBS. ASME

Trans v40 nl643 1918 p 139-48 6 figs. Reports results of experiments with balls pressing against flat surfaces. Results show that the identation is proportional to the twothirds power of the pressure. Comparator for a Vertically-Placed Standard Meter, G. DIMMER. Akad Wiss Wien Ber 129 1920 p 223 ; Zeit fur InstrumKde v42 Jan 1922 p 24- 7 Abstract. Hooke's law would give a different length for a metal standard meter according as it lies horizontal or vertical. This

difference in length is known from given values of Young's modulus. The apparatus actually used to measure this difference consists of a frame carrying the meter, which can rotate on a horizontal axis on a large grad- uated circle attached to a vertical wall. Measurements

31
of the length are made with microscopes as in the ordinary comparator. The results for meters of steel, iron and

platinum are in general agreement with Hooke's law.

tiber die Giiltigkeit der Hertzschen Formeln zur Berech- nung der Abplattung von Messkorpern (Regarding the

Validity of the Hertz Formulas for Computing the Defor- mation of Measuring Bodies, G. BERNDT. Zeit fur tech Phys v3 nl 1922 p 14-21, n 3 p 82- 7. See also Zeit fur Feinmech und Praazision n 19-20 1923 p 210. The Contact Area of an Elastic Sphere When Compressed Between Flat Elastic Plates, J. GOODMAN. Eng, vll6 Aug 3 1923 p 133 4 figs. Methods of ascertaining area in contact between a steel ball and steel plates, and results

of tests. Contact area is larger than Hertz theory

.indicates (13%). Hertz terms defined. Applied Elasticity, J. PRESCOTT. Longmans, Green and

Co. 1924. Chapter 19 is on elastic bodies in contact. Some Effects of the Atomsphere upon Physical Measurements, E. W. WASHBURN, Sci v61 Jan 16 1925 p 49-56. Presence of atmosphere in contact with substance or system subjected to quantitative investigation affects situation in two ways namely, (1) direct-pressure effect, and (2) air-solubility effect. Deflection of Bars, J. H. DOWELL. J Sci Instrum v3 June

1926 p 305- 8. The question of the best position of the supports of bars for accurate optical benches, such as

etalon mounts, is considered, and the deflection of the bars

is calculated and depicted. Die Abplattung von Stahlkugeln und Zylindern durch den Messdruck (The Oblateness of Steel Balls and Cylinders due to Measuring Pressure), H. BOCHMANN. Zeit fiir Feinmech und Prazision v35 Apr 27 May 11 25 June 8, July 6 20 1927 p 95-100 110^ 122-5 134-9 161-165 175-178. The Hertz theory, review of literature, experimental ar- rangements, experiments on steel balls between planes, groove experiments and steel balls, experiments on steel, wires between planes, experiments on bores between

planes, general evaluation, miscellaneous cylinder experi- ments, experiments on crossed cylinders, groove experi- ments on steel wires, summary.

Richtige Unterstutzung langer Parallelendmasse in zwei Punkten. (Proper Support of Long Parallel End-Standards at Two Points), E. PREGER. Zeit fiir Feinmech und Prazision v35 July 20 1927 p 169-74. Theoretical

discussion. Die Abplattung von Stahlkugehn und Zylindern Durch den Messdrucke (The Flattening of Steel Balls and Cylinders by Measuring Pressure), G. BERNDT. Zeit fiir Instrum Kde v48 Sept 1928 p 422-32. Discusses the Hertz theory, previous work on its proof, experimental arrangement, ex- periments on steel balls between steel planes, steel balls in a steel V groove, steel cylinder between two steel planes, experiments on crossed cylinders, steel cylinder in a Vgroove. Summary.

Interferometer Method for Investigating the Form of

Steel Balls and for Testing Hertz Pressure Equations

(Interferometrische Methode zur Untersuchung von Stahl- kugeln auf ihre Gestalt sowie zur Priifung der Hertzschen

Druckgleichungen), O. SCHONROCK, E. EINSPORN.

Zeit fiir InstrumKde v49 July and Aug 1929 p 317-31 369-385 8 figs. (1) Introduction; (2) Interference patterns

as basis; (3) the method; (4) effect of plate pressure, temperature, and air pressures; (5) accuracy of measure- ment; (6) definition of the roundness of balls of desig- nated sizes; (7) specific weights of steel balls; (8) summary.

Stresses Due to the Pressure of One Elastic Solid Upon

Another, H. R. THOMAS, V. A. HOERSCH. Univ Illi- nois Eng Experiment Station Bui 27 n 46 July 15 1930 56 p

4 figs. Review of theories and results of theoretical math- ;J ematical analysis of problem ; check of mathematical

solution ; tests of cylinder on plane ; tests of crossed \ cylinders ; effect of various factors on calculated stresses ; j numerical examples. A Simple Approximate Theory of the Pressure Between

two Bodies in Contact, J. P. ANDREWS. Proc Phys

Soc London v43 Jan 1 1931 p 1-7 25. When two solid bodies are pressed together without any point exceeding

the elastic limit, their common area of contact is fre- quently circular, and in such cases the normal stress at each point of this area may be calculated by a simple t approximate method giving results correct, as a rule, to ! within 1 or 2 percent. The principle remains near-true

for elliptical areas of contact. Deformation of Sensitive Levers, G. BERNDT, W. VOGT. Zeit fur Instrumtkde v58 Oct 1938 p 389-408. The authors discuss the deformations which tend to fal- sify the measurements made with various types of lever. Such deformations are principally of three kinds; (1) Hooke's law compression due to forces uniformly distrib- i uted over the cross-section; (2) Hertzian flattening of j curved surfaces; (3) Bending, resulting in variation of I the distance from the support. These effects are thor- s oughly investigated for six different types of levers com- , prising (a) simple optical lever, (b) simple mechanical r lever, (c) double mechanical lever with one lever working

on a geared drive, (e) meter mechanism with spur-wheel worm and wheel drive, (f) torsion and electric levers. The results obtained are tabulated and discussed. Young's Modulus of Diamond, P. R. PISHAROTY. In- dian Acad Sci Proc A vl2 Aug 1940 p 208-11. It is shown

that the section of the elastic surface of a cubic crystal by an octahedral plane is a circle. Voigt's "scale and tele- scope" method for determination of Young's modulus of crystals is improved by the use of a narrow slit and a long focus camera, the shift being recorded photographically and measured by a Hilger micrometer. The experimental

value of Young's modulus of diamond in any direction lying in the octahedral plane is found to be 5.5 X 10" dynes/cm2

. The maximum value for a cubic crystal being

in a direction normal to this plane, a higher value for a

rod cut normal to the octahedral plane may be expected. 5 A Simple Method of Finding Poisson's Ratio, M. D. WAL- : LER. Phys Soc Proc v52 Sept 1940 p 710-3. The paper I describes how Poisson's ratio can be measured in terms of 1 the ratio of 2 specified natural frequencies of a vibrating i free square plate. Results for glass, steel, brass, copper and aluminum, are given. It is suggested that such a simple method of estimating this elastic constant might be

of value in the determination of deformation under measuring force. Precision Extensometer and Its Use for Measurement of i Poisson's Ratio, W. LETHERSICH. J Sci Instrum v21 nlO Oct 1944 p 180-3. Simple optical arrangement for > measuring Poisson's ratio under various conditions of

stress and strain. Analysis of Stresses and Deflections, A. B. JONES, 2 vols. New Departure Div., General Motors Corp. 1946. Contains formulas and graph for solving deformation problems ; based on the Hertz equations.

Elastic Constants of Diamond, M. BORN. Nature (Lon- don) vl57 May 4 1946 p 582. An identity connecting the \ three elastic constants and the main lattice vibration fre- quency has been obtained by a reconsideration of Nagendra Nath's theory ( Abstr 550, 1935) of the action of second 32
neighbor as well as first neighbor atom on the vibration

of a C atom in the diamond lattice. This is not satisfied by the experimental values of Bhagavantam (Abstr 310, 1945) whose confirmation of Xagendra Nath's theory is here stated to be accidental. The theory of the vibrations

of the diamond lattice is briefly discussed. Indentation Method for Measuring Wear, S. A. McKEE.

J Res XBS v39 n2 Aug 1947 RP1819 p 155-61. Method for accurately measuring wear that takes place on bearing

surfaces of machinery ; measurements of dimensions of indentation marks before and after wear provide means

for determining amount of wear that has taken place; apparatus described for measurement of wear in cylinders

of aircraft engines. See also Tool Engr vl8 n5 June 1947

p 41-3 5 figs. On Highly Compressible Helical Springs and Rubber Rods, and Their Application for Vibration-Free Mountings,

V. J. A. HARIXGX. Philips Res Rept 4 p 375-^00 Oct

1949. Deals with the behaviour in space of the different types of vibration-free mounting, starting from the simple

construction of a resiliently supported body up to the damped dynamic vibration absorber provided with an auxiliary mass. To simplify the problems of forced and free

vibrations an attempt is made to split up the movements

in space into a number of one- and two-dimensional movements to be treated independently.

Finite Extension and Torsion of Cylinders. A. E. GREEN,

R. T. SHIELD. Phil Trans A v244 n876 1951 47-86. The

theory of finite elastic deformations of an isotropic body,

in which a completely general strain-energy function is used, is applied to the problem of a small twist superposed upon a finite extension of a cylinder which has a constant

cross-section. The law which relates the force necessary

to produce the large extension, with the torsional modulus

for the small torsion superposed on that extension, is given by a simple general formula. The problems of a

small twist superposed upon a hydrostatic pressure and

tension, are also solved. Attention is then confined to iso- tropic incompressible rubberlike materials using a strain energy function suggested by Mooney, and the secondorder effects which accompany the torsion of cylinders of constant cross-sections are examined. On the Smooth Reactions of Two Solid Bodies in Contact,

J. BODZITAT. CR Acad Sci Paris 232 Feb 19 1951 683-

5. The results originally obtained by Hertz for the dis- tribution of normal pressure and the shape and area of

1 the surface of contact are established by an alternative and more direct method. The resulting distribution of tension in the two bodies near the surface of contact is also discussed. A Note on Elastic Surface Deformation, M. KORNHAUSER. J App Mech vl8 Sept 1951 p 251-2. Surface deformation of elastic bodies having the same modulus is treated by the standard texts on elasticity, but the applicability of the solution is limited to the range of the tables

of coefficients presented. This note extends the tables to cover the range that applies to bodies having one principal curvature much larger than the other. Some inaccuracy

in the tables in current use also is noted. Determination of Local Wear by Use of Disappearing

Marks. Metallurgia v45 n269 Mar 1952 p 151-3 5 figs. Possibility of measuring wear of metal by noting change

in dimensions of depression in surface concerned ; marks

produced by indentation, by abrasion and by cutting, and

their respective advantages ; photographs.

Elastic Deformation Effects in Precision Measurement,

P. FERGUSSON : Microtecnic vll n6 Dec 1957 p 256-8. Test on hardened steel balls and rollers, in which defor- mation under loads of up to 16 lb was measured for varying conditions of point and line contact ; test results lead

to simplification of Hertz theory, so that all cases of point contact can be expressed in graphical form.

Investigation into One of the Assumptions of the Hertz Theory of Contact, C. STOREY. Brit J App Phys vll n2 Feb 1960 p 67-8. One of the limitations of Hertz's solu- tion of the contact problem is the assumption that, in the neighborhood of contact, the surface of the bodies and

hence, the distance between their corresponding points can be represented by second degree equations. Subse- quent theoretical work, mainly by Shtaerman, has pro- vided a more general solution free from this limitation.

It is the purpose of the present work to examine the effect of the inclusion of terms of higher degree than the second

in the expression for the distance between the two bodies. Attention is confined to spheres and cylinders. The Influence of Measuring Force, Stylus Radius, and

Surface Finish on the Accuracy of Measurement of Workpieces by a Comparator, L. W. NICKOLS, T. R. J. OAKLEY. Inst of Mech Engrs 1961. See 1.3.2 for abstract. Anti-Distortion Mountings for Instruments and Apparatus, R. V. JONES. J Sci Instrum v38 nlO Oct 1961 p

408-9. Principles for mounting of instrument platforms

for many optical and mechanical instruments, working

platform may best be protected from external mechanical

distortion by supporting or suspending platform by members, usually 3, whose stiffness is much less than that of platform. Tables for Calculating the Compressive Surface Stresses and Deflections in the Contact of Two Solid Elastic Bodies Whose Principal Planes of Curvature do not Coincide, A. KOZMA and H. CUNNINGHAM. Industrial Mathematics, Detroit vl2 pt 1 1962 p 31-9 1 fig 6 refs. Transcendental equations result from application of the Hertz

theory to calculate the stresses and deflections between two

solid elastic bodies which are in contact under pressure and whose principal planes of curvature do not coincide. These equations are reviewed, and a more extensive table

of applicable special functions is given than has been pre- viously available. Contact Stress Analysis of Normally Loaded Rough

Spheres, L. E. GOODMAN. ASME—Paper 62-WA-19 for meeting Nov 25-30 1962 8 p. Hertz analysis of contact

stresses is extended to include effects of friction on inter- face between 2 elastic spheres compressed along line con- necting their centers ; problem requires incremental for- mulation ; stress functions of interest in connection with

analysis of shear loaded half-space in linear theory of elasticity are developed ; distribution of shear stress needed to prevent relative slip of surflcial points after they

enter contact region is found to be finite everywhere in region. The Parallelism of a Length Bar with an End Load, D. C. WILLIAMS. J Sci Instrum (GB) v39 nl2 Dec 1962 p

608-10. The flexure of an engineer's length bar standard

supported horizontally at two positions with a flat wrung

to one end is analysed. Formulae are given for support

positions which do not introduce errors in parallelism of the ends. The effect of the flexure on the length of the bar is shown to be negligible.

33
1.6. Vibration Isolation and Control

Vibrationless Supports for Instruments, W. H. JULIUS. Ann der Phys und Chemie 3ser v56 1895 p 151-60. Three

wires are attached to an over-head beam at the angular

points of an equilateral triangle ; carrying at their lower ends a triangular plate for the support of the instrument. The center of gravity of the whole suspended system is to be at the center of the triangular plate. For damping

effects of air currents, sidevanes are fixed to the plate which dip vertically into dash pots. Vibrationless Supports for Instruments, W. EINTHOVEN.

Ann der Phys und Chemie 3ser v56 1895 p 161-6. Instru- ments are supported upon iron plates floating on mercury.

Previously used by Michelson and Morley. See Am J Sci v3 p 34. New Vibrationless Method of Mounting Delicate Instru- ments (Ueber eine neue erschuetterungsfreie Aufstellung

fuer empfindliche Messinstrumente), R. MUELLER. Ann

Phys vl n5 Mar 12 1929 p 613-56 6 figs. Critical review shows that Julius suspension gives satisfactory results

in most cases; underlying principles of method depend

on three principles; (1) no attempt made to weaken vertical component of vibration; (2) period of translatory

vibration in horizontal direction made very large; (3) new form of damping employed using liquid of suitable

viscosity. Air Cushions as Supports for Instruments, E. GEHRCKE,

B. VOIGT. Zeit fur techn Phys vl2 1931 p 684-6. Describes three different methods of combining air cushions with R. Muller's apparatus, to prevent the transmission

of vibrations to a table on which apparatus is to be placed. The Miiller apparatus absorbs the horizontal tremors sat- isfactorily, while the air cushoins absorb vertical components. Three different forms of apparatus are

described. Air Cushions as Supports for Instruments, E. GEHRCKE,

B. VOIGT. Zeit fur techn Phys vl3 1932 p 387-90. The

arrangement has been tested when used for supporting

a galvanometer which is very sensitive to vibration. It was found that the best results were obtained with air at a pressure of about 900 mm of mercury, and that other

gases were equally effective. On Highly Compressible Helical Springs and Rubber Rods, and Their Application for Vibration-Free Mountings, V.

J. A. HARINGX. Philips Res Rept v4 Oct 1949 p 375-400. Deals with the behaviour in space of the different types of

vibration-free mounting, starting from the simple con- struction of resiliently supported body up to the damped

dynamic vibration absorber provided with an auxiliary mass. To simplify the problems of forced and free vibrations an attempt is made to split up the movements in space into a number of one- and two-dimensional move- ments to be treated independently. Etude sur la Flexion des Etalons de Longueur (Study of the Deflection of the Standard of Length). C. VOLET.

Trav et Mem du BIPM v21 1952 20 p 3 figs. Equations of the neutral fiber ; projection of the neutral fiber ; resume

of the formulas and particular cases ; application to proto- types of platinum-iridium ; traces outside of the neutral

fiber; conclusion. Erschuetterungsfreies Aufstellen und die Erschuetterungsfeste Konstruktion von Messinstrumenten, A. VON

WEISS. VDI Zeit v98 n6 Feb 21 1956 p 205-8. Vibrationfree mounting and vibration .proof construction of measuring instruments ; mechanical stress of latter ; vibration and bumping test suggested. Instrumentation Precision as Affected by Vibrational Environment, C. E. WHITE. Avco R.A.D. 201 Lowell St.,

Wilmington, Mass. May 1959 13 p 9 figs 3 refs. Presents

analysis of several commonly used instruments whose

functions are reduced by the presence of transmitted vi- bration, normally considered inconsequential. Case his- tories of troublesome incidents are outlined ; corrective measures are mentioned. A plea is made for a more detailed study of the problem with the hope that the manufacturers of instruments will establish criteria of maximum allowable vibration wherever sensitive instru- mentation is employed. Problems of Insulating Against Shock Loads, R. HAMMOND. Insulation ( London ) v3 n5 Sept-Oct 1959 p 282-5. At Smith's Stamping Works, Coventry, Brett drop stamp

has tup weighing 50 cwt falling through 6 ft 6 in. height with velocity at impact with work being 250 in./sec;

electric driving motor and friction clutch lifting gear is mounted on structural steel gantry ; foundation comprises

concrete lined pit with inertia block resting on 34 helical springs, each consisting of 14 springs ; Metropolitan Cammell Carriage and Wagon Co, Ltd, installation described.

Isolation of Vibration When Machine and Foundation are

Resilient and When Wave Effects Occur in Mount, A. O. SYKES. Noise Control v6 n3 May-June 1960 p 23-7, 30-8. Isolation by massless spring-dashpot mount or by arbitrary two-terminal mount ; limitations in application of single- mount effectiveness theory ; effectiveness of mounts in many-mount systems ; wave effects in isolation mounts

;

approximate formulas for estimating effectiveness ; esti- mating characteristic impedances, frequency constants, and damping factors of simple mounts.

Vibration Isolation Design, D. S. HANLEY. Machine Design v32 nl6 Aug 4 1960 p 123-8. Description of new

method for dynamic analysis of displacement-excited motions where loads carried by spring and damper must be determined ; examples illustrate numerical solution of problems. Shock and Vibration Handbook, C. M. HARRIS, C. E. CREDE. McGraw-Hill Book Co. Inc. New York. 3 vols 50 chapters 1961. Vol. 1 : Basic theory and measurements.

Vol. 2: Data analysis, testing, and methods of control. Vol 3 : Engineering design and environmental conditions. Chapters 30-33 deal with theory of vibration isolation, theory of shock isolation, application and design of

isolators, and air suspension and servo-controlled isolation systems. These chapters contain 64 references. Inherent Limitations of Accelerometers for High-Frequency Vibration Measurements, F. SCHLOSS. J Acoust Soc Am v33 n4 Apr 1961 p 539. When an accelerometer is attached to a vibrating mass the inertia of the transducer

together with the elasticity of the mass produce a fre- quency-dependent error which sets an upper limit to the measurable frequency. A formula is given which enables

this critical frequency to be calculated for a large plate. The transducer resonant frequency is assumed to be higher than the critical frequency. On Certain Dynamic Properties of Elastic Bar Immersed

and Non-Immersed in Liquid with Free Surface, J. WIECKOWSKI. Acad Polonaise des Sci Bui Ser des

Sci Tech vlO nil 1962 p 635-42. Theoretical investigation of vibration in elastic bar; there exist frequencies

of forced vibrations for which progressive mechanical waves propagating from point of excitation are damped

;

it seems that choice of adequate parameters for machinery

foundation can localize vibration at point of excitation. Vibration Control, K. W. JOHNSON. Sound (USA) vl n3 May-June 1962 p 34-8. Vibration control by the use

of resilient mounts requires the control of the supporting
structure, the correct placement of the isolators, and the

control of the internal construction. Emphasis is placed on the correct usage of available commercial mounts. There is some description of the common types of damping now in current use. Theory of Vibration, G. NISHIMURA, Y. JIMBO, Japan

Soc Mech Engrs Trans v28 nl91 July 1962 p 859-91. In

old theory of vibration prevention, earth's crust is treated

as equivalent simple spring-mass system ; in this paper

earth's crust is assumed to be infinite elastic medium,

and problems of insulation and prevention of vibration

of any machine are treated on basis of elastic wave prop- agation theory ; many new results are obtained which can- not be seen in old theory. In Japanese with English

abstract. Vibroshchup i Vibrometr Dlya Izmerenlya Kolebanii Stankov, S. S. KEDROV. Stanki i Instrum n7 July 1962 p

17-20 ; English translation in Machines & Tooling v33 n7

1962 p. 20-3. Vibration pick-up and seismometer de- scribed suitable for measuring vibration of machine tools, particularly for quick estimation of vibration level at various points on machine tool and for determination of vibration areas ; vibration pick-up device with wire strain

gages, and vibration seismometer with inductive pick-up work in conjunction with amplifiers, transducers and type N-102 or MPO-2 oscillograph.

Isolators Cushion Industry's Shocks, C. J. VLAHOS. Mill & Factory v71 n3 Sept 1962 p 68-71. Review of operating

characteristics of various isolation pads used for absorbing machinery vibrations; elastomer floor mounts and

hangers, rubber channel mountings, rubber truss config- urations, mountings of composite materials, and steel springs and their use are discussed. Vibrazioni Mecchaniche—Teoria Dello Smorzatore Aggiuntivo Nell'-Oscillatore Meccanico a Due Masse, C. BRUTTI. Ingegnere v36 nl2 Dec 1962 p 1155-61. Mechanical vibrations ; theory of antivibration mounting in- vestigated by means of mechanical vibrator with two

masses ; generally vibration damping of machine part is solved by analogy with single vibrating mass; this ap- proximation is not sufficient; approximation with two

vibrating masses, which are elastically connected is ad- vanced; theory with single mass appears as particular

case of that two masses. Electromechanical Machine for Analysis of Periodic

Functions, S. C. GUPTA. Electromechanical Components & Systems Design v6 nl2 Dec. 1962 p 34-7. Applications

of simple Grutzmacher analyzer (1943) for finding amplitude and phase of any harmonic of given periodic wave

form quickly and with good accuracy. Phase Angle in Vibration Work. L. YEH. Instrum & Control System v35 nl2 Dec 1962 p 88-90. Application of phase meter by design engineer in troubleshooting, research, and design, especially of rotating machinery ; measurement of modal shape or dynamic deflection forms of structure; measurement of phase angle between force and velocity in use of impedance technique

measurements of phase angle for comparison of damping

characteristics of similar structures. Analiticheskoe Vyrazhenie Kharakteristik Rezino-kord- nogo Pnevmaticheskogo Amortizatora (Analytical For- mulation of Characteristics of Rubberized-cord Pneumatic Shock Absorbers), V. V. IGNATENKO. Izvestiya Vysshikh Uchebnykh Zavedenii, Mashinostroenie n7 1963

P93-107. Strain analysis of pressurized toroidal shock

absorbers having shape and construction similar to that

of wheel with tubeless tire and placed in horizontal posi- tion under machine's base plate; structural parameters and deformations of shock absorber are determined. A Vibration Isolating Mounting for a Sensitive Balance,

J. A. MACINANTE, J. WALDERSEE, J. Sci Instrum (GB) v40 n2 Feb 1963 p77-8. This note briefly states the general requirements for seismic mountings for sensitive balances, and describes an inexpensive mounting

consisting of a seismic slab on helical springs with pitch (bituminous) dampers. This form of damping has over- come the difficulty of maintaining the level of a balance which is supported on "soft" spring isolators. Floating Foundations Isolate Vibration, Eng vl95 n5053 Feb 22 1963 p 296-7 5 figs. Experiences of four

firms who have floated equipment or whole rooms on rub- ber ; two cases pertain to antivibration mountings for roll grinder and for newspaper printing press ; examples of

floating rooms are Standards Room at Nat Eng Laboratory and sound studios for BBC, for both of which rubber

carpet mountings are used. How to Analyze Shock Effects, W. P. BARNES. ISA J

vlO n3 Mar 1963 p 63-6. Four methods are summarized

for analyzing shock effects to valuable equipment ; tech- niques range from manual methods to those using analog and digital computers. End to Chatter Problems, R. L. CARLSTEDT. Am

Mach/Metalworking Mfg vl07 n7 Apr 1 1963 p93-5. New

carbide boring bar called DeVibrator, with row of loose slugs inside, can now eliminate chatter problem from

boring operations, and in very large measure, also from

turning operations ; it operates on principle of dissipating vibrational energy ; design and operation of device which

is made in two sizes, DV-4 with 4-in. wheel, and DV-5

with 5-in. wheel, with choice depending on mass of workpiece involved. Solution to Acute Vibration Problem. Insulation ( London

)

v7 n6 Nov-Dec 1963 p 257. Isolating machine mounts are based on use of molded core of oil-resistant neoprene which is bonded to dished steel upper easing and steel base plate ; mounts were used to eliminate severe vibration disturbance caused by operation of 40 machines for production of nylon fabric at factory in Baldock, England.

Vibration Isolation of a Quasi-Linear System, H. K. SACHS. J Indus Math Soc vl4 pt2 1964 p 27-44 10

figs 14 refs. Describes a method for the determination

of the transmitted force of a quasi-linear mass-elastic system which is subjected to a harmonic input force. It

is shown that even very small non-linearities in the re- storing force function affect the dynamic response of the system, yielding an entirely different configuration of transmissibility curves than the linear system. Also, the force transmitted to the supporting structure depends

not only on the system parameters and perturbation fre- quency, but on the relation between the generating force and the perturbation frequency, e.g. centrifugal force

excitation of the support structure. Finally, methods for optimization are considered, and it is found that no uni- que criterion for optimum isolation properties exists. Vibration Isolation, I. VIGNESS. Physics Today vl8 n7 July 1965 p 42-8 9 figs 3 refs. Describes principles and

devices that are useful in determining how to isolate equip- ment from disturbing vibrations. Discusses ; linear single- degree-of-freedom systems ; nonlinear devices ; bouncing

conventional isolators; cushioning materials and air springs ; isolators capable of responding in all directions

pendulum isolators ; multiple-degree-of-freedom linear sys- tems and uncoupled modes of vibration ; center-of-gravity mounting system ; inclined mounts ; dynamic vibration absorbers ; what method to use. 35
1.7. Effects of Surface State and Texture

How Surface Affects Measurement With Plug and Ring

Gages, F. C. HUDSON. Am Mach v56 June 8 1922 p 860, Discusses effects of lubrication. The Relation of Finish to Life of Plug Gages, L. M. McPHARLIN. Am Mach v66 May 12 1927 p 775-81 16

figs. Tests show that gages with mechanically lapped sur- faces have much longer wear-life than hand-lapped gages, which excell ground gages; photomicrographs indicate progressive stages of wear. Geometrical and Physical Conditions of Polished Surfaces, G. SCHMERWITZ. Phys Zeit v34 Feb 15 1933 p

145-58. Method previously described is applied to de- termine the minute irregularities in the polished surfaces

of precision balls and cylinders made from steel and glass. Cross-sections are usually constant-diameter figures. Variations of a few Angstrom units can be detected. Local variations of the order of 0.003/* occur from time

to time due to Brownian movements of particles. Desired Characters of Surface Finishes, J. E. KLINE.

Mech Eng v57 12 Dec 1935 p 749-52 ; Mech Wld v98 n2555 Dec 20 1935 p 593-5 and 608. Importance pointed out of

affinitive surfaces possessing more nearly "run-in" characteristics, other than absolute smoothness ; of diametric

precision relating to operating tolerances ; and of conse- quent danger of having too smoothly finished surfaces when operated with insufficient running clearances. Desired Characters of Surface Finishes, E. J. ABBOTT.

Mech Eng v58 n9 Sept 1936 p 596-8. List three con- clusions ; making as objective obtainment of affinitive sur- faces possessing more nearly "run-in" characteristics, rather than absolute smoothness ; importance of diametric

precision relating to operating tolerances ; and consequent danger of having too smoothly finished surfaces wben op- erated with insufficient running clearances. Surface Quality, R. E. W. HARRISON. Am Mach v80

n22 Oct 21 1936 p 878-9. Citation of nine major reasons why surface qualities should be controlled. L'Etude des Etats de Surfaces Melalliques. Mecanique

v21 n274 Sept-Oct 1937 p 203-16 (discussion) 216-9. Symposium on condition of metal surfaces ; Influence of surface condition on sliding forces in clamping fits, O. KIENZLE; New method for measuring condition of machined surfaces, H. TORNEBOHM ; Relation between

surface condition and luminous dispersion, F. CANAC

;

Condition of metallic surface qualification and influence

of surface condition on fits by pressing, P. NICOLAU.

Etude des couches fines extGrieures des Materiaux, N. W. SAWIN. Mecanique v21 n275 Nov-Dec 1937 p 269-^75. Study of fine surface finishes of materials ; analysis of causes of metal surface wear ; results of tests made on Skoda-Sawin machine for study of resistance to wear of machine finishes. Les Etats de Surface. Technique Mod v32 nll-12 June

1-15 1940 p 171-3. Study of surface state of metals and

its application to metal working ; investigation refers

to geometric, structural, mechanical and chemical state; illustrated description of surface testing apparatus.

Bibliography. Physics and Chemistry of Surfaces, N. K. ADAM. Oxford Univ. Press, 3d ed 1941. Section V, p 168-208 is a

discussion of the general properties of solid surfaces. Succeeding sections deal with spreading and lubrication

;

fine structure; electrical phenomena at interfaces. Surface Finish and Structure, J. WULFF. Am Inst Min & Met Engrs Trans (Iron & Steel Div) vl45 1941

p 295-300. To ascertain depth and nature of deformation induced by such finishing processes as cold rolling, jl dry and wet grinding, lapping, honing, sanding, superfinishing, and metallographic polishing, electron diffrac- tion pictures were taken of successively etched 18.8 stainless steel surfaces; there is no intention to imply that

results or conclusions apply to all materials although some exhibit deformation effects to corresponding depths.

j Bibliography. "Soft Skin" on Highly Finished Surfaces, P. LEIN- WEBER. Engrs' Digest ( Brit Ed ) v5 n3 Mar 1944 p 65-7

;

Engrs' Digest (Am Ed) vl n5 Apr 1944 p 273-5. It is often claimed by makers of instruments that measuring , surfaces have to lapped to obtain high accuracy and to I remove soft layer produced by grinding; based on tests,

it is concluded that, because of small zone in which exist- ence of soft skin is possible, measuring surfaces should not be lapped ; with exception of gages with very small toler- ances. English abstract from Werkstattstechnik Betrieb I June 1943 p 241-3. Capillarity of Metallic Surfaces, E. R. PARKER, R. j

I SMOLUCHOWSKI. Am Soc Metals—Preprint nl3 for meeting Oct 16-20 1944 10 p. Phenomena observed in brazing and coating operations can be correlated on basis

of surface energies and geometrical factors; balance of changes of solid liquid, solid air and liquid air surface j j energies depends upon capillary roughness of metallic

j surface ; liquid metal spreads best on finely ground or on , j polished and etched surfaces both of which have fine capillary structure. Les Etats de Surface, L. ROBIDA. Technique des In- 1 j dustries Mecaniques 1945 p 51-5. Surface state of metals ; ; j definition; micro- and microgeometrical deformations of surface; measurement by means of optical, electric or , , pneumatic method ; state of surface from physicochemical

j , point of view ; Chrysler superfinishing process.

! Symposium on Surface Finish. Eng vl59 n4131, 4132, j j 4133, 4134, 4135, Mar 16 1945 p 215-20, (editorial com- ment) p 211, Mar 23 p 237-9, Mar 30 p 258-60, Apr 6 *] p 277-80, Apr 13 p 299-300; see also Machy (London) „

: v66 nl692, 1693, 1694, 1696, 1697, 1698, 1700, 1703, Mar

15 1945 p 290-2, Mar 22 p 318-21, Mar 29 p 345-8, Apr J

I 12 p 403-5, Apr 19 p 427-9, Apr 26 p 457-8, May 10 p 514-5, ,j . May 31 p 596-600; Engr vl79 n4653, 4654, 4655, Mar 16 1945 p 218-20, (discussion) p 209-11, Mar 23 p 230-1 (dis- j) E cussion) 234-6, Mar 30 p 250-1; Automobile Engr v35 (

j n461 Apr 1945 pl41-6; Engrs' Digest (American Ed) v2 j ; n7 July 1945 p 341-4 ; S African Eng v56 n4 Apr 1945 p 95.

J . Symposium before Instn Mech Engrs, Mar 9 1945 : Struc- ture of Sliding Surfaces, G. I. FINCH ; Surface Finish in [ j Relation to Friction and Lubrication, D. CLAYTON;

Principles and Methods of Surface Measurement, R. E. \ j REASON ; Measurement of Surface Waviness, C. TIMMS ; , a Drawing Office Specification, H. J. GRIGGS; Rational J } Specification of Surface Finish, W. A. TUPLIN ; Require- „ „ ments in Surface Finish, D. McCONNELL ; Surface Finish J

( on Production Methods, W. E. R. CLAY; Results of rJ : Modern Practice, F. NOURSE ; Continuity in Produc- . ,! tion of Specified Surface Finish, E. SWAIN; Effect of Fatigue Strength, W. KER WILSON; Locomotive Practice, F. C. JOHANSEN. * j New Evaluation of Surface Finishes, W. F. KLEMM. f Tool Engr vl4 11 June 1945 p 42-^. Analysis of prob- ^ lems in surface wear; methods of inspection of finished , i surfaces ; factors determining stability of bearing or wear

% surfaces in relation to dimensional characteristics of sur- face irregularities. Les Etats de Surface, LASNIER, PLAGNOL. Soc des \ | Ings de 1' Automobile J vl8 n4 July-Aug 1945 p 117-30. 36
Present knowledge of surfaces; definition; examination

with mechanical and optical apparatus, electron microscope, electrical and other methods ; study of behavior of

surfaces. State and Properties of Metallic Surfaces, C. H. DESCH.

Nature (London) vl57 Mar 2 1946 p 271-2. A report of

the Paris conference, Oct 23-6 1945 of the Commission

Technique des Etaits et Proprietes de Surface des M&taux,

established in Aug 1942, Xew Developments in Study of Surface Chemistry, E. A. GULBRAXSEX. Metal Progr v49 n3 Mar 1946 p 553-9. Review of newly developed techniques and interpretations pertaining to use of electron microscope, electron

diffraction camera and vacuum microbalance, as applied

to study of fundamental factors involved in relating properties of given surface to any practical problem ; physical form of surface ; chemical nature of surfaced layer ; velocity at which chemical and physical changes occur on

or through surface. L'Etat des Surfaces Metalliques, P. BASTIEX, C. de SEXXEVILLE. Technique Mod v38 nl5, 16, 19, 20 Aug

1, 15, 1946 p 169-76, Oct 1, 15, p 223-8. State of metal

surfaces. Aug; Physical and physical chemical state; methods of study constitution and structure. Oct : Study

of shape of surfaces ; macro and micro roughness ; in- fluence of surface state on friction, electric conductivity, hardness, fatigue and corrosion. Surface-Roughness of Bearing-Surfaces and its Relation

to Oil Film Thickness at Breakdown, A. CAMEROX.

Instn Mech Engrs Proc vl61 (War Emergency Proc n48)

1949 p 73-7 (discussion) 77-9; Engr vl87 n4868 May 13

1949 p 540-1. Tests show that for Michell pads there is definite relation between surface roughness of rubbing

surfaces and calculated outlet film thickness at seizure and at point where initial metal to metal contact occurs

when steel collars are finely finished surfaces sometimes

seized on initial contact ; thus it may be possible to finish surface too finely or incorrectly. Surface Reactions of Metals, G. TOLLEY. Metal Industry v75 n4, 5, 6, July 22 1949 p 68-70, 73 July 29 p 89-91, Aug 5 p 112-3. Physicochemical and physicomechanical

reactions studied ; measurements of surface roughness,

surface area determination ; experiences in treatment of aluminum foil and chromium plated nickel ; corrosion

high temperature oxidation ; problems of mechanical

wear, friction and lubrication. Bibliography.

Effect of Surface Roughness on Rolling Friction, J. J. BIKERMAXX. J App Phys v20 Oct 1949 p 971-5 3 figs 7 refs. Rolling tests showed that the roughest surfaces gave an almost quantitative agreement between this height

of elevations and the height of hills calculated from a theory attributing rolling friction to surface roughness. Surface Finish Control, C. R. LEWIS. Prod Eng v21

n8 Aug 1950 p 91-5. Effect of finish on metallic structure

effect of surface finish on bearing performance ; performance of machined parts ; test results regarding influence

of surface finish on friction, wear, lubrication and fatigue endurance; discussion of new SAE standards. Bibliog- raphy. Surface Finish and Designer, R. P. TROWBRIDGE,

Prod Eng v21 n9 Sept 1950 p 122-7. Practical aspects of new approach to measurement, specification and application of surface finish control of metallic parts; types of instruments, standards for various production methods, and physical properties relating to condition of metallic

surface are compared and evaluated. Bibliography. Messung der Oberflaeehenguete, G. SCHLESIXGER.

Springer-Verlag, Berlin, Goettingen, Heidelberg, 1951

248 p, illus, diagrs, charts, tables. Practical applications

of results obtained from measurements of surface quality

nature and terminology of surface finish defined ; various measuring instruments for macro and micro determination discussed; respective ranges of their applications;

results of industrial applications in aircraft, automotive, railroad, tool, electric machinery and other industries, Eng Soc Library, N.T. Surface Finish, R. E. REASOX. Australasian Engr

v44 Oct 1951 p 48-59 discussion 59-64. Difference between primary and secondary texture ; methods of measuring

surface finish and instruments used for purpose ; calibrat- ing surface finish measuring instruments proposed ; fac- tors to be considered in identifying optimum surface for particular purpose. Bibliography. "Gold Standard" Precision Specimens of Surface Roughness, C. R. LEWIS. Standardization v23 n8 Aug 1952

p 238-42. Explanation of production of calibration speci- mens, with values corresponding to American Standard

B46.1-1947 and meeting specifications of B46.2-1952, developed by Chrysler Corp; instructions for use of precision reference specimens of 20, 32, 50, 80 and 125

microin., which are now available. Properties of Metallic Surfaces. London : Inst of Metals

1953 370 p. [Monograph and Report Series Xo. 13]. The

volume contains 13 papers presented at a symposium

held in London in Xovember, 1952. Contents : Specialized microscopical techniques in metallurgy, S. TOLAXSKY.

Radioisotopes in the study of metal surface reactions in solutions, M. T. SIMXAD. The influence of machining and grinding methods on the mechanical and physical condition of metal surfaces. P. SPEAR, I. R. ROBIXSOX,

K. J. B. WOLFE. The effect of lubrication and nature

of superficial layer after prolonged periods of running,

F. T. BARWELL. The crystalline character of abraded

surfaces, P. GAY, P. B. HIRSCH. The effect of surface

conditions on the mechanical properties of metals, mainly

single crystals, E. X. da C. AXDRADE. The effect of surface condition on the strength of brittle materials, C. GI'RXEY. The influence of surface condition on the

fatigue strength of steel, R. J. LOVE. The influence of surface films on the friction and deformation of surfaces,

F. P. BOWDEX, D. TABOR. Diffusion coatings, D. M. DOVEY, I. JEXKIXS, K. C. RAXDALL. The nature and properties of the anodic film on aluminum and its alloys, H. W. L. PHILLIPS. Chemical behavior as in- fluenced by surface condition, U. R. EVANS. The effect of method of preparation on the high-frequency surface

resistance of metals, R. G. CHAMBERS, A. B. PIPPARD.

The Effect of Compressive and Shearing Forces on the Surface Films Present in Metallic Contacts, M. COOKS.

Proc Phys Soc (London) B v67 Mar 1954 p 238-48. Two

electrical methods were used to examine the extent to which the oxide or other natural surface films can prevent

intermetallic contact when metal bodies are pressed to- gether. One consisted of measuring the electrical resist- ance of the contact, the other of measuring the thermoelectric force which arises when there is a temperature

gradient across the film ; crossed cylinders were used for the contact members. Precautions1 were taken to mini- mize vibration and shearing forces when applying normal

loads. The contact resistance was often as large as

several ohms, showing that penetration of the films was

negligible, and in some cases the variation of resistance and thermoelectric force with load was consistent with

the assumption that the contact contained a uniform film. Friction forces up to a certain critical value could generally be exerted in the normally loaded contacts before any metallic contact appeared, and in certain cases the

films remained intact even during sliding. When the film was penetrated, the area of metallic contact was small at

first, but grew as sliding proceeded ; there was a simul- taneous growth in the force resisting sliding. Microscopic examination showed that the metal surfaces 37
suffered severe damage only after an appreciable distance

of sliding ( of the order of 0.1 mm)

Re-Evaluation of Surface Finish, L. CHANEY, C. H. GOOD. ASMS Paper n54—A—192 for meeting Nov 28- Dec 3 1954 9 p. There are no adequate guideposts for

really sure surface specifications ; what has been done in relating performance to surface finish; importance of "roughness width cutoff" specification; definition of this criterion and implications of its use. Symposium on Optical and Surface Methods of Nondestructive Testing, S. TOLANSKY, R. W. B. STEPHENS,

0. S. HEAVENS. Brit J App Phys Supp n6 (Physics of non-destructive testing) 1957 p S5-S9 S9-S10 S10-S12.

1. Tolansky reviews the optical methods used in his labo- ratory for the examination of micro-structures of metal

surfaces. The methods described are two-beam inter- ferometry, multiple-beam interferomtry, the light-profile microscope, optical shadow casting and the total reflection contact method. The usefulness and limitation of each method are discussed. Examples of the application of each method are given. II. Stephens briefly discusses the various types of optical measurement which might be

applied to the examination of surfaces. Consideration is given to the possible use for specific problems of the u.v., the visible, the i.r. and the microwave regions of the electromagnetic spectrum. III. Heavens presents a brief survey of the type of information which may be obtained by the application of optical methods to the study of the

surfaces of materials. Consideration is restricted to the kind of method which is likely to be of use as a nondestructive test. Measurement of the Molecular Attraction Between Dif- ferent Types of Solid Bodies, I. I. ABRIKOSOVA. Zh

Eksperimental'noi i Teoreticheskoi Fiziki v33 n3 (9) 1957 p 799-801 in Russian. Experimental data are given for the attractive force and surface energy against the gap

between surfaces of fused quartz. These agree with

theory and with other experimental work done in a

different way.

Surface Characteristics of Gage Blocks, A. G. STRANG.

Metrology of Gage Blocks. NBS Cir 581 Apr 1 1957 p 87-

97 10 figs. "The quality of the surface microfinish largely governs the ability of the gage blocks to wring together, the resistance to wear, and to some extent the accuracy

of length measurement by both mechanical and inter- ferometric methods." Some Aspects in Production and Measurement of Surface

Finish, M. A. CHAPPLE. Australasian Engr May 7 1957 p 57-9, 72. Surface finish as applied to plastic molds, wire drawing dies and gaging surfaces ; precision grinding; diamond lapping; types of machines used to check

surface finish. Funktion und Beschaffenheit der technischen Oberflaeche, W. SCHMIDT. Metall vll n6 June 1957 p 473-80. Function and quality of technical surfaces; characterization

of surfaces on basis of tests and measurements ; clarifica- tion of relations between function and nature of surface

determining conditions for production of prescribed

surfaces. Pruefen und Messen teehnischer Oberflaechen, A. WIE- MER, R. LEHMANN. Technik vl2 n7 July 1957 p 477-83. Testing and measurement of surfaces; characterization and determination of surface quality ; pertinence to contacts of machinery parts, such as bearings, shafts, gears, gages, press fits, etc. Surface Finish, K. S. COLLART. Prod Eng v28 nlO

Sept 16 1957 p 82-3. How function and economics deter- mine complex relations between size of part, its tolerance, and surface finish ; effect of various variables ; tool life

as function of surface finish; measuring techniques for constant accuracy of readings. Experiments Using a Simple Thermal Comparator for Measurement of Thermal Conductivity, Surface Roughness and Thickness of Foils or of Surface Deposits, R. W. POWELL. J Sci Instrum v34 nl2 Dec 1957 p 485-92. The thermal comparator described consists of two metal

balls similarly mounted in a block of balsa wood, but one

is at a slightly lower level so that it touches any surface on which the block rests. After heating to a small fixed temperature excess, the block is laid in contact with the

test surface. Differentially connected thermocouples at- tached to each ball measure the increased rate of cooling

of the ball that makes contact. The differential e.m.f.

is observed 10 sec after contact is made and is shown to be a function of the thermal conductivity of the material on which the ball rests. When calibrated in terms of at

least two substances of known thermal conductivity, deter- minations of thermal conductivity can be quickly made. The accuracy from single readings made on several alloys of Fe, Al and Mg is about ±6%, but Pb departs considerably, due, it is thought, to its softness. The condition of the surface affects the readings, so the calibration should be made for a similar surface condition. Alternatively, the device can be used as a means of measuring the

thickness of surface deposits and for non-destructive

sorting or identification of solid materials. Die Oberflaeche von metallischen Werkstoffen, etc. H. WIEGAND. Metalloberflaeehe vl2 n2, 3 Feb 1958 p 33-7, Mar p 53-8. Influence of surface of metallic materials on

service behavior of structural parts ; effect of mechanical

forces, friction and sliding ; influence of corrosion, oxidation, erosion and cavitation on behavior of material; composition of various protective coatings and their effect. Nature of Mechanically Polished Metal Surfaces ; ElectronDiffraction Examination of Polished Silver Surfaces, L. E. SAMUELS, J. V. SANDERS. Inst Metals J v87 pt5 Jan

1959 p 129-35. Electron-diffraction patterns obtained show that range of misorientations, and hence magnitude of deformation at surface, produced by polishing de- creases progressively with increasing fineness of polish

with finest polish investigated, misorientations were only about plus or minus 5° ; no evidence found of layer of peculiar structure of type postulated by G. Beilby. 29

refs. Surface Specifications: Their Use and Meaning, C. H. GOOD. Tool Engr v43 n4 Oct 1959 p 77-80. Problems

arising in cases where more complete specification is re- quired ; need for upper, as well as lower, limit on surface roughness; importance of roughness width cutoff; two ways to determine what roughness width cutoff to specify

surface lay; waviness spacing. Surface Finish and Other Surface Specifications, F. W. WITZKE. Am Soc Tool & Mfg Engrs v61 book 1 paper

340 1961 15 p 19 figs. Discusses need for further stand- ardization of surface specification, their interpretation and measurement; necessity for all engineering, production and inspeciton personnel to understand thoroughly

the fundamentals of surface finish and geometry specifications, and to re-evaluate the capabilities of some of the very common measurement techniques. Need for Research on Abraded and Polished Surfaces,

L. E. SAMUELS. Plating v48 nl Jan 1961 p. 46-9. Appraisal of some topics which are important for better understanding of nature of surfaces; atomic structure

of surface : nucleation of growth and dissolution, surface oxide films; surface plastic deformation: surface flow; surface heating. A New Look at Some Surfaces with Multiple-Beam In- terferometry. Part 1, S. TOLANSKY. Discovery Jan

1961 p 4-13 16 figs 4 refs. By making it possible to look

.38
at surfaces with a vertical magnification of millions, this technique is throwing new light on such widely diverse phenomena as patterns of crystal growth, the wear of

glass-cutting diamonds, and the surface distortion from

hardness tests and high-speed impacts. Surface Roughness Effects on Metallic Contact and Friction, M. J. FUREY. Am Soc Lubrication Engrs Trans

v6 nl Jan 1963 p 49-59. Study was made in transition zone between hydrodynamie and boundary lubrication

system used was fixed steel ball riding on rotating steel cylinder ; it was found that very smooth and very rough

surfaces gave less metallic contact than surfaces of intermediate roughness; very smooth surfaces also gave

less friction; 4 different types of antiwear/antifriction

additives (including tricresyl phosphate) studied had

little effect in reducing surface roughness; with rough

surfaces, improvement in load-carrying capacity with

increasing viscosity was less than that shown previously with smooth surfaces. Relationship of Surface Finish to Physical and Functional Behavior, R. COURTEL. Int Prod Eng Res Conf

Proc Sept 9-12 1963 p 675-83. Published by ASME.

Surface finish is shown to be not, in present state of art, characteristic that can be exactly described and measured ; nevertheless, with examples of different metals, it is shown what the problems are and what kind of research

is most likely to further state of art. On the Mechanism of Contact between Metal Surfaces

The Penetrating Depth and the Average Clearance, T. TSUKIZOE, T. HISAKADO. ASME Trans Paper 64- Lub-18 1964 7p 11 figs 7 refs. The analysis of the mechanism of air leakage through the interstices between metal

surfaces in contact or of the mechanism of thermal resist- ance between them is dependent on the average clearance between opposite surfaces or on the distribution of the

real contact area; i.e., the mechanism of contact. Assuming that the distribution curve obtained from the profile curve of the surface has a normal distribution, the

relation between the applied load and the average clear- ance or the penetrating depth, i.e., the distance through which the one surface moves into the other surface, is obtained theoretically. A comparison of calculated values based on this theory with experimental data shows good

agreement.

Theoretical and Experimental Relationship between Leak- age of Gases through Interface of Two Metals in Contact and Their Superficial Micro-Geometry, G. ARMAND,

J. LAPUJOULADE, J. PAIGNE. Vacuum v 14 n2 Feb

1964 p53-7. Flowing rate of gas through interface to two

metallic surfaces in contact is in close connection with

their micro-geometries ; interfacial conductance is proportional to square of mean roughness of surfaces ; experi- mental and theoretical results are in good agreement

phenomena occurring at metal-to-metal contact especially from leak rate viewpoint and measurement of mean roughness of surfaces in contact under loading.

Effects of Roughness of Metal Surfaces on Angular Distribution of Monochromatic Reflected Radiation, R. G. BIRKEBAK, E. R. G. ECKERT. ASME Paper n64-HT26 Aug 1964 9 p 12 figs 16 refs. A detailed experimental

study has been carried out to examine the influence of sur- face roughness conditions on the reflection characteristics

of metal surfaces for monochromatic thermal radiation. Surfaces used were prepared by standard optical grinding

techniques using a range of sizes of grit of the grinding compounds. Various definitions of reflectances are pre- sented to facilitate in the discussion of the results. Bian: gular, specular, and hemispherical-angular reflectance measurements are discussed in terms of the optical root- mean-square surface roughness, wavelength of reflected radiation, and surface material. The experimental results are compared with the available predictions from

theoretical analysis. Addendum to Section 1

1.1. General Physical Metrology

Mensuration for Senior Students, A. LODGE. Longmans,

Green and Co., London, 1895 274 p. Boston Public Library

John Crerar Library, Chicago.

Essai de Bibliographie Metrologique Universelle ( Attempt

at a Universal Metorological Bibliography), P. BURGUBURU, Auguste Picard, Paris 1932 327 p 4206 refs. Provides references in two parts, 3844 in the French language and 362 in foreign languages, dealing with measurements

. in a variety of units, ancient and modern. Contains an

authors' index. Mass und Messen im Spiegel physikalisch-techniseher Ent- wicklung (Standards and Measurements as Reflected in Physical, Technical Development). U. STILLE, PTB.

, Electrotechn und Maschinenbau v74 n2 Jan 15 1957 p 25-9

n3 Feb 1 1957 p 57-63 12 figs 31 refs. Discusses units for

length and current; magnetic units; light intensity unit.

1 Mensuration, R. E. LANGER. Encyclopedia Brittanica. 1959 Ed., vl5 p 253-7 2 refs. Defines mensuration as that branch of mathematics which deals with the measures or

the approximate measures of lengths, areas, and volumes.

Treats the following subjects : I Plane rectilinear figures : (a) elementary plane areas and lengths ; (b) general poly- gons—areas under rectilinear graphs. II Circles: (a) lengths of circular arcs ; (b) areas of circular sectors and

segments. Ill Quadrature: (a) areas of plane curvili- near figures; (b) polynominal approximations—Lagrange's interpolation formula. IV Approximate quadrature: (a) the trapezoidal rule ; (b) Simpson's rule. V

Polyhedral volumes: (a) prisms; (b) pyramids; (c) prismoids. VI Cylinder, cone, and sphere. VII Vol- umes and surface areas by integration: (a) simple integrals; (b) multiple integrals. VIII Theorem of Pappus

on centroids. IX Approximate volumes. Measurement Standards, A. G. MeNISH. International

Sci and Technol n47 Nov 1965 p 58-66 10 figs. All units

of measurement, including the ampere of current and

candela of light intensity—two base units included in the new International System of Units, are ultimately derived from four original prototype units—the meter of length, kilogram of mass, degree Kelvin of temperature, and

second of time. To make all measurement units more

effective tools, the standards that physically embody or

define three of the prototypes—length, time, and temperature—have been changed in recent years. In the case of

length, the change has replaced the man-made meter bar

with a more accurate and more easily reproducible natural

constant, the wavelength of an energy transition in krypton-86, and before the decade is out this in turn may be

replaced by a length standard based on the laser. This

rapid overthrow of long-established standards is not with- out precedent ; the second of time has been redefined twice in the last ten years and it soon may be again. Temperature scales seem to have achieved a stability of

sorts, however, with the partial success of attempts to

relate the International Practical Temperature Scale to the Thermodynamic Scale. Status of the National Standards for Physical Measurements, R. D. HUNTOON, NBS. Science vl50 n3693 Oct 8 1965 p 169-78 8 figs 7 refs. Discusses the evolution of a measuring system, the meter, kilogram, second, and

degree Kelvin; the measurement chain for dealing with

various magnitudes ; and future trends.

771-846 O—6<
1.2.1. General Dimensional Metrology

Langenmessung (Length Measurement), F. G5PEL,

Chapter 2 of Handbueh der Physik, Verlag Julius

Springer, Berlin v2 1926 p 42-90 38 figs refs. Discusses

the length unit, the embodiment of the length unit, length measurement arrangements, error influences in length measurement, examples from physical length measurements.

Precision Machines and Instruments for the Measurement

of Length. G. K. BURGESS, NBS. World Eng Congress, Tokyo, 1929 v5 pl-78 58 figs refs (Paper n335). Distributed by Kogakkai, Marunouchi, Tokyo, 1931. In this paper the importance of progress in the art of length measurement, in science, engineering, and industry, is pointed out ; the basis of precision length measurement is discussed, and the following types of measuring apparatus and their uses are described in detail: Comparators for

line standards of length ; comparators for end standards,

gages, and machine parts ; comparators for geodetic tapes and wires ; precision measurements in geodetic surveying

the use of wavelength standards in the test of end stand- ards and graduation of line standards ; optical projection and measuring apparatus and optical measurements:

thermal expansion apparatus; optical lever system and

optical strain gage ; the carbon-pile telemeter ; some basic

principles of limit gaging ; and automatic machine gaging.

Solid Mensuration, with Proofs, W. F. KERN, J. R. BLAND. John Wiley and Sons, Inc. New York 1938

172 p. Chapter headings : 1 ) Plane figures ; 2 ) lines, planes, angles; 3) solids for which V=Bh ; 4) solids for which V=Bh/3; 5) solids for which V=(mean B)h; 6) the sphere ; 7) volumes and surfaces of revolution—poly- hedrons; 8) the general prismatoid; 9) summary and

review. Aims to present the fundamental, practical es- sentials of solid geometry in a new and concise but comprehensive manner. La Metrologie dans les Musees de Province et sa Contri- bution a l'Histoire des Poids et Measures en France depuis

le Treizieme Siecle (Metrology in the Musees de Province and its Contribution to the History of Weights and

Measures since the 'Thirteenth Century), A. MAOHABEY.

Ouvrage publie avec le contours du Centre National de la Recherche Scientifique 1959 512p. Chapter 1 deals with

the history of length measures. Zur Geschichte des Metermasses ( Regarding Standards of the Meter Measurement), K. CLUSIUS. Experentia vl9

n4; 15 IV 1963 p 169-77 6 figs 12 refs. Discusses the

necessity for a universal length standard ; regarding nat- ural standards ; the Metre des Archives ; the diplomatic meter convention and the prototype meter of 1889, division of a fixed meter standard ; optical definition of the length

unit and the cadmium lamp ; the new meter definition with

the aid of Kr88 ; the Kr8e lamp ; progress in the definition of the meter. 1.2.2. Units of Length and Angle

On the Present State of the Question of Standards of Length, W. A. ROGERS, Proc Am Acad Arts and Sci, Boston vl5 1879-80 p 273-312. Presents a consideration

of those standards of length which are in actual use, and

On the Flexure of a Uniform Bar, Supported by a Number

of Equal Pressures Applied at Equidistant Points, and on

the Positions Proper for the Applications of these Pres- sures in Order to Prevent any Sensible Alteration of the Length of the Bar by Small Flexure. G. B. AIRY. Mem

Roy Astron Soc vl5 1846 pl57-63. Presents a mathematical analysis of the relationship between the positions of the points of support of a length bar and the extension

or contraction of the upper surface. A conclusion drawn

is that when the bar is on two supports, in order that the

extension may be zero, the distance between them must be a/VG3, where a is the length of the bar. (This is the

which have the authority of sanction of either national; ) or international law. Also discusses attempts to estab-i ( lish standards which should conform to a natural unit. | I Bibliography. Measures and Weights, L. V. JUDSON, NBS. Encyclo-jjj pedia Britannica 1959 Ed. vl5 p 135-42. Treats in detail : j the U.S. customary system, the British imperial system, \i and the metric system. The systems and units used in j

1 some foreign countries are briefly considered. Presents i \ table of equivalents. Bibliography. 1.2.4. Surveying Methods Applied to Large Mechanical Structures

Remote-Measuring Wire Distance-Gauge DPD-2, B. E. i KOSTICH. Meas Techns n7 Feb 1965 p 576-7 1 fig 5 refs. j j Translated from Izmer Tekh n7 p 17-8 July 1964. Dis- i tance gauge DPD-2 has been developed for measuring i lengths up to 30 m at inaccessible places in large-size welded objects. 1.3.1. Precision, Accuracy, Uncertainty,—

General

Discussion of the Precision of Measurements, S. W. I HOLMAN. 2d Ed. John Wiley and Sons, New York j 1901 176 p. Examples include distance by a steel tape !t and others from physics and electrical engineering. I Elements of the Precision of Measurements and Graphical ' | Methods, H. M. GOODWIN. McGraw-Hill, New York j

1920 116 p. Contains classification of measurements, dis-

] cussions of direct and indirect measurements, deviations, ( errors, etc. 1.3.2. Instrumental Errors On the Error in Standards of Linear Measure, Arising I from the Thickness of the Bar on which they are Traced, \\ H. KATER. Reprint from Phil Trans London n 23 1830 I p 359-81. Describes comparisons of three scales with the ll Imperial Standard Yard, a bar which is 1.07 in. square. 3 Precision in Measuring Lengths and Angles in Mechanical 1 Engineering, M. G. BOGUSLAVSKII, L. K. KAYAK. I Meas Techns n4 Nov 1964 p 310-3. Translated from \ Izmer Tekh n4 p 26-8 Apr 1964. Reviews problems of |j hi ensuring the precision of technical measurements by ; means of Soviet measuring instruments. The dimensions [ | of components made on precision metalworking machines j | are usually checked either by means of measuring tools ! or directly by measuring instruments. The instrument- ; % making industry has developed in recent years, for the . lj use of factory test laboratories, several new types of

„ | measuring instruments which have already passed their D | state tests, such as a universal measuring microscope, pneumatic micrometer, optimeters, cathetometers, measur- 3 E ing machine, linear-graduated measures, polyhedron

quartz prisms, interferometers, etc. Maximum Deviation in the Readings of Measuring In- i struments, A. I. IVANTSOV, V. V. ASANOV. Meas !] Techns nil Apr 1965 p 950-3 1 fig 4 refs. Translated from i is Izmer Tekh nil p 11-3 Nov 1964, Deals with distribution fi laws of deviations in the readings of measuring instru- I 11 ments, a deviation being regarded as an error A <p in the I position of the output element (for instance, a pointer). < i

origin of the now well known "Airy points.") When

there are eight supports the distance between each and ' the next must be a/V63. U. S. Naval Observatory Li- ! brary.

\

I Air Mounts Maintain Surface Plate Flatness, G. E. 1 McKEWEN. Tool and Mfg Engr Apr 1962 2 p 2 figs. . 1 1 When heavy parts are checked on a surface plate, deflection caused by the weight of the part limits measuring

accuracy. An air-mount system offsets variations in load- ing and keeps the surface plate flat. It also eliminates

the effects of shock, vibration, and changing temperatures. \

1.5. Deformation, Deflection, and Wear

4(1
Section 2. Length and Diameter Measurements by Interferometry

CONTENTS

Page

2.1. Interferometry, general 41

2.2. Interferometry theory 44

2.2.1. General 44

2.2.2. Method of coincidences 48

2.2.3. Aperture correction : 50

2.2.4. Refractive index of air 52

2.2.5. Phase change at reflection 53

2.3. Wave length standards and light sources 56

2.3.1. General 56

2.3.2. Cadmium 59

2.3.3. Krypton 61

2.3.4. Mercury 63

2.3.5. Helium 65

2.3.6. Atomic beam 65

2.3.7. Lasers 66

2.4. Length and diameter measurements 68

2.4.1. General 68

2.4.2. Fringe count interferometers and dilatometers 72

2.4.3. Fabry-Perot interferometer 78

2.4.4. Interference comparators 81

2.4.5. Measurement of long lengths 84

2.4.6. Measurement of line standards 86

2.5. Metrological gratings 87 Addendum to Section 2 90

2.1. Interferometry, General

Sur les Franges des Lames Minces Argentees, et Leur Application a la Mesure de Petites Epaisseurs d'Air (On

fringes with thin silver coatings and their application to the measurement of thin thicknesses of air), O. FABRY,

A. PEROT. Ann de Chim et de Phys ser 7 vl2 1897 p

475-501. Contents : Fringes with thin silver coatings

fringes of superposition ; application of the fringes of superposition to the measurement of short lengths ; phase

loss ; diffusion ; conclusions. Theorie et Applications d'une Nouvelle Methode de Spectroscopic Interferentielle (Theory and application of a new method of interferential spectroscopy), C. FABRY,

A. PEROT. Ann de Chimie et de Phys ser 7 vl6 1899 p

115--M 3 figs 4 refs. Contents : Introduction ; theory of the

interferential apparatus ; description of the interferential spectroscope; adjustment; account of one experiment;

applications ; production of interference with thin glass. MGthodes Int6rferentielles Pour la Mesure des Orandes

I Epaisseurs et la Comparison des Longueurs d'Onde

(Interferential methods of measuring great thicknesses and the comparison of wave-lengths). A. PEROT, C. FA- BRY. Ann Chim Phys vl6 1899 p 289-338 7 figs 14 refs. More complete and general than previous papers by authors. Contents: Introduction; determination of the numerical order of a fringe including theory of coinci- dences and effect of phase loss; comparison of wave

lengths ; measurement of wave lengths for great thick- nesses; fringes of superposition with convergent light; use of fringes of superposition for length measurement. The Interferometer, H. G. GALE. Am Mach v24 July 11 and 18 1901 p 772-5, 799-802. Illustrated explanation of the principle of this instrument and the method of measuring very small distances and angles in terms of the wave length of light. Direct-Vision Intense Monochromotor, H. DU BOIS. Zeit InstrumKde v31 Jan 1911 p 1-6 and Mar 1911 p 79-87. Communication from the Bosscha Lab. Description of a

direct vision instrument constructed to give a bright monochromatic beam from any part of the spectrum. The dispersion is caused by a three-member prism, and the change of color at the eyepiece is caused by a micrometer

screw which moves objective and prism together. The

readings of the screw are standardized by means of the

sun's spectrum. Measuring the Diameter of the Stars, H. N. RUSSELL.

Sci Am Monthly, v3 n2 Feb 1921 p 100-4. Michelson ap- paratus in which two slits are made in a screen set up

in front of the mirror of a reflecting telescope. Applications of Interferometry, W. E. WILLIAMS. N.Y., E. P. Dutton & Co. 1930 104 p diagrs. Description of various types of interferometers and principles of each

type ; scientific and technical applications of interference methods are pointed out, and useful lists of references are given ; work is useful introduction to subject for engineers and physicists. Eng. Soc. Library, N.Y. Light Waves in Precision Measuring, E. W. MELSON.

Iron Age vl36 n2 July 1935 p 14^5, 42 and 44. Measuring

by optical flats ; checking gage blocks ; measuring balls and cylinders ; examples of precision. Resolving Power of Interferometers and their Use as Monochromators, M. CAU, F. ESCLANGON. Rev d'Optic-ue vl6 p 41-63 Feb, and Mar 1937 p 93-103. The the- 41
ories of Fresnel and Gouy are applied to results obtained by using an interferometer as a monocbromator and

analysing tbe transmitted radiation in a second inter- ferometer. Either tbeory will explain the results. The

problem is investigated theoretically and experimentally. Verwendung von Lichtinteferenzen in der technischen Messung, T. ZOBEL. VDI Zeit v81 n22 May 29 1937 p

619-24. Application of light interference in technical measurements review of origin and application of inter- ference phenomena ; interferometer of Mach and Zehnder

described which separates two light paths in space and

can be applied to many technical measurements. Bibliography. Shop Measurements with Light Waves, J. DAUBER.

Mod Machine Shop v!6 n4 5 Sept 1943 10 p between p

118 and 130, Oct 15 between p 174 and 198. Article comprises clear and practical exposition of theory of

light wave measurement and use of "optical flats" for measuring to millionth of inch. Light Waves as Standards of Length, H. BARRELL.

Res. vl 1948 p 533-40 3 refs. Types of length stand- ards ; length measurements by interferometry ; the meter and the yard in wavelengths of light ; the refractive index

of air; measurement of length standards for precision engineering ; bibliography. Applications of Interferometry, W. E. WILLIAMS.

Methuen, London 1948. In chapter 5 a Fizeau type of in- terferometer is described. A New Principle in Interferometer Design, E. R. PECK,

J Opt Soc Am v38 Jan 1948 p 66. Each of the two mirrors

of a normal Michelson interferometer is replaced by a pair

of mirrors mounted at 90°. The reflection of such a mirror

is not affected by rotation about the line of intersection of the pair, and it can thus be mounted on a rotating arm in- stead of a slide. A further development, using a triple mirror, or a glass corner-cube prism, and needing no an- gular adjustment at all, is discussed. Laengenmessung durch Lichtinterferenz, H. WITTKE.

Archiv fuer Tech Messen nl56, 157, 159, Aug 1948 p T84

(4 p ), Oct p T97 (4 p ), Jan 1949 p T6 (2 p ). Measurement of length by means of light interference. Aug 1948: Part I, II: Historical and general review; de- termination of short lengths and distances. Oct 1948 : Part

III, IV : Determination of wedge thicknesses ; determination of long sections and distances. Jan 1949 : Part V, VI

Instruments employed ; calibration of invar wires ; ac- curacy of interferometric length measurements. Theory of the Corner-Cube Interferometer, E. R. PECK,

J Opt Soc Am v38 Dec 1948 p 1015-24. The corner-cube interferometer is analysed geometrically and analytically. When the prisms are used near their axis, the instrument

is found to behave essentially like an interferometer using

triple sets of front-surface mirrors. Equations are ob- tained describing the fringe patterns when one prism is used far off its axis, and also when both are used near

their axis. These fringe patterns are discussed and il- lustrated. Sensitive Adjustment for Interferometer Plates, O. S. HEAVENS. J Sci Instrum v27 n6 June 1950 p 172. Sys- tem for providing sensitive adjustments of position and

tilt frequently required in optical systems employing in- terferometry ; device is of simple rugged construction and

is not susceptible to vibrational disturbances ; fine ad- justment enables points of support of one of interferometer plates easily to be set to within one quarter wavelength. Multiple-Beam Interferometry, S. TOLANSKY. Endeavour v9 Oct 1950 p 196-202. An account is given of the application of multiple-beam interferometry to the study

of metals, surface polish, hardness testing, and formation of slipbands in stressed metallic crystals. The tech- nique is also used in studying the mechanism of crystal growth in certain minerals, the hardness anisotropy of diamond undergoing abrasion test, and the modes of oscil- lation of quartz. A new method of obtaining sharp fringes and the adaptation of an older method for examining

defects in mica are described. The Michelson Interferometer at Millimetre Wavelengths, W. CULSHAW. Proc Phys Soc London B v63 Nov 1950 p 939-54. The required frequency stabilization of the 12.5 mm source is achieved by using a high Q cavity as an r.f. discriminator. Wavelength measurements have been made

with various spacings of the interferometer, the meas- ured wavelength increasing as the spacing is reduced. Results indicate that the interferometer gives more accurate measurements of the wavelength when operated well in the Fraunhofer region of diffraction. The operating fre- quency has been measured using a calibrated frequency

meter, and hence the velocity of electromagnetic waves

deduced. The value obtained for this velocity agrees, within the accuracy attempted with the present instru- ment, viz. one part in 10 4

, with the generally accepted

value for this velocity. The possibilities of increasing the accuracy of its determination with the interferometer are

discussed. Measurements of the dielectric constants of low-loss materials by means of the interferometer have

been made. Results obtained using ordinary commercial

sheets of materials agree within a few percent with values obtained otherwise. The use of the interferometer as a substandard of length is also discussed. A Method for the Adjustment of the Compensator Plate of a Michelson Interferometer, J. E. H. BRAYBON. J Sci Instrum v27 Dec 1950 p 331-2. The method is a modification of the usual interference method of adjustment for parallelism between compensator and splitter plates of a Michelson interferometer. Adjustment is made by reducing to zero the fringes obtained when a spectrometer is used to analyse white light which has passed through the interferometer arm containing the compensator. Parallelism may be assessed to within 0.2' of arc. New Techniques in Optical Interferometry. I-V, H. KUHN.

Rept Phys Soc Progr Phys vl4 1951 p 64-94. Part I deals with optical properties of thin films. Multiple dielectric

films, deposited on glass, can have reflection coefficients up to 0.9 for visible light, and much higher values can

be reached for silver films. The intensity distribution in the reflected and transmitted light in multiple beam inter- ference is discussed and applied to interference filters.

' Frustrated total reflection" filters and polarization filters are briefly described. Part II deals with recent methods

of using Fabry-Perot etalons. The theory and practical performance of the double etalon, the photoelectric method

of recording etalon fringes and the use of etalons in solar spectroscopy are described. Part III deals with standards and testing methods, pure isotope light sources, testing of gauges, etc., and gives a description of the "wavefront

shearing interferometer." Part IV deals with the inter- ferometric study of surfaces, and Part V with recent modifications of the classical methods of interference re- fractometry and with the application of interferometers

to the study of gas flow at high speeds. Modern Interferometers, C. CANDLER. Hilger & Watts,

Ltd. London, 1951. 502 p illus diagrs charts tables (Obtainable from Jarrell Ash Co. Boston, Mass.). Descriptions and simple theory essential for use of interferometers in astronomy, chemistry, engineering, nuclear physics and surveying; material is organized according to prospective use of each type of instrument; diffraction gratings; Fabry-Perot etalon; Twyman interferometer, Michelson interferometer, Lummer-Gehrcke plat; Rayleigh refractometer ; Jamin interferometer. Eng Soc Li- brary, N.Y. 42
An Improved Beam Divider for Fizeau Interferometers, H. BARRELL, J. S. PRESTON. Proc Phys Soc London B v64 Feb 1951 p 97-104. A transparent material, pre- sumed to be Ti02 , is suggested for replacing Al or Ag as a

coating for glass beam dividers in Fizeau interferometers,

particularly those adapted for measuring length or dis- placement in the reflected fringe system. The method

of depositing the films, and their optical properties, are

described ; the coatings are very resistant chemically and

mechanically. Evidence produced in photographs and

microphotometer records, supplemented by calculations

of fringe intensity distributions, shows that the performance of the new material in the interferometer is superior

to that of Al and plain glass. A New Constant-Deviation Prism Arrangement, S. MAKISHIMA, Z. KOANA, K. OSHIMA. J Opt Soc Am

v41 Apr 1951 p 249-52. Describes a new arrangement

w»hich is characterized by higher brightness, greater

resolving power and increased accuracy of wavelength as compared with types hitherto known. This arrangement

consists of two equal half-prisms placed separately with

their divided surfaces outward and a rotative plane

mirror properly placed in some position between them. It

is easily shown that the condition of minimum deviation

is satisfied at every angular position of the mirror. When

used as a monochromator, therefore, no errors occur in the wavelengths of emergent rays computed for the condition of minimum deviation, even when errors occur in the mounting of the prisms or the mirror. This was

proven by tests on a quartz monochromator constructed on this principle. Further, the aperture of the instru- ment suffers no change by rotation of the mirror. Since

the prisms are held fixed with their divided surfaces perpendicular to the axes of the collimator and the tele- scope, the aperture remains constant at its largest value

available, quite independent of the wavelengths used. This results, naturally, in some gain of resolving power.

Interference Measuring Accurate Within 1/10,000,000

Inch, G. WEBBER. Am Mach v97 n25 Nov 23, 1953 p

121^. Multiple beam interferometer, world's most precise instrument for determination of length is produced

by Webber Gage Co., Cleveland, Ohio; gage blocks are made from chrome carbide which has 30 times greater

resistance to corrosion than other carbides and 10 times more resistance than 18-8 stainless steel ; measurements

with Zeiss instrument are made in three different wavelengths of monochromatic light. Some Applications of Interferometry to Precision Measurement, C. F. BRUCE. Commonwealth Sci Indus Res

Organization Australia, Nat Stand Lab Tech Paper n4

p 16 1954. A general account is given of some applications

of optical interferometry to the measurement of length,

angle, flatness, surface finish and vibration. Particular

reference is made to multiple-beam interferometry and its application to surface structure and vibration problems. The Interferometry of Length, H. BARRELL. "Maintenance of standards" symposium PTB Feb 1954 p 23-34. The development of the use of a wavelength standard

of length is reviewed, and new types of spectroscopic sources for such a standard, using the isotope Hg188

, Kr84 or Ki^6

, are described and compared. The techniques and

accuracies of interferometric measurements of length, both

of standard end gages and of long distances [c. 20 m] for

geodetic work, carried out at various national laboratories are reviewed. Some discussion is reported. Inexpensive Michelson Interferometer, E. F. CAVE, L. V. HOLROYD. Am J Phys v23 nl Jan 1955 p 61-3. The

construction and operating characteristics of a Michelson

interterometer designed on kinematic principles are outlined. The main components are ground steel dowel pins and ball bearings which are commercially available. The

construction requires only a moderate amount of mechanical skill. Preliminary results indicate that the device

is quite suitable for use in the undergraduate optics laboratory. An Improved Mirror Mounting for Optical Interferometers, T. F. W. EMBLETON. J Opt Soc Am v45 n3 Mar

1955 p 152-3. A mirror mounting is described which en- ables the relational adjustments of the optical surface

to be made about axes passing through the center of that surface. This feature resulted in considerable simplification of the adjustment of a Mach-Zehnder inter- ferometer in which it was used. Some special properties

of the mounting are mentioned. Metrology of Gage Blocks—Proceedings of Symposium

on Gage Blocks Aug 11-12 1955. NBS Cir n581 Apr 1 1957 119 p. Precise Interferometric Measurement of Gage

Blocks, E. ENGELHARD; Calibration of Gauge Blocks

in Canada, K. M. BAIRD ; Use of Light Waves for Controlling Accuracy, F. H. ROLT ; Achromatic Interferometer for Gage-Block Comparison, T. R. YOUNG.

Light Waves and Length Standards, I. C. GARDNER.

J Opt Soc Am v45 n9 Sept 1955 p 685-90. Historical review of early standards of length and of presently used

Imperial Standard Yard, International Prototype meter and red spectral line of cadmium ; discussion of various

sources of monochromatic radiation for providing length standard in terms of light wavelength.

Precision to Fraction of Light Wave, M. S. HOSKINS.

Machy (NY) v62 n7 Mar 1956 p 190-3. Types of inter- ferometers used with gage blocks to determine precise measurement between two parallel surfaces of gage ; light sources employed; fringe pattern, spacing of fringes and

fringe behavior ; how interferometer picks up light wave

interferences. Fine Measurements, J. R. ADAMS. J Sci Instrum v33 nlO Oct 1956 p 369-75. The limitations of the existing

legal standards of linear measure are considered. The

use of light waves as a universal reference of linear measure depends on the availability of a source of truly monochromatic light and considerable progress has been made

using the isotope Hg198

. Many aspects of engineering

require measurements accurate to a few micro-inches and

instruments capable of meeting such demands have been

designed. Several typical instruments, together with details of the principles on which they are based, are briefly reviewed. Interferometric Measurements in Metrology, M. F. ROMANOVA. Optika i Spektrosk v3 n5 1957 p 457-72. In Russian. This review article gives accounts of work on (1) the determination of the wavelength of the standard Cd

line; (2) measurement of 1 m length standards; (3) the wavelength of the Cd red line for the isotopes 112, 114, and 116; and (4) a method for finding the velocity of

light. Results are given in each section with diagrams

of the apparatus used. Koesters Interferometer, J. B. SAUNDERS, J Res NBS

v58 nl Jan 1957 (RP2730) p 27-31. Results of investigation of Koesters double image prism ; some of results are

not in harmony with those given by other investigators

modification of Koesters prism is described that forms

simple interferometer that is easy to apply to testing of

lenses, mirrors, and combinations of these elements;

practical test given for determining maximum size of source that is usable in any interferometer. Construction of Koesters Double-Image Prism, J. B. SAUNDERS. J Res NBS v58 nl Jan 1957 (RP2729) p

21-6. Interferometric method for use in constructing and

adjusting double image prisms of Koesters type; faces

of prisms form elements of several interferometers used

for testing and making adjustments during construction

prisms are cemented together and are quite stable; pre- 43
cision attainable in adjustments approaches interfero- metric perfection. A New Interferometer with Three Waves, J. J. HUNZINGER. Rev. Opt v36 n6 June 1957 p 285-91 in French. A new type of interferometer is described using three

interfering waves. This is suitable for the measurement of end-standard gauges. There are certain advantages in the system which are discussed. An arrangement for mounting the mirrors is described. In effect the system can

be considered as a compound Miehelson interferometer

in which two dividing mirrors are used behind each other. The intensity distribution in the fringe system is discussed. Latest Wave in Physical Optics, F. ZERNIKE. Opt Soc Am J v47 n6 June 1957 p 466-8. Basic principles and some little known minor subjects discussed ; new concept

of partial coherence treated ; old relative phase shift, as in Fresnel rhomb, gives rise to new effect—destructive inter- ference between two halves issuing from roof prism; phase differences which are otherwise unobservable be- come visible on coherent background obtained in simple manner by diffraction. Spherical Aberration in Fizeau Interferometer, W. G. A. TAYLOR. J Sci Instrum v34 nlO Oct 1957 p 399-402. Re- view of drawbacks of types of instrument in common use

primary aberration theory predicts quite accurately errors introduced even by simple collimators with large aberration ; advantages of using collimating lens based on multiple meniscus design ; comparison of performances of several lens-systems. Interferometry—Symposium Held at National Physical Laboratory June 1959. Great Britain NPL—Symposium nil 1960 471 p. Contains 14 papers on absolute length measurement and light sources for interferometry, and

optical testing and measurement of relative position;

topics treated include accuracy of light wave sources and

wavelength comparison, wavelengths of helium lines, po- larization interferometers, accurate interpretation of microinterferograms, study of optical images, possibilities of moir<§ fringe, and interferometry with electronic aids. Precision Millimeter Wave Interferometry at the U.S. National Bureau of Standards, W. CULSHAW, J. M. RICHARDSON, D. M. KERNS. NPL Symposium nil

Interferometry. H.M. Stationery Office, London 1960 (Paper 4-3) p 329-53 9 figs 17 refs. Describes techniques

of precision millimeter wave interferometry for purposes

of determinations of wavelength, velocity of light, and

length on the basis of the extreme coherence and sensitivity available. Develops a solution for the diffraction correction. Describes present status of experimentation. Introduction to Interferometry, T. J. O'DONNELL. Am

Mach/Metalworking mfg vl04 nl2 June 13 1960 p 123-46. How interferometers can be used in shop to measure and compare length, angles, parallelism, and surface condition.

Methods of Narrowing Spectral Lines for Interference Measurements of Length, A. P. KIRICHENKO. Uspekhi I fiz. Nauk (USSR) v78 n3 Nov 1962 p 525-38 in Russian,

j English translation in Soviet Physics-Uspekhi (USA) v5 il n6 May-June 1963 p 998-1005. A detailed review is given 1

of some methods employed for the production of strictly 1 monochromatic radiation having breadth smaller than 1 the Doppler breadth. The methods described are inter- I ference monochromatization using a spherical Fabry- 1 Perot etalon, absorption monochromatization in which 1 radiation is transmitted between two close-lying absorpj tion lines produced by Zeeman splitting and an interfer- 1

ence-compensation optical scheme. Laser techniques are 1 only briefly mentioned. Two Interference Methods for Measuring Amplitude of J

Oscillations of Mechanical Systems, B. S. DAVYDOV. I

Instruments & Experimental Techniques (English trans- I lation of Pribory i Tekhnika Eksperimenta) nl Jan- 1 Feb 1963 p 132-3. Principles of contactless methods are I examined, for determining total amplitude of oscillations J

from tens of microns to several millimeters, in wide fre- ;I quency range, with error from 0.1 to 6% or less, by using i jj phenomenon of interference of light. Interference Monochromator with a Spherical Fabry- 1 Perot Standard, N. R. BATAROHUKOVA, A. P. KI- I RICHENKO. Meas Techns 1962 n8 Feb 1963 p 633-6 5 figs I 2 refs. See abstract under 2.4.5. Large Aperture Interferometers with Small Beam Divid- I ers, J. B. SAUNDERS, J Res NBS C Eng and Instru- j mentation v67C n3 July-Sept 1963 p 201-205 7 figs 11 refs. I This paper shows some practical interferometers for test- 1 ing very large and very small specimens. This is accomj plished by using a particular type of beam divider that I operates near the vertex of a convergent or divergent beam of light that permits almost unlimited size fields of view. Thus very large or very small specimens can be i tested. Also, the wave front reversing properties of this ! beam divider permit tests to be made without the necessity of using standards of reference, thus eliminating the '] requirement for large standards that are usually expensive i and require large working areas. The principles of these interferometers are so closely related to previously de- scribed instruments that very little additional explana- | tion is required for an understanding of their operation. ; Several variations of the Kosters prism type of interferom- a eter are shown schematically. The Use of a Single Plane Parallel Plate as a Lateral (! Shearing Interferometer with a Visible Gas Laser Source, | M. V. R. K. MURTY. App Optics (USA) v3 n4 Apr 1964 r

1 p 531-4. A high-intensity interference pattern can be ob- tained in a shearing interferometer with the use of a 8 visible gas laser and a simple construction. The high in- tensity of the laser per unit of solid angle gives an inter- ference pattern that is visible in room light. The narrow

spectral width of the source allows a simple plane parallel plate to be used to obtain the desired shear.

2.2. Interferometry Theory

2.2.1. General

Uber einen Interferenzmessapparat (Regarding an Inter- ference Measurement Apparatus), O. PULFRICH. Zeit fur Instrumkde vl8 Sept 1898 p 261-7. Description of Pulfrich interferometer, based on the principle of the simultaneous use of monochromatic lights of different wave-lengths and micrometric measurement of the inter- ference fringes. On a Method of Increasing the Sensitiveness of Michelson's Interferometer, H. C. POCKLINGTON. Cambridge

Phil Soc Proc vll May 1902 p 375-9. In the modified arrangement the two interfering beams consist of circularly polarised light, and a retardation of either causes rotation

of plane of polarization of resultant. The incident light employed is plane polarised. Accuracy of an observation

is increased nearly 200 times. Interference of Light with Great Path Difference, O. LUMMER, E. GEHRCKE. Deutsch Phys Gesell Verh

v4 Oct 17 1902 p 337-46. Method, based on multiple

reflection within a plane parallel plate, by means of which

interferences can be investigated for a path difference as

great as 2,600,000 wave lengths.

4 !
Sensibility of Interferometers. Improved Half-shadow

Instruments, A COTTON. CR Acad Sci Paris vl52 Jan

16 1911 p 131-3. While instruments using polarized light

will detect a difference of X/10,000, ordinary interferometers will scarcely detect a difference of X/100, due to the

irregularities of surface of the media traversed, to acci- dental variation in temperature, and to cruder method of measurement. Tells how a more accurate half-shadow

instrument may be constructed and also how Miehaelson

interferometer may be improved.

Resolving Power of Interferometers, H. NAGAOKA.

Math Phys Soc Tokyo Proc 8 Oct 1915 p 214-20. Discusses

in some detail the resolving power of various instruments

having high resolving power, and advocates the employ- ment of crossed systems in preference to making attempts

to increase the resolving power of individual instruments.

Attention is paid to the question of the resolution of a

strong line accompanied by a much weaker satellite. Miehaelson Interferometer, G. KRAUSE. Ann der Phys

v48 Feb 1 1916 p 1037-60. Abstract of dissertation, Breslau. Gives mathematical theory, with experimental

verification, of the interference phenomena obtained when

the compensating plate in a Miehaelson interferometer is inclined to the reflection plate. Fringe Systems in Uncompensated Interferometers, J. GrUILD, Proc Phys Soc v33 Dec 15 1920 p 40-52. It is shown that the form of fringes in this case is unaffected by lack of compensation in a Miehaelson interferometer, mt the visibility of fringes is conditioned. Die Anwendung der Intreferenzen in der Technik (The

Application of Interference in Engineering), H. SCHULZ.

Zeit fur tech Phys v3 n9, 10 1922 p 284-90, 313-20. General principles, interferences of equal thickness in optics, interfences of equal thickness in mechanics, the Michaelson and Mach arrangement, interference of equal inclinations. The Lummer-Gehrcke Parallel Plate Interferometer, F. SIMEON. J Sci Instrum vl July 1924 p 296-304 3 figs 39 refs. Gives simple approximate expressions for order

of spectrum, separation of consecutive orders, dispersion, and resolving power, together with notes on methods of

use, appearances obtained and interpretation of these appearances. Precautions to be observed in order to ob- tain finest definition. On the Passage of Light Through Transparent Plates, A SCHUSTER. Phil Mag v48 Oct 1924 p 609-19. Mathematical discussion. Grating Interferometer, B. P. RAMSAY. J Opt Soc Am

v24 n9 Sept 1934 p 253-8. Discussion of Michelson inter- ferometer indicates that fringes are formed by superposition of two approximately parallel wave fronts ; wave

fronts having necessary characteristics can be obtained by mounting gratings on arms of interferometer in places

of customary reflecting mirrors; construction and action

of such interferometer has been studied and is described. Theory of Interference Apparatus, A. BOGROS. J de Phys

et le Radium v8 Mar 1937 p 88-92. A comparison of spec- troscopic instruments which depend on the interference

or diffraction of radiation and are geometrically similar shows, by a simple argument, that in the case where the

fringes are observed at a finite distance the linear dispersion for a given radiation is proportional to the dimensions of the apparatus. In the case where the fringes are observed at infinity the angular dispersion is independent

of the dimensions of the apparatus. In both cases, however, the dispersion counted in fringes and the power of

resolution are proportional to the dimensions of the instru- ments. These remarks permit of the correlation of known

results obtained with different spectroscopic instruments, and can facilitate the study of certain particular cases,

such as that of the fringes due to layers of air of different thicknesses. Distribution of Intensity in Interference Fringes, J. ROIG.

J. de Phys et le Radium v9 June 1938 p 241-4. A method

is described for separating the width of the fringe due

to the line width from that due to the apparatus in the

case in which the former is large (line widened by the Doppler effect) and the effect of the latter is small (a large path difference). Harmonic Analysis of Interference Fringes Produced by

Multiple Reflection, P. M. DUFFIEUX. Rev d' Optique

vl8 p 1-19 Jan and June-July 1939 p 201-22. The intensity curve for fringes given by an infinitely narrow spectral

line can be developed as a harmonic series. For a perfect optical system the amplitudes of the terms in this

series are successive powers of the reflecting power; but

for imperfect surfaces they need to be multiplied by fac- tors derived from the errors of planity and parallelism, treated as curves of probability. A number of simple

cases are considered, and a new intensity distribution function is calculated. By examination of effective amplitudes for various reflecting powers the range of applicability of such functions can be determined. The classical formula for a perfect system is only valid for reflecting powers less than 0.5. No general formula can be applied

to very high reflecting powers. A relationship is estab- lished between the intensity curve for fringes given by a wide spectral line and the intensity distribution in the

line. The cases of a simple line and of a line with satellites, with thermal broadening, are examined. In the

latter, the system of equations which resolves the hyperfine structure shows that the number of resolvable components depends on the amplitude of the errors of planity. Superposition fringes for Optical Etalons with Parallel Faces, N. CABRERA, J. TERRIEN. L'Optique (Rev Opt

Theor Instrum) v20 1941 p 35-46. An extensive theoreti- cal study is made of the superposition fringes and rings obtainable at infinity using two etalons. The effects ob- tained, as the path difference and thickness of etalons is changed, are discussed mathematically and the application

of the results to problems such as the determination of small differences in the evaluation of the standard metre

is examined. General Interferential Method, L. STURKEY, B. P. RAMSAY, London, Edinburgh & Dublin Phil Mag & J Sci v31 n204 Jan 1941 p 13-23. Derivation of general intensity equation directly applicable to all instruments ; special cases of resulting intensity equation are discussed ; process of applying general function to specific optical prob- lems is defined as interferential method. Bibliography. Interferometers and the Group Index, A. C. CANDLER.

Nature London vl57 Apr 6 1946 p 444. The group in- dex G=N+v8N/Sv where N is the refractive index and

v the wave number. Its use simplifies determination of

effective range and limit of resolution for all inter- ferometers. Low-Order Multiple-Beam Interferometry, S. TOLANSKY.

Proc Phys Soc London v58 Nov 1946 p 654-62. A discus- sion is given of the various factors affecting the intensity and sharpness of the multiple-beam Fizeau fringes and

fringes of equal chromatic order used for the study of surface topography. The effects of absorption in the Ag

film, phase condition, linear displacement of the beams,

finite size of source, departure from parallelism and source

line width are considered. It is shown that Fabry-Perot

fringes, multiple-beam Fizeau fringes and fringes of equal chromatic order have all the same fringe shape if certain conditions are fulfilled. Optical Conditions in the Use of Photo-electric Cells in Spectrographs and Interferometers, P. JACQUINOT,

C. J. DUFOUR. Rech Cent Nat Rech Sci n6 1948 p 91- 45
103 in French. From considerations of the spread of the image of a slit due to diffraction and scatter in the photo- graphic emulsion it is shown that increased resolution implies reduced luminosity, the best compromise being obtained when the diffraction image of the slit is equal

to the spread in the emulsion. A photographic spectro- graph must be designed either for high resolution or luminosity ; a universal instrument is not possible. With

a photo-electric cell, which responds to total flux (not

luminosity), it is shown that a universal instrument is possible. The optimum slit-size and slit-magnification are

considered. A similar treatment is applied to the case of a photo-cell used with the Fabry-Perot interferometer. Theory of the Corner-Cube Interferometer, E. R. PECK.

J Opt Soc Am v38 Dec 1948 p 1015-24. The corner-cube

interferometer is analysed geometrically and analytically. When the prisms are used near their axis, the instrument

is found to behave essentially like an interferometer using

triple sets of front-surface mirrors. Equations are ob- tained describing the fringe pattern when one prism is used far off its axis, and also when both are used near

their axis. These fringe patterns are discussed and

illustrated. Multiple-Beam Interferometry : Intensity Distribution in Reflected System, J. HOLDEN. Phys Soc—Proc v62 Pt 7 n355B July 1 1949 p 405-17. Investigation of reflected intensity distribution given by interferometer whose re- flecting surfaces are formed by thermal deposition of silver upon optical flats, covering range of reflectivities from 4

to 92% ; use of Fizeau fringes localized on zero order Feussner surface for observations ; results apply to fringes

of equal inclination and to fringes of equal chromatic

order in reflection. The Angle Mirror Interferometer and the New Interfer- ence Effects, J. RIENITZ. Optik v8 nl2 1951 p 561-9 in German. A description of the Michelson interferometer

in which the two planje mirrors are replaced by either right angle mirrors or right angle prisms. The optical properties of the system are discussed including the sideways

displacements of homologous points. The adjustment of the system is simplified. Sideways displacement of a mirror leads to horizontal movement of the fringes in the

field. Measurement of Thickness of Microscopic Objects Using Three-Beam Interference, B. MENZEL. Note in Naturwissenschaften v39 nl7 1952 p 398-9 in German. A micro- scope modification of a technique formerly described, wherein the thickness of a thin object is obtained from

change in localization of fringes produced by three slits. A microscopic reduced image of the three slits is projected on to the small object on the microscope stage and by

observing changes in localization of fringes with beams

going through and missing the microscopic object, thick- nesses can be measured as small as 100 A units. Wide-Angle Interference from a Quadrupole Source of

Light, M. V. FOK. Dokl Akad Nauk SSSR v89 n3 p 439-42

1953 in Russian. English translation, U S Nat Sci Found

NSF-tr-20. A computation is made for the visibility of

interference fringes in so far as they depend upon the angle between the interfering rays. Rules are given for

distinguishing between the dependence of the visibility on whether dipole or quadrupole radiation is involved. Polarization effects are also calculated. The theory de- veloped is an extension for any quadrupole of that formulated originally by Vavilov (Miterostrukturu sveta, 1950)

for linear dipoles and quadrupoles. The Geometrical Optics of Two-Beam Interferometers, H. SLEVOGT. Optik vll n8 1954 p 366-79 in German. A survey of the optimum geometrical conditions necessary

in the use of the Michelson interferometer, the TwymanGreen interferometer and the Linnik interferometer, for

the testing of optical components (including a Zeiss modi- t fication of the Linnik interferometer). Discussion of the if sharpness and localization of the fringes. In general the I middle points of the aperture and field stops must be I imaged in the two auto-collimation points of those mirrors which form the generalized Michelson interferometer. Interference Fringes of Equal Thickness in the Measure- ment of Length with Light Waves, G. SCHULZ. Ann Phys

(Leipzig) vl4 n3-5 1954 p 177-87 in German. A theory

is developed for two-beam interference in a simple wedge. On the basis of this, spatial distribution, contrast and

intensity distribution are calculated. Corrections due to the aperture are introduced for apertures 0-90°. It is J demonstrated that two-beam interference of equal thickness, even using strictly monochromatic radiation, should show alternations caused by the aperture and not by the ; source. Proposed corrections as a function of the real aperture increase from 0 up to some 6% for 30° apertures. Determination of Order of Interference in White Light, R. C. FAUST, H. J. MARRINAN. Brit J App Phys v6 nlO Oct 1955 p 351-5. Achromatic fringe observed in white light does not necessarily correspond to position of zero path difference, since optical paths of two interfering beams do not usually have same wavelength dispersion; general theory of this effect; how it can be applied to Rayleigh interference refractometer, Babinet compensator, and interference microscope ; experimental verification. An Interference Optical Alinement Method, G. A. HARLE,

B. S. THORNTON. Nature (London) vl76 Oct 1 1955 p 651-52. A system is described which is applicable to the alignment of coaxial optical systems with a large number

of surfaces. A spatial distribution of non-localized inter- ference fringes is employed. Thus, the necessity of image

location is eliminated and a technique combining the advantages of aperture sight and image alignment is available. Various interferometrie arrangements are described. One uses a bi-prism and slit. Another uses a point source and the Michelson interferometer with mirrors parallel. ! A third uses a Fabry-Perot etalon and multiple-beam i fringes are employed of the non-localized type described by Tolansky. The theories of the methods are similar to those of the image alignment method.

Integrated Flux from a Michelson or Corner-cube inter- ferometer, E. R. PECK. J Opt Soc Am v45 nil Nov 1955 ' p 931-4. Flux in the circular fringe pattern of a Michel- » son or corner-cube interferometer is integrated over a

centered, circular or rectangular field stop, as is done i experimentally by a photoelectric cell in fringe counting. The results are discussed in terms of fringe amplitude, modulation depth, and phase shift. Effect of Source Size on Visibility of Fringes in Inter- ferometer Employing Division of Amplitude, M. DE. J Assn App Physicists v3 n2 Sept 1956 p 51-60. Simplified geometrical optical treatment of problem of finding optir mum size of source for interferometer employing division of amplitude; criterion, instead of being arbitrary, is chosen in relation to limiting visibility of fringes ; appli- . cation to almost generalized case of two beam interferometer is also given. Interference In An Optical Wedge, U. OPPENHEIM, J. H. JAFFE. Am J Phys v24 n9 Dec 1956 p 610-15. Many ' standard textbooks treat interference in an optical wedge j quite inadequately. Elementary treatments of this prob- lem often leave much confusion about the exact conditions under which the fringes are formed and observed. Here ] a unified introductory treatment is presented both for two-beam and multiple-beam interference. Special atten- I tion is given to the localization of the fringes around the wedge. Factors governing the fringe visibility are ex- amined. 46
Uncompensated Corner-Reflector Interferometer, E. R. PECK. J Opt Soc Am v47 n3 Mar 1957 p 250-2. Analysis

is made of the effect of omitting the compensating plate

in a corner-reflector interferometer. It is concluded that

a non-compensated instrument has disadvantages when

compared to a compensated one, but when properly adjusted it may still be useable with a photoelectric detector. The flux is integrated over rectangular field stops. A High-Sensitivity Interferometer for Measurement of Phase Shift and Other Applications, J. B. SAUNDERS.

XBS Cir 581 Apr 1 1957 p 51-9 8 figs. With highly reflec- tive surfaces, such as fresh silver, as many as 50 reflec- tions may be used, in which case one order of interference

will correspond to about 0.01X. A method of applying this interferometer to the measurement of phase shift from

metallic surfaces and for the comparison of gage blocks is described. Applications of Coherence Theory in Microscopy and In- terferometry, H. H. HOPKINS. J Opt Soc Am v47 n6

June 1957 p 508-26. General treatment of influence of size

of source on visibility of fringes in two-beam interferometers ; use of coherence theory in microscopy summarized

how concept of "effective source" helps study of influence

of abberations under various conditions of coherence ; dis- cussion of theory of chromatic coherence.

Spherical Aberration in the Fizeau Interferometer, W. G.

A. TAYLOR. J Sci Instrum v34 nlO Oct 1957 p 399-^02. The drawbacks of types of instruments in common use are

reviewed. It is shown that primary aberration theory

predicts quite accurately the errors introduced even by

simple collimators with large aberration. The advantages of using a collimating lens based on a multiple- meniscus design are indicated, and the performances of several lens-systems are compared.

Fizeau-type Interference Between Beams of Light Reflected from Three Surfaces, A. H. COOK. J Sci Instrum

v34 nil Nov 1957 p 455-8. Optical interference phenomena

between beams of light reflected from three surfaces are

described and analysed. The distinctive feature of the

fringe system is that the field is crossed by bands of

intensity equal to that of light reflected from one of the

surfaces, delineating the lines of constant separation of the other two surfaces. The use of the phenomena in metrology is briefly discussed. Photoelectric Fringe Signal Information and Range in Interferometers with Moving Mirrors, G. W. STROKE.

J Opt Soc Am v47 nl2 Dec 1957 p 1097-1103. Theoretical and experimental studies of conditions required for ade- quate information content and visibility of fringe signals on photoelectric interferometers ; expressions for fringe

visibility with simple isotope lines of Gaussian shape are used to estimate interferometric range ; application to high precision measuring instruments. The Setting Accuracy in Two-Beam Interferometry, M. BOTTEMA. Physica v24 n6 1958 p 519-28. The accuracy

of some setting methods applicable in two-beam inter- ferometry is investigated with regard to its dependence

on the conditions of observation. Photometric methods

prove to be the most advantageous. With these, an ac- curacy of a few thousandths of a wavelength in one setting

is attainable under favourable conditions.

Effect of Natural Line Width on Resolving Power of Fabry Perot Etalon, M. S. SODHA, S. S. MITRA. Optik

vl5 nl Jan 1958 p 47-50. Discussion of effect of natural

line width due to Doppler effect and resonance damping

on resolving power of Fabry Perot etalon ; table of variations. Photoelectric Observations with the Michelson Interfer- ometer, J. TERRIEN. J Phys Radium, vl9 n3 Mar 1958 p 360-6 in French. It is possible to improve measurements

with the Michelson interferometer by a photoelectric method, which allows extension beyond the visible spec- trum. The photomultiplier is the only useful detector for narrow weak lines ; it is supposed that fluctuations are due

to shot-noise. Optimum conditions are calculated for measurements of fractional order of interference, and

wavelength comparison : the diameter of the hole isolating the central part of the interference pattern, and the order

of interference. The accuracy of wavelength interferometer imperfections. The most necessary improvements are

indicated. The improvements obtained justify the hope

that the theoretically obtainable accuracy, of magnitude

10~B

, will be reached when the causes of systematic errors, more numerous and serious than was previously supposed, have been removed. Multiple-Beam Fringe Sharpening With the Series Inter- ferometer, D. POST. J Opt Soc Am v48 n5 May 1958 p

309-12. The parallel mirror Series Interferometer exhibits fringes that are qualitatively similar to the well-known

multiple-beam fringes of two mirror interference systems. Contrary to the case of two mirror systems, however, no

stringent restrictions on mirror separation or monochromatic purity of light source are involved, for the relative path lengths of interfering rays is independent of mirror

separation. Thus, sharpened fringes can be employed for applications that require moderately large test zones, such

as problems in fluid flow, thermal expansion, optics testing,

etc. An experimental verification and analytical treat- ment are presented. The analysis yields an intensity- fringe order relationship that is effectively corroborated by experimental observation. Fringe Sharpening in Divided Beam Interferometer, W. PRIMAK. J Opt Soc Am v48 n6 June 1958 p 375-9. The

development of sharpened fringes in long path length interferometers (like the Twyman-Green, Mach-Zehnder, and series) by intensity and by multiple reflection is described. The cause of the extreme localization of some

of the multiple-reflection fringe patterns is discussed. Limiting Precision in Optical Interferometry, G. R. HANES. Can J Phys v37 nil Nov 1959 p 1283-92. The

fundamental limit to the precision of setting on a fringe peak due to photon noise is evaluated for a certain class of interferometric methods in terms of parameters characterizing the source, the interferometer, and the detector.

It is shown that changes in path difference of 10"10 should be detectable with an observing time of 1 sec, using only modest equipment. Some of the experimental conditions required to attain this precision are discussed. Measures de Longeurs par Methodes Interferometriques,

et Principes d' Incertitudes en Optique a Trois Dimensions,

B. VITTOZ. Optics in Metrology, P. MOLLET. Per- gamon Press 1960 p 73-81 2 figs 12 refs. Influence of spectral line width upon interferometric measures of

lengths. One comes to an absolute limitation of the sensibility, which is analogous to the general principle of uncertainty in quantum mechanics, and which is a comple- ment to the optical uncertainty principle of Ingelstam. The analogy of the quantum mechanics of the photon ap- pears in a very general way by the help of the Fourier

transformation. Photometric Setting Methods in Interferometry, M. BOT- TEMA. Optics in Metrology. P. MOLLET. Pergamon

Press 1960 p 42-49 2 figs 6 refs. Great precision is attainable. Two methods are compared with a common geo- metric method.

Discovery of Interference by Thomas Young, R. W. POHL. Am J Phys v28 m6 Sept 1960 p 530-2. Thomas Young

contributed to philology and to the problems of vision, as well as to the understanding of wave motion and inter- ference for which he is principally known. The steps by which he achieved understanding of the phenomena of

interference, from his first work in 1801, through the pub- 47
lication of Course of Lectures on Natural Philosophy, and

up to his development of the theory of the interferometer

in 1817, are outlined. Ueber den Einfluss der teildurchlaessigen Schichthen auf den Wirkungsgrad von Zweistrahlinterferometern, J. RIENITZ. Deutsche Akad der Wissenschaften zu Ber- lin—Klasse fuer Mathematik, Physik und Technik—Abh

n2 1961 46 p. Influence of partially transparent layers on efficiency of 2-beain interferometers ; analyses of Michelson and of MachZehnder type of instruments. 67

refs. Analysis of Some New Possibilities of Interference of Electromagnetic Waves, A. H. COOK. Optica Acta (Int) v9 nl Jan 1962 p 55-64. It is shown that with sources

available now or shortly to become available, there is correlation in the radiation emitted at distances as great as 270 m at 1 A or 600 km at 7000 A. Possibilities of detecting this correlation by means of a Michelson inter- ferometer and by means of an intensity interferometer are discussed in terms of the limits set by resolution and

noise. Adjustable Compensators for Two-Beam Interferometers, W. H. STEEL. Optica Acta (Int.) v9 n2 Apr 1962 p 111-

19. When a two-beam interferometer is adjusted to satisfy particular compensation conditions, high-contrast fringes can be obtained when the light source is neither small nor

highly monochromatic. In some interferometers a con- tinuous variation of compensation is desirable. Two adjustable compensators are discussed and their application

to a lens-testing interferometer is described. Limiting Precision in Scanning Optical Interferometer,

R. M. HILL, C. F. BRUCE. Austral J Phys v 15 in 2 June

1962 p 194-222. Interferometer uses photoelectric detection and it is shown that principal noise sources limiting accuracy of detection are shot noise in vacuum photocell and photon noise from light source; from limiting preci- sion of pointing on fringe, limiting precisions of measure- ment of small wavelength shifts and of measurement of wavelengths have been calculated. On the Factors Contributing to the Formation of Multiple- Beam Fizeau Fringes, N. BARAKAT and S. MOKHTAR.

J Opt Soc Amer v53 n2 Feb 1963 p 300-1. The approxi- mate formula derived by Tolansky in 1948 for the phase

lags and beam displacements in multiple-beam Fizeau in- terference fringes are now refined and extended. The

earlier formulae are correct to a first approximation. In- tensity effects and contribution of different numbers of beams are discussed. Numerical apertures of collecting lenses are considered. The displacement between 1st and

nth beam in zero order formerly given as 2n2 et is shown now to be 2n2 et[l- e

2/3 (1 + n2

) ]. Theory of Frustrated Total Reflection Involving Metallic

Surfaces, T. R. YOUNG, B. D. ROTHROCK. J Res NBS

A. Physics and Chemistry v67A n2 Mar-Apr 1963 p 115-

25 9 figs 6 refs. See abstract under 11.2. On Order of Interference in Michelson Interferometers in Case of Circular Light Sources Central on Optical Axis,

Z. ERDOEKUERTI, K. KANTOR. Optik v20 n5 May

1963 p 243-58. Changes in order of interference in Michelson-type interferometers have been determined experimentally by phase detecting method in terms of source size, interferometer geometry amd spatial coordinates of point

of observation for case of circular light sources centered on optical axis ; measured values of order of interference are in good agreement with those predicted by theory. Quantum Limit to Precision of Wavelength Determination, G. R. HANES. App Optics (USA) v2 n5 May 1963 p 465-70. The precision of wavelength determination is

ultimately limited by noise arising from the quantum

nature of light and light detection. Expressions are de- rived for the limiting precision attainable by various inter- ferometers and conventional spectrometers in terms of parameters characterizing the instruments, the source, and the detector. A comparison of five different instru- ments shows the superiority of the interferometers and

indicates that they are divided into three classes, accord- ing to the role played by the half-width of the radiation from the source. Frequency Spectrum of Photoelectric Signal from Oscillat- ing Interference Fringe Pattern, J. L. GOLDBERG.

Australian J App Sci vl4 n3 Sept 1963 p 231^2. Conditions for optimum signal-to-noise ratio, in multiple-beam

interferometer; optimum signal-to-noise ratio is deter- mined by aperture width in relation tlo fringe spacing;

since some bandwidth restriction is essential to limit white

noise spectrum of detector, theoretical limits are derived

for bandwidth required to pass acceptable amount of detail in photoelectric signal, for case where motion of fringes is oscillatory. Forty Years of History of a Grating Interferometer, V. RONCHI. App Optics (USA) v3 n4 Apr 1964 p 437-51. Deals with the development of studies concerning the em- ployment of diffraction gratings as interferometers, start- ing in 1922 when they were used to test optical systems. After reporting how a concave surface was tested by means of gratings, their elementary theory is described. The phenomenon is further studied from the interferential standpoint and a wave theory of shadows formulated which is analogous to Abbe's theory on images. A series of studies follows demonstrating that interferential theory accounts for the form of the fringes recorded when a grat- ing is placed on the path of a wave affected by any aberration. In conclusion some simple rules are derived which

allow evaluation of both the quality and the amount of the aberration of the wave under test on the basis of the form

of the fringes. The sensitivity of the method is then

studied, and the most recent developments and better- known applications of the gratings reported, concerning

their employment as achromatic interferometers. High-Precision Pointing Interferometer, G. H. LOVINS.

App. Optics v3 n7 July 1964 p 883-7. By adjusting Koester's prism interferometer so that zerojorder fringe is parallel to beam splitter and to apex, parallel-beam Michelson-type interferometer was produced which is cap- able of pointing with precision of 0.02 sec of arc ; sensitivity is proportional directly to beam spacing and in- versely to wavelength; described are schemes for using instrument for measurement of film thickness, plane mirror rotation, divided circle accuracy, refractive index

differences, ball-bearing sphericity, absolute pressure, tilt, etc. 2.2.2. Method of Coincidences

Millimeter and Centimeter Standards, R. BENOIT. Bui

Soc France Phys n97 1897 p 2-3. Standards, by the Bureau

international des Poids et Mesures, are described, on the

principle of measuring displacements by the travel of

circular fringes in a Michelson's refractometer, taking

the four cadmium radiations simultaneously; absolute

coincidence of the limit of the standard with the plane of reference in the instrument being indicated by certain

characteristic fringes. tiber einen Interferenzmessapparat. (Regarding an In- terference Measurement Apparatus), C. PULFRICH. Zeit fur InstrumenKde vl8 Sept 1898 p 261-7. Description of Pulfrich interferometer, based on the principle of the simultaneous use of moncchromatic lights of different wave-lengths and micrometric measurement of the inter- ference fringes. 48
Sur un Proc6d6 pour la Comparaison et la Mesure en

Valeur Absolue des Etalons a Bouts Plans, au Moyen des

Interferences Lumineuses (Absolute Measurement of Length Gages by Optical Means), A. PERARD. OR Acad

Sci vl70 Feb 16 1920 p 390-2. Describes a method for determining the dimensions of Johansson gages in terms

of wave lengths of monochromatic light It has been shown previously that the interspace between the surfaces

of two gages is less than .02/i and the method of measure- ment proposed consists in placing the gage to be measured

in contact with a plane steel surface of greater area. Upon the other surface of the gage is placed a reference plane of glass. Thus, by suitable arrangements described

it is possible to deduce the thickness of the gage. Measurements up to 15 mm are possible. Interference Methods for Standardizing and Testing Precision Gage Blocks, C. G. PETERS, H. S. BOYD. NBS

Bui 17 1922 p 697-713 21 figs. (Sci Paper 436.) Interfer- ence methods are described by which the planeness and

parallelism errors of precision surfaces can be measured

and the length of standard gages determined by direct comparison with the standard light waves with an uncertainty of not more than a few millionths of an inch. The errors of other gages can be determined by comparison with these calibrated standards with equal precision. Proc§des Actuels pour L'Etude des Calibres Industriels au moyen des Interferences Lumineuses. (Interference Methods for Measuring Johansson Blocks), A. PERABD.

Rev d'Optique vl May 1922 p 209-31 14 figs. Interference method consists in placing the block between two parallel

plates, the upper one being glass so that a uniform air layer remains between the glass and the upper surface of the block and proceeding as in the usual Fizeau experi- ment to observe the fringes due to the air layer formed by monochromatic light. By using several kinds of monochromatic illumination, 8 in all, whose values of X vary from 640.224mu to 43o.832m/t, the actual length required

is evaluated by certain series formula quoted. An apparatus for comparing 3 blocks set up between the parallel

plates is also described and sketched. Uber die Lange eines Parallel-Endmasses bei Messung in Lichtwellenlangen (Regarding the Length of a Parallel End Standard with Measurement in Light Wavelengths),

H. PIETZSCH. Buch druckerei Wilhelm Volkman, Dres- den 1928 30 p 6 refs. Applies Kosters interference comparator with a mean error of ± Sm/i (omitting the wringing

film). Discusses "springing on" and wringing correction. Measuring Gauge-blocks by Light Waves, F. KONIG.

Machy (London) v32 July 5 1928 p 425-8 8 figs; Machy

(NT) v34 July 1928 p 809-13 8 figs. New Zeiss inter- ferometer is primarily intended for taking absolute meas- urements but is readily converted into a comparator; measurements computed to millionths of inch; two fea- tures of this new interferometer are swiveling prism for

effecting spectral dispersion, and adjustable virtual plane

of reference about midway between two surfaces of gage

block; conditions involved when poly-chromic light is used ; slide rule used in conjunction with interferometer. Applications of Thallium and Zinc Spectral Lines in Metrology, A. PERARD. CR Acad Sci Paris v225 Dec 1 1947 p 1045-7 in French. In metrology the direct obser- vation is the fractional excess of an order of interference, and the whole number is deduced by combining observations of the excess fraction given by several spectral lines. This assumes that the wavelengths of the lines are constants, independent of the path. This is only strictly true

for monochromatic lines. By comparison with a suffic- iently monochromatic line (e.g. Cd red), it is possible to evaluate corrections for lines less monochromatic, which

can be added to the fractional excesses observed. Working in this way, with a Michelson interferometer, complex lines were studied in Os, Tl and Zn spectra, chosen because of their brightness. In graphs, corrections are given for the green Tl line (5 350 A) and the red (6 363 A) and blue (4 811 A) Zn lines, as functions of the path

difference up to 200 mm. This allows these more intense sources to be used in spite of the lines not being strictly monochromatic. A Spectrograph Unit for Use with the N.P.L. Gauge Inter- ferometer, C. F. BRUCE, V. R. FINDLAY. J Sci Instrum

v30 Sept 1953 p 297-9. The unit enables photographic

recording to be used satisfactorily in the routine deter- mination of length in terms of cadmium light waves with

this interferometer. The time taken to record and measure is no longer than that taken with the normal visual method and the photographic method has advtantages of permanent recording, reliability of measurement and

lower fatigue effects on observers. The unit can also be used very effectively for improved visual observation. The present unit is primarily designed for dispersing the cadmium radiations satisfactorily and does not, for example, separate adequately the two mercury yellow 5791 A

and 5770 A. Abstandsmessung von Rontgeminterferenzen. Bin neues Langenmessgerat (Intervals of Rontgen interference

fringes. A New Length-Measuring Instrument), C. HOF- FROGGE, H. WEYERER. Zeit fur angew. Phys v6 m9

1954 p 419-20 3 figs 1 ref. A simple measuring instru- ment is described consisting of a translatable scale in a frame and a dial indicator which shows the displacement. Uncertainty is 0.01 mm. Through its coincidence setting the instrument appears to be especially suitable for the measurement of faded (reflected beam) lines. The Accuracy of Interferometric Length Measurement,

R. LANDWEHR. Zeit fur angew Phys v8 nil Nov 1956 p 561-8 in German. A review article; summarizes the sources of error in the measurement of the fractional order of interference and discusses the effect of errors in the fractional order on the accuracy of the measurement

of length, particularly on the use of the method of exact

fractions to determine the order of interference. The re- sults of some experimental tests are reported. Multiple-Beam Fringes of Equal Chromatic Order. VIII. Method of Coincidence, W. F. KOEHLER. J Opt Soc Am

v48 nl Jan 1958 p 55-7. An interferometric method of coincidence for the measurement of a large step height A * is reported. The method is based upon the more rig- orous interference equation n=2ti>+f. The term / is a

function of v and is necessary to account for phase changes upon reflection at the boundaries of the interference film when other than zero or jr. Determination of the Interference-Band Order using a "Monoprism" and a Plate, V. G. KHOMAZYUK. Optika

i Spektrosk v8 n2 Feb 1960 p 261-3 in Russian. Describes a procedure for determination of the interference-band order using two plane-parallel quartz plates, one 0.9 mm

thick and the other 1 mm thick (one of the faces of the

latter is bevelled at an angle of 5° and is called a "monoprism").

Photoelectric Recording of Interference Fringes, Iu. P. EFREMOV. Meas. Techns 1958 n6 Mar 1960 p 630-2 3 figs 10 refs. Translated from Izmer Tekh n6 Nov-Dec 1958 p 15. Up to 1000 mm gage blocks are measured on a

large VNIIM horizontal interferometer by comparing their lengths with the length of a 100 mm Fabry and Perot master gage. The accuracy of these instruments depends mainly on how precisely the length of the master gage is known at the moment when the comparison is made. The

length of these master gages can be measured most ac- curately in wavelengths of visible light by the absolute

interference method, which in essence is reduced to the
determination of the fractional part e of the order of interference in the center of rings with equal slope. This paper deals with the replacement of the visual observation method by photoelectric recording, which makes the measurement of the fractional part of the order of inter- ference e more objective and accurate. Advantages of the photoelectric recording method include : its objectivity,

reliability, and the speed with which the result is ob- tained. In addition, the use of this method offers wide

possibilities for using in the interference length-measure- ments of spectral lines from the part of the spectrum close

to the infra-red region, which makes possible the extension of the range in which absolute measurements of gage

blocks in wavelengths of light can be performed.

Fractional Order Slide Rule for Interferometric Length

Measurement, K. H. HART. Rev Sci Instrum v31 n4

April 1960 p 438-40 ; nlO Oct 1960 p 1166. A description

is given of a slide rule of special design for use with the method of exact fractions in interferometry. The instru- ment computes lengths from measured excess fraction

orders. A New Method of Measuring Gage Blocks, J. B. SAUNDERS. J Res NBS v64C n3 July-Sept 1960 p 173. The

parallel testing interferometer is quite applicable without

modification, to the comparison of lengths of gauge blocks. This note describes the testing of gauge blocks of all lengths, up to several meters, without having to contact them to optical flats. Tables for Absolute Measurements of Gage Blocks, Engineering Metrology Section, NBS Jan 12 1961. Contains 6

tables of fractional band constellations for nominal gage

lengths for Cd, He, and Hg 198. Also 6 tables of length equivalents of hundredths of a band and vice versa. The Calculation of Excess Fractions from Measurements

on Optical Interference Rings, D. C. WILLIAMS. Optica Acta (Int) v9 n3 July 1962 p 269-75. An improved method is described for obtaining excess fractions from

observed diameters of optical interference rings of the Haidinger type which enables the accuracy of certain in- terferometric length determinations to be doubled. In

appropriate cases ambiguity between orders of interfer- ence can thereby be removed. The method is extended to include spectrographic recording of the fringes. Simple Device for Measurement of Fringe Displacement

in Gauge Interferometer, M. J. PUTTOCK. J Sci Instrum

v39 nlO Oct 1962 p 498-9. Device for direct measurement

of fractional displacement of fringes on gage relative to fringes on base plate. Influcene de la dispersion sur les phenomenes d'inter- ferences (Influence of dispersion on interference phenomena), D. TINAUT. Acad Sci CR v258 n25 June 22 1964 p 6110-11. When 2 beams of interferometer pass through

2 media of different dispersion, colors observed are very

different from Newton scale ; colors are classified as function of dispersion difference and so facilitate interferential measurements; this can be particularly useful for calculation of indeterminate form of entire part of interference

order. 2.2.3. Aperture Correction On the Admissible Width of Slit in Interference Experi- ments, J. WALKER. Phil Mag v46 1898 p 472-8. A

mathematical investigation. The angle subtended by the

slit at the interference apparatus must be a small proportion of that subtended by the width of the bands at the same point. When the variations of the width of the bands

are due to variations of the distances of the slit and screen

of observation from the apparatus, as the bands become

finer the slit may be made wider without loss of distinct- ness. A progressive widening of the slit causes a periodic

disappearance of the bands, the system of bands at the

successive reappearances being alternately bright and dark

centered. Paper deals solely with visibility of bands. Interference of the Pencils which Constitute the Remote

Divergences from a Slit, C. BARUS. Nat Acad Sci Proc

v4 May 15 1918 p 134-6. Describes the lay-out of the apparatus used for obtaining interference between the edge rays from a slit. The fringes are difficult to find and, when lost, are not easy to rediscover. The behavior of the images is otherwise as described in the case of achromatics

obtained by the use of a cleavage prism.

Effect of Size and Spectral Purity of Source on Fringe Pattern of Mach-Zehnder Interferometer, F. D. BENNETT.

J App Phys v22 n6 June 1951 p 776-9. In analysis of MachZehnder interferograms of axisymmetric flows above su- personic projectiles, question arises whether errors in fringe width occur because of finite size and non-zero spectral width of source ; in order to solve problem quantitative

investigation was made of intensity pattern of interferometer ; results obtained. An Arrangement for Measuring the Angle of Incidence of the Beam in a Fizeau-Perard Interferometer, J. HAMON.

Rev Opt (Theor Instrum) v30 Aug-Sept 1951 p 366-8 in French. When length standards are required to be known

to one in 10' a correction due to non-normal incidence is needed. A method for evaluating this is described. Experimental Verification of Source Size Theory for MachZehnder Interferometer, G. D. KAHL, F. D. BENNETT.

J App Phys v23 n7 July 1952 p 763-7. Test of simplified theory ; reduction in visibility of fringes formed by inter- ferometer due to extended area light source is shown

experimentally; effect is caused by superposition of two

separate effects characteristic of two angular coordinates

of unit vector pointing from center of collimating lens toward each point in plane of area-type source; other

results. Effect of Source Size on Coherence of Illuminating Wave,

L. R. BAKER. Phys Soc Proc v66 n407B Nov 1 1953 p 975-83. Study relating to image formation in optical instruments ; calculation of intensity distribution in dif- fraction pattern of two parallel interferometer slits il- luminated by slit source of variable width ; dependence

of fringe visibility on choice of slit widths ; effect of source

size on coherence of wave front. Interference Fringes of Equal Thickness in the Measure- ment in Length with Light Waves, G. SCHULZ. Ann

Phys (Leipzig) vl4 n3-5 1954 p 177-87 in German. A

theory is developed for two-beam interference in a simple wedge. On the basis of this, spatial distribution, contrast and intensity distribution are calculated. Corrections due to the aperture are introduced for apertures 0-90°.

It is demonstrated that two-beam interference of equal

thickness, even using strictly monochromatic radiation, should show alternations caused by the aperture and not by the source. Proposed corrections as a function of the

real aperture increase from 0 up to some 6% for 30°

apertures. The Effects of Collimation and Oblique Incidence in Length Interferometers. I, C. F. BRUCE. Austral J Phys

v8 n2 June 1955 p 224-47 ; vlO n2 June 1957 p 324-5. An

investigation has been made of the effects of position and

size of diaphragm apertures on the interference fringes

in length interferometry. The results indicate that, while

the well-known correction formula for the effect of the oblique rays from a point source off the optic axis is al- ways applicable, the effect of finite area of aperature is a more complex one and is not in general proportional to the length measured. This effect depends essentially on

the phase differences arising from different points of the aperture and is oscillatory in character. For a narrow 50
slit the maximum fringe displacement arising from this

effect is not greater than about 0.15 fringe. Obliquity Correction Curves for Use in Length Interfer- ometry, C. F. BRUCE. J Opt Soc Am v45 nl2 Dec 1955 p 1084-5. In Fizeau-type interferometers the aperture is often placed slightly off-centre in order to view the returning light. The effect of the size of the apertures and

their positions can introduce fringe displacement effects which are computed. The fringe displacement computed

is wavelength dependent. Correction curves are presented which enable a rapid application of the correction to be made in precision interferometry. The fringe displace- ment is computed as a function of the phase difference between the centre and the edge of the aperture. Computations are made for a maximum path difference of 800 mm which might be attainable with isotope mercury

and krypton sources. The results found are given in the form of curves. Fringe Spacing in Interference Microscopes, J. W. GATES.

J Sci Instrum v33 nl2 Dec 1956 p 507. In high-power

interference microscopes fringe spacing is greater than

half a wavelength, depending on the numerical aperture, and this arises from obliquity of incident light, when a

converging beam is used. A formula is derived, and predictions are compared with observations for N.A. values

0.30, 0.60, and 0.65. There is close agreement.

Obliquity Effects in Interference Microscopes, C. F. BRUCE, and B. S. THORNTON. J Sci Instrum v34 n5 May 1957 p 203-4. A theoretical analysis is made of the

influence of oblique rays on the fringes produced with

interference microscopes. The convergency of the light, which is determined by the numberical aperture of the

objective, results in the fringes being displaced from the

position for ideally collimated light at normal incidence. The analysis accounts fairly well for measurements of

step heights with microscopes of different numerical apertures by Tolmon and Wood. The correction due to obliq- uity is of the order of 10% and over a limited range of

step heights, a simple correction rule of a/4 per unit is satisfactory to about 2%, where a^sin"1 (n.a.) . The more

rigorous formula shows a nonlinear relation between

obliquity-correction and step-height. Obliquity Effects in Interferometry, C. F. BRUCE, Optica Acta v4 n4 Dec 1957 p 127-35. The present author and

Thornton have previously described the influence of oblique rays on the measurement of length by interferometry. On-center apertures were treated approximately.

This paper deals with a more exact treatment of the off- center cases for circular and rectangular apertures. The

treatment is adequate for all cases that may occur in practice and the expressions for on-center cases are quickly

derivable. The results show that approximate formulas

can give quite incorrect results at path difference and

obliquity values which still allow fringes to be observed when isotope light sources are used. Fringe displacement

curves are given to show the main characteristics of the

obliquity effects, and these have been confirmed experi- mentally. Correction Due to Aperture in Transmission Interference

Microscopes, E. INGELSTAM, L. P. JOHANSSON. J Sci Instrum v35 nl Jan 1958 p 15-17. The fringe spacing in transmission interference microscopes is shown to require a correction due to the oblique rays, with respect to the ordinary value valid for perpendicular rays. The spacing, and accordingly the measured path differences, are

smaller than the normal values (opposite to the case of

reflection microscopes) . Calculations are made for differ- ent values of condenser N.A and varied parameters, showing corrections up to —15%. The fringe intensities also decrease with the order of interference when it is low. Experiments confirm these findings. The effect is dis- cussed in relation to some general ideas of {x,y) -fidelity

and (s) -fidelity as obtained in a limited optical information channel. On the Improvement of the Precision of Microinterferometry. Investigations Concerning Interference Spherometry, R. LANDWEHR. Zeit InstrumKde v66 n7 Aug 1958 p 134-8 in German. A geometrical analytical examination

concerning the calculation of corrections in exact two- beam interferometry. The displacements arising both from the small angle of inclination between the sur- faces and also from the finite angles of the incident cone of light are computed. Tables of corrections are

given for numerical apertures up to 0.65. The application of these computations to the possibility of accurate

interference spherometry is discussed. Abhaengigkeit des Kontrastes der Fizeau-Streifen im

Michelson-Interferometer vom Durchmesser der Aperturblende, G. HANSEN, W. KINDER. Optik vl5 n9 Sept

1958 p 560-4. Dependence of contrast of Fizeau fringes in Michelson interferometer on diameter size of diaphragm

aperture ; computation of values for intensity and position

of maxima and minima of Fizeau fringes; contrast of Fizeau fringes disappears completely for first time, when

in Lummer-Haidinger system, phase difference between

center and rim of diaphragm just amounts to one complete

wavelength. Estimation of Two Causes of Error in the Photoelectric Observation of Interference Fringes at Infinity with a

Michelson Interferometer, J. TERRIEN. J Phys Radium

v20 n2-3 Feb-Max 1959 p 446-8 in Russian. In an earlier study the author assumed (1) perfect centering of the

receiving aperture on the ring center, and (2) uniform

illumination of this aperture in the absence of interfer- ence. The accuracy in centering and uniformity of illumi- nation required to justify these assumptions are here

estimated. To attain an accuracy of 0.001 of a fringe, the

error in centering must be less than 0.05 of the aperture diameter and the illumination must not fall by more than 12% from the center of the aperture to its rim. Some Remarks on the Question of Aperture Corrections in Interferometric Length Measurements, R. LANDWEHR.

J Opt Soc Am v49 n7 July 1959 p 733-4. A summary of the computations made in particular in connection with

the practical measurements of end standards. Some of the

calculations of Bruce are modified. Aperture corrections are shown graphically for the cases of ( 1 ) a circular hole

(2) a narrow slit (3) a square aperture. A Correction for the Dimensions of the Exit Diaphragm

in Photoelectric Recording of Equal-Inclination Interfer- ence Bands, TU. P. EFREMOV, YU. P. KANEVSKII.

Optika i Spektrosk v8 n2 Feb 1960 p 266-8 in Russian. Derives a correction for the dimensions of rectangular, square and slit-shaped exit diaphragms used in photoelectric recording of the order of equal-inclination interfer- ence bands. On the Order of Interference in Michelson Interferometers

in Case of Circular Light Sources Centered on the Optical

Axis, Z. ERDOKURTI and K. KANTOR. Optik (Ger- many) v20 n5 May 1963 p. 243-58. Changes in the order

of interference in Michelson-type interferometers have

been determined experimentally by a phase-detecting method in terms of source size, interferometer geometry and the spatial coordinates of the point of observation for the case of circular light sources centered on the optical

axis. The measured values of the order of interference are in good agreement with those predicted by the theory

of Bakas et al. (1961).

Visibility and Order of Interference in Michelson Inter- ferometers in the Case of Rectangular Light Sources Centered on the Optical Axis, Z. ERDOKURTI and K. KANTOR. Optik (Germany) v20 n6 June 1963 p 304-18. 51
The order of interference (phase) and the visibility of the interference produced in Michelson interferometers are determined for rectangular sources centered on the opti- cal axis. The measurements are performed in terms of the geometrical parameters of the light source and the inter- ferometer, as well as with respect to the coordinates of the point of observation. The calculated results are

listed, also separately grouped with respect to various parameters.

Visibility and Order of Interference in Michelson Inter- ferometers in the Case of Eccentric Light Sources, Z. ERDOKURTI and K. KANTOR. Optik (Germany) v20

n7 July 1963 p 325-32. The visibility and order of inter- ference in Michelson interferometers are determined for the case of eccentric light sources. The results readily obtained on the basis of the theory of partial coherence were also confirmed experimentally. 2.2.4. Refractive Index of Air

Measurements on the Refractive Index of Air for Wavelengths from 2218A to 9000A, W. F. MEGGERS, C. G. PETERS. NBS Sci Paper 32T Oct 31 1918 p 697-740 7

figs 59 refs. Discusses various methods of measurement

and gives summary of previous work. In this investigation a Fabry-Perot interferometer was used.. Observations were made from the infra-red light through the

visible spectrum and into the ultra-violet. Apparatus and experimental procedure are described. A total of 1165 index measurements for different wavelengths were made in dry air at temperatures at 0°, 15° and 30 °C. Dispersion equations are derived which are a sufficiently accurate representation of the observations. Variations in Refractive Index of C02-free Dry Air and

a Statistical Correlation with Solar Activity, L. W. TILTON, NBS. J Res NBS vl3 (RP 695) July 1934 p 111-24 2 figs 38 refs. All refractive-index data taken on

air since 1857 have been examined for evidences of sys- tematic variations, and a correlation between refractivity and annual sunspot number has been found. Standard Conditions for Precise Prism Refractometry,

L. W. TILTON. J Res NBS vl4 n4 Apr 1935 (RP766)

p 393-418. Air as standard reference medium for precise refractive-index measurements, discussed with respect

to precision necessary in control and measurement of its temperature, pressure, humidity, and carbon-dioxide content ; preparation of accurate correction tables for reduction of refractive-index observations to standard conditions of reference described and exemplified. Standards of Length. Optical Metrology. Refractive Index of Air. Eng vl42 Aug 21 1936 p 205-6. Phase loss of light reflected from surfaces differs appreciably among

apparently different surfaces. Method of measuring re- fractive index to 1 part in 10s is outlined. An accuracy

of 1 part in 10' has been attained in measuring 10 cm,

using Kr. Refractive Indices of Water Vapor and Carbon Dioxide

at Low Pressure, K. B. NEWBOUND. J Opt Soc Am

v 39 nlO Oct 1949 p 835-^0. Fabry-Perot interferometer used to obtain dispersion curves for water vapor and for carbon dioxide in wave length range 2500 to 8600A at pressures below 20 mm of Hg at 20 C ; results formulated

to permit computation of refractive index of air contain- ing these substances. Apparatus for Recording Fluctuations in the Refractive Index of the Atmosphere at 3.2 Centimeters Wave-length,

C. M. CRAIN. Rev Sci Instrum v21 May 1950 p 456-7. The equipment is a modification of that previously used

for measuring dielectric constants of gases. The fre- quency of each of 2 microwave oscillators is controlled by

the resonant frequency of its associated cavity resonator.

One cavity is sealed off and the other modified by drilling holes in one end plate, through which air is pulled. The Dispersion of Air between 2500A amd 6500A, H. BARRELL. J Opt Soc Am v41 n5 May 1951 p 295-9 9 refs. A new dispersion curve for air is derived from reasonably concordant refractivity data previously obtained in the

visible spectrum at three different laboratories. The Refractive Indices of Water Vapour, Air, Oxygen,

Nitrogen, Hydrogen, Deuterium and Helium, L. ESSEN.

Proc Phys Soc (London) B v66 Mar 1953 p 189-93. The

method described by Essen and Froome has been used to measure the refractive indices at 9200 Mc/s. The value

of (n—1)10" obtained for water vapour at 10 mm Hg

pressure at 20° C is 60.7 which is the same as the value

obtained at 24000 Mc/s, showing that the absorption line at 22 000 Mc/s, has a negligible effect on refractive index. The values obtained for air, O and N also agree with those

previously obtained within the limits of error and there- fore confirm the earlier results. The values of (n—1)10" obtained for H amd D are higher than those calculated by Ishiguro et al. by 2% and 3% respectively. The cal- culated values were expected to be a few per cent lower than the true values, and they are therefore supported by the experimental results. The Dispersion of Standard Air, B. EDLEN. J Opt Soc Am v43 n5 May 1953 p 339-44 2 figs 17 refs. By combining Barren's and Sears' measurements in the visible and

Koch's and Traub's in the ultraviolet, a dispersion for- mula for standard air has been derived. Index of Refraction of Air in the Infrared, D. H. RANK,

J. N. SHEARER. Letter in J Opt Soc Am v44 July 1954 p 575. New measurements are reported for the refractive index of air at about 1.5ju. These show that the formula due to Edlen predicts values of (/*— 1) too small by slightly more than one part in 1000 in the infrared

region of the spectrum beyond Measurement of the Index of Refraction of Air At 1.74/*, F. LEGAY. CR Acad Sci (Paris) v242 tn8 Feb 20 1956 p 1008-10 in French. A description is given of the de- termination of the refractive index of air which is dry and

free of COs at the wavelength 1.737/*, using a Twyman

interferometer. The interferometer was simultaneously il- luminated with a mercury lamp and a Nernst filament. The circular fringes were projected on to the slit of spec- trograph. The value found for the refractive index is (/*-l)Xl0e =273.13. Tables of Refractive Index for Standard Air and Rayleigh

Scattering Coefficient for Spectral Region Between 0.2 and

20.0 fi and Their Application at Atmospheric Optics, R. PENNDORF. J Opt Soc Am v47 n2 Feb 1957 p 176-82. Refractive index tabulated for range 0.2 to 20.0 fi; for computation of Rayleigh scattering, scattering cross sections, mass and volume scattering coefficients are tabulated for same values of wavelength as for refractive index; optical thickness and transmissivity of standard atmosphere given. Refractivity of Air in the Near Infrared, D. J. SCHLUETER, E. R. PECK. J Opt Soc Am v48 n5 May 1958 p 313-5. Measurements are reported for the refractive index of air

in the infrared up to 2 microns. These are both absolute and relative in nature, the latter being more precise. It is concluded that the measurements support the validity of Edlen's refractivity formula in this region. Measurements of the Dispersion of Air from 3651 to 15 300 Angstroms, D. H. RANK, G. D. SAKSENA, T. K. Mc- CUBBIN, JR. J Opt Soc Am v48 n7 July 1958 p 455-8. The difference between the index of refraction for green mercury light and for 7 other mercury emission wavelengths from 15 300 A to 3651 A was measured using a Twyman-Green interferometer as a refractometer. A

52
photoelectric method was used for the infrared determination. A method depending upon photography of interfer- ence fringes which were caused to appear crossing the

lines in the mercury spectrum was used for the visible and

ultraviolet measurements. The mean observed deviation

of the measurements of from the predictions of the Edlen formula was 1 part in 105

. Measurements of the Dispersion of Air for Wavelengths

from 2302 to 6907 A, K. F. SVENSSON. Arkiv Fys vl6

paper 35 1960 p 361-84. Measurements of the dispersion

of air have been carried out with a Jamin refractometer

within the wavelength region from 2302 to 6907 A. The

investigation has confirmed Edlen's formula for the dis- persion of standard air, as far as the relative values are concerned; the differences are everywhere less than ±2X10~8 and exceed ±1X10-8 only in a few cases. The

measurements have been made at different temperatures from 6 °C to 23 °C. According to the observations by

Meggers and Peters in 1918, the effect of the temperature

on the density factor of the refractivity would depend on

the wavelength. It has not been possible to confirm any

such dependence in the present investigation. In any case, a possible effect of this bind is less than one per cent of

the value that Meggers and Peters have stated. When the

air was dried with both silica gel and P2O5, the dispersion curve showed a steeper course than when the drying had

been done only with P206. This may be explained by

assuming that silica gel absorbs proportionately more

nitrogen than oxygen. If this is the case, it would also cause the refractivities for air dried with silica gel to be lower than for air of normal composition at the same

temperature and pressure. The reduction to standard

conditions of wavelengths measured in non-standard air

Is discussed, and tables to be used for this reduction are

given. Dispersion of Air in the Near-Infrared, E. R. PECK,

B. N. KHANNA. J Opt Soc Am v52 n4 Apr 1962 p 416-9. Methods of computation are described for determination

of the refractivity of air from measurements made with

a corner-reflector Michelson interferometer. Results are

given for eleven vacuum wavelengths from 703A to 20

587A. These results support Svensson's conclusion that

Edlen's dispersion formula may be increased in precision by raising it slightly in the near-infrared. They indicate however an increase of 0.12X10~8 X (3.35 a

"2—<?) over

Svensson's formula. The existence is discussed of appreciable variations, perhaps seasonal in nature, in the re- fractivity of out-door air. Investigation of the Invariance of Atmospheric DisperI sion with a Long-Path Refractometer, K. E. ERICKSON.

J Opt Soc Am v52 n6 July 1962 p 777-80. An investigation was made of the extent to which the relative refractivity of the atmosphere is invariant under changes in pressure and humidity. To achieve the necessary preci- sion a refractometer with double-passed chambers 14.3 m

long was designed for use in the photographic region. No fiducial line is employed. The relative refractivity of dry air was found to vary by less than 3X10"6 over the

region from 3890 to 6440 A for a change in pressure of % atm. The relative refractivity of water vapour at low

pressure in the region from 3610 to 6440 A was found to be 8H2O=0.961646+0.0086062 fc3 —0.00010547 fc

4 +0.00001312 k°, where fc is the vacuum wave-number in p~\ An Air Refractometer for Interference Length Metrology,

J. TERRIEN. Metrologia vl n3 July 1965 p 80-3 3 figs 6

refs. A refractometer for the measurement of the refractive index of the surrounding air is described, in which in- terference fringes are produced between two beams, one

propagated in air, the other in vacuum. The accuracy aimed at is one part in 10", corresponding to the accuracy

of the best vacuum wavelength standards used in the

length measurement of mechanical standards. The re- fractometer is placed with the comparator inside an air- tight isothermal enclosure and is operated from outside. 2.2.5. Phase Change at Reflection

See also Section 11 Ueber die Phasenanderung des Lichtes bei der Reflexion an Metallen ( Regarding the Phase Change of Light by the

Reflection on Metals), P. DRUDE. Ann der Phys und

Chemie 3 ser v50 nl2 1893 p 595-624, v51 1894 p 77-104

6 figs, Part I, experimental : A_ Phase change with reflec- tion at the boundary air-solid silver, the method : the meas- urement of the relative phase shifts, measurement of the

silver thickness, 'the results of observations. B : Phase

change with reflection at the boundary glass-solid silver

the method, the significance of thickness change of the

glass film, results of observations, comparison with the re- sults of other observers, an investigation of the surface

layers between the silver and glass. C : Phase change with

reflection at the boundary air-thin silver. D: Phase

change with reflection at the boundary glass-thin silver. Part II, theoretical : Derives general formulas for the in- tensity of the light reflected by two thin layers of any

media. Discusses results from various material combinations. Draws 6 conclusions, including : The Fresnel light

vector, with reflection by a solid silver layer in air, undergoes a phase acceleration of 0.412 wavelengths ; with re- flection in glass an acceleration of 0.365 wavelengths. The Neumann light vector in these two cases undergoes

a retardation of 0.088 and 0.135 wavelengths. Ueber normale und anomale Phasenanderung bei der Reflexion des Lichtes an Metallen (Regarding Normal and Anomalous Phase Changes with the Reflection of Light by

Metals), W. WERNICKE. Ann der Phys und Chemie 3

ser v51 n3 1894 p 448-59 6 figs. Questions Wiener's conclusion that phase change corresponds to a retardation and not an acceleration. Describes experiments from the , results of which he concludes: (1) That with a silver layer between two transparent media, of which the front one has the larger index of refraction, the phase change

produced is an acceleration which constantly increases from zero to about % to % wavelength as the thickness

of the silver increases from zero to opacity. (2) If the metal layer is not solidly hound to the front medium but

lies between thin layers of a foreign substance, the phase change is a retardation of about % to % of a wavelength. Such apparent phase change must be called anomalous.

(3) In undertaking measurements, if the applied metal

layer shows anomalous phase change it is unsuitable for the determination of optical constants. A thickness of foreign substance equal to the diameter of one or a few

molecules is sufficient to produce the appearance of anomalous phase change. P. DRUDE discusses Wernicke's work in v53 nl3 1894 p 841—4 and credits him for having

eliminated certain uncertainties. However he claims

priority for developing a better method for attaining knowledge of the properties of a 'body of molecular dimensions and for deriving the necessary equations. Zur Phasenanderung des Lichtes bei der Reflexion an

Metallen (Change of Phase through Metallic Reflection), H. KATH. Ann Phys Chem v62 1897 p 328-52. The ex- periments were made with absolutely pure metallic mirrors obtained by placing glass plates next kathodes of

silver or gold in a vacuunntube. An even deposit on the

glass was produced by the disintegration of the kathode in an atmosphere of hydrogen. It was found that the change

of phase is an acceleration in the case of silver and gold, amounting to 0 55X in the case of silver in air, and to about

0-25X in the case of gold in air. The acceleration is in- dependent of the incidence in the case of silver, but in the case of gold it increases to 0-5\ grazing incidence. For

platinum the acceleration is 0-39X. 53
Measurement of the Change of Phase at Reflection, A. PEROT. CR Acad Sci vl42 March 5 1906 p 566-8. Describes dispersion measurement of phase change. Variation de la Surface Optique Avec la Longeur D'Onde Dans la Reflexion sur les Couches MetaUiques Minces

(Variation of the Optical Surface with Wavelength in the

Reflection from Thin Metallic Coatings), C. FABRY, H. BUISSON. J Phys Ser 4 v7 1908 p 417-29. Introduction, methods and measuring accessories, results. Interferometer Method of Measuring the Phase Difference

at Metallic Reflection, H. P. WORAN. Phil Mag v43 Mar

1922 p 471-7. During the experiments on the use of a thin layer of transparent liquid floated on mercury acting as a parallel plate interferometer it was suspected that the difference in the conditions at which reflection takes

place at the two surfaces might be a disadvantage. When

a Lummer plate was silvered along one half in the direc- tion of the length the number of interference bands was

doubled due to phase difference introduced at metallic

reflection. From theory developed it is concluded that

this may be an accurate method for the determination of the phase difference introduced at metallic reflections. The Difference between the Mechanical and Optical Lengths of a Steel End-Gauge, F. H. ROLT, H. BARRELL.

Roy Soc Proc. vl22 Jan 1 1929 p 122-33. It is pointed out

that as the ends of such a gauge have sufficient polish to observe interference rings the optical length can be found by placing the gauge between the mirrors of a FabryPerot etalon. The factors which make this length dif- ferent from the geometrical and mechanically measured

lengths are discussed, and a method of arriving at the

differences by wringing a number of such gages together

is worked out. The experimental realization of this is described, and results for two neon radiations are given. For visible radiations longer than 0.55 n in wave-length

the difference (M —O) of the mechanical and optical lengths is found to be 0.27\+0.005ai where \ is expressed

in microns. The method of calculation of excess fractions by a method of least squares is appended. Standards of Length. Optical Metrology. Refractive In- dex of Air. Eng vl42 Aug 21 1936 p 205-6. Phase loss of light reflected from surfaces differs appreciably among

apparently different surfaces. Method of measuring re- fractive index to 1 part in 108 is outlined. An accuracy

of 1 part in 107 has been attained in measuring 10 cm,

using Kr. Graphical Method for the Rapid Determination of Phase

Changes Occurring on Reflection at Compound Plates, M. PERROT, P. COTTON. Ann Phys (Paris) Ser 11 v20 Nov-Dec 1945 p 585-600 in French. The phase changes

occurring on normal reflection of a light wave at the sur- faces of a layer separating two transparent media are

investigated theoretically. Based on the relations for the complex amplitudes for the reflected waves given by

Rouard, a simple graphical method is described which

permits the variation of the phase changes with thickness

of the layer to be determined rapidly. The dependence

of the phase changes on the optical interpretation is given

for several curious results obtained in experiments by Rouard on thin metallic films deposited on a transparent

support. Some Further Applications of Multiple Beam Interferomtry. I. Interferometric Method for Measuring Differential Polarization Phase Change at Metallic Reflection,

S. TOLANSKY. J Phys Radium vll July 1950 p 432-3. The differential phase change on reflection at a thin Ag

film is measured from the doubling of white light fringes

of equal chromatic order. Data are given for Ag using

\5461 A with a film thickness of 350 A over an angle of incidence 0-70°. The observations closely fit the values

calculated from classical electromagnetic theory. The

precision of measurement exceeds that reported earlier

(Tolansky, Phil Mag 35 149 1944) using Fizeau fringes. Even for a film thickness of 350 A the multiple beams

lead to very sharp fringes. Differential Phase Change at Reflexion, P. M. AITCHISON. Letter in Nature (London) vl66 Sept 23 1950 p

522—3. Phase change effects are measured on polished and etched glass surfaces which have been silvered, using

the multiple-beam interference technique. By measuring

steps with light of two different wavelengths the differential phase change can be derived. For etched steps on

glass a value of 14° is found. This is attributed to sur- face roughness. Some Optical Properties of Evaporated Layers of Silver, Copper and Tin. D. G. AVERY. Phil Mag v41 Oct 1950 p 1018-3. In earlier work by Tolansky a description was

given of the use of multiple-beam interferometry to deter- mine relative phase changes on reflection at the silvered surfaces of an interferometer. This method has been ex- tended and critically examined. It is shown that the method does not approach the accuracy of the older polari- metric methods, and that its optimum use is restricted to reflecting surfaces of fairly high reflection coefficient. Within its limitations the method has advantages. Meas- urements of the relative phase changes on reflection at a number of layers of Ag, Cu and Sn have been made,

together with measurements of the ellipticity of the light reflected at these layers. The variation of these quantities with the thickness of some layers of Ag has been dis- cussed in relation to the use of evaporated layers for the measurement of the optical constants of bulk materials, and the optical constants of evaporated layers of Cu and

Sn have been determined and the results discussed. The Dependence on Angle of Incidence of the Variation of Phase Change on Reflection at Silver, G. DORNENBURG,

R. FLEISCHMANN. Zeit Phys vl29 n3 1951 p 300-6 in German. The phase displacements are measured with a Jamin interferometer for the reflections glass-silver and

air-silver over a wide angular range. The two beams are brought to equal intensity by polarization methods. The

phase change is separately determined for the two direc- tions of polarization. Some variation is found in differ- ent samples and this is attributed to surface films whose

thickness and optical properties are evaluated by the method of Drude. The Effect of Phase Changes in White Light Interferometry, L. G. SCHULZ. J Opt Soc Am v41 Apr 1951 p 261-4. The phase change accompanying the reflection of white

light from metal films was studied experimentally by

interferometric methods. As predicted by electromagnetic theory, the phase change was found to vary with

the wavelength of light. Corrections for this variation must be made in white light multiple-beam interferometry

if the full sensitivity of the method is to be used in making

thickness measurements. Practical suggestions are given

for making the required corrections. It is demonstrated

experimentally and theoretically that these corrections are practically independent of the film thickness. Precise measurements of phase changes on Ag films gave results

closely consistent with those calculated from published

values of the optical constants of Ag. No such agree- ment was found for Al. The Correction for Dispersion of Phase Change in FabryPerot Interferometers, H. BARRELL, P. TEASDALEBUCKELL. Proc Phys Soc London B v64 May 1951 p

413-8. A technique based on well-known interferometric procedures is described for determining the corrections

for phase-change dispersion at reflection in Fabry-Perot

interferometers. Results obtained during precise deter- minations of mercury-198 wavelengths are quoted to il- lustrate its application. A marked difference is found between the dispersion corrections for the silvered and

aluminized mirrors actually used, and it is established 54
that the latter have negligible corrections in the region

4 047 to 6 438.A. Multiple-Beam Fringes of Equal Chromatic Order. I. Phase-Change Considerations, W. F. KOEHLER. J Opt

Soc Am v43 Sept 1953 p 738-^3. An equation of the form nX=2f+f\ is necessary to represent multiple-beam fringes

of equal chromatic order. Experimental values of f are

reported for several silver coatings of various reflectivities and ages in the working range. The experimental values

of f for new coatings are independent of \ in the range

4500 A to 6300 A. The experimental values of / for aged

coatings with reflectivities greater than 60% agree reasonably well with a value estimated from the known optical constants of bulk silver. The systematic error inherent in the result of determining a thickness or a change in thick- ness when using the elementary equation n\=2t is of the

order of 1% in the working range of age, reflectivity, and

order of interference. Some Problems Arising From the Use of Interference for the Precise Measurement of Plane-Ended Gauge Blocks. The Studv of Fringes From an Air Wedge, J. TERRIEN.

J Phys Radium vl5 Apr 1954 p 6S-8S in French. Tbe

length of steel gauge blocks can be found by comparison

of the two fringe systems formed by interference between beams reflected from a reference glass surface, the upper

gauge block surface and the surface plate on which the

block is resting. For large gauge blocks, an error arises from the different character of the two sets of fringes, that from the upper surface arising from multiple reflec- tions. The error is calculated and a method of measuring

it is suggested. Remarks on the Function of the Multiple-Beam Inter- ferometer Used for the Detection and the Measurement of Small Differences in Phase, G. NOMARSKI. J Phys Radium vl5 June 1954 p S 26-S 30 in French. A theoretical analysis of the optimum conditions for best contrast when using the Fabry-Perot interferometer as an

instrument for the detection of small phase differences. The paper discusses both application to large objects and

to objects of very small lateral dimensions. A new ex- pression is derived for the resultant amplitude for inter- ference from the infinite series of diffracted waves. Attention is drawn to the modulating effect at infinity on the

diffracted light A new experimental set-up is proposed. The Question of Phase Relationships at the Boundary of

Dielectric and Metal, I. N. SHKLTAREVSKII. Zh teckh

Fiz v26 n2 1956 p 333-42 in Russian. It is alleged that in the majority of published work false values are given for the magnitude and sign of the phase angle of reflection and

transmission coefficients at inter-faces. Correct values are

given. Measurements are made of the dispersion in the phase jump on reflection between air and silver. A cal- culation is made of the dispersion in the same quantity

for a thin sheet. A new method is described for an inter- ferometric method of determining the optical constants of a metal. Phase Shift Effects in Fringes of Equal Chromatic Order,

C. J. KOESTER. J Opt Soc Am v48 n4 Apr 1958 p 255-60. For the calculation of step heights or interferometer plate displacement three methods of analysis are discussed. A

comprehensive expression is derived which requires knowledge of the phase shift of reflection. A simple expression, 2Af=\iAX/(\<j—Xi), is shown to be exact under certain

conditions. Here At is the step height, AX the fringe shift, and X0 , Xi are the wavelengths of adjacent fringes, X0 >Xi. A method is introduced which does not require prior knowledge of the phase-shift dispersion. For one set of fringes an arbitrary integer, N, is selected and the function tN(\) is found by plotting N\0 v. X0, (N+l) Xi v. \i, etc. For the set of shifted fringes the function tN(\) is found

similarly by plotting N\o' v. V, etc. where the fringe at

X0

' has the same order number as that at X0 . It is shown

that the vertical displacement between the two curves is a constant equal to twice the step height. Other uses of the tau function are described. If the tau function is linear with wavelength, the simple expression above can

be used without error. Developments in the Comparison of Lengths Using Fringes

of Superposition in White Light, A. H. COOK, H. M. RICHARDSON. Proc Phys Soc v73 pt4 Apr 1959 p 661-

70. When two Fabry-Perot etalons are placed one in front

of the other, and the length of one is a small multiple of that of the other, fringes are seen in white light and have

been used in the past to compare the lengths of etalons. In the study reported in this paper, these fringes have

been observed photoelectrically while the optical length

of one etalon is varied by changing the pressure of the air inside it. It is shown that the variation of intensity with

path difference is the sum of two Fourier integrals involv- ing an intensity function and the phase shifts at the re- flecting surfaces. By forming cosine and sine Fourier transforms these quantities can be obtained separately and a correction applied for the error introduced into the comparison of lengths by the change of the phase shifts with wavelengths. It is shown that phase shifts can be measured more accurately by this method than by other

interferometric means. It is possible to compare a metre

length with a 20 cm length to about 1 in 10s

. Effect of Surface Roughness on the Phase Change at Reflection in Interferometers, B. S. THORNTION. J Opt

Soc Am v49 n5 May 1959 p 476-9. The effect of the phase change of light due to surface roughness on the precision measurement of length by interferometry is an important

practical problem upon which only little work seems to have been done. This paper investigates the effect from a

theoretical and experimental standpoint and shows that

the phase loss due to surface roughness is a function of wavelength as well as a function of amplitude and wave- form of the roughness. Phase Shift Effects in Fabry-Perot Interferometry, O. J. KOESTER. J. Res NBS v64A n3 May-June 1960 p 191-200

8 figs 37 refs. A method is demonstrated for utilizing in Fabry-Perot interferometry the data on reflection phase

shift dispersion obtained from fringes of equal chromatic

order. Unknown wavelengths can be calculated from the Fabry-Perot patterns obtained with a large etalon spacing, even without prior knowledge of the phase shift of the

reflecting surfaces. When the theoretical phase shift as a function of wavelength is known approximately, then the

correct orders of interference can be determined for both

the Fabry-Perot fringes and fringes of equal chromatic

order. From the wavelengths of the latter the phase shift dispersion can be measured to an accuracy of about 10A. The method is especially useful for reflectors with large dispersion of phase shift, such as multilayers. Results in the visible spectrum are reported for aluminum films and

a pair of dielectric 15-layer broadband reflectors. Phase Dispersion in Interferometry, P. E. CIDDOR.

Optica Acta (Int) v7 n4 Oct 1960 p 399-403. It is shown

that the interference equation for interferometers exhibit- ing phase-change effects should take the form M\—2d—

\v/ir, where v is (/3— jt) and /3 is the phase-change at re- flection for one reflecting surface. Several recent treat- ments of the phase-change on reflection are critically examined and it is shown that the phase-dispersion de- duced from them is inconsistent with generally accepted experimental results for interferometers with silver films. Experimental Determination of Phase Change at Reflec- tion From Glass-Metallic Layer Interface Using a Kosters

Interference Comparator, N. BARAKAT, S. MOKHTAR.

J Opt Soc Am v53 nlO Oct 1963 p 1153-5. Opaque films of 55
copper and indium have been evaporated on a glass substrate, and tbe phase shift at reflection from the glass- metal interface has been determined both with white light and monochromatic fringes. Helium and krypton spectral

lines with a Rosters interference comparator were used. Comparison is made between experimental results and

theoretical calculations based on the electromagnetic theory for opaque copper films.

Determination of Absolute Phase Change on Reflection

at Chromium Films, G. HENDERSON, C. WEAVER

Opt Soc Am v54 n8 Aug 1964 p 1052-6. Determination

of absolute phase change at chromium film-air interface

for thickness up to 400 A at 5461 A wavelength ; comparative measurements show Weaver-Hill-MacLeod method is as valid as well tried method of Rouard, although for films thinner than 100 A Rouard method is more suitable.

2.3. Wavelength Standards and Light Sources

See also Subsection 1.2.2.

2.3.1. General

Wave Length of Sodium as a Standard of Length, A. A. MICHELSON, E. W. MORLEY. J Assn Eng Soc May

1888. Read before the Civil Engineers Club of Cleveland. Gives a method for making the wavelength of sodium light the actual and practical standard of length. Les Methodes Interferentielles en Metrologie et l'esta- blissement d'une Longueur d'Onde Comme Unite Absolue

de Longueur ( Interferometry methods in metrology and

the establishment of a wavelength as the absolute unit of length), A. A. MICHELSON. J de Phys v3 m3 1894 p 5-

22. Sur les Sources de Lumiere Monochromatiques (Sources

of Monochromatic Light), C. FABRY, A. PEROT. J de Phys 3rd ser v9 July 1900 p 369-82. A series of de- scriptions of the various methods used by the authors for obtaining monochromatic lights of varying degrees of

purity. The mos't useful eases were : (1) Simplification of white light by analysis of spectrum ; (2) emission spectrum

of a gas; (3) flames; (4) gases electrically excited by

various sources of power ; (5) electric spark ; (6) electric arc in air ; (7) electric arc in vacuo. The final choice was

fixed on a mercury arc in vacuo, using the green line

chiefly, the other radiations being suppressed by inter- polated solutions of quinine, eosine, etc. Light Waves and Their Uses, A. A. MICHELSON. Univ

of Chicago Press 1903. Republished as PSS 514, Phoenix

Science Series, Univ of Chicago Press, 1962. Contains a chapter on light waves as standards of length. Die Anwendung der Interferenzen in der Spektroskopie und Metrologie. (The Application of Interference in Spectroscopy and Metrology), E. GEHRKE. Published by F. VIEWEG und SOHN, Braunschweig, 1906. Contents

General introduction; production and theory of a few

chosen interference phenonema ; spectral apparatus ; selec- tion of results of the spectroscopic research regarding the mechanism of light ; application of interference to physical measurements in metrology. Bibliography. Some Measurements of Wave Lengths with a Modified Apparatus, LORD RAYLEIGH. Phil Mag ser 6 May 11 1906 p 685-703. Measurements on Cd, Hg, He, Zn, Na. Mesures de Longueurs D'Onde pour l'Etablissement d'un Systeme de Repreres Spectroscopiques (Measurements of Wavelengths for the establishment of a System of Spectroscopic Spectrum lines), H. BUISSON, C. FABRY. J Phys Ser 4 v7 1908 p 169-95. Introduction, sources of

light, methods, description of apparatus, manipulation, measurements, corrections, results. Width of Spectrum Lines and Interference Fringes with Large Path-Difference, C. FABRY, H. BUISSON. CR

Acad Sci vl54 May 6 1912 p 1224-7 ; J de Phys v2 Sec 5 June 1912 p 442-64. Formulas for width of line and number of the order corresponding to the limit of visibility of the fringes ; order number for He, Ne, and Kr.

Nouvelle Determination du Rapport des Longueurs, d'Onde Fondemeintales avec L'Unite Metrique (New

Determination of the Relation of the Fundamental Wave

Lengths to the Metric Unit), J. R. BENOIT, C. FABRY,

A. PEROT. Trav et Mem du BIPM vl5 1913 280 p 23

figs. Part 1, Interference phenomena with silver films: production and properties of fringes of silver films in monochromatic light; theory of coincidences; influence

of dispersion phenomena ; phenomena produced by superposition of films ; influence of variations in the refractive index of air. Part 2, Methods and apparatus ; construction and study of the measuring standard; interferential standards ; cadmium light source. Part 3, Organization,

execution, and calculation of the experiments. Part 4, Results and conclusions. Detailed observations. Sur les Etalons de Longueur d'Onde (Wavelength Standards), C. FABRY, H. BUISSON. J Phys Ser 3 v5 Aug

1913 p 613-22. The exactitude of secondary international standards is first discussed. It is seen that many re- searches lead to the conclusion that the values given by

interference methods are perfectly correct and identical with those found by means of a grating. The paper then

deals in succession with (1) The progress of measure- ments of secondary standards. (2) Variability of wave

lengths. (3) Tertiary standards of wave length. (4) The utility of having more numerous secondary standards measured by interference methods. Limit of Interference in the Fabry-Perot Interferometer, M. N. SAHA. Phys Rev vlO Dec 1917 p 782-6. The

theory of the Fabry-Perot interferometer has been worked

out by Lippich, Rayleigh, and Schonrock. They have shown that when the pressure is small, the critical dis- tance D, or the limit of interference, is connected by the following formula with the wave length \ of the light, the temperature T of the tube, and the mass M of the emission centers

Paper develops an exact value for A which is 1.50x10". Interference Measurements in the Spectra of Argon, Krypton, and Xenon, W. F. MEGGERS. Sci Papers NBS

ii414 Aug 1 1921 p 193-202. Gives values of 50 wave

lengths in spectrum of argon, krypton and xenon, all of which have been compared with wave length of red radiation from cadmium which is international primary

standard. Measurement of Meter in Wavelengths of Light, C. F. SMITH. Machy (London) v28 1926 p 53. Determination of the Yard in Wave-Lengths of Light, A. E. H. TUTTON. Roy Soc Phil Trans v230 Sept 1931 p 293-322. The British Imperial Standard Yard has been

evaluated in wave-lengths of the red hydrogen line Ha,

the yellow line of Nec , and the red line of cadmium Cdr . The author's interferential method was used employing

Grayson-ruling fiducial marks of only half-wave-length

thickness, the author's interferometer, and the Tutton 56
comparator. Results obtained are tabulated and possible

errors discussed. Determination of tbe Relationship between Wavelength

of Light and the Fundamental Standards of Length, J. E. SEARS, Jr., H. BARRELL. Roy Soc Phil Trans v231

Sept 16 1932 p 75-145. Apparatus and methods developed

at the NPL for the establishment of suitable means of

realizing a wave-length standard of length and for deter- mining tbe imperial standard yard and standard meter in terms of it Measurements cam be made either in air under controlled conditions or in vacuum.

Interference Measurements in tbe Spectra of Noble Gases, W. F. MEGGERS, C. J. HUMPHREYS. J Res NBS vl3

Sept 1934 p 293-309 81 refs. Values are given for 3 lines of He, 172 of Ne, 87 of A, 55 of Kr, and 130 of Xe. Many

of the lines have been found to be reproducible to 8 fig- ures and are regarded as highly satisfactory standards

in spite of objections on account of isotopic hyperfine

structure. The Primary Standard of Wavelength, W. F. MEGGERS,

NBS. Rev Mod Phys vl4 Apr-July 1942 p 59-63 19 refs. Discusses various spectrum lines and hyperfine structure

originating in the isotopic constitution of certain chemical

elements. A Method of Cooling Hydrogen Discharge Tubes, H. CHAO-WANG. Rev Sci Instrum vl4 Aug 1943 p 250-3. Experiments are described on cooling by means of rapidly evaporated liquid air. The temperatures were measured

witb a calibrated Cu constantan thermocouple. Special apparatus was constructed to determine the f.p. of the substances used for calibration. Cooling of the light source to 56 °K. is obtained at low cost. Use of the Fabry-Perot Interferometer for the Study of Feeble Satellites. C. DUFOUR. Rev Opt (Theor Instrum)

v24 Jan-Mar 1946 p 11-8 in French. Heavily silvered mirrors are best. Low luminosity due to reflection at the

first surface is overcome by having a clear space for entry. The methods of use, and the advantages obtained, are dis- cussed at length. Attention is also given to the use of long tube "end-on" sources. Direct Determination of Wave-Lengths from Fabry-Perot

Interferometer Patterns, G. R. HARRISON. J Opt Soc Am v36 nil Nov 1946 p 644-54. Data on measuring and

computing engine which determines wavelengths and wave

numbers directly from spectrograms made by crossing

dispersion of Fabry-Perot interferometer witb tbat of concave diffraction grating; wavelength of spectrum line

is determined to six figures from grating dispersion by

automatic comparator, and is then converted to wave

number by mechanical continuous-function computing

arrangement. Bibliography. Relations Entre les Etalons de Longueur Fondamentaux

et les Longueurs d'Ondes Lumineuses. (Relations be- tween Fundamental Length Standards and Wavelengths

of Light), H. BARRELL, NPL. Rev de MStrologie v25

ser 2e n7 Feb 1947 p 33-44 7 figs 12 refs. Recording Interferometer for Precision Wave-Length Determinations, W. R. SITTNER, E. R. PECK. J Opt Soc Am v39 n7 July 1949 p 544-6. Precise measurement of angle by means of interferometric measurement of chord

length ; application to problem of precise wavelength de- terminations ; possibilities for measurement of rotation of linear displacement as small as one microinch. Use of the Fabry-Perot Etalon for the Wavelength Cali- bration of Monochromators, F. DESVIGNES. CR Acad

Sci Paris v229 Nov 15 1949 p 1001-3 in French. Tbe

author considers the conditions required for accurate

calibration by "Edser-Butler" fringes and gives expressions for the fringe width (SX), fringe separation (AX), etalon transmission, and wavelength error («) due to vari- ation of detector-response witb wavelength, as functions

of etalon thickness (e) and plate reflection (r). A flint prism monochromator is calibrated up to X=2/i using an

etalon with e=18-2p. and r=0-7; the receiver response

varied by a factor of not more than 3 from one fringe max.

to the next, giving e<0-18AX-SX/AX was equal to 0-057. The calibration obtained agreed with direct measurement

of Hg and K lines to the experimental error of about lm/i. Electric Discharge Laboratory Lamps, N. L. HARRIS.

Engr vl89 n4906 Feb 3 1950 p 143-6 9 figs. Details of range of Osrain laboratory lamps; thallium vapor lamp

and its application to the interference microscope; other

types of discharge tube; continuous ultraviolet spectrum

used in absorption spectroscopy. Light as Standard of Length. Light and Ligbting v43 n7

July 1950 p 255-7 2 figs. How wavelength of light can be used as basis of specifications for standard of length ; unit

of length is now maintained by bar of platinum iridium of

special cross section ; disadvantage is that it cannot be reproduced from specification; standard based on use of monochromatic light ; use of more precisely defined radiation for mercury isotope. A Note on an Automatic Control for Maintaining Constant

Intensity of a Light Source, K. C. WIGHT. J Sci Instrum

v28 Sept 1951 p 276-7. An electronic arrangement for automatically maintaining constant intensity of a light source using a tungsten filament lamp is described, in which normal electrical components are used. Curves show the stability over a period of some hours and the

effect of mains voltage variation. The regulation of in- tensity for the latter, on a percentage basis, is about 150

to 1. Calibrating Wavelengths in Region From 0.6 to 2.6 Microns, N. ACQUISTA, E. K. PLYLER. J Res NBS v49 nl July 1952 (RP2338) p 13-6. Wavelength of 20 absorption bands measured on grating spectrometer, several emission lines of krypton also measured in near infrared

region ; purpose was to make available additional calibra- tion points for prism instruments. Light Waves, Radio Waves Measure to Millionths, D. E. BROOKS. Can Machy v65 nl Jan 1954 p 108-9, 174. Recent improvements in sources of monochromatic light permit lengths up to 0.5 yd and 0.5 m to be measured with

accuracy corresponding to one millionth of inch in 10 in.

method to be of greatest value in measuring of reference end gages ; possibility of reaching international agreement

on specified wavelength to be used as ultimate standard of

length. Light Waves and Length Standards, I. 0. GARDNER.

J Opt Soc Am v45 n9 Sept 1955 p 685-90. A brief history

of earlier standards of length and of the standards now

in use is given. The plan to substitute a wavelength of

light for the present international platinum-iridium pro- totype metre as a standard of length is now under con- sideration by the appropriate international committees. The advantages of the proposed plan, the different isotope sources of monochromatic radiation that have been sug- gested by different countries, and the present status of the proposed change are presented. Wavelength Data and Correction Tables for Length Inter- ferometry, C. F. BRUCE. Australia. Commonwealth Sci & Indus Res Organization-Tech Paper n8 1956 87 p. Sets

of tables compiled for use in length interferometry ; in- cluded are all relevant data on wavelengths, refractive

indices, and correction factors ; to facilitate reduction of

results, additional tables are given of vapor pressures and

of wavelength fractions with metric and inch equivalents. 57
Fine Measurements, J. R. ADAMS. J Sci Instruni v33 nlO

Oct 1956 p 369-75. The limitations of the existing legal standards of linear measure are considered. The use of

light waves as a universal reference of linear measure

depends on the availability of a source of truly monochromatic light and considerable progress has been made using

the isotope Hg"8

. Many aspects of engineering require measurements accurate to a few micro-inches and instru- ments capable of meeting such demands have been de- signed. Several typical instruments, together with details of the principles on which they are based, are briefly reviewed. Koesters-Type Interferometer, C. F. BRUCE. J Sci Instrum v33 nl2 Dec 1956 p 478-82. Design and perform- ance of instrument which measures lengths of up to 500 mm directly by interferometry ; isotopic light sources are necessary for measurement of longer lengths, and -sources containing mercury 198 and krypton 86, as well as natural krypton and cadmium, have been used; results of some

length and relative wavelength measurements given to illustrate performance of instrument in air and in vacuo. Broadening and Shift of Spectral Lines Due to the Pres- ence of Foreign Gases, S. CH'EN, M. TAKEO. Rev Mod

Phys v29 nl Jan 1957 p 20-73. This comprehensive review

is intended as a sequel to that of Margenau and Watson

(1936-7) and deals with pressure-induced broadening and

shifts of atomic and molecular lines in the ultraviolet,

visible, infrared and microwave regions by neutral particles. The effects of electron and ion collisions and high temperature broadening are not treated. The following

topics are discussed : ( A ) Causes producing broadening and shift of spectral lines; (B) Impact theory; (O) Statistical theory ; ( D ) Theory at general pressures ; ( E

)

Fine structure pressure broadening of atomic lines. Experimental Observations : (A) Pressure shift and broadening of atomic lines; (B) The fine structure and pressure

effect ; ( C ) Narrow diffuse bands of various metals pro- duced by close encounters with foreign particles; (D)

Pressure boardening of molecular bands in the infrared

region; (E) Pressure broadening of lines in the micro- wave region. Line Shape, R. G. BREENE, Jr. Rev Mod Phys v29 nl Jan 1957 p 94-143. This review discusses the development

of the theory of line shape and broadening since Michelson's original contributions to the subject in 1895. The

topics reviewed are : ( i ) Early line broadening theory ; (ii) Stark broadening ; (iii) Statistical broadening ; (iv) Interruption broadening; (v) Resonance broadening;

(vi) Molecular broadening. Secondary and Tertiary Interferometric Wavelength

Standards, in 1.5-2.5 Region, D. H. RANK, A. H. GUENTHER, J. N. SHEARER, T. A. WIGGINS. J Opt Soc Am

v47 n2 Feb 1957 p 144-8. Results of measurement of wavelengths of three absorption lines relative to Hg 198 green

line are; P (1), 002-000 band of HCN, 15,345.2887 A in vacuum; R (15), 01 '1-000 band of HCN, 24.700.065 A in vacuum ; R (18) , 2-0 band of CO, 23,150.023 A in vacuum

29 lines of 002-000 band of HCN have been measured rela- tive to P (1). Coherent Emission Light Source, R. B. GRIFFITHS, R. H. DICKE, Rev Sci Instrum v28 n8 Aug 1957 p 646-8. Sharp,

intense emission line may be obtained by use of resonance

radiation coherently scattered from collimated beam of atoms ; coherently scattered light may be separated from

exciting radiation by placing atomic beam in one arm of Mach-Zehnder interferometer or by diffraction from sev- eral parallel atomic beam pencils ; technique was tested by

observing hyperfine structure in light coherently scattered from beam of sodium atoms. The Possibility of Using Absorption Lines as a Primary

Length Standard, W. G. FASTIE. J Phys Radium vl9 n3 Mar 1958 p 405-8 in French. It is possible to establish

conditions of pressure and temperature in an absorbing

gas so that its absorption lines are invariant in wavelength, whereas emission lines are subject to wavelength

shifts dependent upon the condition of excitation. Experimental limitations have, however, restricted work on

the primary length standard to emission lines. The de- velopment of techniques is described which make it possible to achieve comparable measurement accuracy with

absorption lines of I2 vapour at a pressure of 2 /i and at a temperature of 250° K. A Hg 198 source was viewed

along a variable magnetic field. A quarter wave plate in combination with a polaroid sheet isolated one of the Hg

5461 components which illuminated a long path FabryPerot interferometer-monochromator which was scanned

by variation of air pressure. When the L absorption tube was placed in the light path, the magnetic field could be

adjusted until one of several L absorption lines overlapped

the Hg line. The shape of the absorption line was measured photoelectrically by scanning the interferometer. Likewise photographs of the Fabry-Perot patterns in ab- sorption were obtained. The half width of the two lines which have been carefully studied was found to be 0.030 wave numbers, about 2.5 times the theoretical Doppler

width, presumably due to the nuclear spin effect of I

137

. In spite of the width of the lines, their absolute invariance

in wavelength makes them appear to be at least comparable to presently proposed emission line standards. However, the presence of the nuclear spin effect precludes the

possibility of narrowing the lines by molecular beam

techniques. Fabry-Perot Fringes in White Light Used as Wavelength

Standards, F. S. TOMKINS, M. FRED. J Phys Radium

vl9 n3 Mar 1958 p 409-14 in French. The term analysis

of the complex rare earth and heavy element spectra re- quires highly accurate descriptions of these spectra in. order to avoid the masking of real regularities with spuri- ous ones, and wavelength accuracy approaching that ob- tainable interferometrically is desirable. Such accuracy can be obtained by photographing white light interference

fringes as wavelength markers instead of the iron arc or

other conventional standards, without the loss of light attendant on the usual methods of interferometry. The

white light fringes provide equally spaced standards of uniform intensity and sharpness, whose wavelength values can be easily calibrated by comparison with a source such

as Hg 188

, thus avoiding the deficiencies of the iron lines with respect to accuracy, sharpness, and number. The

spacing between fringes is determined by the etalon thick- ness and can be chosen at will. The wavelengths are determined as in the conventional method using a FabryPerot interferometer, by measuring the fractional order

of the unknown by interpolation between neighbouring

fringes, and the whole order number either by counting

fringes from a known line or by calculation from the known etalon thickness if the wavelength is already known to approximately 0.1 A. In either case the inter- polation distances actually measured are quite small and

errors due to emulsion shrinkage or errors in the focal surface of the plateholder are minimized. Wavelengths

accurate to ±0.0003 A can be obtained using this system

in the 5th order of the Argonne 30 ft. spectrograph, and

typical measurements are shown. Some applications of the method to the calibration of the spectrograph are

discussed. Interferometric Calibration of Quartz End Standards, E. ENGELHARD. Zeit Instrumkde v67 n3 Mar 1959 p 59-65

in German. See abstract under 2.3.3. Accuracy of Lightwave Scales in Interferometry, E. ENGELHARD, PTB. NPL Symposium nil 1959, Inter- ferometry. H. M. Stationery Office, London 1960 (Paper

2-1) p 19-47 22 figs 14 refs. Describes investigations dealing with linearity of visible radiation sources. Light- wave scales often have periodic or progressive errors caused by deficiencies depending on spectroscopical con- ceptions such as line width, line asymmetry, line struc- 58
rure, and line shift. Paper illustrates certain errors by some earlier, mostly unpublished measurements as well

as by some recent observations made with different kinds

of commercial cadmium lamps and with the Kryptonisotope lamp developed at the PTB. An addendum presents line profiles of various Cd and Kr lines and the pres- sure shift of the Kr 6056A line. Discussion. On the Accuracy of Wavelength Comparison, K. M. BAIRD, NEC Canada. NPL Symposium nil, 1959, In- rerferometry. H. M. Stationery Office, London. 1960 (Paper 2-2) p 49-66 2 figs 10 refs. Declares that an uncertainty of the order of ±0.00021 to ±0.0003A must be

ascribed to determinations of wavelength' values up to

the present, but that as far as the sources themselves are concerned agreement in the fifth decimal place should be

possible. Discusses pointing on interference fringes and maximum attainable precision of setting. Concludes that with refinement of techniques now being developed something approaching the limit imposed by quantum effects will be reached.

Spectral Lines of Narrow Breadth, M. BOTTEMA. Nederlands Tijdschrift voor Natuurkunde (Netherlands) v26

n6 June 1960 p 188-91 in Dutch. A survey of recent work

on the production of fine spectral lines using discharge lamps containing pure isotopes. Particular mention is made of the work at the National Bureau of Standards and that of Gardner and Nefflen. The least breadth

quoted (the breadth at half the height) is 0.003 cm-1 found

for Ca* by an atomic beam method and for Hg188 by the use of a spherical interference filter. Grating Diffraction Spectra as Coherent Light Sources for Two- or Three-Beam Interferometry, A. LOHMANN.

Optica Acta (Int) v9 nl Jan 1962 p 1-12. It is common

practice in two-oeam and three-beam interferometry to obtain coherent light sources by using slits in a coherent

field (division of wave-front) or by means of suitable mirror devices (division of amplitude). The purpose of

this paper is to show that better coherence properties may

be realized if one uses grating diffraction spectra as co- herent light sources. As a result one may use a source

larger than that permissible in a conventional slit-inter- ference set-up and thereby gain in photometric efficiency. Further, it is shown that the fringes with slit interference

are, in general, inhomogeneously distributed in space. The proposed method of interference between the disturb- ances from the different grating spectra does not suffer from these disadvantages. Also one gets achromatic

fringes, and hence the grating interference technique is ideally suited for interferometry in the ultraviolet or in- frared region of the spectrum. The physical reason for

the achromatism of the fringes is easy to understand, if one considers the fringes as images of the grating pro- duced by lenses which have no chromatic aberrations.

Finally, other interferometric devices are also discussed

in terms of coherence. Limiting Precision in Scanning Optical Interferometer,

R. M. HILL, C. F. BRUCE. Austral J Phys vlo n2 June

1962 p 194-222. Interferometer uses photoelectric detection and it is shown that principal noise sources limiting accuracy of detection are shot noise in vacuum photocell and photon noise from light source; from limiting precision of pointing on fringe, limiting precisions of meas- urement of small wavelength shifts and of measurement of wavelengths have been calculated. A Thallium Beam Frequency Standard, J. BONANOMI.

IRE Trans Lustrum (USA) v 1-11 rx3-A Dec 1962 p 212-5. Following a proposal by Kusch, a thallium atomic beam

frequency standard was constructed and put into operation. The main characteristic is that its frequency of 21

310 Mc/s is only very weakly affected by inhomogeneities

of the C-field. The construction, which is similar to con- ventional caesium standards, differs from these in the following main points: a high (1000° K) oven temperature, high (14000 G) A- and B-fields, an oxidized tungsten fila- ment detector. The interaction length is 90 cm ; the Q

factor of the resonance is 160 million. The measurements show that the uncertainty in the Zeeman-shift is negligible, while the error arising from an unsymmetrical cavity

is the same as in the case of caesium. Vacuum Wavelength of Kr86 Hg198 and Cdut

. K. M. BAIRD, D. S. SMITH, K. H. HART. J Opt Soc Am v53 n6 June 1963 p 717-20. Vacuum-wavelengths values are

given for a number of visible lines, emitted by Kr6a

, Hg168

, and Cd"4

, which are useful spectroscopic and metrological standards. The wavelengths are based on a number of Fabry-Perot interferometer measurements during the past few years : some of the values have also been confirmed by

independent measurements on Michelson interferometers. Perturbations to the wavelengths are discussed. 2.3.2. Cadmium

Determination Experimentale de la Valeur du Metre en Longeurs d'Ondes Lumineuses (Experimental Determination of the Value of the Meter in Terms of the Wave

Length of Light), A. A. MICHELSON. Trav et Mem du

B.I.P.M. vll 1895 p 3-85. Appendix, 1, "Determinations

Metrologiques" by J. R. Benoit and Ch. Ed. Guillaume, p 86-111. Other appendixes p 112-237. Paper covers in- troduction, theory, description of apparatus, methods of observation, Cd light source, results. Cadmium Lamp for Interference Fringes, M. HAMY. CR

Acad Sci. 1897 p 749-52. Michelson's lamp (cadmium

vapor in a Geissler tube with aluminum electrodes) does not last well. The author describes a form without inte- rior electrodes, in which the tube is terminated by metal

caps lined with black lead, with a sufficient condenser, in derivation, in the induced circuit for the purpose of pre- venting perforation of the glass by sparking. Michelson's Reference of the Meter to certain Wavelengths of Cadminum Light, P. CULMANN. Zeit fur In- strumtkde v22 Oct 1902 p 293-311. Extract from Bui Soc Enc Ind Nat vlOl 1902 p 146. A description of Michelson's experiments carried out at Sevres, in which, by an

optical interference method, he obtained the meter in terms of certain wavelengths of the cadmium spectrum. According to Guillaume the meter has been obtained to an

accuracy of .001 mm in terms of those wavelengths. On Standards of Wave-length, H. KAYSER. Astrophys

J vl9 Apr 1904 p 157-61 ; Phil Mag v6 n8 1904 p. 568. Dis- cusses discrepancy between Michelson's and Rowland's

values. Nouvelle Determination du Metre en Longueurs d'Ondes Lumineuses ( A New Determination of the Meter in Terms

of the Wave-length of Light), R. BENOIT, C. FABRY,

A. PEROT. CR Acad Sci vl44 May 21 1907 p 1082-6. The

authors have redetermined the length of the standard meter in terms of the wave-length of the red line of cad- mium and find that 1 m=1553164.13x\, and \=0.6438,

4702, the measurements being reduced to 760 mm and 15° on the hydrogen scale. Determination of Length of International Meter in Terms

of the Red Cadmium Line, N. WATANABE, M. IMAI- ZUMI. Imperial Acad of Japan Proc v4 July 1928 p 350-3

in English. Results of author's determination coincides

fairly well to that of Fabry, made 21 years earlier ; change

of length of international meter prototype during this time has not been detected ; at same time it has been con- firmed that red cadmium line of Michelson's lamp is quite

reliable as standard of length. Settling the Primary Standards Controversy. Black and

White, vl n4 Feb 1929 p 22-6. Question of selecting pri- 59
mary standard of measurement is discussed ; wave length

of red ray of cadmium light is advocated as primary

standard in place of present bar standards whose lengths vary in Washington, London and Paris. Interferential Comparison of Radiations Emitted by a New Cadmium Lamp and the Miehelson Lamp, J. E. SEARS, Jr., H. BARRELL. Roy Soc Proc vl39 Jan 2 1933 p 202-18. Comparisons were made by means of a

Fabry-Perot interferometer, of the wavelengths of the red

radiation emitted by the two sources at a series of path

differences. Wavelengths are the same to an accuracy of

at least 1 part in 16,000,000. Reversal of the Red Line of Cadmium, A. PfiRARD. CR

Acad Sci vl98 Feb 19 1934 p 727-9. Spontaneous reversal

of the cadmium red line has been previously noted in the Hamy lamp, and also, under special circumstances, in the Miehelson lamp. The effect is easily observable in the hot- kathode lamp excited by the normal current of 2 amperes, but the reversal is suppressed when the current is reduced

to about one ampere. Using a hot-kathode lamp with a

constriction at the middle of the discharge tube and a

current of 1.15 amperes, the highly intense red line pro- duced is unreversed and is capable of interference over path differences up to 280 mm.

Use of Cadmium Red Radiation as a Standard in Metrol- ogy and Spectroscopy, C. FABRY. CR Acad Sci vl98 Mar

5 1934 p 861-4. Objection is raised to a statement by

Perard that the possibility of self-reversal in the red radiation of Cd disqualifies it from future use as the funda- mental unit of length. All radiations are reversible, but

they can be produced without reversal by suitable control

of the conditions of excitation. Discusses adopting a wavelength of light as the international unit of length and possibilities of radiations of Kr and Xe as suitable additional standards. Determinations of Fundamental Standards of Length in Terms of Wavelengths of Light, J. E. SEARS, H. BARRELL. Roy Soc London Phil Trans Ser A v233 June 22

1934 p 143-216. Definite determinations have been completed of lengths of yard and meter in terms of wavelength

of cadmium-red radiation, both in air and in vacuum, re- sults of these determinations given. Intercomparaisons D'Etalons Metriques au Moyen des Longueurs D'Onde Lumineuses ( Intercomparison of metric etalons by means of the wavelength of light), W. KOSTERS, J. E. SEARS, JR. Comite International des Poids et Mesures. Proces-Verbaux des Seances 2d ser vl7

1935 p 113-28 2 figs 3 refs. Contents : Introduction ; in- fluence of phase loss ; optical comparison of etalons ; re- verification of national prototype meters of England and Germany Nos. 16 and 18 ; repetition of the determination

of the wavelength of the red radiation of cadmium by NPL; correlation by PTR of the red ray of cadmium with

the German prototype No. 18 by Kosters and Lampe

summary. Cadmium Red Line as Standard of Wave-Length, C. V. JACKSON. Roy Soc Proc vl55A June 2 1936 p 407-19. An investigation of the condition necessary to ensure ac- curate reproducibility of the wave-length of the Cd red

line from various sources is described. The sources used were Miehelson lamps of the original vacuum type, and

as modified by Perard containing air at a pressure of about

1 mm., Osram hot-kathode discharge lamps and a Sehuler hollow-kathode lamp. Under certain specified conditions

all sources give a wave-length identical and reproducible with an accuracy of about ±0.0001 A. The Miehelson lamp as modified by Perard is found to be superior to the

original vacuum type, and in the Osram lamp the exciting current needs to be limited to a value of 1.1 A, to ensure reproducibility with other sources.

Interferometric Wave-Length Comparison of the Red Cadmium Radiation Emitted by Different Sources, W. E. WILLIAMS, D. V. GOGATE. Roy Soc Proc vl6 7A Sept

23 1938 p 509-16. A comparison is made between the wavelengths of the red Cd line 6438 A emitted by a G.E.C. Osira Cd lamp and a Sehuler hollow-kathode discharge by

photographing the Fabry-Perot fringes due to the two

sources side by side in the same horizontal plane by means

of a specially designed plate-holder. Interferometer gaps up to 10 cm. were used, and the greatest difference re- corded was less than 1 part in 100 X106 or 0.00006 A. Comparison of the Prototype Metre with the Wavelength

of the Red Line of Cadmium, M. F. ROMANOVA, G. V. WAHRLICH, A. I. KARTASHEV, N. R. BATARCHUKOVA. CR Acad Sci URSS v37 n2 1942 p 46-51. Values

previously obtained for their wavelength of the red line of Cd are set out, in their original form and corrected to apply to dry air at 15° C. and 760 mm. Hg, containing 0.03% C02 . Technique and results obtained in a new comparison between the std. USSR metre (metre No. 28) and the wavelength of this line are described in detail. The method employed involves the use of a Fabry and

Perot interferometer, measurement being made on a flat- ended steel metre bar. Mean values obtained for the red

line of Cd were ; normal air, \=6440.2488 A. The mean

quadratic error was ±0.0002 A. A Light Source for the Primary Standard of Wave-Length,

C. W. HSUEH. J Opt Soc Am v36 Mar 1946 p 160-4. A

light source for the red Cd line, 6438.4696 A, was devel- oped in which the important objections against the Michel- son type lamp were eliminated. It consisted of a dis- charge tube of two Pyrex bulbs joined by a U-shaped

capillary in an electric furnace maintained at a temperature between 300° C and 320° C. The current was 2.5A. The intensity of the standard line was strong, as shown

by the short exposure time (30 min) required to produce an interferometer spectrogram. The effective light-emit- ting area was 50x2.5 mm3 which was large enough to cover most spectrograph slits. The Cd standard line was

narrow, as shown by the interferometer spectrograms. The Doppler-effect broadening was reduced by observing

the light in a direction perpendicular to that of the dis- charge current.

Effect of Change of Argon Pressure in an Electrodeless Discharge upon the Reproduction of Wavelength of the Cd114 Red Line, N. R. BATARCHUKOVA, F. B. DUBROVSKII. Optika i Spektrosk vl n3 1956 p 330-3 in Russian. A spectrum line used as a standard of length should be symmetrical in form and stable to ensure reproducibility and it should have no hyperfine structure. The Kr84 line has been shown to give a shift in its maximum line under

change of pressure. Present authors set out to determine

the shift and broadening of the Cd 114 line, with change of argon pressure, in an electrodeless discharge. A FabryPerot type interferometer was used set up between the

collimator and prisms of a Frish spectrograph. On a

length of film photographs were taken of the Cd spectrum

over a range of some 40 pressures ranging from 1 to 48 mm

Hg. A graph of shift v pressure (roughly linear) is given with an expression for its calculation. Preliminary Report on the Isotopic Structure of the Cad- mium Primary Standard of Wavelength, J. F. WISE, K.

L. VANDER SLUIS. J Opt Soc Am v46 n8 Aug 1956 p 587-9. With enhanced samples of the eight isotopes of cadmium in electrodeless discharge tubes, measurements

of the centre of gravity line position of X 6438 have been made to better than one part in 25 million or to about

0.0003 A. The estimated resolution, based on Doppler

broadening, was 500,000. The observed shifts, compared

to a similar normal cadmium source, have been treated by

a least squres analysis of a matrix multiplication by the ORACLE. The preliminary results indicate a difference for the extreme masses of about 0.008 A, which is comparable with the half-width of the red line in an atomic 60
beam source. With exception of mass 108, there is a regular increase in wavelength for the even mass numbers. The odd mass isotopes appear to give anomalous shifts, falling near the shift for the adjacent larger even mass. The principal source of error in the procedure is associ- ated with apparent shifts due to differences in density of the patterns. Interferometric Measurements in Metrology, M. F. RO- MAXOYA. Optika i Spektrosk v3 n5 1957 p 457-72 in Russian. This review article gives accounts of work on

(1) the determination of the wavelength of the standard Cd line; (2) measurement of 1 m length standards; (3) the wavelength of the Cd red line of the isotopes 112, 114, and 116; and (4) a method for finding the velocity of

light. Results are given in each section with diagrams of the apparatus used. Some Considerations About the Precision of the International Standard of Wavelength, S. Y. CH'EN. Am J Phys

v26 n7 Oct 1958 p 464-6. The precision of the accepted

value for the wavelength of the red line of Cd is discussed. The uncertainty due to the setting of the end marks by a microscope in the interferometric measurement, the cor- rection for the refractive index of air, and the difficulty in controlling precisely the conditions of excitation of the

light source are reviewed with considerations for a new

standard of wavelength and a new pair of end marks.

Preparation of Hg 198 and Cdn* Electrodeless Lamp, T. TAKO. Report of the Central Inspection Institute of Weights and Measures, Japan v8 n4 report 20 1960 in Japanese. To obtain the best data to use in the making

of the lamp and its operation, several Hg1* and Cd114 elec- trodeless discharge lamps with various amounts of iso- topes and argon or neon of various pressures as carrier gas are prepared. The isotope Hg196 used is the Atomic

Energy of Canada Limited's of which composition is re- ported to be, by mass-analysis, Hg188

: Hg1" : HgMO=98.74

1.19: 0.07% and the sum of the rest is less than 0.01%. An ingenious method for taking a small definite quantity

of Hg168

: say 0.2 mg out of its reservoir is explained. The

isotope Cd114 used is Oak Ridge's and its purity is published to be 98.2%. The reduction of Cd114 from CdU4 O is simply carried out by the use of hydrogen. For both eases

the procedures in making the lamps are thoroughly ex- plained with figures and photographs. Some considerations for these lamps are given. The author adds that

the half-value width and broadening of the spectral lines

of the lamps are under observation and examination, and

their results will be reported in more detail later. Wavelengths of Krypton 86, Mercury 198, and Cadmium

114, C. F. BRUCE, R. M. HILL. Austral J Phys vl4 nl Mar 1961 p 64-88. The vacuum wavelengths and the

spectral line profiles for four lines of Kr6

", four lines of Hg186 and four lines of Cd114 were measured. One line, the

radiation 2pio-5d5 of Kr86( 6057 A) , was used as the refer- ence standard in the wavelength measurement A vari- able gap Fabry-Perot interferometer with electromagnetically controlled plate holders was used throughout under vacuum conditions. The use of photoelectric recording methods and mechanical scanning made it possible to compare wavelengths with an accuracy of better than 1 part in 10s

, and half-intensity widths of lines were measured with an accuracy of 0.5 mK (0.0005 cm"1

) . The 6057 A line of Kr6* was examined under different operating

conditions of the Engelhard-type and small wavelength

shifts due to variation of temperature, pressure, and cur- rent density were measured. The Doppler shift and in- teratomic Stark shift annul each other if the lamp is viewed in the direction cathode to anode to observer, and

is operated in a liquid air bath with the temperature near

the capillary surface of the lamp at 63±1°K and with a

current density of 0.28±0.05 A/cmJ

. The Doppler shift under these conditions was found to be +0.014±0.003 m"1 (—50±10 mA) and the interatomic Stark shift —0.014

±0.003 m"1 (+50±10 mA). Under these conditions also the half-intensity width is 13.4±0.5 mK, and the wavelength emitted is that for the unperturbed state of the atoms to 2-3 parts in 10s

. This line is superior to the

other lines examined for sharpness and reproducibility and other wavelengths may be established in terms of it to at least 1 part in 10s

. This is the line that has been recommended as the new primary standard of length. 2.3.3. Krypton

Eine neue Methode hochster Genauigkeit zur interfero- metrischen Wellenlangenmessung und ihre erstmalige Anwendung zur Vorbestimmung der fur den deutschen Anschluss des Meters an Lichtwellen vorgesehenen Kryptonlinien (A New Method of Highest Precision for Inter- ferometric Wave-Length Measurements and their Primary

Application to the Predetermination of Designated Krypton Lines for the German Relation of the Meter to Light Waves ) , A. P. WEBER. Phys Zeit v29 Apr 15 1928 p 233-

9 3 figs. ( English translation is available )

The First Spectrum of Krypton, W. F. MEGGERS, T. L. DE BRUIN, C. J. HUMPHREYS. J Res NBS v3 (RP89)

July 1929 p 129-62 6 figs 42 refs. About 200 lines were

photographed with concave grating and quartz spectro- graphs. From these spectrograms a new list of estimated

intensities and measured wave lengths was obtained. Interference Measurements in the First Spectra of Krypton and Xenon, C. J. HUMPHREYS. J. Res NBS v5 Nov

1930 p 1041-57. Determinations of the stronger arc lines made with the Fabry-Perot interferometer. None of the krypton lines exhibit fine structure under the resolving power employed, and the intensities of any satellites which may exist are too small to influence the wave-lengths.

First Spectrum of Krypton, W. F. MEGGERS, T. L. DE

BRUIN, C. J. HUMPHREYS. J Res NBS v7 Oct 1931 p 643-57 7 refs. Wave length and intensity data have been

improved, several close pairs of lines have been resolved, and total number of lines increased to 460, as the result of a change in technique. Au Sujet de la Recherche d'une Raie Nouvelle comme

£talon de Longueur d'onde Lumineuse (New Line Stand- ard of Wavelength), A. PERARD. CR Acad Sci vl94 May 9 1932 p 133-5. By means of the Michelson interfer- ometer comparisons have been made between the provi- sional standard red line of Cd and four Kr lines, and

reasons are given at length for adopting KrI (5562.22576 A) as standard. Krypton Vacuum Wavelength Measurements, T. A. LIT- TLEFIELD. Proc Roy Soc A vl87 Oct 22 1946 p220-8. The wavelengths of 31 lines in the spectrum of Kr were compared directly with the red Cd standard using a

reflecting echelon in vacuo. Uncertainties connected with

dispersion in air are thus eliminated. The values are given to 8 significant figures and this accuracy is justified. For details of the optical apparatus see Abstr. 4466

(1933). Mercury and Krypton Isotope Electric Discharge Lamps,

their Applications to Interferometry, N. L. HARRIS.

Engr vl90 n4095 Nov 3 1950 p 409-11 5 figs 5 refs. Dis- cusses increased sharpness of interference fringes ; the

artificial preparation of Hg"8 isotope; Hg188 lamps; the use of the Kryton discharge. Isotope Electric Discharge Lamps as Spectral Sources for the Exact Measurement of Length, R. D. KNOTT. Gen

Elec Co. J vl8 July 1951 p 169-75. Describes the way

in which Hg198 is made and the factors which affect the sharpness of the spectral lines given by such an isotope. The form of lamp found most suitable for interferometry SI
is a water-cooled cold cathode lamp with large hollow Mo

cylinders as electrodes and A at 10 mm pressure as carrier gas. Lengths up to 20 cm, corresponding to an order

of interference of about 350 000, can be measured with

such a source. To obtain higher source intensities and minimum line width a water-cooled electrodeless lamp has

been developed. Future work includes the development

of a Kr 84 lamp, cooled in liquid air to reduce the Doppler

broadening effect on the lines. The Present State of a Lightwave Standard of Length,

E. ENGELHARD. "Maintenance of standards" sym- posium PTB. Feb 1954 p 13-23 6 figs 8 refs. The proposal

to establish a lightwave standard of length is reviewed. The basic problem is two-fold ; the development of ap- paratus for the comparison of the lightwave with the

metre, and the development of suitable light sources of the chosen standard wavelength. A new interferometric ap- paratus for the former is described, for the comparison and measurement of end gauges, in which corrections for the refraction of air can be made without the necessity

for having the gauges themselves in vacuo. The estab- lishment of a lightwave standard of the required preci- sion and reproducibility is discussed in terms of the causes

of line-broadening in spectroscopic sources. In particular, the merits of a source using the isotope Kr84 cooled to 63 °K are mentioned.

Spectral Profile and Causes of Broadening of Certain Highly Monochromatic Radiations of Krypton-86, J. TERRIEN, J. HAMON, T. MASUI. CR Acad Sci (Paris) v245 nil Sept 9 1957 p 960-3 in French. Interferometric meas- urements were made upon the 5649A and 6056A lines of krypton. They are extremely narrow (,~0.01A) and do

not suffer from self-absorption effects. The 6056A line in

particular, which arises from the 2pi0-5ds transition, is suggested as a new primary standard of length. In comparison with the 6438A line of Cd, its wavelength is

6057- 8021 X10"10 m ±0.0001 X 10-10m, the error being in the lack of reproducibility of the Cd radiation. Optical Definition of the Meter, H. BARRELL. Nature

(London) vl80 Dec 21 1957 p 1387-8. The Comite Consultatif pour la Definition du Metre has recommended

that the meter should be defined as equal to 1 650 763.73 times the wavelength in vacuo of the orange—red radiation 2pio-5ds of the Kr80 atom. The background to this recommendation is explained and it is stated that with

a suitable source, the new definition is reproducible to within 3 parts in 109

. Interferometric Measurements of Vacuum Wavelengths

of Radiations of Hg198 and Kr86

, T. TAKO, I MIYASATO,

H. NIU, T. KANEKO. Report of the Central Inspection

Institute of Weights and Measures, Japan, vl7 nl report 14 1958 in Japanese. The vacuum wavelengths of three

radiations of Hg198 (0.456, 0.577 and 0.579^) and three of Kr86 (0.565, 0.606, and 0.646/t) were measured in terms

of the vacuum wavelength of the red line of Michelson

type cadmium lamp, of which value is taken as

0.644024907*1 deduced from Edlen's formula. A FabryPerot etalon with a pair of optical glass flats separated by

62.5 mm invarspacer was used in an evacuated enclosure

to obtain the interference fringes. The observations of interference patterns were made photographically with

the aid of a large dispersion spectrograph. Hg198

: The NBS electrodeless Hg198 lamp (with 3 mm Hg argon) was

excited by high frequency (200 MHz). The discharge column was viewed from the side through the surrounding water jacket and was maintained at temperatures be- tween 0 and 5°C by running water. Kr86

: The Engelhard

type Kr86 hot cathode lamp (with 1~2 mm Hg Kr86

) cooled

in liquid nitrogen was viewed from the end. The results were reported to Comite Consultatif pour la Definition du

Meter on the 23d Sept 1957 and are in good agreement

with those of BIPM, PTB, NPL, and NRC.

Standard Wavelengths in the Visible Spectra of Krypton- ; [ 86 and Mercury-198, J. TERRIEN. CR Acad Sci (Paris) v246 nl6 Apr 21 1958 p 2362-4 in French. Measurements 1 of X5650 A in the krypton spectrum and of W5791, 5770, J

5461 and 4358 A in the mercury spectrum by comparison j with the standard \6056 A in the krypton spectrum. The Jl uncertainties are less than 1 in 10s

. Preliminary Measurements of Some Wavelengths of | Krypton 86 and Mercury 198 Lines, K. M. BAIRD, D. S. 1 SMITH. J Opt Soc Am v48 n5 May 1958 p 300-1. Vac- ! uum wavelength values for some of the lines in the spectra

of Kr8a and Hg198 have been derived by comparison with a Michelson type Cadmium lamp, by using a 67.5 mm Fabry- | Perot etalon as the intermediary- The same lines have ' been intercompared by means of a Twyman-Green inter- / ferometer, referring to the Hg198 green line wavelength as | ! 5462.2704A. The half-widths of the lines were also measured.

Interferometric Calibration of Quartz End Standards, E. | j ENGELHARD. Zeit InstrumKde v67 n3 Mar 1959 p 59-65

in German. A review is given of the interference methods j in use in different countries for the testing and prepara- I p tion of end standards. The definition of the official metre I J is discussed. It is considered that the uncertainty in the

best cases approximates to 0.1/<. It is estimated that a

five times smaller uncertainty could be attained by using

the red cadmium wavelength as the standard instead of i the standard metre. A ten times smaller uncertainty is B attainable using Kr88

. Discussion of The Reproducibility of the Wavelength of t „ the 2pio-5<Z5 Emission Line of Kr86

, the Proposed Standard j y Unit of Length, J. TERRIEN. CR Acad Sci (Paris) v248 nl5 Apr 13 1959 p 2171-2 in French. The variation of the - wavelength of this line with current density and pressure j j, has been investigated. From the results obtained the non- t

tl perturbed wavelength can be found by extrapolating the ; results to zero current density and pressure. It is esti- | s mated that the determination of the wavelength can be ;| ^ reproduced to an accuracy better than 2x10"". Kr 86 and Hg 198 Wavelength Standards, K. M. BAIRD,

D. S. SMITH. Can J Phys v37 n7 July 1959 p 832-40. t. New values are given for the vacuum wavelengths of six

lines Kr86 and five lines of Hg198 in the visible spectrum. E 1( The wavelengths were referred to the Kr88 primary stand- ,,\ ~ ard line, 6057.80211, by a series of very careful measure- j| }{Jj ments over a period of several years. The accuracy with

j ^ which wavelengths can be compared by present methods is '•: ~ discussed at some length. Determination of the Wavelength of the 2picH5<Js Line of r - Kr88 for Non-Perturbed Atoms, E. ENGELHARD, J. TER- i" RIEN. Rev Opt (France) v39 nl Jan 1960 p 11-18 in ;

r French. Extrapolations from measurements on Kr89

; lamps at varying pressure and temperature were used to V obtain the wave-number for unperturbed atoms as a func- | j tion of temperature correct to 3 parts in 109

. The wave- L 1 number is given as 1650763.73±0.004 m"1 at zero pressure ,

' and 56° K. Measurements of Half-Widths of Spectral Lines by Means

1 P' of a Fabry-Perot Interferometer with Photoelectric Re- \ ^ cording, Yu. P. EFREMOV. Meas Teehn 1959 nlO Aug 1 * 1960 p 756-60 2 figs 9 refs. Translated from Izmer Tekh 1 » nlO Oct 1959 p 7. Concludes that the lines of the near in- frared region of the spectrum of Kr88 can be successfully 1 1 used for interference measurements of length, especially ft for difference rates exceeding 500 mm in cases when mea- '» surements by means of visible lines of the spectrum become &

difficult or altogether impossible. World's New Standard for Length, P. A. MCKEOWN. j Eng vl90 n4930 Oct 14 1960 p 514-5. It was decided at TM 11th General Conference of Weights and Measures, in

[ session during Oct 1960, that meter is to be redefined in |

115 terms of wavelength of light ; new definition will almost 5! 02
certainly be 1 m equals 1,650,763.73 wavelengths of orangered line radiation in Krypton-86 spectrum (in vacuo) ; design, and advantages, of photoelectric microscope in measuring are discussed, and new comparator installed at Int Bur Weights and Measures is described. Kr88 and Atomic-Beam-Emitted Hg198 Wavelengths, R. L. BARGER, K. G. KESSLER. J Opt Soc Am v51 n8 Aug

1961 p 827-9. The present investigation was undertaken in order to calibrate the Hg198 resonance line in terms of the wavelength of the 6057 A line of Kr86 as part of the inves- tigation into the problem of redefining the standard of

length in terms of a wavelength of light. Vacuum wavelengths are given for the Hg198 2537 and 3132 A lines and

the Kr88 6013 and 5651 A lines, referred to the Kr85 primary

standard line 6057 A. The light sources were an Hg188 atomic beam and a Kr88 hot-cathode lamp. A vacuum

Fabry-Perot interferometer was employed for the measurements. The wavelength of the Hg198 3132 A line was

determined by using the Hg188 2537 A line as the reference

standard. The accuracy of measurement of the Hg108 lines

is about a factor of 5 higher than that of Kr88 lines. Primary Standard of Length, K. M. BAIRD, D. S. SMITH.

J Opt Soc Am v52 n5 May 1962 p 507-14. The primary

standard of length is defined in terms of the unperturbed

2pio-5d5 radiation of Kr88

. This paper reports new meas- urements of the perturbations due to the conditions of excitation necessary for its practical realization. The

results confirm that the present recommendation of the International Committee of Weights and Measures yields the defined standard to an accuracy of better than 1 : 108 and they indicate how an improvement by about an order

of magnitude may be realized by more exact specifications. Wavenumber Reproducibility of the Radiation 2pio-5<J5 of Krypton 86, C. F. BRUCE, R. M. HILL. Austral J Phys

vl5 n2 June 1962 p 152-61. The vacuum wavenumber of

the radiation 2pio-5<Z5 (6056 A) of krypton 86 emitted by

a hot cathode Engelhard-type discharge lamp was established for the temperature range 58°-70 °K and current

density range 0-1.0 A/cma

. Wavenumber relative to the value for the unperturbed state of the radiation were

measured with a reliability of 1 part in 10e using a photoelectric recording and electromechanical scanning FabryPerot interferometer. However, this reproducibility is not possible for different lamps without a more exact

specification for the form and operation of the lamp and

for the . interferometric system used. With the present

international specification for the lamp, the reproducibility of this new primary standard of length is better than 1 part in 10s

. Krypton Lamp for Reproducing the Standard Unit of Length, N. R. BATARCHUKOVA, YU. P. EFREMOV, G.

S. POPOV. Meas Techns 1962 n8 Feb 1963 p 636-8 3 figs 4 refs. Translated from Izmer Tekh n8 p 14-6 Aug 1962. Describes a lamp consisting of a discharge tube with verti- cally placed capillaries, a Dewar flask for cooling the dis- charge tube, a hermetically sealed chamber made of perspex, and adjustable devices for illuminating the inter- ferometer mounted on a table. Tests showed that there

is no displacement in the orange line wavelength as compared with the Engelhard lamp. It is easy to manufacture and completely meets the requirements of the Inter- national specification. The International Length Standard, K. M. BAIRD, L. E. HOWLETT. App Opt (USA) v2 n5 May 1963 p 455-64. Describes the characteristics of the 2pio-5ds radiation of Kr88 which was adopted in 1960 as the primary standard

of length. After a brief history of the development lead- ing to the adoption of this spectral line, its physical characteristics are discussed with a view to showing its merits

as a standard. The relative merits of possible alternatives are also considered. It is concluded that the 2pia-5d* radiation is superior to any available alternative.

2.3.4. Mercury

Constancy of Wave-Length of a Spectral Line, G. C. OMER, JR., J. L. LAWSON. Astrophys J v84 Nov 1936 p 477-8. The Hg line \4358 was observed with Fabry and Perot etalon from June 24 to Aug 27 1935. The wavelength of this line was found to be constant to within 2

parts in 1,000,000. Possibility of Employment of Hg Lamp as Stable Monochromatic Source, G. BLET. Rev Opt (Theor Instrum)

v21 1942 p 65-70 in French. The influence of variations

of voltage and frequency on the intensity of the various

radiations emitted by a Hg high pressure lamp (type, Philips H.P.-300) are studied, the radiations being isolated by means of filters and measured by Se cells. It is con- cluded that the lamp can be used as a stable source of monochromatic light but that for the flux to be maintained

constant to 0.5% the voltage and frequency must be maintained constant to 0.1%. Production of Hg198 as a Possible Source of an Improved Wavelength Standard, J. H. WIENS. Phys Rev v70 Dec 1 and 15 1946 p 910-4. The green line 5 461 A from any of the even isotopes of Hg is superior, in many respects, to the red line 6 438 A of Cd. Hg198 was produced by utilizing the

reaction toAu197 + n -^eoHg198 + p One oz of pure Au sealed

into a quartz tube with pure A 4 mm Hg pressure was ex- posed to stray neutrons from a cyclotron for 10 months

the Hg produced was then distilled into an attached capil- lary and the spectrum of an h.f. discharge observed with a Fabry-Perot etalon. Hg lines in the correct position for the isotope of mass 198 were observed. The production

of larger amounts should present no difficulties. Light Wave of Artificial Mercury as Ultimate Standard of Length, W. F. MEGGERS. J Opt Soc Am v38 nl Jan 1948 p 7-14. Efforts to use light as constant, reproducible standard of length traced back to Babinet in 1827 ; work

of Michelson and Morley culminating in use of cadmium

red light for accurate determination of meter; improved method resulting from transmutation of Au197 to Hg198 yielding material for lamps emitting superior standards

of length; discussion of lamp characteristics. Bibliog- raphy. The Ultimate Standard of Length, W. F. MEGGERS, NBS.

Sci Monthly v68 nl Jan 1949 p 3-11 7 figs. J Opt Soc Am

v38 1948 p7. Suggests recognition of the wavelength in vacuo of the green light of Hg198 as the ultimate standard of

length. Possibility of Enhanced Hg292 as Source of Monochromatic

Light, J. R. McNALLT, JR., P. M. GRIFFIN, L. E. BURKHART. J Opt Soc Am v39 nl2 Dec 1949 p 1036-7. Dis- cussion of electromagnetically enhanced Hg202 as source

material for highly monochromatic radiation ; relation to

effects of isotopic impurities; Fabry-Perot interference pattern shows line purity in 98.06% Hg202

; applicability to production of monochromatic lamps of 5461A wavelength. Lamps and Wavelengths of Mercury 198, W. F. MEGGERS, F. O. WESTFALL. J Res NBS v44 (RP2091) May

1950 p 447-55 4 figs 25 refs. The production and extraction '$5 Hg from *% Au bombarded by neutrons is described, and the procedure in making electrodeless lamps

with 'lo Hg is given in detail. These lamps are excited by high-frequency radio waves; they emit the mercury

spectrum entirely free from isotope shifts and hyperfine

structures that characterize natural mercury. FabryPerot interferometers and a prism spectrograph were employed for measuring relative to Cd 6438-4696 angstroms,

the wavelengths of the stronger lines in the visible spec- trum of 19J Hg. Preliminary values for Hg radiations

in normal air are reported 5790-6627, 5769-5984, 5460-7532, 4358-3377, 4077-8383, and 4046-5717 angstroms, with prob- able errors not exceeding ±0.0001 angstrom.
Interference Measurements in the Spectra of Neon and

Natural Mercury, K. BURNS, K. B. ADAMS, J. LONG- WELL. J Opt Soc Am v40 June 1950 p. 339-44. Accepted Ne standards cover the region 6 929-2 852 A. The first spectrum of Ne has been observed throughout the region

8 919-3 126 A to assist in establishing secondary stand- ards in the part of this range where none exist. The first spectrum of natural Hg was observed from 7 020 to 2 200 A

to discover in what part of this range standards of suit- able intensity will be available when lines emitted by Hgies have been measured ; and to find out which lines (if any) of the natural element may serve as standards when Hg is accidentally or unavoidably present in a low pres- sure source. It is shown that some lines of natural Hg

are suitable for secondary standards, and nearly all may

be useful when an accuracy of no more than a part per

million is required. Interferometric Measurements of Wave-Lengths in the Spectrum of Mercury Isotope 198, J. M. BLANK. J Opt

Soc Am v49 June 1950 p 345-6. Six lines in the spectrum

of Hg368 in the range 5 790 to 3 650 A have been measured

with Fabry-Perot etalons. The wavelengths obtained were 5 790-6627, 5 769-5984, 5 460-7531, 4 358-3376, 4 046-5715 and 3 650-1569 A. These results are compared

with those previously reported. First Observations on the Metrological Qualities of the Rays Emitted by a Non-isotopic Mercury [Hg198

] Pro- duced by Transmutation of Gold; and Comments on the Standard of Length, A PERARD, J. TERRIEN. J Phys Radium vll June 1950 p 249-54 in French. The use of the wavelengths of certain spectra lines as secondary

standards of length, and the essential qualities of such

lines for that purpose are discussed. The radiation emitted by a Meggers Hg198 electrodeless discharge lamp

has been examined with a Michelson interferometer and

the radiation compared with that of other elements. The

lamp used, shown photographically, was excited by an

external 100 Mc/s alternating field and was water-cooled. By rotating the lamp it could be viewed either end-on or

broadside. The results showed that the lamp should be used at a temperature <30 °C and in the broadside position. The Hg198 green and two yellow lines (5 460-7532,

5 769-5984 and 5 790-6330 A) were compared with the red cadmium line (6 438-4696 A). The view is expressed that one of the wavelengths of the spectral lines emitted by say

a Kr84

, Kr86 or Hg198 lamp could now be considered by the International Conference on Weights and Measures as a primary standard of length. Wave-Lengths of Mercury 198, W. F. MEGGERS, K. G. KESSLER. J Opt Soc Am v40 Nov 1950 p 737-41. The

wavelengths of 26 visible and U.V. radiations from Hg198 have been measured to 8 figures relative to 5460-7532 A,

provisionally adopted for the green line. A water-cooled

electrodeless lamp containing 2 mg of artificial Hg198 served as a light source when excited with radio waves of 100 Mc/s frequency. This lamp illuminated a FabryPerot interferometer and a large quartz spectrograph with which the interference patterns were photographed. Measurements of these patterns yielded relative wavelengths with probable errors usually less than 0-0001 A. In addition to demonstrating that Hg188 5460-7532 A pro- vides a practically perfect primary standard of length,

this paper presents preliminary values of 27 superior

spectroscopic standards which show that differences among vacuum wave numbers recur within the accuracy

of the measurements, and that all the existing dispersion curves for air are incorrect. The Fundamental Standard of Wavelength, W. F. MEGGERS. Astron J v56 Oct 1951 p 116-8. Lists are given

of measures of the red Cd line and, relative to this, of the more accurate and practical artificial Hg198 isotope

line whose mean \ is found to be 5460-75318±.00006. Applications of the robust Hg193 lamp are mentioned, and it

is suggested that this standard should be used in future

astrophysical work. Comparisons of Wave-Length Standards Emitted by Mercury-198 Lamps, H. BARRELL. Proc Roy Soc A v209 Oct 8 1951 p 132-41. The reproducibility of high-quality wavelength standards emitted from water-cooled mercury198 discharge lamps of the electrodeless and cold-cathode

(Geissler) types has been investigated by means of a Fabry-Perot interferometer. These lamps contain a small

quantity of the isotope Hg188 with argon, as carrier gas, at a nominal pressure of 3 or 5 mm in electrodeless and 10 mm in cold-cathode lamps ; electrodeless lamps containing

only the isotope and its vapour are also available. Employing for excitation a 100 Mc/s oscillator with electrodeless lamps and a transformer delivering 750 V at 25 mA

and 50 c/s with cold-cathode lamps, the wavelengths of

six Hg198 lines between 4046 and 5791 A, emitted from a sample of each kind of argon-filled lamp, have been measured in terms of the Cd red line at retardations of 5 to 25

cm. These measurements, supplemented by intercompari- sons of argon-filled and argon-free electrodeless lamps at a retardation of 20 cm, reveal that Hg198 lines are probably

subject to an asymmetrical pressure-broadening effect, producing a red shift of about 0-0001 A (—0-0004 cm"1

) per mm of argon. Wavelength reproducibility among dif- ferent samples of the same kind of lamp with the same

filling is of the order of ±0-00005 A, or ± 1 part in 108

, for electrodeless lamps and ±0-0001 A for cold-cathode lamps. Atomic Standard of Length. Gen Elec Rev v54 nil Nov

1951 p 12-3. Note on availability of ultimate standard of length announced by National Bureau of Standards, based upon wavelength of green light emitted by lamp; wavelength, near 21 millionths of inch, is consistently emitted with reproducibility greater than one part in billion; length measurements can readily be made with accuracy

of one part in 100 million. From NBS Tech News Bui v35 n3 Mar 1951. Simple 500 Mc/s Oscillator for Use with Electrodeless Mercury-198 Lamps, A. THULIN. J Sci Instrum v32 n7

July 1955 p 257-8. Mercury-198 discharge tubes for inter- ferometry have restricted life owing to clean-up of mercury, although they can be regenerated by heating ; clean- up diminishes rapidly with increasing frequency of excitation ; for such excitation, oscillator was developed which is simple, adjustable in frequency from 300 to 500 Mc, and consists of parallel line resonator associated with

Philips double tetrode type QQE 06/40. Excitation of Mercury-198 in a Liquid Nitrogen Cooled Hollow Cathode Lamp, K. M. BAIRD, K. H. HART, J. Opt Soc Am v46 n4 Apr 1956 p 304-5. Reduction in Doppler broadening is investigated qualitatively by comparative tests using a Michelson interferometer. Fringes may

be observed for path differences of up to 65 cm. Fine Measurements, J. R. ADAMS. J Sci Instrum v33

nlO Oct 1956 p 369-75. See abstract under 2.3.1. Measurement By Photoelectric Fringe Scanning of the Pressure Shift of Hg 198 Emission Lines, K. M. BAIRD,

D. S. SMITH. Can J Phys v35 n4 Apr 1957 p 455-61. Photoelectric fringe scanning apparatus has been devel- oped for the measurement of very small wavelength

changes (of the order of 5X10"5 A). This paper describes

its application to a direct measurement of the shift of some of the visible lines of Hg198 caused by the presence

of the various rare gases used as a carrier. The values found for the shift in wave-number are all of the order

of 2X10"'1 cm"1 per mm (Torr) pressure and to the red, except for He, for which it is somewhat less than 1X10"1 cm"1 per mm and to the blue. Spectral Profile and Causes of Broadening of Certain Highly Monochromatic Radiations of Mercury-198, J. 04
TERRIEN. J. HAMON, T. MASUI. CR Acad Sci (Paris) v245 nlO Sept 2 1957 p 926-9 in French. The yellow and

green radiations of B.^ from an electrodeless lamp with

the external temperature maintained at 2 °C were studied with a Fabry-Perot etalon and by the visibility of two- beam interference fringes with a view to their use as a fundamental standard of length. The half-width of the green line is about 20 mK. Analysis of the visibility curve shows that the Doppler half-width is 16 mK, corresponding to a temperature of 38 °C; the additional broadening

is mainly collision broadening and increases with the pressure of the argon carrier gas. If the external temperature of the lamp is allowed to rise, self-absorption is observed. Excellent agreement between the theoretical and calculated visibilities was found for a lamp at 22 °C assuming the effective temperature to be 60 °C. Interferometric Measurements of Vacuum Wavelengths of Radiations of Hg196 and Kr88

, T. TAKO, I. MIYASATO, H.

NIL", T. KAXEKO. Report of the Central Inspection Institute of Weights and Measures, Japan v7 nl report 14

1958 in Japanese. See abstract under 2.3.2. Standard Wavelengths in the Visible Spectra of Krypton86 and Mercurv-198. J. TERRIEN. CR Acad Sci (Paris) v246 nl6 Apr 21 1958 p 2362-4 in French. See abstract under 2.3.3. Kr 86 and Hg 198 Wavelength Standards, K. M. BAIRD,

D. S. SMITH. Can J Phys v37 n7 July 1959 p 832-40. See abstract under 2.3.3 Preparation of Hg198 and Cd114 Electrodeless Lamps, T. TAKO. Report of the Central Inspection Institute of Weights and Measures, Japan, v8 n4 report 20 1960 in Japanese. See abstract under 2.3.2. Wavelength Shifts in Hg183 as a Function of Temperature,

S. H. EMARA. J Res NBS v65A n6 Nov-Dec 1961 p

473-4. The wavelength shifts for the green (5460 A) and

blue (4358 A) lines emitted from an electrodeless dis- charge lamp of Hg168 were studied as a function of the temperature of the water jacket of the source. The

values of the wavelength shifts observed for the green and

the blue lines are (8.5±3) 10"9 A/°C and (2±1) lO"8 A/°C, respectively. Wavelengths, Energy Levels, and Pressure Shifts in Mercury 198, V. KAUFMAN. J Opt Soc Am v52 n8 Aug 1962 p 866-70. The vacuum wavelengths of 27 lines of Hg198 and 6 lines of Kr* have been measured relative to the

international standard of length, the Kr80 line at 6057- 80211 A, by photographic Fabry-Perot interferometry. These measurements were made with Hg196 electrodeless lamps containing argon at pressures of 3 and 10 mm

Hg and a Kr8" hot-cathode lamp operated according to the

conditions prescribed by the International Conference on Weights and Measures in 1960. Energy-level values have

been derived from the wavelengths of each of the Hg199 sources, and on the basis of these values, the energy level and wavelength shifts per unit pressure of argon have

been calculated. The suitability of the Hg193 electrodeless lamp as a source of wavelength standards for inter- ferometric measurement of length and wavelength is discussed. Measurement of the Isotopic Displacement of Mercury198

, C. CASSIGNOL, R. LENNUIER. J. Phys. (France) v24 n5 May 1963 p 348-9 in French. The profile and isotopic displacement of the Hg198 line at 2537 A was observed in absorption using the magnetic sweep method with an Hg"8 discharge as the source. The transmitted intensity is plotted as a function of the magnetic field and gives a shift

of 0.138 cm"1. Using natural mercury in the same apparatus, the displacement for Hg198 to Hg200 was 0.161 cm"1 and for Hg200 to Hg202 was 0.178 cm"1

.

2.3.5. Helium

Uber die Verwendung von Heliumlicht zur Messung

optischer Konstanten (The Application of Helium Light

to Optical Measurements), H. HARTING. Archiv Optik

vl 1907 p 97 ; Zeit fur InstrumKde v28 Sept 1908 p 273-5. In spectral measurements the employment of the sodium

flame is subject to certain disadvantages, and the use of the helium tube and the bright helium line \ 587.7 is rec- ommended in place of the D line. An interpolation for- mula is given for the change of refractive index with change of color, and the change of index is calculated

for all the glasses given in Schott's catalog ; it varies from

5 to 23 in the fifth decimal place. Further Measurement of Wave Lengths, and Miscellane- ous Notes on Fabry and Perot's Apparatus, LORD

RAYLEIGH. Phil Mag vl5 Apr 1908 p 548-58. In a pre- vious paper the author described a modified Fabry and

Perot apparatus and gave some wave-length determinations made with it. In the present paper is described an

interference standard with 5 mm invar distance pieces so that the temperature coefficient is as small as possible. The value obtained previously for the Zn line \ 6362.350,

is now confirmed, and the wave lengths of the helium

lines are now given as 7065.200, 6678.120, 5875.625,

5015.680, 4921.920, 4713.144, and 4471.482. A 30 mm stand- ard is also described with a glass tube having three pro- tuberances at each end as distance piece. Wave Lengths of the Stronger Lines in the Helium Spec- trum, P. W. MERRILL, NBS. Sci Papers NBS n302 June

18 1917 p 159-66 8 refs. Helium spectrum consists of a comparatively small number of lines well distributed from

the ultraviolet to the red. Precise measurements of the stronger lines were made. The Fine Structure of the Helium Arc Spectrum, W. V. HOUSTON. Proc Nat Acad Sci vl3 Mar 15 1927 p 91-4

1 fig 6 refs. It has been shown that helium lines have

a structure similar to that predicted by Heisenberg. Energy level designations and wavelengths are tabulated. Scheme of energy levels which will produce the observed

lines is illustrated. The Wavelength of the Helium Line 5016A, G. W. SERIES.

J. C. FIELD. NPL Symposium nil, 1959, Interferometry. Stationery Office, London 1960 (Paper 2-4) p 93-107 20

refs. Has obtained the value 5015.6775 ±0.00041 in standard air. Discusses previous work, experimental details and technique, comparison of the helium and cad- mium lines in the hollow cathode source, dispersion of phase change, comparison of the wavelength of the cad- mium red line from the hollow cathode source with other

standards, gives conclusions. Further results are pre- sented by W. C. MARTIN and J. TERRIEN. Discussion. New Wavelengths for Some Helium (He I) Lines, W. C. MARTIN. J Opt Soc Am v50 n2 Feb 1960 p 174-6. New

vacuum wavelengths for nine lines of He I in the near

ultraviolet and visible regions are given. They were ob- tained by measurement relative to 5462.2707 A and

4359.5625 A of Hg198 I with an evaculated Fabry-Perot

interferometer. Liquid-nitrogen cooled helium lamps were

used. Interference fringes were obtained for the helium

line 5017 A with spacers up to 50 mm in length. The

wavelength of this line, which was used as a reference wavelength in some previous work on the Rydberg constant, is found to be 5017.0772±0.0003 A (vac.) relative

to the stated values for the two standards. 2.3.6. Atomic Beam

Mercury Atomic-Beam Lamp, R. L. BARGER, K. W. MEISSNER. J Opt Soc Am v84 n7 Jan 1958 p 22-7. The

construction and operation of a simple atomic-beam source employing natural mercury is described. Lines of great 65
sharpness are obtained when the emitting beam is viewed

perpendicularly to the direction of the flight of the atoms. The Hg198 component of the line 2537 A is isolated from

the other components by proper selection of the inter- ferometer spacer so that is can be compared with the same

line of the Hg188 Meggers lamp. This comparison shows

that the atomic-beam line is much sharper and that it is feasible to construct an atomic-beam lamp employing a

single even isotope of mercury. Atomic Beam Sources and the Standard of Length, K. G. KESSLER, R. L. BARGER, W. G. SCHWEITZER. IRE

Trans Instrumentation vI-7 n3^ Dec 1958 p 181-4. Three devices which utilize the wavelength of optical transitions in an atomic beam of mercury as a standard

of length are described: (1) a beam of atoms excited by

electron impact ; (2) a beam in absorption which utilizes a Michelson interferometer to produce a narrow line in emission ; and (3) a beam in absorption utilized as a narrow band detector. The half-width of the 2537 A line, ob- served in both emission and absorption, is 0.002 cm"1 and

is equivalent to a coherence limit of 500 cm. The comparable half-widths for the 5462 A mercury and the 6058 Akrypton lines produced in cooler discharge tubes are

0.018 cm"1 and 0.011 cm"1

. See also NPL Symposium nil,

1959, interferometry, H.M. Stationery Office, London 1960 (paper 2-3) p 67-91 12 figs 8 refs. Interference at Great Retardations Obtained with a Cal- cium Atomic Beam source, K. W. MEISSNER, V. KAUFMAN. J Opt Soc Am v49 n5 May 1959 p 434-8. By employing a calcium atomic beam source in emission and by

using a beam of high eollimation very clear Fabry-Perot

patterns of the resonance line of calcium, X4226 A, were

obtained with retardations of 60, 78, 94, 108, 120, and 130

cm. The corresponding order numbers are about 1.42,

1.85, 2.22, 2.56, 2.84, and 3.08 million and greatly surpass

those obtainable with the best conventional cooled source

available at present. The good definition of the fringes obtained with the retardation of 130 cm suggests that

the limit of interference is considerably higher. Calcium Atomic Beam Source and Interference Beyond Two Meter Retardation, K. W. MEISSNER, V. KAUFMAN. J. Opt Soc Am v49 nlO Oct 1959 p 942-3 FabryPerot interference patterns of the resonance line of cal- cium, X4226 A, have now been obtained at retardations of 153 and 204 cm by employing a highly collimated calcium atomic beam source in emission. The correspondence

order numbers are 3.62 and 4.82 million. The appearance

of these fringes suggests that the half-width of the line is less than 3X10"3 cm"1 which is one-fourth that of the pro- posed primary standard of length and one-tenth that of the present primary standard of wavelength. The

use of an atomic beam source for the production of the

length standard is discussed. Correction for Systematic Wavelength Shifts in Atomic Beam Devices, R. L. BARGER, K. G. KESSLER. J Opt

Soc Am v50 n4 Apr 1960 p 352-6. Light emitted or ab- sorbed by atoms in an atomic beam is shifted in frequency

relative to the frequency for a stationary atom if the light ray is not normal to the trajectory of the atom. The

magnitude of this shift is calculated and several devices which correct for this effect are described. For photoelectric recording of interference fringes, complete compensation can be achieved. In the case of photographic

recording, it is shown that the residual error is negligible. Sealed-Off Hg183 Atomic-Beam Light Source, R. L. BARGER, K. G. KESSLER. J Opt Soc Am v50 n7 July 1960 p 651-6. A sealed-off atomic-beam light source which

utilizes the single isotope Hg198 is described. The emitted 2537 A line was investigated interferometrically with

Fabry-Perot interferometers. Interferograms are shown

for retardations of 0.4, 1.53, and 2.04 m with order numbers 1.6, 6.0, and 8.1 million, respectively. For each re- tardation, the theoretical contour of the observed fringes

is shown. Theoretically predicted fringe contours are shown for retardations up to 6 m, the approximate limit of interference. It is concluded from the interferograms

that the Hg198 2537 A line has a half-width of 0.0016 cm"1

, as compared to 0.012 cm"1 for the Kr89 6056 A line proposed <j as the new primary standard of length. Owing to the small half-width and the extremely low level of perturbation in the atomic beam, this Hg198 line would be suitable j for the primary standard of length. Operation and Improvements of a Cesium Beam Standard i Having 4-meter Interaction Length, P. KARTASCHOFF.

IRE Trans Instrumentation (USA) vl-ll n3-4 Dec 1962 ; p 224-30. Some factors affecting the accuracy of a long ! ; caesium beam standard are discussed and the results of operation over 2 years are given. Increasing the inter- ; action length reduces the linewidth and thus the errors ! t in measuring the line center, as long as the s/n ratio is ! | sufficient. Errors due to nonlinearity of f.m. used in servo locking a crystal oscillator to the resonance are ]

j below 1X10"11

; other servo errors are smaller. The de- scribed variable C-field measuring technique and demagnetizable Armco iron shields reduce errors due to C-field uncertainty to 1.2x10"". Cavity phase shift effects are i below 1.5X10"U. Standard deviation of single measure- 'it ments with 4.6 sec averaging time is 2.7 X 10"u under good j conditions. Considering all effects, including those of I; microwave power and of cavity tuning, the stated figure of j accuracy is ±3XlO~n

, V.I.f. comparisons over 2 years J show agreement to about ±10"10 with respect to US Frej quency Standard. 12 figs refs. 2.3.7. Lasers

Resonant Modes in a Maser Interferometer, A. G. FOX, |

: j T. LI. Bell System Tech J (USA) v40 n2 Mar 1961 p 453-88. A theoretical study is made of the diffraction electromagnetic waves in Fabry-Perot interferometers when they are used as resonators in optical masers. An L electronic digital computer was programmed to compute

the electromagnetic field across the mirrors of the inter- ferometer where an initially launched wave is reflected ! I

' back and forth between the mirrors. It was found that it after many reflections a state is reached in which the rela- >\- tive field decays at an exponential rate. This steady-state

field distribution is regarded as a normal mode of the in-

| terferometer. Many such normal modes are possible de- . | pending upon the initial wave distribution. The lowest- order mode, which has the lowest diffraction loss, has a „

, high intensity at the middle of the mirror and rather low j j intensities at the edges. Therefore, the diffraction loss is ,| much lower than would be predicted for a uniform plane r

i wave. Curves for field distribution and diffraction loss are given for different mirror geometries and different modes. Since each mode has a characteristic loss and | phase shift per transit, a uniform plane wave which can be § resolved into many modes cannot be resonated in an in- J . terferometer. In the usual optical interferometers, the j j resolution is too poor to resolve the individual mode reso- , | nances and the uniform plane wave distribution may be

| maintained approximately. However, in an oscillating ( | maser, the lowest-order mode should dominate if the mirror spacing is correct for resonance. A confocal ; | spherical system is also investigated and the losses are | shown to be orders of magnitude less than for plane , mirrors. Atoms Inside a Perot-Fabry Interferometer, A. KAST- 1 * LER. App Optics (USA) Suppvl 1962 p 67-74 in French. 1 In the optical masers realized so far a Perot-Fabry device P is used as a multimode cavity. It may be interesting to investigate the general properties of such a device when

the emitting or the absorbing atoms are put inside the

reflecting mirrors. Even in the case when this device works below the threshold of maser action it shows re- markable properties which are worthwhile studying ex- perimentally. The following aspects are considered in

j 66
the paper. In the ease of external illumination, the dis- tribution of light intensity inside a Perot-Fabry interfer- ometer is calculated. It is shown that the local light intensity in the stationary waves inside can be much

higher than the intensity of the incident light beam. The

properties of light emitted by atoms inside the Perot- Fabry and emerging from it are investigated. Narrow

fringes of very strong intensity can be obtained. If the

emitting atoms are located in an atomic beam the central

fringe has natural line width, the Doppler broadening

being suppressed. The realization of a fluorescent me- dium of lamellar structure is discussed. This structure favours one special mode of emission fringes. Finally, the absorption of atoms inside the interferometer is studied. It is shown that this device is equivalent to a

long absorption path in an ordinary light beam.

Gaseous Optical Maser with External Concave Mirrors, W. W. RIGROD, H. KOGELNIK, D. J. BRANGACCIO,

D. R. HERRIOTT. App Optics (USA) Supp vl 1962 p

125-6. A helium-neon optical maser was operated successfully with concave mirrors external to the gas-discharge

tube. The latter is sealed at both ends with optically flat windows at the Brewster angle to the beam axis. This arrangement simplifies the tube construction and en- hances its versatility. The alignment of concave mirrors

is considerably less critical than that of plane mirrors. Measured beat frequencies between several pairs of con- cave resonator modes agree closely with computed values. Bibliography on Lasers, P. W. BECKER, S. E. BECKER

1962 51 p. Becker and Warren, Oak Ridge, Tenn.

Optical Properties of a Continuous Helium-Neon Optical Maser, D. R. HERRIOTT. App Optics (USA) Supp vl

1962 p 118-24. A continuous optical maser was operated

at five wavelengths in the near infrared. Such a maser

oscillator consists of a medium having optical amplification at the wavelength of interest and a Fabry-Perot inter- ferometer as a resonant cavity. The optical amplification is provided by maser action in a discharge through a mixture of helium and neon gas. The Fabry-Perot inter- ferometer is constructed within the gas volume using two

very flat, and highly reflecting, parallel silica plates. The

transmission of the Fabry-Perot plates, although small, allows a beam to pass through each end window, with

four milliwatts of continuous output power in the strongest transition at 1.153/* wavelength. Examination of the beam shows that it is almost diffraction limited for its one-centimeter diameter. The spectral line shape at each

transition is made up of three or more components each

less than a few hundred cycles in width separated by the

spacing of orders in the interferometer.

Optical Properties of a Continuous Helium-Neon Optical Maser, D. R. HERRIOTT. J. Opt Soc Am v52 nl Jan

1962 p 31-7 15 figs 8 refs. A continuous optical maser was

operated at five wavelengths in the near infrared. Consists of a medium having optical amplification at the wavelength of interest and a Fabry-Perot interferometer

as a resonant cavity. Fringes have been observed out to a

path difference of 48 in. Gaseous Optical Maser with External Concave Mirrors, W. W. RIGROD, H. KOGELNIK, D. J. BRANGACCIO,

D. R. HERRIOTT. J App Phys v33 n2 Feb 1962 p 743-4. Helium-neon optical maser operating with concave mirrors external to gas discharge tube ; alignment of concave

mirrors is considerably less critical than that of plane

mirrors ; measured beat frequencies between several pairs

of concave resonator modes agree closely with computed

values. Measurement Units Used with Lasers, B. F. LUDOVICI.

Electronics v35 nl6 Apr 20 1962 p 54 56. Nomograph de- termines relationships between units that express characteristics of lasers and other optical and infrared devices

among these units are Angstroms, electron volts, tera- cycles/sec. and wave numbers. Zeeman Effect in Gaseous Helium-Neon Optical Maser,

H. STATZ, R. PAANANEN, G. F. KOSTER. J App Phys

v33 n7 July 1962 p 2319-21. Strongest emission in helium- neon gas maser corresponds to transitions between 2s2 and

2pi states of neon which have angular momenta of 1 and 2, respectively ; these levels split up in a magnetic

field and maser output contains differently polarized radiations of slightly different frequencies ; interesting effects may be observed when various Zeeman components res- onate in different cavity modes of Fabry-Perot inter- ferometer. Construction of Gaseous Optical Maser Using Brewster

Angle Windows, D. J. BRANGACCIO. Rev Sci Instrum

v33 n9 Sept 1962 p 921-2. Materials, tools and techniques used to make successful gaseous optical maser ; details of gas discharge tube that consists of two optical quality

glass windows, held at Brewster angle, mounted in hemispherical bulbs and connected together with quartz tube through appropriate graded seals ; other design features. Frequency Stabilized Lasers, J. LaTOURRETTE, P. RABINOWITZ, G. GOULD. IEEE Nat Aerospace Elec- tronics Conference—Proc 1963 p 99-101. Theoretical ad- vantages of optical heterodyne detection and its experi- mental verification; application of automatic frequency

control (afc) to laser which has successfully traced fre- quency of 2nd free-running laser; using 10.7 Mc IF, spread in beat-frequency spectrum was plus or minus 3 kc with afc feedback, 100-to-l improvement over short- term frequency stability without feedback, giving track- ing accuracy of plus or minus 1 part in 10u of oscillator frequency ; beam splitter makes output of transmitter and

local-oscillator lasers spatially coherent, impinging them

into photodetector. Modes in Maser Interferometer With Curved and Tilted Mirrors, A. G. FOX, T. LI. IEEE Proc v51 nl Jan 1963 p 80-9. Two simple forms of aberrations in Fabry-Perot

interferometer are studied; first is represented by tilted plane mirrors and second by curved mirrors ; tilting mirror causes mode patterns to become asymmetric and dif- fraction loss to become greater ; in case of interferometers with mirrors of arbitrary radii of curvature, there exist regions of low loss and high loss as mirror spacing is varied ; loss function can be represented by contour map

of 3-dimensional model ; model is useful in choosing proper mirror spacing for low loss operation of optical masers.

Isolation of Axi- Symmetrical Optical-Resonator Modes, W. W. RIGROD. App Phys Letters v2 n3 Feb 1 1963 p 51-3. Photographs of 15 isolated TEM modes of concave

mirror interferometer used as external cavity of gaseous He-Ne maser tube with Brewster angle windows ; isolation mechanism appears to depend on physical processes in maser medium, rather than on purely optical Lasers, T. R. LAWRENCE, NBS. J Washington Acad Sci v53 Feb 1963 2 figs 13 refs. Discusses atomic processes and coherent light amplification, oscillators using co- herent light amplifiers, solid state lasers, gas lasers, re- search and applications. Interference Fringes With Long Path Difference Using He-Ne Laser, T. MOROKUMA, K. F. NEFFLEN, T. R. LAWRENCE, T. M. KLUCHER. J Opt Soc Am v53 n3 Mar 1963 p 394-5 3 figs 3 refs. Interference fringes pro- duced by coherent light from a He-Ne gas laser have

been observed at optical path difference up to 9 m (mirror

separation =4.5 m) on a Michelson interferometer. Frequency Stability of He-Ne Masers and Measurements

of Length, T. S. JASEJA, A. JAVAN, C. H. TOWNES.

Phys Rev Letters (USA) vlO n5 Mar 1 1963 p 165-7. Experiments to determine the frequency stability of He-Ne

67
optical masers under carefully controlled conditions are

described ; measurements were taken on the laser transi- tion at 1.153/x. The technique of photoelectric mixing

between two similar lasers was employed. A frequency

stability of about eight parts in 1014 and a frequency re- settability of 10" are claimed. A frequency drift of a few tens of cycles per second was measured. The short term stability is within one order of magnitude of the

theoretical limit of the device. This frequency stability

is discussed in relation to accurate measurements of length and preliminary measurements, repeating the Michelson- Morley experiment, confirm the Lorentz-Fitzgerald con- traction due to the earth's orbital velocity to one part

in 103

. Optical Maser Frequency Stabilisation and Precise Wavelength Measurements, E. A. BALLIK. Phys Letters (Netherlands) v4 n3 Apr 1963 p 173-6. The output from a

photomultiplier, illuminated by maser light travelling

via 2 corner reflector mirrors in a Michelson interferometer, is used to control (a) an external "cavity" (the

difference in length between the two interferometer paths

)

or (b) the maser wavelength. The control voltage is ob- tained by sinusoidal variation of the position of one of the mirrors. Control of the "cavity" to 1 part in 10s is possible. Block diagrams are shown of the system as applied

to precise measurement of lengths and wavelengths.

Interference Fringes Produced by Superposition of Two

Independent Maser Light Beams, G. MAGYAR, L. MANDEL. Nature (GB) vl98 Apr 20 1963 p 255-6. The in- terference of light from two slits has been observed when

the slits are illuminated with two ruby lasers, which emit

light with a photon degeneracy parameter much greater than unity. The output from each laser is coherent for only about % microsecond, and the emission is in the form

of random spikes. Photographs showing fringes were

obtained by the use of a gated image tube ; the interfering beams fell on the photocathode and the grid of the tube was normally biassed off except when two coincident

spikes were emitted from the lasers. Photographs of the screen of the image tube occasionally show fringes of the expected spacing and visibility. Fringes are not always

obtained because of the variations in frequency from the two lasers due to thermal effects. The observed effects are describable in completely classical terms. Construction of a Gaseous Optical Maser Using Brewster

Angle Windows, K. M. BAIRD, M. J. TAYLOR, R. TURNER. Rev Sci Instrum (USA) v34 n6 June 1963 p 697. A technique is described for sealing the windows

to an all-quartz discharge tube for use in an external re- flector He-Ne optical maser. The ends of the tube are ground at the Brewster angle and the windows are fused on by localized heating, followed by annealing. No dimensions are given. Wave-Length Stabilization of Optical Maser, W. R. C. ROWLEY, D. C. WILSON. Nature (London) v200 n4908 Nov 23 1963 p 745-7. Use of 6328 A line of helium-neon maser for interferometric length measurements is hin- dered because, in spite of its narrow bandwidth at any

instant, wavelength of light can vary ; simple way of im- proving wavelength or frequency stability is to adjust

length of cavity ; servo-control system does it continuously by simple electromechanical coupling.

Sur des interferences avec grande difference de marche

obgenues avec un laser a gaz, R. GRUDZINSKI, M. PAIL- LETTE. CR Acad Sci v257 n25 Dec 16 1963 p 3842-

3. Interferences with large differences of modes obtained with gaseous laser; Michelson-type interferometer was

constructed for determination of limitations in duration

of temporal coherence caused by conditions of practical use

of gas laser, i.e., fluctuations of air indices and mechanical

vibrations of soil ; photographs of fringes presented. Coherent Light and Abbe's Sine Law, P. W. WEBER.

Int Sci and Techno n25 Jan 1964 p 13. Discusses angular

spread in the far field for a laser oscillating in a single mode. A Laser With a Multihole Diaphragm, T. MOROKUMA.

J Res NBS v68C nl Jan-Mar 1964 p 25-34 20 figs 6 refs. The properties of a laser with a multihole diaphragm were

both theoretically and experimentally examined. This

laser may be called a multibeam laser. Laser action was

observed in the optical paths which were defined by the

position of the holes and the cavity configuration. Inter- ference fringes were observed on one of the cavity mirrors. A wavelength dependent interaction among the beams was

observed. It is believed that the wavelength of a beam

can be stabilized by the intensities of the other beams. A

possible method will be proposed for the stabilization. Helium-Neon Laser and its Potentiality for Length Measurement, D. C. WILSON. Machy (London) vl04 n2683 Apr 15 1964 p 875-8. Functioning of helium-neon laser is described in simple terms and nature of its light dis- cussed ; laser offers considerable advantages over normal

light sources for application to precise length measurement. Lasers for Length Measurement, A. G. McNISH. Science vl46 n3641 Oct 9 1964 p 177-82 6 figs 8 refs. Lasers are

useful in metrology because of the high coherence and

intensity of the light they produce. Discusses the laser

principle, measuring with light waves, wavelength of laser light, measurement applications, lasers as length standards. Laser Interferometer, F. H. LONDON. Instrum Control Syst (USA) v37 nil Nov 1964 p 87-9. A single-mode laser with special optical and digital techniques has been de- signed for accurate industrial gaging, termed an absolute interferometric laser (AIL). It is of the double- beam type with a reflector on the travelling part of the machine using a gas laser at 6328 AU; the operating j length is 100 in. and accuracy is either 0.00003 in., or

0.0001 in. per ft. The problems involved are stated with

their solutions in tabular form. A block diagram an<1 outline specification are given. Accurate Length Measurement of Meter Bar With Helium- Neon Laser, K. D. MIELENZ, H. D. COOK, K. E. GIL- LILLAND, R. B. STEPHENS. Sci vl46 n3652 Dec 25

1964 p 1672-3 1 fig 4 refs. A helium-neon gas laser has

been successfully used in conjunction with an automatic

fringe-counting interferometer to measure the length of a meter bar. The agreement obtained was 7 parts in 100

million with respect to the assigned length of the bar.

2.4. Length and Diameter Measurements

2.4.1. General

Sur la Mesure en Longueurs d'Onde des Dimensions d'un Cube de Quartz de 4 cm de Cote (On the Measurement in Wave-lengths of the Dimensions of a Quartz Cube 4 cm

on a Side), C. FABRY, J. M. DE LEPINAY, A. PEROT. CR Acad Sci vl28 1899 p 1317-9. The solid to be measured

is placed between two planes of silvered glass, AA', so that

the faces a, a' of the solid are parallel to the planes. Results are accurate to 0.1/* in 4 cm.

Optical Measurements of Thickness, J. M. DE LEPINAY. CR Acad Sci vl34 Apr 21 1902 p 898-900. A differential fringe method is described which obviates the necessity GH
of knowing the refractive index of the lamina to be $ measured.

:al

1 1 Optical Measurements of Thickness, J. M. DE LEPINAY,

H. BUISSOX. CR Acad Sci vl35 Aug 4 1902 p 283-6. The

method of carrying out the principle given in a former

paper is briefly described, and results are given of the measurement of the thickness and refractive index of a

plate of quartz, cut parallel to the axes, for the ordinary

ray. The method is considered accurate to 0.02-0.01^

for the thickness, and to the sixth decimal place for the

V; refractive index. Errors of Micrometer Screws, E. KEIL. Zeit fiir In- strumkde v28 Aug 1908 p 243-5. Determination of mi-

... crometer screw errors by mounting them in conjunction

Iz with a standard Michelson interferometer.

z! La Mesure de Petits Etalons Industriels a Faces Planes

par une Methode Interferentielle (Measurement of Small

"V Gages by Interference), A. PERARD. CR Acad Sci vl54 Z June 24 1912 p 1798-1800. Small Johansson gages from _ ' 5 mm downwards are measured by interference bands formed between glass slabs and the gage surfaces. The

errors for 5 mm gages average 0.11m and for 1 mm gages

|| OMn.

Sur un Proeede Pour la Gomparaison et la Mesure en

. Valeur Absolue des Etalons a Bouts Plans, au Moyen des

Interferences Lumineuses (Absolute Measurement of

, Length Gages by Optical Means) , A. PERARD. CR Acad

Interferences Lumineuses (Absolute Measurement of

Sci vl70 Feb 16 1920 p 390-2. Describes a method for determining the dimensions of Johansson gages in terms

of wave lengths of monochromatic light. It has been shown previously that the interspace between the sur- faces of two gages is less than .02/i and the method of measurement proposed consists in placing the gage to be measured in contact with a plane steel surface of greater area. Upon the other surface of the gage is placed

a reference plane of glass. Thus, by suitable arrange- ments described it is possible to deduce the thickness of the gage. Measurements up to 15 mm are possible. The Calibration and Dimensional Changes of Precision Gage Blocks, C. G. PETERS, H. S. BOYD. Am Mach v53

Sept 30 and Oct 7 1920 p 627-32 and 674-9 20 figs. Sept. 30 : How planeness and parallelism errors of precision sur- faces in gage blocks are determined ; and Oct. 7 : Comparison of gages by means of light waves. Tables and

charts showing results of experiments. Force required to separate optically plane surfaces (precision gage blocks). Thickness of oil film on precision gage blocks. Priifung von Johansson Endmassen mit Lichtinterferenz

(Testing of Johansson End Measures by Light Interfer- ence) , W. KOSTERS. Feinmeehanik vl Jan 7 14 21 1922 p 2-5 19-20 39-41. Interference Methods for Measuring Johansson Blocks,

A. PfiRARD. Rev d'Optique vl May 1922 p 209-31. In- terference method consists in placing the block between

two parallel plates, the upper one being glass so that a uniform air layer remains between the glass and the upper

surface of the block and proceeding as in the usual Fizeau experiment to observe the fringes due to the air layer formed by monochromatic light. By using

several kinds of monochromatic illumination, 8 in all, whose values of X vary from 640.224 m/i to 435.832 m/i, the

actual length required is evaluated by certain series for- mula quoted. An apparatus for comparing 3 blocks set up

between the parallel plates is also described and sketched. Interference Methods for Standardizing and Testing Precision Gage Blocks, C. G. PETERS, H. S. BOYD. Sci Papers NBS n436 May 2 1922 p 677-713 21 figs. Use of

interference of light waves makes possible detection of errors within a few millionths of an inch.

Measurement of Primary Standards by the Interferometer Method. Machy (London) v20 May 18 1922 p 189-93 6

figs. Checking gage blocks by NPL comparator: an ex- tremely sensitive mechanical apparatus for testing accu- racy of precision slip-gages. Metodi Attuali per lo Studio dei Calibri Industriali per Mezzo Delle Interferenze Luminose (Present Methods of Testing Industrial Standard Measures by Means of Optical Interferences). Rivista d'Ottica e Meccanica di Precisione v2 Dec 1922 p 60-73 5 figs. Application of

optical method to Johansson's standards for extreme

precision. Precise Length Measurements, J. E. SEARS. Roy Soc

Arts J v71 Oct 5, 12, 19 1923 p 775-91, 793-818, 819^1.

Cantor lectures. Describes in outline the methods used

for maintenance of the fundamental standards of length, the yard and the meter, and their mutual comparison.

Describes principles underlying the use of wave lengths as absolute units, and determining legal standards in terms of wavelengths. Methods used for comparison of substandards are described in detail, with precautions to eliminate errors. Whole paper forms a useful summary

of the theory and practice of length measurements to the highest accuracy attainable at present. Die Anwendung der Interferenz des Lichtes im Lehren- bau (Application of Interference of Light in the Construction of Gages), G. BERNDT. Deutsche Optische Wochensehrift vlO June 1 8 and 15 1924 p 265-9 and 282-

5 302-8 14 figs. Discusses use of light waves as constant

length measure and application of its property of inter- ference for testing accuracy of gages ; particulars of Rosters interference comparator.

Interferometers for Calibrating Standards of Length. Eng vll8 Oct 3 1924 p 491-2 2 figs. Describes apparatus made by Adam Hilger, Ltd., by which accurate standards

of length can be originated ; apparatus was ordered by

Japanese Government because meter has been adopted as

sole legal standard of length, and authorities wished to have apparatus by which residual error in existing inter- national standard could be accurately measured, and other standards produced. Gives exact method of halving

lengths of 20 in., etc. Ein neuer Interferenzkomparator fiir unmittelbaren Wellenlangenanschluss (A New Interference Comparator for Directly Measuring by Light Waves), W. KOSTERS.

Zeit fiir Feinmeehanik und Prazision v34 Apr 5 1926 p 55-

9 5 figs ; Deutsche Optische Wochensehrift vl2 3 figs 5

refs. Describes the Kosters absolute interferometer and

auxiliary slide rules. tiber die Langenmessung mit Hilfe der Lichtinterferenz (Measuring Length by Means of Light Interference), Y. VAISALA. Zeit fiir Instrumkde Aug 1927 p 398-402 2 figs. Description of quartz-meter apparatus and methods used

at the University of Turku, Finland, in measuring a dis- tance of about 24 m with error not exceeding 1 in

10,000,000. Calibration of an End-Gage Comparator by the Interfer- ence Method. Eng vl24 Nov 4 1927 p 577 4 figs. Design by

J. E. Sears for measurement between flat faces which must

be maintained in perfect parallelism. Measuring Standards of Length With Light, H. SIMON.

Eng Progr v9 Oct 1928 p 265-9 10 figs. How reference standards and other parts are measured directly by means

of light interference within limits of less than millionth of inch ; new instrument, absolute interference comparator,

designed by W. Kosters and built by firm of Carl Zeiss, Jena ; measurements are made by direct comparison with wavelengths of light, yet as rapidly as measuring with

such extreme precision will probably ever be ; comparator
or "Inko" is mainly intended to check size blocks and

gages of size-block type ; light used is derived from helium

lamp.

Applications Pratiques des Interferences Lumineuses, a L'Etude des Calibres Industriels et Autres Longueurs a Bouts (Practical Applications of the Interference of Light, a Study of Industrial Gages and other End Length Standards), A. PERARD. Trav et Mem du BIPM vl8 1930 85 p 32 figs 4 appendixes. Describes a new industrial inter- ferometer for comparative and absolute measurements. Research on the whole number of the order of interference. Simultaneous determination of several gages. Influence of the quality of surfaces. Optical Measurement of Thickness. Interference Micrometer, H. KREUSLER. Zeit fiir techn Physik vl3 1932 p

241-3. A wedge-shaped air film of constant length (10 cm)

is formed between two glass plates which are in contact

at one end and separated at the other by the object whose

thickness is required. Parallel interference fringes are obtained when the film is illuminated normally with

parallel monochromatic light, and the thickness of the

object can be deduced simply from the fringe width, meas- ured by means of a low-power traveling microscope. For

thicknesses less than 0.02 mm the accuracy obtainable is about 0.1/*. Axial Arrangement for the Measurement of Length by the Interference of Light, J. STULLA-GOETZ. Zeit fuer Instrumkde v52 Dec 1932 p 521-4. A Michelson inter- ferometer, illuminated with parallel white light, carries a half-silvered plane-parallel glass plate in one path. The

multiple reflections arising in this path enable optical multiplication of length to be performed by a simple process in which the mirror in the other path is used as an

auxiliary to increase by 3 times the original separation of the mirrors in the first path, using the central white-light fringe as an indicator. Interferometer for Testing Gauges, C. F. SMITH. Machy

(London) v42 nl082 July 6 1933 p 393-5. Apparatus de- signed primarily for use in connection with manufacture

of silica plates employed in Williams echelon ; extreme ac- curacy required in order that requisite optical effect should be produced made it necessary to design means

for testing, and double interferometer developed by F. Twyman and J. H. Dowell enabled this to be done; ap- paratus suitable for examination and testing of gages. Note sur la Determination D'Etalons Millimetriques et Centim6triques en Longueurs D'Onde Lumineuses (Note on the Determination of Millimeter and Centimeter Standards in Wavelengths of Light), J. R. BENOIT, A. PERARD. Trav et Mem du BIPM vl9 1934 54 p 9 figs. Interferometric comparison of Michelson etalon and small

scales. Reduction of observation including correction for the refractive index of air. Interference-Type Indicator for Precision Micrometer. Eng vl48 n3835 July 14 1939 p 57-8. Description of instru- ment known as Van Keuren light wave micrometer, used

in production of numerous types of Galex precision gages, made by G. H. Alexander Machinery, Ltd. Etude des Etalons en Quartz, Temoins de L'Unite' M£trique

Internationale. Valeurs. Di'latabilites. Indices. (Study

of Quartz Etalons, Embodiment of the International Metric Unit. Values, Expansions. Indices.) A. PERARD.

Trav et Mem du BIPM v20 1944 176 p 26 figs 13 ap- pendixes. Principles of the methods of measurement by

interferometry ; instruments ; execution of the measure- ments—calculation of the excess fractions ; form and rela- tive position of the end faces; indices of refraction of quartz. Hilger Gauge-Measuring Interfermoters. Machy (Lon- don) v69 nl770 Sept 12 1946 p 340-3; see also British

Patent 555, 672 23 Feb 1942. Operating details of gage comparing interferometer, and gage interferometer for measurement of absolute length, developed by Adam

Hilger, Ltd. Interferometers. Automobile Engr v37 n487 Apr 1947 j p 137-8. Illustrated description of Hilger instruments for comparative or absolute measurements in wavelengths of

light. Measurement of Thickness of Infra-Red Absorption Cells.

J. H. JAFFE, H. JAFFE. J Opt Soc Am v40 Jan 1950 p 53-4. A new interferometric method is described. An

accuracy of 0.2/u is obtained independently of the thickness. The advantages over methods previously described are that the cell plates need not be parallel and the wedge !! angle between them is determined with the thickness. The thickness measured is not an average value. It is possible to map out the profile of the cell. The method may be used even when the cell plates are very irregular.

I Interference Methods for Producing and Calibrating End

Standards, C. G. PETERS, W. B. EMERSON. J. Res NBS

v44 n4 Apr 1950 (RP2089) p 419-42. To compare results : : of interferometric methods of measurement used at Bureau with those of other national laboratories, etalons of i fused quartz were made and calibrated; they were then 1 sent to Bureau International des Poids et Mesures, Physi- I kalisch-Teehnische Bundesanstalt, and National Physical Laboratory for calibration ; lengths of etalons as determined by various laboratories are given. Bibliog- raphy. |: Interference Method for Measurement of Microscopic

Spheres, B. W. WILSON. Austral J App Sci vl n3 Sept

1950 p 235^1. Measurement of size of glass spheres ranging from 0.5-25 microns in diam ; interference method was used, consisting essentially of packing spheres into very shallow wedge shaped cell for size classification and ;

i for viewing against background of interference fringes ;

i results given for two types of cell. Length-Determination, L. E. GLOVER. Aircraft Prod

vl3 nl54 Aug 1951 p 230-3. Principle and application of

direct measurement interferometer; instrument designed i by National Physical Laboratory and manufactured by

Pitter Gauge and Precision Tool Co., requires light of ,

! several colors to be available in order to determine any , given length and for this purpose, hot cathode cadmium

lamp radiation is used to provide red, green, blue and ,„ violet colors. Interferometers for Measurement of Gauges. Engr vl92 i n4989 Sept 7 1951 p 300-2. Two forms of instrument de- veloped by Hilger and Watts; comparison interferometer used in toolroom for comparative measurements on gages up to 10 in. long and interferometer for measuring absolute '< length of gages up to 12 in. long ; illustrations. Interferometer for Measuring Slip Gauges, D. C. BARNES, , M. J. PUTTOCK. Eng vl76 n4585 Dec 11 1953 p 757-9

Engineer vl96 n5107 Dec 11 1953 p 763-6 ; Machy (London) ,j v83 n2143 Dec 11 1953 p 1170-5, 1178 ; Machine Shop Mag iil

,' Dec 1953 11 p 5 figs 4 refs. New interferometer, intended ji for routine measurement of length dimension of high i\ t- quality slip gages up to 4 in. in terms of light waves, de- ,| veloped by National Physical Laboratory; optical a ; principle. Use of Light Waves for Controlling the Accuracy of Block 1 [ Gauges (Gauge Blocks), F. H. ROLT. Hilger and Watts, \ Ltd. London Jan. 1955 19 p 19 figs. All requirements for i i flatness, parallelism, surface finish, smoothness of edges of J

faces, and absolute size lend themselves to checking by ,j 1 interferometry. On the Principal Errors of Measurement in Schlieren and I

: Interference Methods, H. WOLTER. Ann Phys (Leipzig) 1 70
vl9 nl-2 1956 p 1-9 in German. The limits of sensitivity are roughly the same for both methods, but the experi- mental limits of error are higher for schlieren methods. The scatter of the measured values (e.g. of refractive index) is equal to the geometric mean of the limit of sensitivity and the experimental limit of error. The Measurement of the Thickness of Thin Objects with an Incident-Light Interference Microscope, G. SCHULZ.

Naturwissenschaften v43 n2 1956 p 31-2 in German. A

description is given of a Michelson-type interferometer with a microscope object in the aperture which enables

the thickness of opaque thin bodies to be measured. In

essence the arrangement measures the location successively of the planes from the front and back of the object with respect to a reference mirror in the Michelson inter- ferometer system. The separation between the front and

back surface is thus secured even for completely opaque On the Interferometric Measurement of Length with a

Photoelectric Method of Observation, J. TERRIEN, J. HAMON. CR Acad Sci (Paris) v243 n9 Aug 13 1956 p

740-2 in French. The real image of the interference rings formed at infinity in a Michelson interferometer is focused

)n an aperture behind which there is a photoelectric cell. By adjusting a compensating plane, the phase of the cen-

;re of the ring pattern may be set to a standard value and

hus lengths may be measured in terms of light waveengths. The method is more sensitive than visual or motographic measurements and with it a number of sys- :ematic errors should be avoided ; it has been checked by

re-determining certain wavelengths in the Hg198 spectrum

in terms of that of the green line 5461 A, the results agreeing to ±1 X 10"V- Measurement of a Profile in Coherent Light, J. C. VIENOT. Rev Opt v35 nlO Oct 1956 p 517-25 in French. The measurement of the diameter of a small object, such

as a thread, is difficult with incoherent light because of the

out of focus images of the third dimension. The diameter

can be measured more precisely from the diffraction fringes formed with coherent light. Conditions are ob- tained for best definition and most accurate measurement.

Sample results are quoted. Modified Method of Fizeau Fringes for Thickness Measurements, H. OSTERBERG, D. LaMARRE. J Opt Soc Am

v 46 nlO Oct 1956 p 777-8. The exit slit of a monochromator is focused upon a pinhole located in the first focal plane of an objective utilized for viewing the multiple- beam fringes formed by interreflections between two in- clined surfaces, one of which is stepped. The step is focused into the plane of an eyepiece whose reticule contains a pair of parallel lines between which successive

fringes are set and measured by rotation of the wavelength drum. The preferred, and possibly novel, method

of interpreting the observations is discussed. Precision Measurement, I. C. GARDNER. Ordnance v41

n222 May-June 1957 p 1099-1100. Reports good progress

in producing an interferometric system which gives a precision of 10"7 in. as a standard for measuring gage blocks. New Techniques in Interferometric Metrology at the National Research Council of Canada, K. M. BAIRD. J Phys Radium vl9 n3 Mar 1958 p 384-9 in French. Deals

with some of the new techniques which are being used to

assist in the redefinition of the international meter. The

first of these is a method of cyclical scanning of the inter- ference fringes formed by the Fabry-Perot etalon. The

scanning is done by pressure changes in the atmosphere

surrounding the etalon. This method has been applied to the measurement of small wavelength shifts. A modification of this technique, using a photographic record, enables a great many spectral lines to be recorded simultaneously. An interferometer, based on Michelson's type,

makes use of a technique whereby precise determination of the order of interference can be made conveniently ; it enables line standards of length to be calibrated as easily as end standards. New Gauge Interferometer, P. HARIHARAN, D. SEN.

J Opt Soc Am v49 n3 Mar 1959 p 232-4. An interferometer

for the absolute measurement of the length of end stand- ards is described in which the optical path difference in- troduced between the interfering beams is only half the

length of the gage. This permits the direct measurement

of gage blocks up to 1 m long with the isotope sources

currently available. Other advantages of the instrument

are its relatively compact layout and simplicity of operation. Application of Interferometry to the Routine Measurement

of Block Gauges, S. P. POOLE, J. H. DOWELL, NPL.

Optics in Metrology, P. MOLLET. Pergamon Press 1960 p 405-19 8 figs 2 refs. An interferometer designed at NPL in 1937 deals with twenty gages in one operation. Methods employed are given with a brief survey of sources

of error. Interferometer is illustrated with details of im- provements.

Introduction to Interferometry, T. J. O'DONNELL. Am

Mach/Metalworking Mfg vl04 nl2 June 13 1960 p 123-46. How interferometers can be used in shop to measure and

compare lengths, angles, parallelism, and surface condition. Interferometric Instrument for the Rapid Measurement of Small Diameters, D. H. BLACKBURN. Rev Sci Instrum (USA) v32 n2 Feb 1961 p 137-9. The test fibre is placed between two optically flat surfaces and, using the fibre as a fulcrum, the upper flat is adjusted until the surfaces

are parallel ; the absence of interference fringes between

the surfaces is used to indicate parallelism. Controlled

tilting of the upper flat is obtained by adjusting, with a micrometer screw, a sliding wedge under a lever attached

to the upper flat. The fibre diameter is a linear function

of wedge position as indicated by micrometer screw set- ting. Spectrophotometric Studies on Inorganic Crystals. II. Measurement of Thickness of Thin Crystals by Interfer- ometry, Y. KONDO. Sci of Light Japan vlO n3 Dec 1961 p 167-75. Twcnbeam and multiple-beam interference methods are applied to the measurement of thickness of some inorganic monocrystals and the advantages of the two methods are compared with each other. Although the multiple-beam method has greater accuracy than the two- beam one, the latter is more suitable than the former for microspectrophotometry of rather thick and coloured

crystals. Use of monochromatic light from a monochro- mator is advisable, for continuous varying of wavelength

simplifies the measurement. In some instances, use of continuous variation of refractive index of medium is advantageous. The relation between interference fringes due to monochromatic light is experimentally investigated. Certain Changes in the Regulations for Checking and

Using Block Gauges, L. K. KAYAK. Meas Techn 1961 n6 Dec 1961 p 427-31 1 fig 4 refs. Translated from Izmer Tekh n6 p 1-5 June 1961. Evaluates measurement errors

of interferometric methods of measuring gage blocks. Causes of Errors in Interference Metrology, M. CONSTANS. Rev Opt (France) v40 nl2 Dec 1961 p 601-48 in French. The universal use of interference methods in aerodynamics makes evident the need for a systematic study of the errors associated with such methods. These

errors are classified into four different types: (1) errors due to the refraction, i.e. to the curvature of the rays owing to the refractive index gradient ; (2) errors altering the gradients themselves (draught, vibrations, change in temperature . . .) ; (3) errors due to the instrument itself and to the adjustment conditions ; (4) errors due to the 71

771-846 0—66 6
interpretation of results. The first errors due to refrac- tion are theoretically studied for a two-dimensional medium where the refractive index is varied continuously. The calculation was carried out in the second order ap- proximation. Two types of errors may occur; (a) errors

affecting all real objects placed into the jet or up-stream ; (b) errors affecting only the interferogram fringes. It

is shown that the last ones can be cancelled out, provided

that the focusing plane is situated at the second third down-stream of the jet. Formulae for an evaluation and

correction of errors are given. The values obtained are compared with the accuracy yielded by the measuring in- strument. It is concluded that those errors are very often

negligible both in interferometry and in strioscopy. For

the experimental checking, the gradients are obtained by

diffusion of a hyposulphite crystal into distilled water or by diffusion of a concentrated solution of hyposulphite salt into distilled water. The results obtained concern a zero incidence angle : ( 1 ) The errors affecting the interfero- grams appear to be very small as compared with those re- sulting from the instrument imperfections, wherever the focusing plane may be inside the jet and whatever the thickness of the jet may be ( 100 or 10 mm) , provided the

gradients remain smaller than 5 X

10~5 mm-1

. (2) The

formulae giving the deformation of a real object are checked for several positions of the object and for several gradient values. Very often the checking corresponds to an accuracy of about 6 or 8%. It is always better than 15%. Errors not resulting from refraction are studied experimentally : the equipment described makes it possible

to get rid of them. It consists of a horizontal MachZehnder interferometer realized in silica. Over the whole

field (60 x 60 mm) the residual defect is smaller than

X/13. By an isothermal jacket the temperature is kept

constant to better than 0.03 °C in the course of 12 hours. Vibrations are eliminated by means of an elastic suspension. A Method of Measuring Very Small Optical Paths', A. MARECHAL, O. DUPUY, M. RENAULT. Optica Acta

( Int) v9 nl Jan 1962 p 47-54 in French. Describes a method, derived from the three-slit method of Zernike, which

permits the measurement of differences of optical path

length of the order of 10 A, while giving a much higher luminous flux than the original method. It can be used,

for example, for the measurement of phase plates, of very small refractive index differences ( in glass, liquids or gases) and it can be used on very small samples. Interferometry in Length Measurement, J. L. GOLDBERG, R. H. BROOKMAN. Electronic Technol v39 n4

5 6 Apr 1962 p 140-4, May p 186-91, June p 238-43. Electronic counting of interference fringes enables automatic and accurate measurement to be made ; problem of extracting useful signal from moving 2-beam interference

fringe pattern is discussed; circuit for amplification of small photoelectric currents encountered in transduction

of light output of interferometer by photomultiplier, and

subsequent generation of counting waveform by trigger

circuit ; application of circuit to reversible counting. Inspection Time Slashed on Parts Adaptable to Coordinate Measuring Techniques, C. H. WICK. Machy (NT) v69 n2 Oct 1962 p 107-9. Inspection time was reduced by about 80% (on applicable parts) and quality control greatly im- proved by means of Sheffleld-Ferranti coordinate measuring machine at Plymouth (Mich) Div of Burroughs Corp;

bole and surface locations can be quickly and accurately measured on this machine, With dimensions of both X and Y coordinates being displayed simultaneously on direct readout panel ; lengthy and laborious bench checks with

gage blocks, surface plates, and height gages are no longer

required. Methods of Narrowing Spectral Lines for Interference Measurements of Length, A. P. KIRICHENKO. Uspekhi flz Nauk (USSR) v78 n3 Nov 1962 p 525-38 in Russian.

English translation in : Soviet Physics- Uspekhi (USA) v5 n6 p 998-1005 May-June 1963. A detailed review is given

of some methods employed for the production of strictly monochromatic radiation having breadth smaller than

the Doppler breadth. The methods described are inter- ference monochromatization using a spherical FabryPerot etalon, absorption monochromatization in which

radiation is transmitted between two close-lying absorption lines produced by Zeeman splitting and an interfer- ence-compensation optical scheme. Laser techniques are only briefly mentioned.

Application of Microwave Techniques to Noncontact

Precision Measurement, D. H. PARKES. ASME-Paper

63-WA-346 for meeting Nov 17-22 1963 5 p. Developments

in application of microwave interferometry in cases where

standard gaging equipment is limited either by contact

characteristics, or frequency response, or peculiarities of material or gaging situation. Method for Precise Evaluation of Interferograms, G. D. DEW. J Sci Instrum v41 n3 Mar 1964 p 160-2. Photoelectric scanning device is described, capable of evaluat- ing interferograms of 2-beam interference systems to 1/100

fringe or better ; precision is attained with barest mini- mum of equipment. Fringe Pattern of Oscillating Fabry-Perot Interferometer, K. D. MIELENZ. J Res NBS Eng & Instrum v68C n2 Apr-June 1964 p 73-81. Experiments and theory of de- pendence of fringe pattern upon vibration amplitude; if fringes of stationary interferometer are wide, fringe pat- tern tends to disappear at certain values of amplitude;

if stationary fringes are narrow, splitting of fringes oc- curs at certain amplitudes ; in both cases, stationary pat- tern reappears, with reduced contrast, at intermediate amplitudes; applicability for measurement of vibration amplitudes is discussed. Measurement of Fringe Displacement in a Gauge Inter- ferometer, M. J. PUTTOCK. J Sci Instrum (GB) v42 n4 Apr 1965 p 298-9. A description is given of a second de- vice for the measurement of fringe displacements in a gauge interferometer. This device is located in the parallel beam of the interferometer whereas the original device was located in a plane conjugate with the lapped surface

of the baseplate. 2.4.2. Fringe Count Interferometers and

Dilatometers

Tiber die Ausdehnung starrer Korper durch die Warme

(Regarding the Expansion of Rigid Bodies by Heat), H. FIZEAU. Ann der Phys vl28 Oct 3 1866 p 564-89. In- cludes a brief review of the methods of observation applying fringe count methods. These had been previously described in CR Acad Sci May 1864 and Ann Ohim Phys

Ser IV T II vl23 p 515. Millimeter and Centimeter Standards, R. BENOIT. Bui

Soc Franc Phys n97 1897 p 2-3. Standards, by the Bureau

International des Poids et Mesures are described, on the

principle of measuring displacements by the travel of cir- cular fringes in a Michelson's refrac-tometer, taking the four cadmium radiations simultaneously ; absolute coin- cidence of the limit of the standard with the plane of reference in the instrument being indicated by certain

characteristic fringes. Interferential Calibration of Screws, M. HAMY. CR

Acad Sci 126 1898 p 1772-4. A plane mirror, thickly sil- vered, is placed on the carriage of a micrometer or dividing

engine, and opposite to it, but attached to the micrometer

screw, is placed a lens of very slight curvature, the side nearest the plane mirror being half silvered. Circular in- terference fringes are seen and screw is calibrated by n
luteE j I* 0»

determining variation in number of bands produced as

lens is advanced.

Application des Phenomenes d'Interference a des Deter- minations MStrologiques (Determinations of Length by

Interference), R. BENOIT. J Phys v7 1898 p 57-68. Ar- rangement used by Michelson to express the length of the meter in terms of wave-lengths of cadmium radiation is used by Benoit for standardizing mm and cm. A Compensated Interference Dilatometer, A. E. TUTTON.

Phil Trans Roy Soc A vl91 1898 p 313-64. A form of Fizeau interference dilatometer of increased sensitiveness. Illuminating and observing apparatus is described, p 324-32. Extensometers, Calibration of an Interference Apparatus for the Calibration of Extensometers, J. MORROW,

E. L. WATKIN. Phys Soc Proc vl9 April 1905 p 365-70

2 figs ; Phil Mag v9 Jan 1905 p 129-35 2 figs. An inter- ference apparatus is described by which extensometers may be accurately calibrated. Specimen tests are given. Interference Extensometer, E. GRUNEISEN. Zeit In- strumKde v27 Feb 1907 p 38-51. Communication from

the Phys. Tech. Reichsanstalt. Describes, with illustrations, an instrument by which elastic extension of test pieces of metals is measured, using the principle of Haidinger's rings. The elastic modulus is given for about 25

various metals and alloys, together with the chemical

composition and density, and modulus as observed by

transverse vibrations, and in a few cases the modulus

found by longitudinal vibrations. A Wave-Length Comparator for Standards of Length

An Instrument for Fine Measurement in Wave-Lengths

of Light. With an Appendix on the Use of Wave-Length

Rulings as Defining Lines on Standards of Length, A. E. H. TUTTON. Phil Trans Roy Soc A v210 1910 p 1-34 13 figs. Interference comparator constructed for the Standards

Dept. of the Board of Trade. Microscope cross-hairs are

set on graduations. Differences are measured by counting

interference bands as screw is turned.

Interferential Contact Lever Experiments Relating to the

Elastics of Small Bodies, C. BARUS. Proc Nat Acad Sci vo Feb 1919 p 44-9 9 figs. Apparatus designed by writer

in which interferential contact lever measures strain cor- responding to stress imparted by pushing springs. The Use of the Interferometer in the Measurement of Small Dilatations or Differential Dilatations, C. G. PETERS. J Washington Acad Sci v9 May 19 1919 p 281^. Equations for determining changes in length ob- servable with dilatometer originated by Fizeau. An im- proved form of Fizeau's interferometer consists of three coned pins, 4 mm across the base, 10 mm long. Three

conical holes 0.5 mm diam., 0.2 mm deep, 15 mm apart

are drilled in the lower surface of the cover-glass plate. The pins rest on the lower glass plate. These holes keep

the pins in place and stop any creep of the cover glass, and also serve as reference marks in determinations

of the change of length of the pins. The fringes formed

by interference are viewed by a Pulfrich interferometer. Simple theory given and uses for small samples. A New Interferential Dilatometer, I. G. PRIEST. Sci Papers NBS vl5 Feb 28 1920 p 667-78 2 figs. Apparatus is designed to measure small changes in length by "change

in width" of interference fringes, instead of measuring them by displacement of fringes. The substance whose

thermal expansibility is required is used as a pillar to support a glass plate. The other side of the plate is sup- ported by some standard substance, such as glass, quartz,

or metal, of known expansibility. A Universal Interferometer, A. E. H. TUTTON. Roy Soc Proc vl04 Aug 1 1923 p 47-62 6 figs. Describes apparatus constructed for author by Troughton & Simms for measurement of small amounts of motion, slight deformations, short distances, and minute objects, of any nature

whatsoever. Instrument provides steadiness and perfect control of the movement of the interference bands ob- tained. The interval between two interference bands is readily divisible into 0.01 parts by a micrometer. An Optical Method of Measuring Small Vibrations, H. A. THOMAS, G. W. WARREN. Phil Mag v5 May 1928 p 1125-30. An interferometer method of measuring small mechanical vibrations is described and its application to the measurement of the vibration of a stiff reed is considered. Interferometer for the Investigation of the Processes of Growth, K. W. MEISSNER. Phys Zeit v30 Dec 15 1929 p 965-71. Paper read before the Deut. Physikertag, Prague, Sept 1929. An interferometer of the Michelson

type is described having the following features: (1) In- stead of the usual horizontal mounting the movement is vertical. (2) The one interferometer mirror is movable

horizontally by means of a slot and screw, while the second may be moved vertically or by a sensitive Roberval balance arrangement so that it may be moved by very small forces (20-^0 mgm. weight), such as those involved in plant

physiological problems. (3) In place of the plane inter- ferometer mirror a combination of curved mirrors (con- cave and convex) with a plane mirror is employed. The

interference fringes are then concentric Newton's rings. By simple adjustment straight line interference bands may be obtained. (4) With the help of an auxiliary scale achromatic interference fringes may easily be obtained,

so that an objective demonstration by projection with

white light is easily possible. Quelques Etudes Particulieres au Dilatometre Fizeau (Some Special Studies in Dilatometry), A. PERARD.

Trav et mem BIPM vl9 1932 127 p 17 figs. Contents : In- troduction ; Principles of the Fizeau dilatometer (and

illustrated description) ; execution of the experiments for the determination of those due to the tripod ; determination of the relative expansions of the prototype meters

refractive index of air; tables of observations and

calculations. Amplifying Lever for Measurement of Small Displace- ments, G. A. FINK, G. W. FOX. Rev Sci Instrum v4 May

1933 p 276-9. System used for measuring piezo-electric deformations of quartz and tourmaline plates, involving use of interference fringes. Arm ratio is 1864 to 1. Der Interferenzmessapparat als Hifsmittel der Kera- mischen Forschung (The Interference Measuring Apparatus as an Aid in Ceramic Research), H. LEHMAN, M. T. SCHULZE. Zeiss Nachr nlO Jan 1936 p 6-13 6 figs. Contains description of Pulfrich viewing device. Contents

The principle of the Fizeau method ; optical path and

arrangement of the viewing apparatus ; heating arrange- ment ; measuring process ; test pieces ; computation of

air layer thickness. New Type of Interferometer, A. HOYT. J Opt Soc Am

June 1936 p 262-6. A description is given of an extremely

simple interferometer which is easy to construct and adjust. It is admirably suited to the measurement of small

displacements. It can be adjusted and used with either monochromatic or white light. Each of the small, light mirrors used needs only one optical surface. The sensitivity can be increased by using multiple reflections with- out unnecessary loss of intensity, since the surfaces are

all fully aluminised. Tests on the interferometer have shown that it is capable of detecting displacements of \/2n where X is the average wave-length of the light used and n is the number of reflections from the moving mirror (nearly normal incidence). Under best (easily attain- able) conditions 14 reflections can be obtained, whence

a shift of 1 fringe would correspond to X/28. Extreme

73
care in the preparation of optical parts might yield 20

reflections and a displacement sensitivity of X/40 for each

fringe shift. A compound multiple reflection interferometer is also described which gives twice the sensitivity mentioned above. Improved Interferometric Procedure with Application to Expansion Measurements, J. B. SAUNDERS. J Res NBS

v23 July 1939 p 179-95. The Fizeau interferometric method, as applied to thermal expansion measurements, has been studied in order to determine the source of some very

serious errors and to find means of reducing such errors. Two types of errors were found to predominate. These may be termed ( 1 ) error caused by tilting of the spacers under mechanical forces, and (2) error caused by variations in air-film thickness at the contact points. Such

errors often amount to 10% and may, under certain conditions, exceed in magnitude 50% of the value sought. In

this paper the two types of errors are considered in detail, and a modified procedure is given whereby the errors are reduced to a magnitude comparable to other unavoidable

errors, such as those in reading the fringes and in deter- mining the actual temperature of the specimen.

Characteristics of Tuckerman Strain Gage, B. L. WILSON. ASTM Preprint n94 for meeting June 26-30 1944

10 p. By means of interferometric calibration device used

at National Bureau of Standards for calibrating gages and autocollimators, experimental results are secured which indicate variations of calibration factor with dif- ferent conditions of use; description of autocollimator and strain gage; calibration device; behavior of gage. Interferometer Measurements on the Expansion of Iron,

J. B. SAUNDERS, J Res NBS v38 Aug 1944 p 75-86. Several sets of data, taken on relatively pure Fe by different observers and different procedures, are compared. The

results show agreement between data taken with those interferometer methods that are free from tilting of spacers and air-film errors, whereas the failure to elimi- nate these two errors produces data that cannot be dupli- cated except by chance. The interferometer data that are

free from these errors agree with data obtained by other

precision methods. Some investigators claim to have

found indications of a characteristic temperature effect in the expansivity curve of iron in the temperature range from 0° to 250° C. When the expansion data are freed from errors of tilting and changes in air films, the in- dications of such effects do not appear. Apparatus for Photographing Interference Phenomena,

J. B. SAUNDERS. J Res NBS v3 n35 Sept 1945 (RP

1668) p 157-86, 4 supp plates. Description of photographic instrument designed for recording changes produced

in order of interference fringes over long periods and for recording large changes in order of interference; when

this instrument is used with interferometric system for studying changes caused in transparent solids by heating,

it can be made to yield continuous record of simultaneous changes in temperature, time, index, strain, and density. Bibliography.

Optical Method of Determining Thickness of Geiger Tube

Windows. F. W. BROWN III, A. B. WILLOUGHBY,

Rev Sci Instrum vl9 Nov 1948 p 820-1. The banded

spectrum of white light formed by reflection from the mica window with an angle of incidence (r) of 10°, is compared

in a direct-vision pocket spectroscope with the Hg spec- trum (of white fluorescent light) and the number (n) of interference fringes between the yellow (\i=577 nu*) and

blue (\2 =436 m/i) Hg lines is counted. Then the surface

density of the window,r ywo-« [

\_2n cos r(Xj —

2 ) J

w.=0.163 n m/cm1, where p=density of mica (2.85 g/cm3 ), Ai=index of refraction (1.58).

Multiple-beam Interferometry, S. TOLANSKY. En- deavour v9 Oct 1950 p 196-202. An account is given of the

application of multiple-beam interferometry to the study

of metals, surface polish, hardness testing, and formation

of slipbands in stressed metallic crystals. The technique

is also used in studying the mechanism of crystal growth

in certain minerals, the hardness anisotropy of diamond

undergoing abrasion test, and the modes of oscillation of quartz. A new method of obtaining sharp fringes and the adaptation of an older method for examining defects in mica are described. A Photoelectric Interferometer for Measurement of Di- mensional Changes, R. N. WORK. NBS Tech Rept n5 Oct 30 1950 5 figs 8 refs. Several applications are cited. Photoelectric Recording Interferometer for Measurement

of Dimensional Changes, R. N. WORK. J Res NBS v47 n2 Aug 1951 (RP2230) p 80-6. Method for recording of

light intensity at reference point in image of interference pattern for automatic plotting of fringe count vs. thermocouple electromotive force in interferometric dilatometry

application of technique to measurement of coefficients of expansion and to determination of transition temperature

of coefficients of expansion and to determination of transi- tion temperatures in rubber-like materials. Wavelength or Length Measurement by Reversible Fringe

Counting, E. R. PECK, S. W. OBETZ. J Opt Soc Am v43 n6 June 1953 p 505-9. Optical and electronic methods for reversible counting of fringes from corner-cube or Michel- son interferometer ; counter operates in either direction

at least as fast as 1000 per sec. Electronic Location of Interference Fringes, J. PETERS,

G. STROKE. J Opt Soc Am v43 Aug 1953 p 668-72. A

device is described which determines a zero reference

position in terms of interference fringes and measures any shift to a small fraction of a fringe. It can be used with static or slowly moving fringes, and is based on the

principle of superposition of two images of the fringe pattern in polarized light on the single slit of a photoimult'iplier tube. By means of a rotating Polaroid as

optical shutter an alternating signal is produced of which

the amplitude and phase are a function of the displace- ment. A Bidirectional Electronic Counter for Use in Optical In- terferometry, F. H. BRANIN, JR. J Opt Soc Am v43 Oct

1953 p 839-48. A bidirectional electronic counter has

been developed for both additive and subtractive counting

of electrical impulses in either binary or decimal notation. Using two coherent syncopated sine-wave input signals, such as may be derived from a Twyman-Green interferometer with a stepped mirror and two phototubes, direc- tion sensing is obtained by pulse forming and selecting

circuits which feed pulses to either the "add" or "subtract" channel, depending on the phase relation between

the two input signals. In the binary counting circuit, the add and subtract channels each operate separate coin- cidence amplifiers which select the proper phase for trans- ferring the trigger pulses from one binary stage to the

next. In the decimal counting circuit, which consists of binary stage followed by a reversible ring-of-five additional coincidence amplifiers determine the direction in which

the trigger pulses transfer the count around the ring. Counting rates in excess of 150 kc have been achieved with both circuits and higher rates are possible with

proper design. Although the best directional counting

circuit was designed primarily for the purpose of elimi- nating the tedium of counting interference fringes visually, it can also be used for differential counting with two

separate (incoherent) pulse inputs. A review of con- temporary development in this field is given, along with a

discussion on applications of the circuit in interferometry and analogue-to-digital conversion devices. 74
Electronic Fringe Interpolator for an Optical Interferometer, R. D. HUNTOON, A. WEISS, W. SMITH. J Opt

Soc Am v44 n4 Apr 1954 p 264-9. Electronic fringe counter

for use with interferometers; provisions for automatic

counting of integral fringes, interpolation to within 1/200

wavelength, and indication of motion direction of inter- ferometer plates. An Optical Dilatometer, J. TERPSTRA. App Sci Res B

v4 n6 1955 p 434-46. An instrument is described which

enables displacements of 2 X 10"6 cm to be determined by means of interference phenomena of monochromatic light. The measuring pin is pushed against the specimen with

a force of 4000 dynes. The instrument setting remains

stable for a period of several hours. Interferometrie Control of Grating Ruling with Continuous^ Carriage Advance, G. R. HARRISON, G. W. STROKE.

J Opt Soc Am v45 n2 Feb 1955 p 112-21. Control method

for manufacture of optical gratings; phase of low fre- quency a-c signal produced by interference fringes passing

across photoelectric pickup is continuously compared

with that of standard signal indicating periodic diamond

motion involved in ruling stroke ; blank positioning is eontrolled within Yio of fringe. A Machine for Measuring Interference Fringes, Y. GRI- MOD. Rev. Opt v34 nlO Oct 1955 p 509-11 in French. An automatic photoelectric device is described which computes the positions of interference fringes automatically, by means of a photocell. The fringes are then counted on an automatic computing machine. The system has a

capacity for counting up to lengths of 100 mm.

Fractional-Fringe Measurements with Corner-Cube Inter- ferometer, E. R. PECK. J Opt Soc Am v45 nlO Oct 1955 p 795-7. Extension of fringe counting by interpolation to about 0.01 fringe ; photoelectric method for providing ref- erence reading of position of interferometer carriage to same accuracy as that of interpolation. An Interference Comparator for Evaluating the Differ- ence Between End-Standards, M. DUHMKE. Zeit In- strumkde v65 nl Jan 1957 p 5-17 in German. By employing a difference method against a standard, lengths of slip-gauges (up to 100 mm) can be evaluated to within

O.Ol/i. The method described enhances the Fizeau-fringe sharpness by multiple reflection. Plucking Millionths Out of Thin Air, J. RITCHIE. Tooling & Prod v22 nl2 Mar 1957 p 83-7. Fringe count micrometer described employs interferometry in combination

with electronic digital counting ; instrument is intended to further extend lineal measurement accuracy by referenc- ing dimensions to wavelength of light ; gage blocks or other secondary standards are not needed to set up or calibrate instrument as built-in light source is itself standard. An Algebraic Electronic Counter for Interference Fringes,

G. RUFFINO. R. C. Aecad. Naz. Lincei v22 v5 May 1957 p 602-5 in Italian. A simple direction-sensitive counter

is described, using dekatron tubes to give an immediate

display of the fringe count. Details of the electronic cir- cuit are given. Photoelectric Fringe Signal Information and Range in Interferometers With Moving Mirrors, G. W. STROKE.

J Opt Soc Am v47 nl2 Dec 1957 p 1097-103. Photoelectric

receptors and electronics have greatly increased the ac- curacy and simplicity of interferometrie measurements.

Theoretical and experimental investigation of instru- mental and light source conditions required to ensure ade- quate information content and "visibility" of fringe

signals were made. Mirror parallelism requirements needed to maintain maximum signal modulation and to reduce apparent local displacement errors, for use with

equal inclination interferometers, are expressed by the

fractional number of equal thickness fringes within the

mirror traverse being reducible by decreasing this aper- ture and ensuring best local parallelism. The "effective" length per fringe, determined by photoelectric flux integration over an angular range within the source angular

radius os is approximately (X/n)2(l—a,

2/4). Theoretical

expressions obtained for the fringe "visibility" with simple

single isotope lines of Gaussian shape are in good accord with experiments, showing that the fringe amplitude with

perfectly adjusted continuously moving interferometers

is governed by an expression usable for estimating in- terferometrie range with such sources as the green Hg196 line with an effective Gaussian width of about two Doppler widths at room temperatures. The further extension of interferometrie range with measurement precisions

of 1 part in 10s over traverses exceeding 300 mm ap- pears feasible. Length Measurement by Fringe Counting (II), Y. SA- KURAI. Report of the Central Inspection Institute of Weights and Measures, Japan, v7 n2 report 15 1958 in Japanese. The operating principle and the error of an

interferometer of which reflecting mirrors are made of a

pair of front-surface mirrors so mounted as to form a right

angle, were discussed analytically. It was found that when the interferometer was used for the measurements

of length by the fringe counting method, the following ad- justments were most important: (1) the positions and

dimensions of entrance apertures of phototubes, (2) the

linearity of the locus of the moving mirror pair, (3) the angle between the intersection line of the moving mirror

pair and the direction of incident parallel light. Interferometrie Systems of Continuously Moving Mirrors and Photoelectric Detection, G. W. STROKE. J Phys Radium vl9 n3 Mar 1958 p 415-23 in French. Interfero- metrie measurements over the large path distances of several hundreds of millimetres have been recently con- siderably improved and simplified by the use of photoelectric receptors and electronics. Theoretical investiga- tions of the conditions required to ensure adequate

information content in the centrifringe range and visibility of the fringe signals in two^beam equal-inclination inter- ferometers permits the examination and separate verifi- cation of (1) mirror parallelism requirements needed to maintain maximum fringe signals and to reduce apparent

local displacement errors by minimizing the fraction number of equal-thickness fringes within the mirror aperture and (2) inherent interferometrie conditions having to do

with the interferometer geometry, the source line shape and photoelectric noise characteristics. Integration of the photoelectric flux within an angular range determined by the source radius and collimator focal length leads in practice to an "effective length" per fringe different from half a wavelength by parts in 10'. Theoretical

fringe signal amplitude curves corresponding to simple

single lines of Gaussian shape, such as the green Hg198 line, are in good accord with experiments performed over path distances of ±320 mm and serve to estimate range and accuracy in measurements with machines where the causes of improper or variable mirror adjustments have

been overcome to a large extent by mechanical perfection and servomechanical control. Reversible Photoelectric Fringe Counting, R. L. EISNER.

Rev Sci Instrum v29 n6 June 1958 p 521-3. Simple

modifications of a Fizeau interferometer are shown which

give a sense of direction to the passing fringes, enabling a

suitable counting system to operate reversibly. Very fast counts can be made accurately using an electronic circuit actuated by four phototubes sighted on four points in the fringe pattern. An oscilloscope display can be used

for fractional fringe interpolation. Calibration of Mirror Extensometers by Optical Inter- ferometry, A. F. C. BROWN. Eng vl86 n4822 Aug 8 1958 p 180-2. Types of mirror extensometer ; typical results of calibrations; factors governing behavior of Rhomb type 75
extensometers. Communication from Nat. Physical Laboratory. Measurement of Small Displacement by Using Newton's

Rings and an Objective Micrometer, I. IKEDA. Mem.

Faculty Eng Hokkaido Univ. vlO n46 Oct 1958 p 491-503. Some details are given of the application of Newton's

rings methods to the measurement of small displacements.

Possible sources of error are examined in detail and a number of examples are illustrated. The method de- scribed is applied to the investigation of the aging of

pieces of concrete. Length Measurement by Fringe Counting (3rd Report),

Y. SAKURAI. Report of the Central Inspection Institute of Weights and Measures, Japan, v8 n2 report 18 1959 in Japanese. The characteristics of interferometers of which reflecting mirrors are a right angle prism or a pair

of front-surface mirrors mounted to form a right angle, are discussed as a continuation of the 2nd report. When

the length is measured by means of fringe counting method with those interferometers, it is confirmed quantitatively that the measured values have the errors essentially

in following cases, what has been expected to some extent, (i) The angle between the reflecting surfaces de- viates from the right angle, (ii) The hypotenuse of right angle prism is not parallel to the intersection of its re- flecting surfaces. Length Measurement by Fringe Counting (4th Report),

Y. SAKURAI, S. TAKAHASHI, K. OTA, T. YOSHIDA.

Report of the Central Inspection Institute of Weights and Measures, Japan, v8 n3 report 19 1959 in Japanese. The experimental apparatus to research the method for calibrating the graduated scales with wavelength of light

is shown in this report. The graduated scale to be measured is set on the moving carriage on which one of the

reflectors of the corner-cube interferometer is fixed and

the lines of this scale are viewed by a photoelectric microscope. The comparisons of mechanical displacement of moving reflector with wavelength are carried out by count- ing the number of interference fringes passing through

the field of the interferometer during transference of the moving reflector. To distinguish the direction in which

fringes move, two photo-tubes are arranged to view two

parts of a fringe pattern where the variations of light intensity resulting from movement of fringes are different

in phase by approximately 90°. The outputs of the photo- tubes are transmitted to a reversible electronic and

mechanical counter, and a fraction indicator. The number of fringes is given by the indications of these instru- ments. The accuracy of this experimental apparatus was

0.03^ in the length of 20 mm.

High-Temperature Rotor Bore Dilatometer Unit, J. WEST. J Sci Instrum v36 nl Jan 1959 p 1-3. The in- strument measures optically the dilation due to centrifugal

Stresses of the bore of a steam turbine rotor under run- ning conditions. The measurements are independent of vibration of the rotor. Light from an illuminated pin- hole within an autocollimator is collimated on to a system

of three mirrors supported kinematically inside a cylin- drical cartridge, which is pushed into the rotor bore of

the turbine. Two of the mirrors are fixed to the cartridge, and the third is hinged and connected to a feeler which

is spring loaded against the rotor bore. With all three mirrors mutually at right angles, the light is reflected back

to the autocollimator in exactly its own path, independent

of any relative movement between the dilatometer and

the autocollimator. On expansion of the rotor bore, the

third mirror is displaced, tilting the returned beam of light. Since the turbine rotor is rotating, the image seen in the autocollimator appears as a circle, the diameter of which

gives a measure of the dilation. The preparation of the mirror surfaces enabling them to withstand the conditions

inside the turbine is discussed. (Not interferometric.

)

Photoelectric Setting Methods for a Three-Beam Inter- ferometer, P. HARIHARAN, D. SEN, M. S. BHALLA. J

Sci Instrum v36 n2 Feb 1959 p 72-5. Some of the photoelectric methods which can be applied to estimate the

fractional fringe order in the three-beam interferometer, previously described, are outlined, and their comparative

merits are discussed. Experimental measurements show

that with the help of such methods settings can be re- peated to better than X/1000, provided care is taken to minimize temperature fluctuations. Estimation of Two Causes of Error in the Photoelectric Observation of Interference Fringes at Infinity with a Michelson Interferometer, J. TERRIEN. J Phys Radium

v20 n2-3 Feb-Mar 1959 p 446-8 in French . In an earlier study the author assumed, (1) perfect centering of the receiving aperture on the ring center, and (2) uniform

illumination of this aperture in the absence of interfer- ence. The accuracy in centring and uniformity of illumi- nation required to justify these assumptions are here es- timated. To attain an accuracy of 0.001 of a fringe, the

error in centring must be less than 0.05 of the aperture diameter and the illumination must not fall by more

than 12% from the center of the aperture to its rim. Length Measurement by Fringe Counting, K. HARA, D. S. SMITH. Rev Sci Instrum v30 n8 Aug 1959 p 707-10. Construction and performance of reversible fringe counter with counting rate of 100 fringes per sec over path differ- ence exceeding 20 cm : fringe excess fraction at zero path

difference could be determined to 0.001 fringe, and rela- tive precision of about 1 : 108 was achieved at path dif- ference of 6.4 cm. Some More Aspects of the Michelson Interferometer With

Cube Corners, M. V. R. K. MURTY. J Opt Soc Am v50 nl Jan 1960 p 7-10. In the application of the Michelson in- terferometer for measurement of length by photoelectric methods there is a choice of either plane mirrors or cube-corners as the end reflectors. In the present paper

it is shown that the guide on which the moving cube- corner moves needs to be only of moderate accuracy whereas it is known that the guide must be made very accurately when plane mirrors are used. Gage Thin Strip Accurately, J. A. BUZA. Iron Age vl85 n7 Feb 18 1960 p 120-1. Operation and performance of Fringeeount Micrometer manufactured by Link Aviation

Inc. which compares thickness of metal strip sample with wavelength of krypton light source ; strip sample used as standard for maintaining gage tolerance on 26 in. wide foil of variety of alloy steels within 30 milliontbs of an inch

at Wallingford Steel Co ; photographs and sketch. Photoelectric Method of Recording Interference Fringes

in White Light, T. S. KOLOMITSOVA, I. V. NOVIKOVA.

Optics & Spectroscopy (English translation of Optika i Spektrosk) v8 n3 Mar 1960 p 189-92. Photoelectric methods of isolation and recording of central white fringe in system of white light interference fringes were examined

results of calculations of magnitude of photocurrents are

presented, and experimental arrangements and investiga- tions are described ; it is shown that, in principle, automation of measurements on white light interferometers is possible. An Interferometric Measuring Apparatus, P. LEINWEBER. Mach Tool Eng and Prod News v93 n6 June 1960

p 140-5 10 figs. Translation from Werkstatt und Betrieb v93 June 1960 p 305-10. Describes an interferometer

of the author's design for testing length measuring devices such as mechanical indicating gages. Discusses "uncertainty of measurement" at some length. Presents novel

fringe-count system. Metodi Electrronici per la Misura Interferoinetrica delle Lunghezze, G. RUFFINO. Alta Frequenza v29 n3-4 July-Aug 1960 p 278-300. Electronic methods for inter- 76
ferometric length measurement ; photoelectric transducer

is described transforming illumination of interference pattern into electric signals ; photoelectric interferometric

devices classified; advantages of photoelectric method

stressed. A Method of Precise Fringe Pointing, D. S. SMITH. Can

J Phys v38 n8 Aug 1960 p 983-90. Three methods of photoelectric pointing on an interference fringe are examined

theoretically and the expected precision of setting is de- rived for each. An apparatus is described which yielded a

precision of 1.2 x ltf compared to the predicted value of

5.8X10°. The reason for this discrepancy is discussed, and modification of the apparatus which would reduce the discrepancy is suggested. Also Oct 1960 p 450. Interference-Fringe Counter for Measuring Small Lengths,

V. P. KOROXKEYICH, TU. I. TRULEV. Meas Techn

1959 nlO Aug 1960 p 581^ 2 figs 3 refs. Translated from Izmer Tekh nlO Oct 1959. For measuring small

lengths (1-2 mm) it was found expedient to construct an

interferometer with a fringe counter by using standard

instruments. The mean-square error of such an interfer- ometer does not exceed 0.22/i, which is perfectly satis- factory for the majority of measurements in the engineering industry. The interferometer can be easily adapted

for measuring micron indicator gages, screws of eyepiece micrometers, for determining coefficients of linear expansion and similar operations. Apparecchi Electronici per la Misura Interferometrica

delle Lunghezze, G. RUFFINO. Alta Frequenza v29 n5

Oct 1960 p 450-82. Electronic apparatus for interferometric measurement of lengths ; performance principles of ir- reversible and reversible (differential) counters, interfer- ence fringes interpolators and automatic interferometric

control; two methods of interpolation described; block diagrams of two automatic interferometric control devices which enhance ability of photoelectronic procedures. An Automatic Fringe Counting Interferometer for Use

in the Calibration of Line Scales, H. D. COOK, L. A. MARZETTA. J Res NBS v65C n2 Apr-June 1961 p 129-

40. A reversible fringe counting interferometer is described in which mechanical, optical, and electronic ad- justments are maintained stable by servomechanism control or by balancing. Mirror parallelism is achieved by

detecting the angular error electronically and correcting by means of barium titanate actuators. An electronic in- terpolator permits recording of the count in digital form

to 0.01 fringe without ambiguity. A rate of more than

1200 fringes/sec was achieved over a range of 14 cm. Higher counting rates are possible over shorter ranges. Design factors and details are discussed. A correction

factor is derived for the error introduced by finite colli- mation of the interferometer beam.

Interference Comparator for Routine Measurement of Length. T. MOROKUMA. Oyo Buturi v31 n3 1962 p 192 22

figs 21 refs in Japanese. English translation available. Theoretical investigation is made on electronic fringe comparator for the purpose of routine measurement of

length. (1) A lens and mirror system is introduced as

the movable reflector system of the interferometer. This

catadioptric system plays the same role as that of a corner cube reflector system when a concave mirror is situated at the focal point of a convex lens. (2) Effects of temperature and atmospheric pressure can be automatically cor- rected if suitable Fabry-Perot etalons are assembled tan- dem to the interferometer and the spacer material of the

etalons has the same thermal expansion coefficient as

that of the part to be measured. Equal inclination fringes are different from those formed with an ordinary inter- ferometer. (3) Effects are calculated on the visibility of fringes due to optical arrangement of reflector systems and spectral distribution of the light which passed through

the etalon. An interference comparator has been con- structed on the basis of theoretical investigation, some

results of the investigation were already described in the

first part of this paper and the rest are here presented. A

pair of interference fringes, having uniform brightness and phase difference of tt/2 rad. is formed in the same

field of view by means of a quarter wave length prism

analogous to a Fresnel rhomb and they are separated by

a Wollaston prism. The direction in which the measuring

head moves can be electronically detected from the phase

relation between them. Measurement can be performed

within the accuracy of 0.03^ with this instrument. An Apparatus for the Determination of the Thermal Expansion of Solids in the Temperature Range 20-1000°

C. V. E. MIKRYUKOV, I. K, KAMILOV. Pribory i Tekh

Eksper (USSR) 1962 n3 p 173-5 May-June in Russian. English translation in Instrum. Exper. Tech. (USA).

Describes a compact quartz dilatometer which may be used to measure the expansion coefficient to an accuracy

of about 2%. It was used to determine the temperature

variation of the expansion coefficient of pure Ni. A dis- continuity was found to occur at the Curie point. Interferometry in Length Measurement—1. Electronic Counting of Interference Fringes, J. L. GOLDBERG, R. H. BROCKMAN. Electronic Technol v39 n4 Apr 1962 p 140-

4 6 figs 7 refs. A study of the photoelectric detection process applied to a steadily moving two-beam inter- ference fringe pattern. Discusses photomultiplier noise,

effect of the aperture in front of the photo-deflector, effect of bandwidth, and experimental details. Interferometry in Length Measurement—2. Practical Considerations, J. L. GOLDBERG, R. H. BROCKMAN. Electronic Technol v39 n5 May 1962 p 186-91 10

figs 5 refs. Experimental results are discussed and the

effects of imperfections in the transducing system are analysed together with a means of overcoming them.

Considers the effects of tilt in the case of straight fringes viewed through a rectangular aperture, straight fringes viewed with a circular aperture, effects of variation of photomultiplier supply voltage, application to the absolute measurement of a meter line standard, and conclusions. Interferometry in Length Measurement—3. Waveform

Generator Suitable for Reversible Counting, J. L. GOLDBERG. Electronic Technol v39 n6 June 1962 p 238-43

11 figs 4 refs. Deals with the design of a suitable type of trigger circuit which produces a counting waveform from

a noisy fringe signal. Discusses current amplifier, trigger

circuit, application to counting, reversible counting. A Versatile Silica Dilatometer, G. G. MATTHEWS, I. H.

R. SATTERTHWAITE, C. CAMERON. J Sci Instrum (GB) v40 nl Jan 1963 p 42-3. The dilatometer described here was constructed to make routine measurements of the

coefficients of linear expansion of uranium specimens. The dilatometer can be used up to 1000 °C or down to liquid

air temperatures if required, with suitable dimensional

modifications. Interference Dilatometer, A. N. KOROLEVA. Meas

Techn 1963 n8 Feb 1963 p 655 1 fig. Translated from

Izmer Tekh n8 p 20 Aug 1963. Consists of a telescope with an autocollimation attachment, an interferometer, an electric oven for temperatures to 800°C, and tem- perature regulators. Applies method of coincidences. Fabry-Perot Interferometer Used as a Dilatometer. NBS Tech News Bui v47 n8 Aug 1963 p 131 1 fig. Measures linear displacement as small as 10"7 cm. An Automatic Recording Differential Dilatometer, J. BARFORD. J Sci Instrum (GB) v40 n9 Sept 1963 p

444-5. The apparatus is suitable for the study of the

kinetics of phase transformations and precipitation proc- esses in the solid state. Relative length changes between

a specimen and a control are measured by means of a

variable inductance transducer. The differential system 77
works to better than 1%, over temperature ranges of up

to 1000°C. Automatic Measuring Interferometers for the Determination of Length and Angle, A. K. CHITAYAT. ASME

Paper n64-Prod-23 Apr 1964 8 p 8 figs. Discusses basic

principles, typical utilizations of linear and angular inter- ferometers, establishing zero reference, stability of in- terferometers, monochromaticity and coherence, effect of environmental conditions, utilization of lasers as light sources, high-order laser modes, selection of laser, traceability to international standard of length. 2.4.3. Fabry-Perot Interferometer

Interference Applied to Metrology, A. PEROT, C. FABRY.

Astrophys J v9 1899 p 87-115. The paper is a translation from the original article in Bull Astron vl6, p 5, January

1899 and describes the author's well-known methods of measuring lengths and thicknesses of observing the in- terference fringes produced between silvered surfaces. See also Ann Chim Phys vl2 (7th series) 1897 p 459-501. Sur la Mesure en Longueurs d'Onde des Dimensions d'un Cube de Quartz de 4 cm Cote (On the Measurement in Wave-Lengths of the Dimensions of a Quartz Cube 4 cm

on a Side), C. FABRY, J. M. de LEPINAY, A. PEROT. CR Acad Sci vl28 1899 p 1317-19. The solid to be measured is placed between two planes of silvered glass, AA',

so that the faces a. a' of the solid are parallel to the planes. Results are accurate to 0.1« in 4 cm. Sur un Nouveau Modele d'Interferometre (New Model In- terferometer), C. FABRY, A. PEROT. Ann Chim Phys

v22 Apr 1901 p 564-74. Instrument made embodying the improvements suggested by experience. Article contains

details of the new instrument.

Optical Measurement of Length Standards, A. PEROT,

C. FABRY. Ann Chim Phys v24 Sept 1901 p 119-39. Details of special means for applying the interferential method to the determination of the absolute length of standard bars, the system adopted depending on the form

of the end of the bar. Sketches of the modifications uti- lized and for the maintenance of uniform temperature

are given. Interference Rings Observable by Plates Whose Surfaces Are Absolutely Parallel, LORD RAYLEIGH. Phil Mag

vl2 Nov 1906 p 489-93. History of discovery. Distinction between contact rings and plate rings. Effects of double

refraction of mica. Quasi-etalon Fabry-Perot Interferometer, H. NAGAOKA.

Math Phys Soc Tokyo Proc v9 Feb 1917 p 49-54. Describes arrangement for swift adjustment of mirrors to parallelism and not easily deranged. Fine adjustment is pro- vided. Interference Methods for Standardization and Testing Precision Gage Blocks, C. G. PETERS, H. S. BOYD. Sci Papers NBS May 2 1922 p 677-713 21 figs. Use of inter- ference of light waves makes possible detection of errors within a few millionths of an inch. Fabry-Perot inter- ferometer is applied. The Fabry and Perot Parallel Plate Etalon, W. H. J. CHILDS. J Sci Instrum v3 Jan Feb 1926 p 97-103 129-

35 4 figs. A concise account is given of the theory and

use of the instrument, together with descriptions of the customary arrangements and the methods of etalon ad- justment. Applications are: Wave-length measurement and detection of small shifts; investigation of resolu- tion and structure ; as a standard of length ; investigation of absorption lines; determinations of refractive index. Bibliography.

Photography of Fabry and Perot Interferometer Fringes I by Using a Simple Optical System, S. E. GREEN. Phys I Soc Proc v42 Apr 15 1930 p 153-5 ; discussion Apr 15 1930 p j 155-6. A simple method of photographing Fabry and J Perot interferometer fringes is outlined, and some I examples of the results obtained with mercury radia- J tlon are given. Nomogram for Calculation of Fractional Values of Inter- I ference Fringes. A. I. KARTACHEFF. Rev Opt vl4 Sept 1935 p 328-31. A nomogram is described for the graphical determination of the value of the expression I (d22 —di)/d*, where d2 , di are the diameters of successive

| rings for the fractional part of the order of interference

| of rings in the pattern produced by a pair of parallel I semi-transparent reflecting surfaces illuminated by a con- I vergent beam of monochromatic light. A Vacuum Interferometer for Precise Measurements, R. M. ELLIOTT. Rev Sci Instrum vll July 1940 p 235-6. The serious effect of pressure and temperature variations ] in the use of a Fabry-Perot interferometer is outlined i together with a method successfully employed to reduce

these variations to a reasonable limit. Fabry-Perot Interferometers in Parallel Arrangement, L. STURKEY. J Opt Soc Am v30 n8 Aug 1940 p 351-4. Intensity equation of two Fabry-Perot interferometers op- erated in parallel is obtained and discussed; it is ob- served that distribution complementary to that of single Fabry-Perot instrument has very significant properties and may be obtained by such arrangement.

Interference Spectroscopy, II. K. W. MEISSNER, J Opt

Soc Am v32 Apr 1942 p 185-210. The compound FabryPerot interferometer and the multiple-interference spec- troscope are described and expressions for their resolving powers and instrumental half-widths evaluated. Appli- cations of the Fabry-Perot interferometer to absorptionline working and to the plotting of line profiles are dis- cussed, and recent work using high resolving power on ! atomic beams is described. Finally the theory of the re- flection echelon and the methods employed in crossing it with auxiliary dispersion are given. New Contribution to Interferometry- Pt I—'New Non- 1 Localized Interference Fringes, S. TOLANSKY. London, Edinburgh & Dublin Phil Mag & J Sci v34 n235 Aug 1943 p 555-65. Interference fringes, produced with small source of Fabry-Perot Interferometer, are described ; these i extend into space in form of cones, producing sharp rings ; when allowed to fall upon screen ; properties of rings ex- [. amined ; striking characteristic is that without lenses

| sharp rings of great diameter can be produced ; possible applications of new fringes. On the Fabry-Perot Interferometer. Importance of Surface Defects, C. DUFOUR, R. PICCA. Rev Opt (Theor Instrum) v24 Jan-Mar 1946 p 19-34 in French. A study

is made of the effects produced by various instrumental

defects—diffusion, plate curvature, surface irregularities. A mathematical treatment is developed and is shown

to account fully for the observations. A simple method

is indicated for distinguishing between effects due to in- » strumental causes ( surface defects, diffusion ) and spectral [ causes (nonresolved satellites, continuous background). The Effect of Finite Aperture on the Fringe Intensity Distribution of Fabry-Perot Interferometer. F. E. GEIGER, , Jr. J Opt Soc Am v39 Mar 1949 p 249-51. An equation

is derived for a square etalon which illustrates clearly the decrease in fringe intensity for increasing angles of inci- dence. The computations show that this effect becomes

significant only for high reflecting powers and comparatively large plate separations. The Resolving Power and Intensity Relationships of the Fabry Perot Interferometer with Silvered Reflecting 78
Surfaces, R. J. BRIGHT, D. A. JACKSON, H. KUHN,

Proc Phys Soc London A v62 Apr 1949 p 225-36. By the

use of a Fabry Perot etalon with very small spacing, the widths of the interference fringes were measured under

conditions where the light could be considered as practically monochromatic. In this way, the resolving power

which can be achieved with Ag deposits of known optical density was determined for light of 5 different wavelengths between 6 438 and 3 610 A. The results can be used for selecting the most favourable thickness of silver- ing of etalon plates, namely that which gives the resolv- ing power required for a given purpose without unnecessary loss of intensity. The application of the results to multiple etalons is discussed. A Mount for a Perot-Fabry Interferometer Without Etalon

Ring, H. HABER. Letter in J Opt Soc Am v39 Dec 1949

p 1050-1. The Functioning of the Fabry-Perot Interferometer; Im- provement in Contrast and Luminosity, C. DUFOUR. J Rech Cent Xat Rech Sci nlO 1950 p 1-16 in French. A

discussion of the factors affecting contrast visibility and

intensity in various interferometers, particularly the Fabry-Perot. By the deposition of alternate layers of cryolite and ZnS on the silvered surface, considerable increase

in resolving power and contrast is obtained. Measure- ments are given and applied also to the thin film inter- ferometric filter. It is concluded that the performance

of an etalon is not so much limited by the properties of the thin film but by the surface imperfections. In the

F.P. interferometer a practical contrast of 200, permitting the detection of a weak satellite of relative strength

1/1000, represents the present limit with a single inter- ferometer. The theory is applied to combinations of etalons in series both with and without intermediate

"focalization." It is considered that the F.P. interfer- ometer presents important advantages over other instru- ments. Combinations of multiple etalons are discussed and it is suggested that the usual semi-transparent mirrors should be replaced by multiple films. Accurate Thickness Measurements With a Fabry-Perot

Interferometer, L. G. SCHCLZ. Letter in J Opt Soc Am

v40 Mar 1950 p 177-8. The Reflectivity of Thin Silver Films and the Performance

of the Fabry-Perot Interferometer, H. KUHN. J Phys Radium vll July 1950 p 442-4. By measuring fringe widths in a Fabry-Perot etalon the reflecting coefficient R of the silvered surfaces can be derived. The transmission factors T of the films are measured directly with a photomultiplier tube. The sum R+T is not markedly dif- ferent for different film thicknesses but increases from

0-84 at X3900 to 0-97 at X6400. Direct measurements of R

are in agreement with those derived from fringe widths. The data permit selection of the most suitable film thick- ness to give reasonable intensity of fringes. A Note on the Resolving Power of the Fabry-Perot Inter- ferometer, J. H. JAFFE. Letter in Bui Res Coun Israel vl Mar 1951 p 113-14. It is established experimentally

with a small-gap Fabry-Perot interferometer that the pre- diction made by Tolansky as to the dependence of resolution on polarization is correct. Direct Method of Measurement of the Characteristics of a Fabry-Perot Interference System, P. GIACOMO. CR

Acad Sci (Paris) v235 Dec 22 1952 p 1627-9 in French. The mean transmission factor of an interferometer is a

function of 1—R. where R is the coeff. of reflection of one

surface. This factor is measured directly by comparing

the illumination on a photocell with and without the inter- ferometer interposed. Results obtained for layers of

cryolite and ZnS, each X/4 thick, are in good agreement

with those calculated from classical Fresnel theory.

Resolving Power of the Fabry-Perot Etalon, M. S. SODHA.

Letter in Current Sci v 22 May 1953 p 139-40. The Rayleigh, Sparrow and Abbe criteria for resolution are applied

respectively to the case of the prism, the line grating and

the Fabry-Perot interferometer. In the case of the FabryPerot instrument there is a large difference between the

calculated resolution criteria. The three different as- sumptions lead to resolution separations in the ratios 1-49 : 2-72:2-08. Thus this interferometer is ideally suited for deciding between the validity of the three dif- ferent criteria. Influence of the Wavelength on the Sharpness and Bril- liance of the Maxima of the Rings Formed by a SemiSilvered Fabry-Perot Etalon, J. ROIG, E. COLLET. CR

Acad Sci (Paris) v236 May 11 1953 p 1866-8 in French. Measurements are reported for fringe sharpness and in- tensity. Although internally consistent, the absorptions

for Ag films appear to be higher than those of other investigators. This is attributed to insufficient pumping speed. Data are reported for eight wavelengths over the range W4500-6800. Some results for Al films are briefly indicated. Selection of Optimal Spacers in Perot-Fabry Interferometry, G. V. DEVERALL, K. W. MEISSNER, G. J. ZISSIS.

J Opt Soc Am v43 Aug 1953 p 673-80. Contains a general discussion of the conditions for optimal separation

of Perot-Fabry patterns. A convenient graphical method

is given which permits the selection of the proper spacer

thicknesses for the clear resolution of the components of a pattern even in complicated cases. New Method in Optical Interferometry, K. M. BAIRD.

J Opt Soc Am v44 nl Jan 1954 p 11-2. Rapid, accurate method for obtaining order of interference in Fabry-Perot

etalon; apparatus for using method in calibrating end

standards ; application to wavelength determinations. Fabry-Perot Interferometer Mirrors with Di-electric Multilayers, S, PENSELIN, A. STEUDEL. Zeit Phys vl42 nl 1955 p 21—11 in German. A description is given of the production of multi-layer mirror for Fabry-Perot inter- ferometers using vacuum evaporation. The mirrors are

quarter wavelength thick and consist alternatively of the

following materials. For 3000 to 4000 A materials are PbCl and MgF2 C. For wavelengths greater than 4000 A

zinc sulphide and cryolite are employed. When freshly prepared films are used reflecting coefficients exceeding 97% are secured with a mean absorption of 0.9% for the

zinc sulphide and cryolite combination. Absorption of 1.9% obtains for the lead chloride and the magnesium

fluoride combination. Reflectivities are such that the

fringe width is determined primarily by errors in the

optical flats and not by reflectivity characteristics. Lead

chloride layers are protected against the activity of dampness with a half-wavelength layer of magnesium fluoride. In the ultraviolet interferometric effects obtained with the multilayers are much superior to those of aluminum

mirrors. A Ney Type of Interference Etalon, K. I. TARASOV.

Optika i Spektrosk vl nl 1956 p 103^ in Russian. The

apparatus is a modification of the Fabry-Perot etalon in which the plane parallel reflector plates are covered on

both sides with interference films of dielectric so that these

reflectors individually form Fabry-Perot etalons. The

plane parallel layer of air between the plates forms a third intermediate interference space. The interference pic- ture observed in such a triple etalon is substantially dif- ferent from the simple fringe system of a normal FabryPerot instrument recalling somewhat what is seen with

the multiplex version. The reflection coefficient of each

of the glass plates has its maximum value for definite angles of inclination of the incident rays and for other

angles it is close to zero. With change of angle incidence

there is a complementary change of phase of the reflected 79
ray and this, added to the phase difference of the inter- fering rays (determined by the air inter-layer), leads to much sharper interference rings and greater resolving power than in the normal Fabry-Perot instrument. Subsidiary maxima may be readily distinguished from line components for a change of pressure of the air inter-layer causes subsidiary maxima to remain in place while line components will move over the field of view. High-Speed, Direct Recording Fabry-Perot Interferometer, M. A. BIONDI. Rev Sci Instrum v27 nl Jan 1956 p 36-9. An interferometer is described which has a high optical speed and provides a direct tracing of spectral line shapes

on a linear scale. A photomultiplier views the centre spot

of the interference pattern. The output of the photomultiplier goes to a vibrating-reed electrometer and then

to a pen recorder. The wavelength of the light at the

centre of the interference pattern is made to vary with

time by changing the index of refraction between the inter- ferometer plates. This is accomplished by enclosing the

plates in a gas-tight housing and admitting an inert gas such as argon or helium to the housing. By the proper

choice of gas and of the rate of pressure change one ob- tains the desired rate of tracing the line shape. Orders of magnitude reduction in "exposure" time are achieved by

eliminating the use of photographic plates. Fabry-Perot Interferometer with Finite Apertures, K. L. VANDER SLUIS, J. R. McNALLY, JR. J Opt Soc Am

v46 nl Jan 1956 p 39-46. Closed mathematical expressions are developed for the Fabry-Perot interferometer with finite apertures for both noncoherent and coherent

illumination. For most practical cases these expressions are substantially equivalent but reveal more serious aper- ture effects than the approximate theoretical treatment

of Geiger. The effects expected are of particular importance in problems involving either compound interferometers or high reflection coatings. However, even at low

reflectivities significant reductions in peak intensity and

resolution are to be expected. The conditions for obtain- ing a 99% efficient interferometer are expressed in terms

of the reflectivity and aperture parameters. These ex- pressions still limited by the assumptions of smooth, plane

parallel films, suggest modifications to the usual applications of the interferometer. Advances in Performance and Applications of the FabryPerot Interferometer, A. STEUDEL. Naturwiss v44 n8

1957 p 249-55 in German. This is a general survey of recent improvements which have been published elsewhere. The importance of absorption of the reflecting film is dis- cussed. Dielectric multilayers are surveyed and their

reflectivity as a function of wavelength is discussed. Materials discussed include single sulphide-cryolite and PbCUMgFz. Registering photoelectric Fabry-Perot spec- trometers are surveyed. A comprehensive literature is reviewed.

Properties of a Fabry-Perot Interferometer Whose Mirrors

Consist of Interference Filters, R. DUPEYRAT. CR Acad

Sci (Paris) v244 nl8 Apr 29 1957 p 2299-302 in French. The device is recommended for the interferometric analysis of Raman spectra where troublesome scattering of the

exciting radiation takes place, the mirrors of the inter- ferometer being constructed to have a reflectivity very low

at the excitation wavelength but high for the Raman rays. A Description of the Fabry-Perot Spectrometer Installed at Bellevue, J. BLAISE. J Phys Radium vl9 n3 Mar

1958 p 335-7 in French. The optical system consists of a Pellin-Broea prism used as pre-monochromator, a Littrow- type spectrograph with a Bausch and Lomb grating, a Fabry-Perot etalon coated with ZnS-cryolite multilayers and a photomultiplier which is liquid nitrogen cooled. The exit slit and the collimating lens of the monochromator are focused respectively on the etalon plates and on

the scanning hole. The photocell is coupled to an elec- tronic recorder through an impedance transformer of the

cathode follower type (consisting of one tube fed by a dry

cell and accumulator). The interferometer mounting

allows any spacing of the etalon plates with only a few

fused silica spacers. Two different devices for scanning

the interference fringe system by changing the air pres- sure in the etalon chamber are described. A Device Permitting the Mechanical Displacement of a

Fabry-Perot Flat, R. CHABBAL, M. SOULET. J Phys Radium vl9 n3 Mar 1958 p 274-7 in French. A mechanical

device giving a parallel displacement to one of the flats of a Fabry-Perot etalon, which is suspended in a flexible scanning which is linear in cm"1

, during which the flats remain parallel to a high degree of precision over one

order of the etalon. This device is thus useful for sawtooth scanning, and yields a "definiance" some five times higher than the resolving power.

L'Etalon de Fabry-Perot Spherique (Fabry-Perot Spherical Etalon), P. CONNES. J Phys Radium vl9 Mar 1958 p 262-9 7 figs 7 refs discussion. English translation available. A Fabry-Perot interferometer can be made with two spherical surfaces, forming an afocal system. This

interferometer can be used in a photoelectric spectrometer

it has the same transmission, contrast, sharpness free spectral range and theoretical resolving power as a plane Fabry-Perot of double thickness. But the "6tendue"

(product of surface by solid angle) of the beam is proportional to the resolving power instead of being inversely

proportional, and the luminosity of the system becomes

greater than that of the plane Fabry-Perot for very high

values (several millions) of the resolving power. The

spherical Fabry-Perot seems to be useful for studying lines whose width is only a few millikaisers. It could equally be used as a generator of artificial lines narrower than

natural ones. See also Rev d'Optique v35 nl 1956 p 37-43

8 figs 3 refs. Developments in the Comparison of Lengths Using Fringes

of Superposition in White Light, A. H. COOK, H. M. RICHARDSON. Proc Phys Soc v73 pt 4 Apr 1959 p

661-70. When two Fabry-Perot etalons are placed one in front of the other, and the length of one is a small multiple

of that of the other, fringes are seen in white light and

have been used in the past to compare the lengths of

etalons. In the study reported in this paper, these fringes have been observed photoelectrically while the optical length of one etalon is varied by changing the pressure

of the air inside it. It is shown that the variation of in- tensity with path difference is the sum of two Fourier

integrals involving an intensity function and the phase

shifts at the reflecting surfaces. By forming cosine and

sine Fourier transforms these quantities can be obtained

separately and a correction applied for the error intro- duced into the comparison of lengths by the change of the phase shifts with wavelengths. It is shown that phase shifts can be measured more accurately by this method than by other interferometric means. It is possible to compare a metre length with a 20 cm length to about 1 in 109

. A Vacuum Contact Dilatometer, V. S. GUMENYUK.

Pribory i Tekh Eksper (USSR) 1961 n4 p 101-3 July- Aug in Russian. A vacuum dilatometer for work in the region of high temperatures (500-1500°C) is described. An electrical contact device, which is connected to the mobile stage of an IZA-2 comparator, is used for measuring the length of specimens at room temperatures as

well as high temperatures. The thermal expansion of tungsten was determined, and it was shown that the ac- curacy of the temperature-dependent elongation values

that were obtained by means of this dilatometer was in good agreement with data from the literature. [English

translation in: Instrum. Exper. Tech. (USA) n4 p 723-5 July-Aug 1961 ; publ Feb 1962.] Double-passed Fabry-Perot Interferometer, P. HARI- HARAN, D. SEN. J Opt Soc Am v51 n4 Apr 1961 p

80
398-9. Increased contrast and resolution can be obtained with the Fabry-Perot interferometer by reflecting the transmitted beams back through the instrument. An

arrangement for this purpose is described in which the double-passed interference pattern is isolated by means

of a simple polarizing system. Zur Technologie des Perot-Fabry-Interferometers, G. KOPPELMANN, K. KREBS. Optik vl8 n8 Aug 1961 p

358-72. Technology of Fabry-Perot interferometers; device is limited by* departures from perfect flatness of

reflecting surfaces and by imperfect parallel adjustment

photoelectric method is used to investigate these defects and ascertain possibilities for improvement.

Cube-Corner Fabry-Perot Interferometer, P. RABINOWITZ, S. F. JACOBS, T. SCHULTZ, G. GOULD. J Opt

Soc Am v52 n4 Apr 1962 p 452-3. Polarized Haidinger

fringes were observed in a Fabry-Perot interferometer with one flat replaced by a cube-corner prism. Orientation of the polarization planes of the fringes and their

relative phase shifts were measured. Some applications

are suggested. Construction of a High-Precision Dilatometer. The Dilatation of Copper, J. L. YERHAEGHE, G. G. ROBBRECHT,

E. VAN OUTRTVE. J Phys Radium (France) v23 Suppl

n6 June 1962 p 109A-110A in French. A precision direct reading dilatometer for the temperature range from —190 to 700 °C was constructed. The characteristics of

the apparatus are described and its possibilities are illus- trated by results obtained on copper. Barium Titanate Ceramics for Fine-Movement Control,

J. V. RAMSAY, E. G. V. MUGRIDGE. J Sci Instrum

v39 nl2 Dec 1962 p 636-9. Barium titanate transducers

are described for use in automatic control of Fabry-Perot

interferometer, to achieve parallel displacements of plate

to accuracy required in interferometry. Fabry-Perot Mirrors from Dielectric Multilayers for the Spectral Region 2350-20000 A, K. HEFFT, R. KERN, G. NOLDEKE, A STEUDEL. Zeit Phys (Germany) vl75

n4 1963 p 391-404 in German. The production and the performance of dielectric multilayer mirrors for FabryPerot interferometers from 20,000 to 2350A are described. Details of the evaporation apparatus and techniques are

given. The optical data, reflection factor, absorption

factor and flatness, are represented graphically and dis- cussed. For all wavelengths cryolite served as low re- fractive material. The high refractive materials used were ZnS for wavelengths from the infrared to \>4120

A, Sb2 03 for \ between 4200 and 3200 A and PbF2 for the

shorter wavelengths to \=2350 A. For PbF2 an excitation band at 2190 A was found. Fabry-Perot Electroptic Modulator, E. I. GORDON, J. D. RIGDEN. Bell System Tech J v42 nl Jan 1963 p 155-79. Analysis of modulation properties of electroptic material

placed in Fabry-Perot etalon; power requirements, heating and bandwidth; microwave phase velocity must be

\ matched to that of light in electroptic medium.

j Some Fringe-Broadening Defects in a Fabry-Perot Etalon,

R. M. HILL. Optica Acta (Int) vlO n2 Apr 1963 p 141-

52. Three forms of defect in the surface finish or alignI ment of the plates of a Fabry-Perot etalon are considered,

: and tolerances are assessed where the etalon is used as

the resonant chamber of an optical maser, and as a spec- trometer of high resolving power. The defects are a regular polishing error of sinusoidal form, a random polish- ing error of gaussian distribution of amplitude, and a

small tilt error between otherwise perfect plates. It is shown that for both uses the plates have to be parallel to about a second of are, and that if the amplitudes of the

error functions are small compared to the wavelength of

the emitted or incident radiation the regular sinusoidal

function gives the greatest loss in efficiency. Asymmetric

line profiles can be obtained if the error in the plates is not symmetrically distributed about the mean planes of the

plates. Resolving Power in Near Infrared of Fabry-Perot Inter- ferometer with Gold and with Silver Coatings, D. A. JACKSON, K. NARAHARI RAO. J Opt Soc Am v53 n5 May 1963 p 558-67. Experiments showing how use of Fabry-Perot interferometer with reflecting surfaces of either gold or silver can increase resolving power of spectrometer in region 0.6 to 2.4/t, or can increase luminosity without decreasing resolving power; optical systems

described for these applications of interferometer. Servo-Techiques in Fabry-Perot Interferometry, H. KOBLER. Instn Radio Engrs, Australia—Proc v24 n9

Sept 1963 p 677-84. Servo-system for position control of

reflecting surfaces of Fabry-Perot interferometer is de- scribed ; position errors are sensed optically with accuracy

of 5x10"° mm ; equipment can compensate for steady er- rors of 4x10"* mm and also reduces amplitude of induced

vibrations. Eine magnetische Feinjustierung fuer ein Perot-FabryInterferometer (magnetic fine adjustment for Perot- Fabry interferometer), G. KOPPELMANN, H. KRAUSE.

Optik v20 n9-10 Sept-Oet 1963 p 475-80. Extremely

small (0.001 of light wave length or less) but reproducible changes can be made in relative position of interferometer's mirror plates by means of device that uses small permanent magnets; efficacy of adjustment is discussed. Remote Controlled Fabry-Perot Interferometer, Z. ERDOKUERTI. Optik v21 n4 Apr 1964 p 167-71. Fabry-Perot

type interferometer is described in which both mirror in- clination and distance between mirrors can be varied in small intervals by means of electromagnets ; design ; cali- bration ; testing. Use of Dielectric Coatings in Absolute Wavelength Meas- urements with Fabry-Perot Interferometer, R. W. STANLEY, K. L. ANDREW. Opt Soc Am v54 n5 May

1964 p 625-7. Discussion showing how absolute wavelength measurements can be made with Fabry-Perot inter- ferometer having dielectric coatings in manner that no er- rors attributable to phase change effects can enter into

final results ; wavelength corrections are due to dispersion

of optical path rather than dispersion of phase change. 2.4.4. Interference Comparators

Optical Measurements of Length, A. PEROT, C. FABRY. CR Acad Sci vl26 1898 p 1779-82. Method utilizes inter- ference fringes produced between two lightly silvered glass

plates. By having a standard pair of plates which have

been accurately calibrated, the fringes produced by them

can be matched with those produced in another system

the distance between which may be some multiple of the

standard.

Tiber einen Interferenzmessapparat (Regarding an Inter- ference Measurement Apparatus), C. PULFRICH. Zeit fur Instrumtkde vl8 Sept 1898 p 261-7. See also "The K & E Interference Viewing Instrument, 1926." Description of Pulfrich interferometer, based on the principle of the simultaneous use of monochromatic lights of different wave-lengths and micrometric measurement of the inter- ference fringes. Sur TApplication de la Chambre Claire de Govi a la Construction d'un Comparateur pour Regies Etalons a Bouts

( On the Application of the Camera Lucida of Govi to the Construction of a Comparator for End Standards), A. LAFAY. CR Acad Sci vl33 Nov 25 1901 p 867-9. Newton's rings are used as indicators for micrometer settings which are made optically on the ends of the bars. 81
Compensation of Interference and Measurement of Small

Thicknesses, G. MESL1N. CR Acad Sci vl38 Apr 18 1904 p 957-9. A ray of light is passed through a thin plate, polarized, received on a plate of crystal (quartz cut parallel to the axis), and analyzed. The retardation in the

thin, isotropic plate is compensated by that due to double

refraction in the crystal, and the method is applied to the measurement of small thicknesses by using plates of

quartz, 1, 2, 5, etc. mm. thick for a kind of optical balancing analogous to the use of a box of weights. Advantage lies in being able to compensate the effect of a thin plate by means of a quartz plate some hundreds of times thicker. See also MESNAGER, CR Acad Sci vl38 Jan 11 1904 p 76-7. Interferenzkomparator fur Endmasze (Interference Comparator for End Measures), F. GOPEL. Werkstattstechnik Nov 1919 7 p 12 figs. Comparator developed at the

Reichsanstalt. Measuring Balls and Plugs by Light-Wave Method, H. L. VAN KEUREN. Machy (NY) v27 Sept 1920 p 14-6 8

figs. Fundamental facts on which method of measuring

plain cylindrical plug gages by interference bands pro- duced by light waves is based. Interferenzmethoden zur Untersuchung von Endmassen

(Interference Methods for the Investigation of Gage

Blocks), G. BERNDT. Betrieb v3 Apr 10 1921 p 389-96

20 figs. Notes on origin of interferences of equal thick- ness and their use in investigation of smoothness of sur- faces and for measurement of differences in length (methods of Bureau of Standards, of Roster, and Gopel) ; absolute determination of length with interferences of equal

thickness ; interferences of equal inclination and their use

in measurement technique. Definition of length of gage

blocks. L'Etude des Calibres Industriels au Bureau International des Poids et Mesures (Study of Industrial Gages at Int Bur of Weights and Measures), A. PERARD. Genie Civ v78 June 4 and 11 1921 p 477-80 and 500-3 20 figs. June 4

Types of gages and comparators employed. June 11

Calibration of standard gages of Johansson type by means

of an interferometer. Gaging by light-interference method. Die Anwendung der Interferenz des Lichtes im Lehrenbau

(The Application of Interference of Light in Gage Work),

G. BERNDT. Deutsche Optische Wochensehrift vlO n22,

23, 24 June 1, 8, 15 1924 p 265-9, 282-5, 302-8 14 figs. Describes Zeiss interference comparator and its application in the comparison of lengths of gage blocks. Light-Wave Interference Comparator. Am Mach v62 1925 p 124. A New Interference Apparatus for Testing Haemacytometers, C. G. PETERS, B. L. PAGE. Sci Papers NBS

v20 n507 June 3 1925 p 221-36. Includes description of an interference comparator by means of which the differ- ence from nominal of the depth of the chamber is indicated by the spacing of the fringes. Method and Device for Examining End Gages, W. ROSTERS. U.S. Patent 1 561 173 Nov 10 1925. Interference

fringes show the difference in length of two gages. An Interference Appliance for the Accurate Comparison

of Length Gauges, F. H. ROLT, C. H. KNOYLE. J Sci Instrum v4 Nov 1926 p 42-45 2 figs. Describes an apparatus for intercomparing two or more length gages, of nominally equal length, by interference methods. It consists of a tilting lever, resting on three ball feet, two of which

are supported from the base of the apparatus, while the

third rests in turn on the various gages to be compared. The lever carries at the top a polished flat steel surface,

over which an optical proof plane can be adjusted to give the desired pitch and direction to the interference fringes which appear when the apparatus is suitably illuminated with monochromatic light. The number of fringes which

occur within a given space is counted. La Verification des Calibres par les Interferences Lumineuses (Standardization of Gages by Light Interference),

E. MARCOTTE. Arts et Metiers v81 July 1928 p 248-9

21 figs. Describes principles which are derived from

Fizeau fringes and applied by several constructors to inter- ference measurement of gages ; study of useful rays ; practical operations. Interferometer for Gage Comparison. Am Mach (Euro- pean ed) v75 p 265. This double-ended interferometer is for comparison of lengths, such as master slip gages. It consists essentially of two Michelson interferometers ar- ranged to observe two ends of the gage and measure by wave length of light to avoid mechanical contact with

the end faces. By means of this unit lengths can be compared to 0.000001 in. Gauge Comparing and Absolute Length Measuring Inter- ferometers. J Sci Instrum vl6 n5 May 1939 p 163-5 4

figs. Describes two forms, one for comparing gages and

the other for measuring absolute length. See also publication by Hilger & Watts Ltd. and British Patent

555,672 Feb 23 1942. Method for Comparing an End-gauge and a Slip-gauge, J. TERRIEN. CR Acad Sci (Paris) v235 Nov 24 1952 p

1288-90 in French. The use of transparent parallel- plane glass or silica end-blocks, the thicknesses of which

are determined by interference, is proposed and the ad- vantages are detailed. Interference Comparator of the Test Laboratory of the Conservatoire National Des Arts et Metiers, J. J. HUNZINGER. Rev Opt v34 nlO Oct 1955 p 512-19 in French. An interferometric circuit is described which is a polyg- onal variant of the Michelson interferometer. With it two length standards can be compared. The method of adjustment is described in detail, and the manipulation and performance surveyed. Standard gages are examined with this system and comparisons are made.

Novel Interferometer Construction, N. O. YOUNG. J Opt

Soc Am v46 nil Nov 1956 p 996. An interferometer related

to the system of Vaisala is described. A simplified construction is used in which the interferometer is built be- tween the jaws of an ordinary small micrometer, the faces

of the jaws acting as two parallel mirrors, a strip plate between them being mounted on the yoke. The system

is rugged. Ein Interferenzkomparator zur Bestimmung der Differenz von Endmasslaengen (An Interference Comparator for Evaluating the Difference Between End-Standards), M. DUEHMKE. Zeit Instrumkde v65 nl Jan 1957 p 15-7. By employing a difference method against a standard,

lengths of slip-gages (up to 100 mm) can be evaluated to within 0.01/u. The method described enhances the Fizeaufringe sharpness by multiple reflection. Interferometer

described has been constructed for comparison of test sample with one that is standard, but can also be used

for absolute interferometric measurement. Achromatic Interferometer for Gage Block Comparison,

T. R. YOUNG. NBS Cir 581 Apr 1 1957 p 43-50 2 figs; NBS Tech News Bui v40 nl2 Dec 1956 p 176-7. Has many

advantages that make it unique as an interference comparator. It is possible to measure absolute lengths with

this interferometer by replacing the white-light source with a monochromatic source. High-Precision Interferometer for Gauge Block Comparison. Engr v203 n5287 May 24 1957 p 814-5. Interfero- 82
metric comparator developed by NBS, Washington, D.C., allowing routine comparisons of length to be made to nearest ten-millionth of inch. Design of a Compact Wide Aperture Fizeau Interferometer. P. R. YODER, JR., W. W. HOLLIS. J Opt Soc Am

v47 n9 Sept 1957 p 858-61. A theoretical investigation of the performance of the Fizeau type interferometer as a function of the collimating lens spherical aberration and

the thickness of the air space between the interferometer

plates is presented. The theory developed is applied to the determination of the maximum relative aperture per- missible in a simple collimating lens system for use in an

interferometer of specified plate separation. It is found

that an f/3 lens system consisting of two plano-convex

lenses can be used in an interferometer of 10 in. aperture with the plates separated as much as 0.050 in. In such

a system, the instrumental error introduced into the fringe pattern is no greater than X/100 for mercury green light. Some Possible Applications of the Interferometer Using

Correlated Rays. R. ULLRICH, W. LOCHTE-HOLTGREVEN. Optik vl4 nil Nov 1957 p 481-9 in German. A discussion of two-beam interferometer systems in which

two beams cover a given cycle in opposite directions and

then recombine. A difference in space coverage is indi- cated according to whether an odd or even number of

reflections is involved. Systems are described for use as

(a) a refractometer, (b) an interferometric system in which fringes and object are superposed, and (c) an inter- ference length comparator. Checking Master Gage Blocks with Interferometer. Tool Engr v40 nl Jan 1958 p 115-6. Interferometric comparator developed by National Bureau of Standards, which makes routine comparisons of length to nearest 10 millionth of in. ; this instrument will be used to check lengths

of master gage blocks that control accuracy of guided

missile, jet aircraft, machine tool and similar high preci- sion parts ; design and operation of instrument. Comparator with Photoelectric Detection for Setting on Broad Interference Fringes with Precision, J. M. BENNETT, W. F. KOEHLER. J Opt Soc Am v49 n5 May

1959 p 466-7. A comparator with photoelectric detection system is described. Experimental data are reported to demonstrate that the same setting precision of ±0.2 micron

is associated with the measured position of a normally

exposed two-beam interference fringe, an overexposed two-beam interference fringe, a multiple-beam interfer- ence fringe, and a spectral line. The corresponding set- ting precisions obtained by the usual visual techniques are

4-6.2±3.0, ±1.1, and ±0.6 microns, respectively. Application of InteTferometry to the Routine Measure- ment of Block Gauges, S. P. POOLE, J. H. DOWELL,

NPL. Optics in Metrology, P. MOLLET. Pergamon

Press 1960 p 405-19 8 figs 2 refs. An interferometer de- signed at NPL in 1937 deals with twenty gages in one

operation. Methods employed are given with a brief sur- vey of sources of error. Interferometer is illustrated with details of improvements. A New Method of Measuring Gage Blocks, J. B. SAUNDERS. J Res NBS v64C n3 July-Sept 1960 p 173. The

parallel testing interferometer is quite applicable, without

modifications, to the comparison of lengths of gage blocks. This note described the testing of gage blocks of all lengths, up to several metres, without having to contact them to optical flats. The Double-Passed Fizeau Interferometer, P. HARI- HARAN, D. SEN. J Opt Soc Am v50 nlO Oct 1960 p

999-1001. When the transmitted beams from a Fizeau

interferometer are reflected back through the instrument,

a new system of fringes is observed in which the intensity

distribution undergoes a periodic modulation as the separation of the plates is changed. Accurate measurements

are possible with the help of these fringes, using a photo- metric setting criterion. The mode of formation of these

fringes, as well as the theoretical intensity distribution

in them under various conditions, are discussed. Study on the Interference Comparator, Y. TOMONAGA.

Report of the Central Inspection Institute of Weights and

Measures, Japan, vlO n2 report 26 1961 in Japanese. In

this paper the author describes the design of a new inter- ference comparator (IC) to be used as precision workshop

comparator. Its principle is based on that of Michelson's interferometer for white light. The experiment on this comparator shows that no change of interference colour

of white light is observed unless the thickness difference between a glass plate and its compensator is over SA/i. Basing upon these data the beamsplitter and the double wedge glass plate are designed. The main body and the column of IC are designed so as to be more rigid than

those of Mikrokator (MK), Ultraoptimeter (UM) and

Projection Optimeter (PM). The measuring spindle is suspended by a pair of parallel sheet springs made of phosphor bronze, and the force necessary to displace the

spindle axially by 1 mm is 28.5 gw. The maximum dis- placement of measuring anvil due to clamping is only 0.2/t. For IC the relation between the change of temperature

Af (deg) and that of indication Ss(fi) is shown to be given experimentally by the following expression : S 2 =0.16Ai. In an ordinary conditioned room in which the temperature

varies with an amplitude of about ±0.5 deg and with a

period of about 30 min. the measuring spindle is to change

its length about 0.5^ for one period. As the column is heated by the lamp of light source, the indication of IC

changes about 0.02/i in the measurement of 100 mm gauge. But the above mentioned changes of indications do not

practically affect the measuring accuracy, so far as IC

is used as a comparator, because they give only shift of zero reading. The dispersion of measured values of IC

ranges over only O.OljU and is proved to be very small. A Contact Interferometer with an Extended Measuring

Range, V. P. KORONKEVICH, V. V. SKIDAN, V. A. AFANAS'EVA. Meas Techns 1960 n5 Jan 1961 p 373-6 5 figs 8

refs. Translated from Izmer Tekh n5 p 2-5 May 196Q. The experimental work carried out makes it possible to conclude that the extended range interferometer can be widely used for accurate measurements of small lengths. The interferometer can be easily adapted for checking

microcators, opticators, ultraoptimeters, strain-gauge

calibrators, optical micrometer screws, angles of small wedges, for measuring magnetostriction, determining the

linear temperature expansion coefficients, and other purposes. Double-Passed Fizeau Interferometer. II. Fringe Sys- tems Formed by the Reflected Beams, P. HARIHARAN,

D. SEN. J Opt Soc Am v51 n4 Apr 1961 p 400-4. The

theoretical intensity distribution in the fringes formed when the beams from a Fizeau interferometer are re- flected back through the instrument is obtained. It is shown that, under certain conditions, the intensity dis- tribution in these fringes exhibits a periodic modulation

as the separation of the plates is changed, so that they can

also be used for very accurate measurements. Messen eines Keilformigen Endmasses (Measurement of a Wedge-Shaped End-Measure), P. LEINWEBER. Fein- werktechnik v67 nl2 1963 p 469-72 4 figs 5 refs. Describes

the application of an interference comparator developed by the author in the measurement of the thicknesses at a

series of points of a gage block having a small wedge angle. The process and results are discussed. Interferometer IZK-57 for Measuring the Diameter of

Balls, YU. V. KOLOMIITSOV, A. S. EGUDKIN. Meas

Techns 1962 nlO June 1963 p 815-8 3 figs 3 refs. Translated from Izmer Tekh nlO p 8-11 Oct 1962. Describes an experimental model of interferometer IZK-57 for precision relative contactless measurements of ball diameters 83
from 1 to 10 mm by comparing them with a reference ball diameter or a block gage. 2.4.5. Measurement of Long Lengths

Melhodes Int6rferentielles pour la Mesure des Grandes

Epaisseurs et la Comparaison des Longueurs d'Onde (In- terferential Methods of Measuring Great Thicknesses and

the Comparison of Wave-Lengths) , A. PEROT, C. FABRY.

Ann Chim Phys vl6 1899 p 289-338 7 figs. More complete and general than previous papers by authors. Useful

in that cross references are given to papers by other workers. Die Anwendung der Lichtinterferenz zu Langenmessungen

auf grosseren Distanzen. (Application of Light Inter- ference Methods to Large Distances), Y. VAISALA.

Helsinski, 1923. See VAISALA ref under 2.4.1/1927. Standardization of a 25m Jaderin Wire in Terms of the Wave-Length of the Cadmium Red Line, N. WATANABE,

M. IMAIZUMI. Imperial Acad Tokyo Proc 5 June 1929 p 223-6. The authors developed a method of Fabry and

Perot to measure the length of a long standard using Brewster's white fringe and removing extraneous rays. Standardization was made first for a 6.25 cm. standard and then extended to 1, 5 and 25 m. standards and to the Jaderin wire. It is concluded that the method may be extended without much difficulty to a length of a few

hundred metres. Any small variation in length can be

traced from time to time by observing the positions of the white fringe in a compensator. The method may find an application in tracing the deformation of the earth's crust and in problems of a similar nature. Application of the Interference of Light in Base Measurements, Y. VAISALA. Translated by M. Wurzinger.

Publications of the Finnish Geodetic Institute nl4 1930. The method consists in a multiplication based on the application of the interference of white light. The interval between two parallel mirrors can be copied or multiplied even at great distances, the movement of the air per- mitting. Die gegenwartige Stand der Meter-Definition, des Meteranschlusses und seine internationale Bedeutung fur Wissenschaft und Technik (The Present State of the Meter

Definition, of the Meter Determination and Their Inter- national .Significance for Science and Technology), W. K6STERS. Werkstattstechnik und Werksleiter v23 Dec

1938 p 527-33. Describes new Rosters interferometer for long lengths. English translation available. Measuring a Large Displacement by Interferometry, H. BARRELL, M. J. PUTTOCK. Brit J. App Phys vl Apr

1950 p 87-91. A modified form of Michelson interferometer is used to calibrate the mechanical displacement sys- tem of an adjustable cavity resonator used to measure

the velocity of propagation of electromagnetic waves. For the calibration a linear displacement of 12.7 cm was

determined in standard Kr wavelengths to an accuracy of one part in a million, utilizing techniques of fringe obser- vation and calculation which do not involve counting a progression of fringes. Displacements >30 cm can be

similarly measured if suitable sources of monochromatic

radiations are employed. Two Interferometric Techniques, C. VOLET, N. CA- BRERA. Rev Opt (Theor Instrum) v30 Apr 1951 p 169-73

in French. A multiplication process ( X 20) is described whereby a 20 cm Fabry-Perot etalon is multiplied to measure a 4-metre distance between two mirrors. The radiation required is that of a single isotope like Hg198 to measure the etalon, and white light superposition fringes are used in the multiplication. The effect of the dispersion

of the phase change on metallic reflection is investigated.

This leads to fringe asymmetry. With the method a

geodetic standard can be measured to some parts in ten

million. The measurement of the metre in terms of light waves is discussed. Some Problems Arising From the Use of Interference for the Precise Measurement of Plane-Ended Gauge Blocks. The Study of Fringes From an Air Wedge, J. TERRIEN.

J Phys Radium vl5 Apr 1954 p 6S-8S in French. The

length of steel gage blocks can be found by comparison

of the two fringe systems formed by interference between beams reflected from a reference glass surface, the upper

gage block surface and the surface .plate on which the block is resting. For large gage blocks, an error arises from the different character of the two sets of fringes, that form the upper surface arising from multiple reflec- tions. The error is calculated and a method of measuring it is suggested. Optical Interference with a Metre Path Difference, J. TERRIEN, J. HAMON. CR Acad Sci (Paris) v239 n8 Aug 23 1954 p 586 in French. Success has been achieved

in obtaining interference over a path difference of 100 cm using a Michelson interferometer ; the source with which this was achieved consists of isolated Kr86

, operat- ing in the triple point of nitrogen (63 °K). The inter- ference over this long path difference could only be secured

in the infrared using the 9856 A. It was not possible to secure fringes over a metre with the shorter wave 8777 and 9752 A. It is now possible to compare in one single operation the length of one metre line standard in terms

of light waves. An Interferometric Method of Distance Measurement:

Frequency Modulation Radar, G. BROUSSAUD. Rev

Opt v35 nil Nov 1956 p 593-603 in French. The equations governing the measurement of distance by optical interference methods are developed to include distance measurement by f.m. radar. This latter method differs from optical techniques not only in the wavelength employed but in the kind of problem which it solves. A Kosters-Type Interferometer, C. F. BRUCE. J Sci Instrum v33 nl2 Dec 1956 p 478-82. The design and

performance are described of a Kosters-type interferometer which measures lengths of up to 500 mm directly by

interferometry. Isotopic light sources are necessary for the measurement of the longer lengths, and sources con- taining Hg198 and Kr66

, as well as natural krypton and cad- mium, have been used with this interferometer. Results

of some length and relative wavelength measurements

are given,' to illustrate the performance of the interferometer operating in air and in vacuo. Das genaueste Langenmessgerat der Deutschen Demokratischen Republik (The Most Accurate Length-Measuring Apparatus in the German Democratic Republic), F. SCHILLING. Techn Gemeinschaft n3 1957 p 110-2.

Interferentielle Vergleichssmethoden fur Endmasse bis 1000 mm (Interferometric comparison methods for end

standards to 1000 mm), M. DUHMKE. Phys Verh Mosbach v8 n5 1957 p 134. A Rosters double prism was

used in the interferential comparison of length and parallelism of 1000 mm bars mounted horizontally. The meas- urement uncertainty was estimated as a. few hundredths

of a micron. Interferenzordnungen fur die Messung langer Parallelend masse (Interference Methods for Measuring End Standards of Great Length), C. HOFFROGGE, PTB. Zeit In- strumkde v65 n7 July 1957 p 123-5 4 figs 7 refs. The

methods are for end standards which are too long to ( measure directly by optical interference. The overall length is therefore virtually subdivided by the images of reference mirrors, interference fringes being obtained be- tween these mirrors and the ends of the standard. The

84
fractional part of the order of interference of the overall length is equal to the sum of the fractional parts of the orders of the subdivisions. Kosters double prisms are used as beam dividers. New Gauge Interferometer, P. HARIHARAN, D. SEN.

J Opt Soc Am v49 n3 Mar 1959 p 232-4. Development

of interferometer for absolute measurement of length of end standards which utilizes optical arrangement in which

path difference introduced between interfering beams is only half length of gage; theoretical principles; experi- mental measurements; advantages include simplicity of

operation, compact layout and suitability for measure- ments on comparatively long gages. Interferometrische Kalibrierung von Endmasstaben aus Quarz ( Interferometric Calibration of End Standards of Quartz), E. ENGELHARD. Zeit Instrumkde v67 n3 Mar 1959 p 59-65 in German. A review is given of the

interference methods in use in different countries for the

testing and preparation of end standards. The definition

of the official meter is discussed. It is considered that the uncertainty in the best cases approximates to 0.1/*. It

is estimated that a five times smaller uncertainty could

be attained by using the red cadmium wavelength as the standard instead of the standard meter. A ten times

smaller uncertainty is attainable using Kr 86. Instruments and Methods for Interference length Meas- urement Developed in the Mendeleev Metrological Institute, A. L KARTASHEV. NPL Symposium nil, 1959, Interferometry. H.M. Stationery Office, London 1960 (Paper 2-5) p 109-24 6 figs 3 refs. Describes results of research on the design of interferometers for measuring

end standards and geodetic bars of fuzed quartz from 100

to 1200 mm in length. Two types were built, one for absolute and the other for comparative measurements. Describes optical scheme and states advantages of the inter- ferometer. Application of Multiple Beam Interference to the Meas- urement of Long End Standards, J. B. SAUNDERS. J Opt Soc Am v50 n2 Feb 1960 p 183-4. A technique is described in which white light fringes of superposition

are secured by combining a Fabry-Perot etalon with a Michelson interferometer. Fringes are obtainable for values of the Michelson path which are integral multiples

of the Fabry-Perot path. The system can be adapted to the measurement of long end-standards.

Interference Fringes with Mercury-198 and a Path Dif- ference of 2000 mm, I. C. GARDNER, K. F. NEFFLEN.

J Opt Soc Am v50 n2 Feb 1960 p 184. A Connes type Fabry-Perot interferometer with spherical mirrors sepa- rated by 100 mm was constructed and was used as a monochromator for the Hg green line. It should have

given a line width of 0.003 cm"1

, with which fringes should have been found over a path difference of 3 meters ; in fact

fringes were easily visible at 2 meters path difference, the

longest obtainable on the available Michelson interferometer. Interferometric Length Measurements on Long Parallel End Standards, M. DUHMKE, K. KANTOR, F. HOCK.

Optik (Germany) vl8 nl0-ll 1961 p 561-6 in German. A

description is given of an interferometer system, essentially a combined Fizeau and Michelson system, whereby

it is possible to secure interference for end standards ex- ceeding 100 mm in length, up to 1 metre in length. A

combined Fabry-Perot and Michelson arrangement is also reviewed. Comment by K. Kantor : It is claimed that by

the aid of a sevenfold multiplication of path between

semi-transparent mirrors 10 cm apart, linked to a Michelson interferometer, path-lengths up to 2.8 metres still give good fringes. Comment by F. Hock: A Michelson

interferometer system is described in which a polarization beam splitter is in one arm following the normal beam

splitter. Thus the two polarization vibrations can be

made to traverse different path-lengths. It is shown that

this enables paths double the coherence length to be measured.

1-m-Interferenzkomparator, M. DUEHMKE. Zeit In- strumkde v69 nlO Oct 1961 p 267-70. 1 m gage interfer- ometer ; description and operation of instrument for 100- 1000 mm slip gages for comparative measurements ; it can

be connected with Fizeau or Michelson interferometers. Wavelength Standard Comparator. Engineer v212 n5519 Nov 3 1961 p 759-60. In accordance with decision of 11th General Conference on Weights and Measures, meter is now defined in terms of wavelength of krypton 86 ; inter- ferometer with photoelectric comparator now being set up

at Int Bur of Standards at Sevres will enable meter stand- ards to be compared within one part in 108 or better. Metre Interference Comparator. Engr v212 n5527 Dec

29 1961 p 1100-1. Design of instrument invented by

Koesters of Physikalisch-Technische Reichsanstalt (PTR)

and now commercially produced by Carl Zeiss ; prototype, completed in 1927, has since been redesigned by Engel- hard ; krypton lamp is hot cathode discharge tube sur- rounded by Dewar flask ; sharpness of krypton lines is such that light scales of 800 mm length can be realized, having over 2,000,000 division lines with uncertainty of no more than plus or minus 0.01/i on any point ; diagram. Ein Meter-Komparator fur interferometrische Langen- bestimmungen in Vakuum-Wellenlangen (A meter comparator for interferometric length determinations in vacuum wavelengths), W. KINDER. Zeiss-Werkzeitschrift n43 1962 18 figs 10 refs. Describes an in- terferometer developed by the firm of Carl Zeiss with which gage blocks from 4 to 40 in. in length can be measured in vacuum wavelengths of the standard Kr line. This instrument represents an advanced development of the meter comparator described by Kosters in 1938. Radiointerferometer for Measuring Long Lengths, G. S. SIMKIN, I. V. LUKIN, L. I. BIRYUKOV. Meas Techns

1961 nlO Mar 1962 p 780-3 1 fig 7 refs. Translated from

Izmer Tekh nlO p 8-10 Oct 1961. Describes a double- beam radio interferometer which operates in the centi- meter waveband and is intended -for measuring lengths up to tens of meters in testing end gages and line measures. Long-Path Interferometry Through an Uncontrolled At- mosphere, K. E. ERICKSON. J Opt Soc Am v52 n7 July

1962 p 781-7. An investigation was made of the degree to which the invariance of the relative dispersion of the atmosphere will permit an interferometric separation be- tween geomagnetic path differences and path differences due to atmospheric inhomogeneities. Humidity variations are the most serious. A difference in average humidity

of 1% of saturation at 15 °C would affect the comparison

of two paths by approximately 2 parts in 10s

. The feasibility of photographing interference for long paths through an uncontrolled atmosphere was investigated. Photographs of channel spectrum interference were readily obtained for path lengths of 115 m near ground level. A Method for Obtaining Interference With a Great Path

Difference, N. R. BATARUCHKOVA, A. I. KARTASHEV,

A. P. KIRIOHENKO. Optika i Spektrosk (USSR) vl4 n2 Feb 1963 p 304-5, in Russian. English translation in

Optics and Spectrosc. (USA) vl4 n2 Feb 1963 p 159. Details are given of a spherical Fabry-Perot system for use with an interference monochromator. Interference patterns were easily photographed with path differences

of over 2 meters. Measurement of Large Path Differences by Means of an

Interference Monochromator, A. I. KARTASHEV, A. P. KIRICHENKO. Meas Techns 1962 n8 Feb 1963 p 630-3

5 figs 2 refs. Translated from Izmer Tekh n8 p 9-11 Aug

1962. Method described which makes it possible to meas- 85
ure large distances without the use of intermediate steps or "multiplier" of the path difference. Interference Monochromator with a Spherical Fabry-Perot

Standard, N. B. BATABCHUKOVA, A. P. KIBICHENKO.

Meas Techns 1962 n8 Feb 1963 p 633-6 5 figs 2 refs. Translated from Izmer Tekh n8 p 11-3 Aug 1962. Describes method of narrowing a spectral line and thereby increas- ing coherence length consisting of optical filtering by means of a Fabry-Perot standard with a preset path

difference. Comparator Measures up to 40" with Accuracy of 0.4 Microinch, W. KINDEB. Instrum & Control Systems v36 n4 Apr 1963 p 123-6. Interferometer type of meter comparator is described, developed by Carl Zeiss of West Ger- many in collaboration with Physikalisch-Technische

Bundesanstalt, Braunschweig; interference problems;

path of rays in meter comparator.

Tilted-Plate Interferometry with Large Plate Separations, H. W. MOOS, G. F. IMBUSCH, L. F. MOLLENAUEB, A. L. SCHAWLOW. Appl Optics (USA) v2 n8 Aug 1963 p 817-22. With very highly oollimated monochromatic light sources, such as optical masers, multiple- beam interference fringes between nearly parallel surfaces are obtained at large separations. Sharp fringes display- ing the surface contours have been observed with separations as large as 20 cm. The requirements and limitations

of the device are described, as well as some possible

applications. Design of Fabry-Perot Standards with Spherical Mirrors,

A. P. KIBICHENKO. Meas Techns 1963 nl Aug 1963 p 25-8 3 figs 10 refs. Translated from Izmer Tekh nl p 18-20 Jan 1963. Deals with the design and manufacture

of a Fabry-Perot standard with spherical mirrors used for

filtering out spectral lines of single-isotope sources of

light. It was possible to observe interference with path

differences exceeding 1 m and to measure by the absolute

interference method gage blocks up to 1 m long. Interferometric Measurement of End Standards up to 1 m,

Y. SAKUBAI, H. YAMAMOTO. Bui Japan Soc Prec Eng

vl nl Oct 1963 p 17-20 3 figs 3 refs. Contents : Measuring

apparatus; factors that affect the accuracy of measure- ment ; results of experiments ; discussions and conclusions. Measuring Distance with the Mekometer, B. H. BBADSELL, NPL. New Scientists vl5 p 206-7 1 fig. Instrument measures distances of the order of 50 m using a centimeter wavelength pattern imposed on a light beam. Long Distance Interferometry with He-Ne Laser, F. T. ABECOHI, A. SONA, Nuovo Cimento v32 n4 May 16 1964 p 117-21. Interference fringes have been observed up to optical path difference of 120 m (mirror separation 60 m)

without substantial loss of visibility ; He-Ne laser operat- ing at 6328 A has been used. Laser Feedback Interferometer, D. M. CLUNIE, N. H. BOCK. J Sci Instruments v41 n8 Aug 1964 p 489-92. Interferometer consists of He-Ne laser, mirror providing

optical feedback, and photodetector ; principle enables interferometry to be performed over path lengths of up to 50 m at either 0.6328 /im or 3.39 fim ; alignment of instru- ment and detection of fringes is performed at 0.6328 /im

interferometer may be used to measure length, and also

velocities up to at least 80 cm sec-1

, and produces fringes when only 1% of output is fed back ; applications include machine tool control and measurement of optical path

length. Laser Calibrator for Shop. Steel vl55 nl3 Sept 28 1964 p 97. Lengths up to 100 in. are defined to accuracy of one

part in one million by instrument called absolute inter- ferometric laser calibator, supplied by Airborne Instruments Laboratory Div, New York; construction of cali- brator which has sensor, light reflector and electronic cabinet ; aligning interferometric axis with motion axis of machine and other problems that had to be solved to de- velop accuracy needed. 2.4.6. Measurement of Line Standards

See also Section 4 Buling Line Standards, H. B. LEWIS, C. G. PETEBS.

Mech Eng v46 mid-Nov issue 1924 p 796-8 7 figs ; Am Mach

v61 Dec 11 1924 p 925-8. Method of producing line stand- ards free from measurable error by application of light interference, and end measuring machine upon which they

are used. Die Eichung der Drahte: C. Interferenzmessungen (The

Calibration of Wires: C. Interference Measurements), E. GIGAS. Handbuch fur die Verwendung von Invardrahten bei Grundlinien messungen; herausgegben von der Trigonmetrischen Abteilung des Beichsamts fur Landes

aufnahme, Berlin, 1934 33 figs. Calibration of land sur- veying wires by applying the Finnish geodetic method of Vaisala. Method for Comparing a Line Standard and a Wavelength

of Light, J. TEBBIEN. CB Acad Sci (Paris) v238 Mar

1 1954 p 1001-3 in French. A discussion is given of a method of using glass plates with a Michelson interfer- ometer so adapted that a line-standard can be converted

optically into an end-standard. The method involves the

introduction of silvered plates into the path, the plates having lines scratched into the silver and by an inter- changing method the line-standard is converted to an

optical end-standard. Ein Interferenzkomparatur fur Strichmasse (An Inter- ference Comparator for Line Standards), C. HOFF- BOGGE, PTB. Microtechnic n6 1956 p 244-8 5 figs 10

refs. Has capacity of 1 m.

Accurate Linear Scales Buled on Grating Engine, D. BICHABDSON, B. M. STABK. J Opt Soc Am v47 nl Jan 1957 p 1-5. Absolute spacing ruled by grating engine

is determined by ruling linear scale and using it as dif- fraction grating; angles of incidence and diffraction are measured with spectrometer; after wavelengths are ad- justed to experimental conditions, average spacing of scale

is calculated from grating equation ; wavelength standards

are thus used directly for determining line standards of

length. On an Instrument for Calibrating Graduated Scales up

to 1 m in Terms of Wavelength of Light, Y. SAKUEAL.

Beport of the Central Inspection Institute of Weights and

Measures, Japan, v8 n4 report 20 1960 in Japanese. A

brief description is given of an interferometric instrument which is designed and constructed in order to evaluate di- rectly graduated scales up to 1 meter in terms of wavelength of light. The graduated scale to be measured is set on the base of the instrument which has the optical parts of the corner-cube interferometer. The lines of the

scale are viewed by a photo-electric microscope through an optical system on a carriage which is movable along

its way by means of a screw and nut. The carriage also holds the moving reflector of the interferometer at its lower surface, and the position of the reflector is made to be related with that of lines of graduated scale by applying the Eppenstein's principle. The evaluation of relative mechanical displacement of the reflector to the reference corner cube, which is on the same base, are carried out by

counting the number of interference fringes which have

passed through the field of the interferometer during the transference of the moving reflector. To distinguish the

direction in which fringes move, two photo-tubes are ar- ranged to view two different parts of a fringe pattern

respectively where the variations of the light intensity
resulting from movement of fringes are different in phase

by approximately 90°. The outputs of the photocubes

are transmitted to a reversible electronic and mechanical

counter and a fraction indicator. As the reference corner- cube itself is to displace in the direction of the incident beam, the interferometric instrument is also usable for

scales longer than the coherent length of light source. With a view to ensure constancy of temperature, the in- strument is set in an aluminum case with double wall and sandwiched sheets of Molto-pren. The accuracy of

this instrument is found to be±0.05,u at its maximum

measurable length of 1 meter, and yet a larger part of measuring error, to be caused by the deformation of the body of the instrument due to the transference of the movable carriage. Unmittelbarer Anschuss von Strichmassen an Lichtwellenlangen, C. HOFFROGGE. Amtsblatt der PTB 1961 n2 p 192-5; Microtecnic vl4 n2 p 51. An instrument

for direct comparison of line standards with wavelengths

of light is described. The two principal components are

a photoelectric microscope and a modified Michelson inter- ferometer. Computation of lengths by the method of coincidences of excess fractions is used. An Automatic Fringe Counting Interferometer for use

in the Calibration of Line Scales, H. D. COOK, L. A. MARZETTA. J Res NBS ( Eng & Instr ) v65C n2 Apr-June

1961 p 129-40 7 figs 10 refs. Interferometer is described

in which mechanical, optical, and electronic adjustments

are maintained stable by servo-mechanism control or by

balancing. A rate of more than 1,200 fringes per second has been achieved over a range of 14 cm. An electronic interpolator permits recording the count in digital form

to 0.01 fringe without ambiguity. On an Instrument for Calibrating Graduated Scales up

to 1 Meter in Terms of Wavelength of Light, Y. SAKURAI. Global Technol Apr 1961 (Digest of original Jap- anese article). Description of an interferometric line standard comparator. The principal components are a

photoelectric miscroscope and an interferometer employing a Roster's double prism and corner-cube reflectors. A reversible fringe counter and interpolator is used to determine the order of interference. Interference Comparator for the Calibration of Line

Standards Directly in Terms of Standard Wavelengths,

K. M. BAIRD. Rev Sci Instrum (USA) v32 n5 May 1961 p 549-54. An interference comparator was built for the

routine calibration of line standards or scales by direct reference to the vacuum wavelength of the 0.606/x line of KrM which recently became the international standard

of length. The principles of construction and the per- formance of the comparator are given ; it is shown to yield an accuracy of calibration which is mostly limited by the nature of present-day line standards or scales, viz, a few hundredths of a micron in lengths up to one meter. High Speed Interference Calibrator of Standard Scales—1, Y. DOI, K. SHIMIZU, T. TSUBOI, T. KONO. J Mech

Lab Japan vl4 n3 May 1962 p 121-38. Method for cali- brating standard scale with resolution of 0.1/i ; it requires no longer than 40 min to obtain calibration data for graduated lines ruled at interval of 1 mm for length of 1 m;

photoelectric microscopes are fixed to bed and electric pulses generated at passage of lines across microscope

axis ; table motion is measured by interferometer ; pulses

from microscopes and interferometer are sent to logical apparatus made of 600 parametrons and calibration data

are printed out automatically. In Japanese with English

abstract. A Method for Obtaining Interference with a Great Path

Difference, N. R. BATARUCHKOVA, A. I. KARTASHEV,

and A. P. KIRICHENKO. Optika i Spektrosk (USSR)

vl4 n2 Feb 1963 p 304-5 in Russian. English translation

in: Optics and Spectrosc (USA) vl4 n2 p 159 Feb 1963. Details are given of spherical Fabry-Perot system for use with an interference monochromator. Interference pat- terns were easily photographed with path differences of over 2 meters. Comparator Measures up to 40" with Accuracy of 0.4 Microinch, W. KINDER. Instrum & Control Systems v36 n4 Apr 1963 p 123-6. Interferometer type of meter comparator is described, developed by Carl Zeiss of West Ger- many in collaboration with Physikalisch-Technische

Bundesanstalt, Brunschweig; Interference problems;

path of rays in meter comparator.

Interference Comparators for Line Standards, K. M. BAIRD. App Optics (USA) v2 n5 May 1963 p 471-80. Reviews progress in the techniques of calibration of scales and line standards by interferometry, techniques that have

been under very active development since the redefinition of the metre in terms of an optical wavelength. After a study of some general consideration, specific examples of interference comparators are described, and, finally, the

effect of the development of these techniques on the use- fulness of scales as secondary standards is discussed. Interference Measurements of Graduated Standards of Length, M. L. BRZHEZINSKII. Meas Techns 1963 n2 Aug

1963 p 111-3 2 figs 3 refs. Translated from Izmer Tekh

n2 p 16-8 Feb 1963. Provides some results obtained from

studying the interference comparator and using it for measuring graduated standards of length. Also examines

the theoretical peculiarities of its optico-mechanical sys- tem and additional improvements, as a result of which

the precision and objectivity in evaluating graduated

linear measures has been substantially raised. Line Standard Interferometry, K. H. HART. Int Prod Eng Res Conf Proc Sept 9-12 1963 p 619-24. Published by ASME. Fundamental aspects of interferometer design are presented which are required to achieve accuracy of

0.1,11 in meter ; problems of convection and refractive index of air are discussed ; results of measurements made

with interferometer developed at Nat Research Council in Canada are presented ; instrument, which is equipped with

photoelectric microscopes, is capable of measuring scales up to 1 m in length, to accuracy approaching hundredth

of micron. Automatic Calibrating Apparatus for Standard Scales by Counting Interference Fringes, Y. DOI, K. SHIMIZU, T. TSUBOI, T. KOUNO. App Optics v3 n7 July 1964 p 817-

23. New device is described with which calibration of standard scale up to 1000 mm long can be made in terms

of interference fringes in 1 hr run with accuracy of plus

or minus 0.1 y. ; position of uniformly moving scale is con- tinuously measured by fixed photoelectric interferometer, while instant of transit of every graduation over definite point is detected by array of photoelectric microscopes; data are processed in data-handling circuit. 2.5. Metiological Gratings

Interference Phenomena, C. BARUS. Sci vl2 1900 p

617-27. Considers interferences observed on viewing one

coarse grating through another, and on the projection of one piece of wire gauze by a parallel piece. Moire Micrometer, F. BURMISTROW. Techn Phys USSR v2 n6 1936 p 640-56 in German. A description of

an instrument using diffraction phenomena for the meas- urement of (a) thickness, and (b) structure of woven

textiles. The idea is not new, such an instrument having

appeared some years ago in Czecho-Slovakia. The present paper employs a photographic reproduction of an engine- ruled plate with a varying number of lines per in. from

one end to the other. Such a plate is superposed on the 87

771-846 0—66 7
silk stocking or other article to be tested and the shift and configuration of the interference lines is used for determinations of structure and thickness. The apparatus is described and its theory discussed. An Apparatus for the Measurement of Small Differential Expansions and Its Use for the Study of Fused Silica, R. W. DOUGLAS, J. O. ISARD. J Sci Instrum v29 Jan

1952 p 13-15. The differential expansion is magnified by an optical lever, the sensitivity of which is increased by an

arrangement of two graticules, the image of one acting as a vernier to the other. Changes of length of 10~6 cm can

be determined. The apparatus has been used to measure

differences in the thermal expansion of samples of fused

silica which had been given different heat-treatments. Interferometer Action of Parallel Pair of Wire Gratings,

J. P. CASEY, JR., E. A. LEWIS. J Opt Soc Am v42 nl2 Dec 1952 p 971-7. Transmission of electromagnetic waves

by pair of wire gratings is treated as boundary value problem, including oblique incidence, arbitrary separation be- tween gratings, and ohmic losses ; relative merits of gratings and conducting films in interferometers; in nu- merical example peak transmission of grating is shown

to be about 8000 times larger. Measure Motion to 0.0001 Inch Without Friction or Wear,

J. H. BROWN. Control Eng v2 n4 Apr 1955 p 50-2. Describes automatic measurement of lineal motion using

optical gratings. The Interference Systems of Crossed Diffraction Gratings. Theory of Moire Fringes, J. GUILD, NPL. Oxford Univ

Press 1956 152 p. Contents: General background; fun- damental considerations ; two gratings in series ; characteristics of the fringe system; metrological characteristics ; influence of grating defects on Moir6 fringes. Mechanical Interference in Measurement of Strain, J. R. LINGE. Aircraft Eng v29 n337 Mar 1957 p 70-4. Details

of simple extensometer with gage length of 0.50 in. which

uses mechanical interference of two sets of parallel straight lines to measure displacement and hence strain

interference effect exhibited by two pieces of Dufaycolor

reseau placed in surface contact is employed for develop- ment purposes. An Elementary Introduction to the Use of the Grating

Interferometer, V. RONCHI. Atti Fonderie Ronchi vl3 n5 Sept-Oct 1958 p 368-403. The elementary theory of the grating interferometer is presented for the benefit of those who want to apply the Ronchi test in practice, with- out being concerned with the intricacies of the exact

theory. A Review of the Application of Gratings to the Study of Optical Aberrations, C. MORAIS. Atti Fonderie Ronchi

vl3 n6 Nov-Dec 1958 p 546-602 in Italian. A review of the theory of the Ronchi fringes and their use in measuring

aberrations. The work of previous authors is unified into a complete account of the effects of the Seidel aberrations. The evaluation of the Seidel sums from the fringe patterns

is demonstrated and sample photographs illustrate the

principal results. Long Path Interferences (Moire Patterns) of Electron Waves as Abbe "Objects," O. RANG, H. POPPA. Zeit Phys

vl53 n5 1959 p 643-52 in German. Bragg reflection of

electrons by overlapping crystal lattices can give rise to a moire pattern in the electron microscope, and additional

spots in the diffraction pattern. These may be thought

of as primary and secondary interference images in the Abbe sense. This is demonstrated by bright and dark

field patterns of gold crystals. The Moire Fringe System as a Versatile Test-Object:

Photoelectric Measurement of Aberrations, A. LOHMANN.

Optica Acta v6 nl Jan 1959 p 37-41 in German. Proposal

for a device in which two gratings in relative rotation provide a moire pattern of variable spacing which is imaged by the lens under test on to a slit backed by a

photomultiplier. At the same time the gratings produce

a diffraction pattern, consisting mainly of three coherent maxima, which scans across the lens aperture as the grat- ings rotate. An a.c. signal is obtained in which the ampli- tude is related to the Twyman-Green pattern of the lens. Other applications of the device as an analogue Fourier

transformer, for thin film measurements and for spectro- photometry are suggested. A Simple Method of Calculating Moire Patterns, G. L. ROGERS. Proc Phys Soc v73 pt 1 Jan 1959 p 142-4. The

calculation is done by means of simple relations between

the reciprocal-space transform of the moire pattern and

the transforms of the two grating patterns. Method of Measuring Displacement Using Optical Gratings, D. L. A. BARBER, M. P. ATKINSON. J Sci Instrum

v36 nl2 Dec 1959 p 501-4. A method using three diffrac- tion or shadow gratings for accurate linear measurement. Comparison between the gratings produces two alternat- ing signals, and the change of phase difference between

the signals is proportional to the distance measured. New Measuring System. Machy (London) v96 n2461 Jan

13 1960 p 103-6. New system of measurement which can

be employed either for linear or angular displacements has been developed by Paton Hawksley Electronics, Rockhill Laboratories, Bristol, largely as result of work in- volved in producing divided circles and diffraction and

metrological gratings ; system has family resemblance to well known arrangement of fixed and moving diffraction grating which is employed to produce moir6 fringe effect; how microscope in which system has been incorporated is employed for measuring spacing of transverse holes in

spool. Diffraction Gratings as Measuring Scales, J. GUILD, NPL.

Oxford Univ Press May 1960 208 p. An exposition of detailed information on practical moire fringe equipment

that can be adapted in the course of design. Contents

General information, linear measurement, fringe counting,

fractional interpolation, gratings, and application to angular measurements. Moire Fringe Reading Head for Use With a Fine Grating,

D. A. PALMER. J Sci Instrum v37 n8 Aug 1960 p 261-2. In the usual moire fringe measuring system, practical diffi- culties arise in the use of very fine gratings. An optical system is described in which the use of a separate index

grating is avoided, the moire fringes being formed between

the scale grating and the image formed by its reflection in a concave mirror. This arrangement has the particular advantage that the sensitivity is doubled. A working

model has been constructed to demonstrate the principle. Production and Performance of Metrological Diffraction Gratings, V. W. STANLEY, R. G. N. HALL. Prod Eng

v40 nl Jan 1961 p 38-44. Technique for producing diffrac- tion gratings for use as scales for measurement, particularly for machine tool control ; superposition of two grat- ings to produce moire fringes; lathe performance and

control for generation of fine helices ; preparation of grat- ings by plastic replica and photographic processes ; grating

errors. Precision Diffraction Gratings for Metrologic Purposes,

G. N. RASSUDOVA, F. M. GERASIMOV. Optics & Spec- troscopy (English translation of Optika i Spektroskopiya

)

vll n2 Aug 1961 p 136-7. Method for preparing trans- mission diffraction gratings by etching reflection gratings

ruled on layers of aluminum by ruling engine; gratings could be used for very accurate measurement of linear displacement by means of moire bands. 88
Concerning an Error in the Method Using Moire Fringes,

A. PONCE. Bol Fac Ingen Montevideo (Uruguay) v7 nl6 Dec 1961 p 553-66 in Spanish. Moire fringes have been

used to determine distortions of a plane surface, for example in elasticity experiments. There are two possible sources of error inherent in the simple theory, the

larger due to the slope of the distorted surface, the smaller due to lateral displacements. These errors are calculated and illustrated in a typical case. Extension de la Methode du Moire a des Problemes Ther- miques—Etudes des Deformations Remanentes d'un Metal au Voisinage d'un Cordon de Soudure, P. DANTU.

Rev Francaise de Mecanique n2-3 1962 p 117-18. Extension of fringe (moire) method to thermal problems ; study

of residual deformations in weld seam zone ; raster design

of 400 points/sq mm was engraved on plates to be welded

after completion of welding, photograph of deformed

raster was superimposed with photograph of reference

raster ; fringe pattern formed permitted measurement of deformations with accuracy reaching 5X10*5

. Before Second International Conference on Stress Analysis, Paris

1962. In French.

Multi-Sectional Gratings for Linear Measurement, G. D. DEW, NPL. J Sci Instrum v39 Apr 1962 p 141-4 6 figs 2 refs. Describes recent improvements in the techniques

of preparing multi-sectional gratings for moire-fringe measuring applications. The system enables adjacent

sections to be phased with accuracy of 5-10 pin. and is applicable to gratings of the finest pitch employed in this work. A method of evaluating the phasing errors at the junctions is also described. Moire Fringes—Powerful Measuring Device, P. S. THEOCARIS. App Mechanics Rev vl5 n5 May 1962 p 333-9. In recent years moire fringes have found increasing application as measuring device ; their applications may be

classified either for measurement, as such, or for auto- matic tool control or monitoring; information obtainable from moir6 fringes ; application to metrology ; measure- ment of topographic irregularities. 85 refs. Widening Applications of Diffraction Gratings for Meas- urement and Control, W. H. P. LESLIE. Int J Mach Tool Design & Res v2 n4 Oct-Dec 1962 p 393-411. Construction of radial gratings having between 90 and 32,400 lines photographed on to plate glass disks of 12 in. diam or less are described ; errors less than plus or minus 3 sec of arc

are obtained; applications of radial and linear gratings

to various machine tools are described; in gear hobbing machine errors were reduced to %o for worm/table rotation and to % in actual cut gears of 20 in. diam ; circuits for phasemeters for servo and for measuring purposes are

contrasted, and new techniques for using batching counters with gratings described ; typical applications to gear measurement and gearboxless lathe are mentioned. Numerical Control of Machine Tools, H. OGDEN. Indus

Electronics vl n2 Nov 1962 p 59-64. Ferranti moire fringe measuring system (Brit Patent Nos 760,321 and 810,478) comprising two optical diffraction gratings superimposed

at slight relative angle, producing moving light (moire)

patterns during relative grating motion, and photoelectrically converted into digital length indications of high

accuracy for direct display or print-out; applications of Ferranti coordinate positioning system to inspection and

control. Metrological Applications of Diffraction Gratings, J. M. BURCH. Progress in Optics v2, North-Holland Publishing Co. Amsterdam, 1963 p 73-108 54 refs. Theory of formation of moire fringe signals by means of diffraction gratings; description of moire system metrological equip- ment comprising photographically replicated gratings, vis- ual and photoelectric reading heads, and electronic devices

for handling moire fringe information ; advantages offered by fringe method measurements over other methods of machine tool control are discussed.

Angular Measurements by Means of a Ronchi Ruling, J. R. MEYER-ARENDT, E. D. MINER, App Optics (USA)

v2 nl Jan 1963 p 77-8. It is shown that a simple optical lever gives an angular accuracy of 2 sec of arc if it is combined with a Ronchi ruling. The system described

is simpler than the two-grid method utilized by Jones. Light is sent through a grid onto the goniometer and re- turns back through the grid, to be viewed by a telescope. The advantages are reviewed. A grid of 133 lines per

inch is best. Angular range is about 3°. Recent Developments in Moire Fringe Measuring Systems

for Machine Tool Control, A. T. SHEPHERD. Int J Mach Tool Design & Res v3 nl Jan-Mar 1963 p 47-59. Basic principles of measuring system ; operating conditions discussed including optical arrangements, factors

affecting fringe contrast, working gaps and prismatic

grating optics ; gratings ; fringe subdivision ; circuit checking facilities. Measuring Displacement with Diffraction Gratings, S. HANDEL. Meas & Control v2 n2 Feb 1963 p 51-6. Principle of moire fringe method of measuring relative dis- placement of rapidly moving parts ; application of displace- ment detectors based on this technique to various types

of machine tools where positioning can be carried out with accuracy of 1 part in 10,000. Use of Reflecting Diffraction Gratings in Interference Sys- tems for Measuring Linear Shifts, I, G. N. RASSUDOVA,

F. M. GERASIMOV. Optika i Spektrosk (USSR) vl4 n3 Mar 1963 p 406-13 in Russian. English translation in

Optics and Spectrosc (USA) vl4 n3 Mar 1963 p 215-19.

Reflecting and transparent diffraction gratings are combined and used to obtain interference moire bands, react- ing to the shift of one of the gratings in its plane. General

properties of such a system are examined. It is shown

that in systems with reflecting gratings, unlike in those

of similar purpose but with two transparent gratings, the

fringe contrast for certain conditions appears to be inde- pendent of the distance between the gratings, angular

dimensions of the source and the wavelength interval

Use of Reflection Diffraction Gratings in Interference Systems for Measuring Linear Shifts, II, G. N. RASSUDOVA, F. M. GERASIMOV. Optika i Spektrosk (USSR)

vl4 n4 Apr 1963 p 559-63 in Russian. English translation

in: Optics and Spectrosc (USA) vl4 n4 Apr 1963 p 295-7. The results of experimental investigations of three variations of an interference system consisting of a reflection grating and a transparent grating are given. Systems are

also examined in which one reflection grating is used and

a semitransparent plate or Wollaston prism is employed

as a beam splitter. The properties of different systems are compared. Moire Patterns, G. OSTER, T. NISHIJIMA. Sci Am v208

no May 1963 p 54-63. A study of the basic properties of the Moire patterns produced when figures with periodic

rulings are made to overlap. Long Range Measurements, R. KIMBLE. ASME Paper n63-PROD-18 May 7 1963 7 p 8 figs. Discusses partic- ularly a system incorporating optical/electronics utilizing transmission or reflective gratings. Optical Gratings in Measurement and Control, S. HANDEL. Meas & Control v2 n6 June 1963 p 242-6. It is shown how use of moire fringes for machine tool position

control, originally developed for continuous path, has been extended to coordinate positioning of machine tool tables ; system is employed in Ferranti coordinate inspection machine, specially developed to facilitate rapid inspection of machined parts. Photoelectric Analogue-Digical Converters for Length and

Angle Measurements. Firm of Dr. Johannes Heidenhain, 89
Traunreut. July 1963 23 p 15 figs. Presents data regard- ing the operating characteristics of both incremental

photoelectric encoders and coded encoders. These are mechanical to electrical converters and thus permit the use of mainly digital electronic means of measurement. Moir6 Patterns Formed with X-Rays. NBS Tech News

Bui v47 n9 Sept 1963 p 160-1. During an NBS survey

of techniques for studying microstructure, it was found

that Moire patterns formed in an X-ray microscope by

structures which act as crossed diffraction gratings may

reveal detail below the projection imaging power of the instrument.

Digital Measuring Systems, A. H. McILRAITH. Int Prod Eng Res Conf Proc Sept 9-12 1963 p 585-91. Published by ASME. Critical survey is made of digital transducers most commonly used in machine tool control and in metrology ; properties of crossed diffraction gratings are dis- cussed and means whereby greatest accuracy is obtained from them. Observation en Incidence Oblique des Phenomenes de Moire par Reflexion sur une Plaque Gauchie ( Observation

in oblique incidence of moire fringes obtained by reflection on deflected plate) , J. EBBENI. Acad Roy de Belgique

Bui de la Classe des Sciences v50 n2 1964 p 114-24, 2

plates. Moire fringes are obtained by super-imposing ref- eranee grating on identical deformed grating ; this allows measurement of deformations ; observation of fringes in oblique incidence permits determination of deflection at every point of tested plate. Moir<§ Fringe Interpolator of High Resolution, A. H. Mc- ILRAITH. J Sci Instruments v41 nl Jan 1964 p 34-7. Interpolator capable of dividing one fringe into thousand

equal parts is described ; 2 photoelectric signals in phase

quadrature are derived from grating system and applied

to sine-cosine potentiometer; grating displacement is de- termined from setting of potentiometer at which its out- put vanishes. Theoretical Interpretation of Moire Patterns, G. OSTER,

M. WASSERMAN, C. ZWERLING.—Opt Soc Am v54 n2 Feb 1964 p 169-75. General mathematical method for

solution of moire patterns produced by overlapping of two

figures ; application to combinations of figures involving

parallel lines, radial lines and concentric circles; theory

of measurement of refractive index gradients by moire method; analysis showing how moire patterns are analogs

of problems in physical optics, hydrodynamics and electrostatics. 16 refs. Interpolation Arrangement to Improve Sensitivity of Dif- fraction-Grating Measuring System, G. S. K. WONG. Int J Machine Tool Design & Res v3 n4 Apr 1964 p 211-7. Description of diffraction-grating electronic interpolation ar- rangement, supported by short mathematical treatment of

its logic ; some possible errors are considered and their maximum possible magnitudes are expressed in terms of equivalent displacement of measuring system ; arrangement described was developed for particular diffraction- grating measuring system (Ferranti 4-fold counting sys- tem), but with some modifications it may be applied to other systems of similar nature. Moire Phenomenon, M. STECHER. Am J Phys v32 n4 Apr

1964 p 247-57. Simple mathematical analysis using shad- ow method predicts shape, disposition and spacing of nioire fringes produced by 2 parallel line grids; method is ex- tended to grids of regularly spaced closed-nested-plane

figures and to repeated cell structures ; for any species of grid "moire magnification" results ; moire fringes are sensitive tool for positioning or for measuring very small dis- placements and rotations; moire patterns are visual aid

for engineering and teaching of physics. Moire Fringes as Visual Position Indicators, L. O. VAR- GADY. App Optics v3 n5 May 1964 p 631-6. Summary of main known forms of moire fringes for visual metrological

applications is given ; to observe and track displacements

of moving fringe in conventional moir6 system presents

certain difficulties, as individual fringes have distinctive character ; new types of moire fringes were found and are

discussed, where recognizable unique fringe indicates also unique position of grating displaced relative to its stationary counterpart. Quality Digital Readout Measuring, O. MOLSTEAD.

Tooling and Prod June 1964 7 p 10 figs. Describes machine for X-Y coordinate measurements using Moire fringe system. The grating system and other units are described

in detail. An Optical Micrometer Suitable for Use at High Speed, M. C. CAREY and M. R. PIGGOTT. J Sci Instrum (GB)

v42 nl Jan. 1965 p 43-4. If a transmission grating is moved across a narrow beam of light the number of oscil- lations of intensity of the transmitted light measures the

distance moved. A micrometer based on this principle can measure movements with a sensitivity to about 10"" in. at speeds of up to 10 ft sec"1

, while being sufficiently robust to withstand shock loading. It can also be used at very low

speeds. Moire-Schattenverfahren zur quantitativen Untersuchung

schnell verlaufender Oberflachendeformationen von Fest- korpern (Moire Shadow Procedures for the Quantitative

Investigation of Rapidly Changing Surface Deformation

of Solid Bodies). E. HAUSELER and J. POLLOK. Optik (Germany) v22 nl 1965 p 12-23 9 figs 10 refs in German. The four possible moire procedures are investigated from

the point of view of their suitability for the measurement

of rapidly changing surface deformations. It is shown

that only one procedure is practicable for materials with

a high E-modulus. The resulting moire lines correspond

in this case to the differential of the deformation profile. A function generator is used to convert these curves into analogue electrical voltages and to perform the integrations. The procedure is illustrated by the case of the dynamic voltage field of a perspex disk which results when

a duralumin bullet is fired into it. Addendum to Section 2.

2.2.2. Method of Coincidences

Application des Phenomenes d'Interference a des Determinations Metrologiques (Application of Interference Phenomena to Metrological Determinations), R. BENOIT.

J Phys ser 3 v7 1898 p57-68 2 figs. Describes measure- ment of length using four Cd lines and the method of coincidences. 2.3.1. Wavelength Standards and Light Sources , —General

Note on the Effect of Pressure upon the Series in the Spectrum of an Element, J. S. AMES, W. J. HUMPHREYS. Phil Mag ser5 v44 nl66 July 1897 p 119-21.

Discusses shifts in wavelengths of spectrum lines when

the pressure on the arc varied. See also other articles by HUMPHREYS, MOHLER, and HUFF: Astro-Phys J v3

1896 p 114-37, v4 1896 p 175-81 and 249-52, v6 1897 p 169-

232, vl4 1901 p 41-8. Uber die Interferenz des Lichtes bei mehr als 2 Millionen Wellenlangen Gangunterschied (Regarding the Inter- ference of Light with more than Two Million Wavelengths Path Difference) O. LUMMER, E. GEHRKE. Verh

Deutschen Phys Gesellschaft v4 nl4 Oct 17 1902 p 337^6 5

figs 7 refs. Describes a method, based on multiple re-

( Continued on p. 276) DO
Section 3. Length and Diameter Measurements by Mechancial

Methods

CONTENTS

Page

3.1. Contact length standards 91

3.2. End measuring rods and measurement of long lengths 94

3.3. External diameters 97

3.4. Internal diameters 101

3.5. Measuring machines and bench micrometers 103

3.6. Manual measuring tools 108

3.6.1. General 108

3.6.2. Micrometers 110

3.6.3. Vernier instruments 114

3.6.4. Dial and test indicators 114 Addendum to Section 3 116 3.1. Contact Length Standards

Standards of Length and Their Subdivision, G. M. BOND.

J Franklin Inst 3d ser vll7 April, May 1884 p 281-95

357-67. Early history of length standards in England

and America. Development of metric standards. Molecular dimension. Methods of comparing standards. Length comparators. The Rogers-Bond Comparator.

Standards of Length as Applied to Gage Dimensions, G. M. BOND. J Franklin Inst 3d ser vll7 May 1884 p 368-86.

Illustrates end standard. Whitworth measuring machine, bench micrometer, plug and ring gage, and snap gage. Discussion of accuracy, tolerances, etc. Standards of Length and Their Practical Applications. Pratt and Whitney Co., 1886 180 p. A resume covering

the methods employed for the production of standard

gages to insure uniformity and interchangeability in every department of manufacture including the reports

of Prof. W. A. ROGERS; the Committee on Standards and Gages, A.S.M.E. ; the Committee of the Master Car

Builders Assn. ; and including also the report of the special committee appointed bv the Franklin Institute April

1964. Edited by G. M. BOND.

Comparaisons des Regies dans le Comparateur Brunner

(Comparison of Standards in the Brunner Comparator),

O. J. BROCH. Trav et Mem du BIPM v7 1890 p B3-B146.

Contents : The comparator ; bending of the standard

placed on two supports ; causes of errors in the comparison

of standards ; comparison of measuring etalons belonging to the Bureau ; tables ; observations. Measurements of End-Standards of Length, P. E. SHAW.

Roy Soc Proc Ser A v84 Feb 15 1911 p 589-95. Deals with

bar gages having flat ends, particularly to recently made

superior Johansson gages. Curves are plotted showing

the variations in the readings for different points distrib- uted regularly over the faces. Some improvements of

the measuring machine are described. A Silica Standard of Length, G. W. C. KAYE. Roy Soc

Proc Ser A v85 Aug 15 1911 p 430-47. A criticism of materials used in making primary standards of length

reveals objection to (1) copper alloys, (2) platinum, (3) iridioplatinum, (4) nickel, (5) invar. Fused silica, however, has a remarkable combination of good qualities (a)

very small thermal expansion, (b) very small thermal hysteresis, (c) cheapness, (d) comparative low elasticity, and (e) slight solubility in water can be treated as negligible when, as in the case of the primary standard, only skilled operators handle it. The present meter

standard, the first of its kind, consists of a tube of silica with horizontal slabs of the same material fused into

its end. Adherence of Flat Surfaces, H. M. BUDGETT. Roy Soc Proc Ser A v86 Dec 22 1911 p 25-35. Experiments on

specially made steel blocks showed (1) that at least 75%

of the adhesions is caused by the presence of a liquid

film; (2) that not more than 25% is due to atmospheric

pressure; (3) that adhesion practically vanishes when

no film is present. Breakage occurs in liquid itself and

not between liquid and steel, only 4% of force required

to rupture film is due to surface tension. Tensile strength

of water may amount to 60 atmos. Adhesion is 300 to 900 lbs. per sq. in. Large Comparator, W. ROSTERS. Kaiserl. NormalEichungs Kommission. Wiss Abh n8 1912 p 87-109. Describes at length, with numerous illustrations, the con- struction and use of the large comparator used by the above commission. Mesures des etalons Johansson par une Methode Optique (The Measurement of Johansson Gages), A. PERARD, L. MAUDET. CR Acad Sci vl54 June 10 1912 p 1586-8. Johansson gages of length varying from 100 mm to 1 mm

were measured by being inserted between the faces of

•other Johansson gages and were thus measured in the usual way by the method of differences. The gages were

in no case wrong by more than 0.2 micron. Further tests of planeness and parallelism resulted in showing the ex- cellence of the gages in shape. Einfaeher Komparator zum Priifen von Endmassen bis zu

5 m Lange (Simple End Comparator for Checking End

Standards up to 5 m Length), W. BREITHAUPT. Zeit InstrumKde v33 n7 July 1913 p 226-7 2 figs. Les Determinations des Etalons a Bouts (Determination

of End Standards of Length), C. E. GUILLAUME. Rev

Gen d'Elec v4 Aug 10 1918 p 171-8. A historic account, HI
brought up to date, of methods of comparing end stand- ards and line standards. The old practice was to observe by microscope the point of contact of a point and its image reflected in the polished square end of the end

standard. Later Benoit and Guillaume improved this method by having a fine thread stretched horizontally on

the squared faces of the ends. Still later, about 1900, a method was used at Sevres in which specially prepared

sphere-ended agate contacts were brought by known con- stant pressure against the ends of the standards. Dis- crepancy of 4/t between contact and optical methods was

discovered. Cause found to be lens aberration, and optical method was henceforth discredited. Two modern

methods are described. Advantages of sphere-ended and

plane-ended standards are considered. Les Calibres Industriels de Longueur (Industrial Length

Standards), C.-E. GUILLAUME. Bui Soc Francaise des

Electriciens v8 Dec 1918 p 383-400 5 figs. Development

of present principles of gaging; comparisons of various standards ; gaging machines of the Societe Genevoise. Writer believes advisability of ascertaining from manufacturers their experience with the various metals used

in manufacture of gages and deciding from study of re- ports on a standard which will satisfy all requirements. Types of End Standards, R. L. RANKIN. Iron Age vl04 Dec 25 1919 p 1331-2 5 figs. Relative value of flat, cylindrical, spherical and other end standards. Comparator, Millionth. The National Physical Laboratory—Slip Gauge Comparator. Eng vllO July 2 1920 p

19-20. Detailed description. See also Dictionary of Applied Physics, R. GLAZEBROOK, p 385-6. Precision Measuring and Inspection Devices, R. J. WHIBLEY. Machy (N.Y.) v27 Oct 1920 p 135-9 10 figs: Nov 1920 p. 242-5 6 figs. Minimeter and gage comparator used by National Physical Lab., England, for inspect- ing precision gage-blocks. Devices permit readings to accuracy of one millionth of an inch. Genauigkeiten der Messzeuge (The Accuracy of Measuring

Instruments) , R. P. SCHRODER. Betrieb v4 Feb 11 1922

p 269-74. Notes on gage blocks, initial comparative, trial and working gages. Measurement of work-pieces. Comparator for Checking Precision Gage-Blocks, F. D. JONES. Machy (N.Y.) v28 May 1922 p 689-93 6 figs. Extremely sensitive mechanical apparatus, which has

proved very effective at plant of Pratt & Whitney Co. for

testing accuracy of precision gage blocks, shown in Figs.

3, 4, 5, and 6. End Measuring—Bars and Slip Gauges, A. J. C. BROOKES. Machy (London) v25 Nov 20 1924 p 244-9 3

figs. How to check them ; recommendations. Etudes sur les Etalons a Bouts. Deuxieme Memoire

Etalons a Bouts, Plans (Study of End Standards. Sec- ond Report: Flat End Standards), A. PERARD, L. MAUDET. Trav et Mem du BIPM vl7 1927 95 p 34 figs 2 appendixes. Description of Johansson gage blocks and

their metrological properties; comparison with line standards using ruled auxiliary blocks ; interferometric method ; study of one block ; measurement of block combinations ; mechanical and optical contact ; phase disper- sion; experimental verification of Hertz formulas for deformation. Contact of Flat Surfaces, F. H. ROLT, H. BARRELL.

Roy Soc Proc vll6 Oct 1 1927 p 401-25. Lubricants, such as vaseline oil and ordinary lubricating oil, form

wringing films between polished surfaces of steel and glass

of thicknesses of 0.007/i and 0.008/* respectively, when

artificial means of spreading them between the surfaces

is applied. The contact between flat surfaces which are wrung together can be repeated with an accuracy of about

0.01 to 0.02/i. This does not represent the thickness of the part of the film separating the planes containing the high regions on the surfaces. Lapped surfaces of gages show evidence of wear during repeated wringings. Beitrag zur Entwicklung von Dehnungsmessern kleiner Messlange ( Contribution to the Development of Extension Instruments for Measuring Short Lengths), K. BOTT- CHER. Zeit Instrumkde v48 Mar Apr May June 1928 p 116-25, 178-87, 234-47, 285-92 21 figs. After a brief survey of known instruments for measuring short lengths, the author discusses a series of requirements which such

instruments should possess. A modification of the double

lever indicator is found to be more accurate than the Okhuizen apparatus, the average error being about 25X10"6 mm. Experiments are described whereby the

efficiency of the new instrument is calibrated. Millimicro Comparator and Gage Blocks. Am Mach v73 Dec 4 1930 p 901-2. A precision measuring instrument

claimed to be accurate within half a millionth of an inch has been announced. This device is mechanical and positive in its measurements and may be readily used by an

inexperienced operator. The instrument employs an adjustable, corrugated anvil to support the work. A vertical plunger carrying an extremely hard contact point is raised and lowered by a slight pressure on the operating lever. Motion of this point is transmitted to a pointer viewed

through a microscope. This comparator is claimed to be

suited to checking the size and parallelism of flat surfaces such as those of shop gage blocks. Apparatus for Comparison of Length of Gages, C. MOON.

J Res NBS vlO n2 Feb 1933 p 249-55 1 supp sheet. Design and operating principles of apparatus for comparing

spherical-ended gages of quartz having very small thermal

expansion with standard flat-ended gages of steel which

have relatively large coefficient of expansion ; sensitivity permits repetition to within 0.1 micron or 1 part in

1,000,000 on gages 10 cm long. A Studv of Glass Surfaces in Optical Contact. LORD

RAYLEIGH. Roy Soc Proc vl56A Aug 17 1936 p 326-49. The method of getting glass and silica plates into optical contact and the behaviour of scratches in hindering contact are discussed. Scratches made with a cutting dia- mond or steel wheel cutter raise a ridge on the glass while

those made with a writing diamond (splinter) do not. A

method to determine the mechanical work done in separat- ing two contacted glasses is given, and of the value found, 70 ergs/cm.2

, half can be recovered on recontacting. Very

variable results are found for the pull required to separate two contacted glasses, the maximum being 4.5 X107 dynes/ cm2

. Reflection from the interface between two contacted wedges of glass or silica is slight but measurable and

varies from one specimen to another. The reflecting power is not affected by pressure, but the cause of variation is not known. Reflection between silica glass and a

liquid of equal index depends on the method of preparation of the surface and is being investigated. End-Gauge Comparator of High Sensitivity, A. TURNER,

F. H. ROLT. Eng vl46 n2787 Aug 12 1938 p 183-5. Illus- trated description of comparator designed at National

Physical Laboratory, principal aim being to produce in- strument with magnification factor at least equal to that

of larger of two existing millionth comparators (30,000 to

1), and of such form that several block gages up to 5 in. in length could, in turn, be readily stood or slid into posi- tion under measuring head. Measuring Millionths of Inch in Gage Room, M. C. COFF- MAN, C. H. BORNEMAN. Gen Elec Rev v41 nil Nov

1938 p 502-3. Higher standards of precision in length measurements are now possible through recent application

of new General Electric electric gage head to tailstock of Pratt and Whitney measuring machine in Schenectady Works Tool and Gage Department; machine originally 92
built to measure mechanically to 0.00001 in. lengths of gage standards up to 80 in. Care of Gage Blocks, K. F. KIRCHHOFER. Tool & Die

J v7 nil Feb 1942 p 27-9 and 34. Suggestions concerning

correct procedure in handling gage blocks ; correct method

of wringing blocks ; testing and checking micrometer with

help of blocks. Care and Use of Slip Gauges, N. A. ESSERMAN, E. E. ADDERLET. Austral Council Sci & Indus Res J vl6 n2 May 1943 p 57-68. Slip gages known as block gages in America ; deals with corrosion, burrs, accessories and

wringing. Master Disks. NBS Commercial Stand (CS(E) 124-45

1945 8 p. Standard covers major essential requirements

for master disks (American Gage Design) from above

0.105 in. to and including 8.010 in. "Microptic" Vertical Measuring Machine. Eng vl59 n4133 Mar 30 1945 p 246-8 ; Indus Power & Prod v21 n235 May

1945 p 229, 231, 234. Illustrated description of instru- ment which embodies new principle in precision measure- ment of gage blocks, small parts, etc. ; there are no multi- plying devices whatever, actual movement of measuring

contact beiug read directly by means of microscope ; it is manufactured by E. R. Watts and Son ; accuracy of instrument may be relied upon under any conditions to within 0.0001 in. Measurement of Long End-Gauges by Comparison with

Precision Line Standards. C. E. ARREGGER. Can J Res F v23 p 185-91 May 1945. The comparison of end- gauges is made by "wringing" short blocks to each end, with lines to convert them to line-gauges. 20-in. and

10-in. end-gauges were compared in turn with a meter

standard, using a microscope line comparator as a transfer. Precautions to ensure max. accuracy are detailed. The greatest deviation from the mean measurement was

less than 2fi. Comparisons between the rules agreed to within 10"s in. Das Messen mit Ednmasseu uud Messeheiben, W. GROTH.

Werkstatt und Betrieb v81 nl2 Dec 1948 p 353-8. Precision measurement of distance between two points, parallel axis or product plane surfaces by parallel limit gages, cylindrical rods and wheels ; angle measuring by limit gage,

sinus and tangent rulers ; conic surface measurement by

rulers and Johansson and Fritz Werner clamps ; drawings. Comparison Measurement of Slip Gauges, A. W. MUSK.

Machy (London) v75 nl940 Dec 29 1949 p 919-24. Anvil

of transparent material developed by Taylor, Taylor &

Hobson, Ltd. Leicester used for checking comparative

dimensions of slip gages against reference gages ; it makes

it possible to check almost simultaneously comparative

size and degree of flatness ; calibration procedure

described. Importance of Surface Finish as Applied to Gage Blocks. H. J. CHAMBERLAND. Western Machy & Steel Wld

v41 nl2 Dec 1950 p 64-6. General discussion of finish standards and practices ; new technique removing all amorphous metal or wire edge on gage blocks protects

their surface finish through introduction of second parabolic curve blending original radius with finished surface

of gage. A New Method of Measuring the Depth of Haemacytometer Counting Chamber Cells, L. O. C. JOHNSON. J

Sci Instrum v29 Apr 1952 p 130. The depth of a hae- macytometer counting chamber is measured by means of a rocker, supported by the base of the chamber, with two

arms which may be rested in turn on the flanking sur- faces to the left and right of the chamber. The angular

displacement of the rocker between these two positions of

rest is measured by ai

of measurement is about

autocollimator. The accuracy

t0.2n. Adhesion and Contact Error in Length Metrology, C. F. BRUCE, B. S. THORNTON. J. App Phys v27 n8 Aug

1956 p 853-9. Studies of nature of strong adhesive contact between finely finished steel and glass surfaces when

trace of liquid exists between them ; these surfaces are

of kind that are of practical use in length metrology where such adhesive action or "wringing" is of considerable importance, for example, in use of slip gages ; how

presence of liquid introduces dimensional contact error. Pneumatic Slip Gauge Comparator, P. J. SIM. Machy

(London) v94 n2425 May 6 1959 p 1009-15. Reference made to direct jet type of pneumatic comparator devel- oped by National Standards Laboratory, C.S.I.R.O., Chippendale, Australia, in which there is no gaging contact

to cause wear or damage; after period of satisfactory operation of instrument in calibrating slip gages, design has been prepared for improved version which is to be

built as single unit; construction and use of prototype

described. On the Use of Slip Gages (Gage Blocks), P. V. DENISOV,

Meas Techns 1958 n2 Aug 1959 p 127-31 3 figs 6 refs. Translated from Izmer Tekhn n2 Mar-Apr 1958 p 7. The

physico-chemical processes taking place on the working

surface of slip gages which substantially affect the wringing are completely ignored. The underestimation of the

role played by the physico-chemical processes causes stick- ing and results in premature wear of the gages. Article describes investigation of adhesive and frietional forces and develops six rules for the use of gage blocks. Gage Blocks of Superior Stability : Initial Developments

in Materials and Measurement, M. R. MEYERSON, T. R. YOUNG, W. R. NEY. J Res NBS Eng & Instrum v64C

n3 July-Sept 1960 p 175-207 ; see also similar unsigned

article in Iron Age vl85 n20 May 19 1960 p 152-3 ; Machy

(London) v97 n2503 Nov 2 1960 p 1025-8. Processes,

technical aspects and techniques involved in development

of three sets of gage blocks are explained, and future

research indicated ; blocks are made from treated 410 and

52100 stainless steel, and have shown dimensional stability of 1 X 10"7 in./in./yr over one year period. 20 refs. Stability of Block Gauges, A. Z. POLKOVA. Meas Techns

1959 nl2 Sept 1960 p 932-3 2 refs. Translated .from Izmera Tekhn nl2 Dec 1959 p 8. Discusses methods of measuring instability and tolerances on stability. Development of More Stable Gage Blocks, M. R. MEYERSON, T. R. YOUNG, W. R. NEY. Matls Res & Stand

vl n5 May 1961 p 368-74 ; see also abstract in Metal Treat- ment & Drop Forging v28 nl93 Oct 1961 p 407-9, 418. Long range research program aimed at accuracy of one

part in 10 million in gage block length calibrations is underway at US Bur of Standards, to meet need for greater precision in production for atomic and space age

development of steel gage blocks with maximum dimensional change of 0.2^ in./in./yr is described ; observations

for one yr on 2 steels (410 stainless and 52100) given

total of 14 treatments are reported. Investigation of the Wring Capacity of Block Gauges,

L. CHAO-TSENG, A. S. AKMATOV. Meas Techns

1960 nlO July 1961 p 839-43 8 figs 6 refs. Translated from

Izmer Tekhn nlO p 19-22 Oct 1960. The authors aimed

at investigating: (1) the effect of the microgeometrical

profile, the metal structure and its defects, hardness, the physical nature of the metal (the grade of steel), mechanical properties, and the physico-chemical purity of the sur- face;. (2) the volumetric physicochemical properties of the lubricant, the physical properties of its molecules, their atomic structure, isomerism, intramolecular mobility,

polarizability, polarity, and chemical activity; (3) the method of obtaining an intermediate lubrication layer, its 93
"training," "thickness," physical condition, structure, mechanical properties, and the nature of intermolecular

interactions. Search for Ideal Gage Block Material, R. A. GIERLICH.

ISA Proc Preprint 2.3.62 for meeting )ct 15-8 1962 5p. Developments of recent years are discussed from stand- point of gage block makers who must somehow reconcile

his methods with findings of US Bur Standards and re- quirements of his customers, if ultimate gage block is to become working tool in laboratories of industry. The Parallelism of a Length Bar with an End Load, D. G. WILLIAMS, NPL. J Sci Instrum v39 Dec 1962 p 608-10

2 figs 3 refs. The flexure of an engineer's length bar

supported horizontally at two positions with a flat wrung

to one end is analyzed. Formulas are given for support

positions which do not introduce errors in parallelism of the ends. The effect of the flexure on the length of the bar is shown to be negligible. Checked Your Gage Blocks Lately?, H. EASTMAN. Am

Mach/Metalworking Mfg vl07 n5 Mar 4 1963 p 56-8. Rec- ommendations on how to conform with government contracts which require adequate gage surveillance programs, with special emphasis on "pedigree" of measurement

standards ; calibration laboratories ; importance of measuring technique and what should be done to minimize

uncertainties ; preparing blocks ; checking flatness ; temperature stabilization ; light contact pressure of comparator recommended ; blocks of different materials ; equip- ment maintenance. The Effect of Micro- and Macro-Configurations of Block- Gauge Measuring Surfaces on Their Wringing Capacity,

Z. I. KREMEN'. Meas Techns 1963 n2 Aug 1963 p 114-7

4 figs 3 refs. Translated from Izmer Tekhn n2 p 19-21 Feb 1963. Among factors affecting the wringing capacity an important part is played by the quality of the measuring surfaces (height, shape and position of mieroirregularities) and by their geometrical precision (their flatness

in the lapped and free condition) . This article deals with

investigations into the effect of the above factors on the wringing capacity. Variation in Contact Error Between Repeatedly Wrung

Surfaces, E. G. THWAITE, R. T. LESLIE. Brit J App

Phys vl4 nlO Oct 1963 p 711-3. A controlled experiment

is described for determining the variability of contact

error between highly flat steel surfaces when repeatedly "wrung" together; this led to an estimated standard

deviation of 0.292 X10"6 in. for the distribution of the contact error and an "on the average" tolerance limit about

the mean at the 90% level of ±0.52x10-" in. A linear increase of length with serial order of wringing of approxi- mately 0.08X10"6 in. per wringing was observed and has been attributed to a progressive formation of asperities on the surface. Gage Block of Superior Stability—2. Fully Hardened

Steels, M. R. MEYERSON, W. A. PENNINGTON. ASM—Trans v57 nl Mar 1964 p 3-25. Possibility of obtaining temporal dimensional stability of 1 to 2 X 10"7 in./in./yr in through-hardened steels with high hardness

levels was studied; effects of various fabricating tech- niques and stress-relieving temperatures on the surface

residual stresses were established and results correlated with observed trends in stability patterns; presence of surface compressive residual stresses was effective in reducing rate of contraction in 52100 steel on submicroinch level ; quantitative relationship between dislocation content and length changes was established and tentative

finding of instability of carbides noted ; it was found that hardened structure of 52100, or of similar conventionally hardened steels without secondary hardening peaks, can- not be fully stabilized at hardness level of RC 65 even with extended tempering. Gage Blocks of Superior Stability—3. Attainment of Ultrastability, M. R. MEYERSON, M. C. SOLA. ASM—

Trans v57 nl Mar 1964 p 164-85. Materials and tech- niques required to produce degree of temporal dimensional

stability of 0.1 to 0.2 /iin./in./yr (ultrastability) and

surface hardness of Rc 65 minimum are described; 3

categories of materials and processes included in study

are steels with annealed cores and hardened surfaces,

steels with partially hardened cores and hardened surfaces, and cermets and ceramics ; 9 of 11 types had

surface hardness of Rc 65 or greater; at or above

these hardness levels, dimensional stability obtained with best surface hardened steels exceeded that of through-hardened steels ; 2 titanium carbide types were

ultrastable.

3.2. End Measuring Rods and Measurement of Long Lengths

Rotary Comparator, J. PERNET. Archives Neerlandaises v5 1900 p 395-406. The form of transverse comparator which is least subject to errors produced by

bending is that of Wild, in which the rods to be compared

are mounted in a frame in a vertical plane and are lifted vertically into sight. This form of comparator fails when

the rods are to be immersed in liquids. The author constructs a rotary comparator which admits of exchange

with extreme smoothness and simplicity. A stout cyl- inder rotates about its own axis which is placed vertically. The cylinder carries a table in the form of a leminscate, on each of the leaves of which one of the rods is mounted, and supported at % and % of its length. Full details are given. Metres a Bouts (Meter End Standards), J. R. BENOIT,

C. E. GUILLAUME. Trav et Mem du BIPM vl2 1902

123 p 13 figs. Describes the comparisons of Tresca sec- tion end standards and a vertical comparator of special design. Two methods of measurement were applied, one

optical and the other mechanical. Some Gaging and Measuring Methods at the Works of the Westinghouse Machine Co. Am Mach v27 Aug 4 1904 p 1013-5. Illustrates instruments and describes methods

of using them. Large inside and outside micrometers, and large calipers. An Analysis of General Flexure in a Straight Bar of Uni- form Cross-Section, L. J. JOHNSON. Trans Am Soc Civ Engrs v56 Feb 1906 p 169-96. States the problem and

gives the solution. Some Gaging and Measuring Methods in American and

British Shops. Am Mach v30 p 328 1907. Methods of using exceptionally large micrometer calipers. Premieres Determinations des Etalons a Bouts ; Executees au Bureau International (First Determinations of End Standards), C. E. GUILLAUME. Trav et Mem du BIPM vl5 1913 31 p 3 figs. Method; measuring instru- ments ; expansion of steel standards ; correction of the

elastic deformations including bending and compression

principal measurements of 100, 200, 400, and 1000 mm.

Etudes sur les Etalons a Bouts. Premier Memoire

Broches et Calibres, (Study of End Standards. First Report of Calibration of End Standards), A. PERARD.

Trav et Mem du BIPM vl5 1913 170 p 54 figs. Various forms of end standards; measurement of absolute value; 94
instruments ; measurement by longitudinal displacement

measurement by transverse displacement. The Hart- mann comparator, its functions, study of the comparator,

principal measurements, carried out with the comparator. Recent determinations of decimeter standards. Conclusions relative to the constancy of standards. Comparator for a Base Unit at Potsdam, F. KUHNEN.

Zeit InstrumKde v33 Jan 1913 p 1-9. An elaborate comparator of the usual type for comparison of 4 meter and

5 meter standard bars with 1 meter standards. Drawings

and photographs. Few details. No results to indicate accuracy are given. Large Measuring Machines Constructed by Societe Genevoise. Eng v98 Sept 11 1914 p 323-6. One of these is adapted to measure a gage of even 3 m long. One new

feature in the machine is a rolling foot, allowing that change in temperature shall produce no strain along the

length of the bed. The most accurate of the machines

described measures to 1 micron. The reference scale, in- stead of being fixed, is placed at the horizontal level of the micrometer screw and moves with it The advantage here

is that a cosine error, instead of as usual a sine error, is introduced. Comparators for the Indian Government. Eng vlOO Aug

20-27 and Sept 3 1915 p 179-82, 208-11, 232-5. A comparator of 24 m. divided into six sections, and a separate

4 m. comparator ; latter used for comparison of length and determination of coefficient of expansion. Measuring in Millionths of an Inch. Practical Engr v68 Xov 16 1923 p 273-^ 2 figs ; Engineer v 136 Oct 5 1923 p

363. Describes generator comparator used by makers,

Pitter Gage & Precision Tool Co., Ltd., Eng.. in process

of manufacturing end gage bars; readily adapted to do

all measurements which can be performed in ordinary

anvil type of horizontal measuring machines.

Application of Micrometers in Railway Shops. M. H. WILLIAMS. Ry Mech Engr v98 1924 p 481 553. Cher die genaue Messung grosser Durchmesser (Regarding the Accurate Measurement of Large Diameters). H. SCHMIDT. Maschinenbau v7 1928 p 720. (English

translation is available.) Sets forth the conditions nec- essary for accurate measurement of large diameters, particularly when micrometers are used, both by direct meas- urement and by indirect measurement wherein the height

of arc corresponding to a certain length of chord is measured. Messung an sperrigen Werkstuecken. P. KUEHNE.

Maschinenbau vl6 n7/8 Apr 1937 p 207-11. Measurements

of unwieldy parts of locomotives, railroad cars, and air- planes; measurements during manufacture, after completion and in operation ; illustrations of equipment measured and equipment used. Accuracy in Large Roller Bearings. E. T. COBB. Steel vl02 nl4 Apr 4 1938 p 44-7 and 78. Accuracy of large measurements maintained by Bantam Bearings Corp., South Bend. Ind., based upon measuring machine which

measures directly up to 80 in. in increments of 0.00001

in. and is periodically checked against Johansson blocks and special long gage pins ; factors entering into accuracy

of bearings, from raw material to finished product,

discussed. Einteilung der Endmasse (Division of End Gages), R. P. SCHRODER. Werkstattstechnik und Werksleiter 1939 n6

p 173. Beitrag zur Aufstellung und Herstellung langer Massstabe

< Support and manufacture of long measuring rods), A. JOTZOFF. Zeit Instrumkde v60 Apr 1940 p 112-6. After

description of the measurement technique and difficulties of fabrication of long measuring rods a proposal is dis- cussed which yields simultaneously a higher measuring

accuracy and reduced manufacturing cost. Das Vermessen von Lokomotivrahmen (Measurement of Locomotive Frames). K. HUPE, Tech Mitteilungen KruppTech Ber v9 1941 p 33. Messgerate fur grosse Langen (Measuring Devices for Large Lengths), H. SCHMIDT. Werkstattstechnik und

Werksleiter v36 1942 p 278. Various items of gaging and

measuring equipment are described, including a measuring machine for measuring lengths to 7 m (23 ft.) with usual

parallel-end standards and longer lengths with special end standards. Messen grosser Werkstucke ; Messgerate ; Passungssystem

fiber 500 mm (Measurement of large workpieces ; measuring equipment; systems of fits over 500 mm), N. N. SA- WIN. Skoda-Mitteilungen v6 1944. English translation is available as paper Xo. 31 of the Symposium on Engineering Dimensional Metrology, NPL, October 1953. An in- terpretation (in German) of the standards proposal, by

Dr. Ing. Leinweber, is available. Stick Micrometer. Engr vl78 n4619 July 21 1944 p 52-3 ; J

Sci Instrum v21 n9 Sept 1944 p 163^; Eng vl58 n4109

Oct 13 1944 p 286. Brief illustrated description of instru- ment made by Pitter Gauge and Precision Tool Co. consists of micrometer head reading in increments of one one- thousandth of an inch, 1-in. spherical end piece, and 1, 2,

3, 5, 12, and as many 24-in. pieces to make up any length

required. Measurement of Long End Gauges by Comparison With

Precision Line Standards. C. E. ARREGGER. Can J. Res

v23 sec F n3 May 1945 p 185-91. Operation of comparing end standard of length with reference line standard is carried out by method which is simple in principle, but which demands careful experimental technique ; in operation described two Johansson type gages of 20 in and 10 in. length, were compared with line standards which themselves had been compared directly with legal Canadian

standard metre. Bibliography. Constant-Length Bar for Outdoor Use, H. I. ANDREWS.

Eng vl63 n4226 Jan 10 1947 p 25-6. Bar used as stand- ard of length in measuring small changes in length (few

thousandths of inch) in railroad ties; design chosen consists of steel tube ; below one end of bar is attached small

cylindrical reservoir heated internally by means of insu- lated electric heating element. In a research in the U.K. on concrete and other forms of railway ties it was neces- sary to measure small changes in length, of a few thou- sandths inch in ties approximately 8 ft. long, in very exposed positions under all weather conditions and temperatures varying from 20 to 90 °F. The standard bar of con- stant length, 9 ft. 3 in. long, consisted of a closed steel tube 2 in. in diameter. Below one end was attached a small cylindrical reservoir which communicated with the

interior of the tube. The system was evacuated, sealed, and charged with 2 pounds of liquid sulfur dioxide. When in use the reservoir was heated internally by an

insulated electrical heating element. A bimetallic ther- mostat was provided. As the S02 began to boil the vapor

pressure increased, and the vapor condensed on the inner walls of the tube, flowing back to the reservoir. Continuous circulation thus established maintained a constant temperature of 94±0.1 °F at which the thermostat was

set. Considering all sources of error, the maximum error

in any gage length was never likely to exceed 0.0OO15 in. By using an invar instead of a steel tube this could be re- duced to 0.000013 in. Measuring Large Precision Parts, N. N. SAWIN. Machy

(London) v71 nl829 Nov 13 1947 p 541^1. Tests to establish system of tolerances for measuring large pieces over

'>o
500 mm during and after machining processes ; factors in- volved in production of large components within pre- scribed tolerances ; departures from geometrical form,

elastic deformation during machining, effects of temperature, inaccuracies of measuring tools, and errors in measuring; measurements and calculation for ring and wheel

assembly given. The Coordinate Setting Machine, as Sponsored by the

U.S. Air Force, published by Fairchild Aircraft Division, Hagerstown, Md., Apr 1952. Contents : Introduction ; its background ; establishing the collimation line ; setting the machine to dimensions ; setting a typical fitting ; the universal positioner ; optical rectangle ; conclusion

specifications. The Precise Establishment of Long Coordinates in Factories, O. S. READING, U.S. Coast and Geodetic Survey. Paper No. 30, Symposium on Engineering Dimensional

Metrology, NPL, Oct 1953 p 485-93, H.M. Stationery Office, London. Report of an Investigation for the British Standards In- stitution into the Accuracy with Which the Industry Measures Large Dimensions, P. W. HARRISON. Paper

No. 32, Symposium on Engineering Dimensional Metrology, NPL, Oct 1953 p 527-36, H.M. Stationery Office, London. A progress report covering the investigation conducted

in U.K. Up to that time the workpieces had been measured by thirteen firms and organizations and repeat checks had been made by NPL.

Instrumentation and Measuring System Employed to Position Some Features of the Harwell B.E.P.O. Pile Over

Distances up to 30 Ft., V. B. HESSEN. Paper No. 34, Symposium on Engineering Dimensional Metrology, NPL,

Oct 1953 p 563-76, H.M. Stationery Office, London. In- cludes establishing on the floor of the pile a normal plane from which all vertical dimensions could be taken ; posi- tioning of the tubes ; description and principle of application of a tape gage for measurements up to 20 ft. Investigation into Accuracy of Industrial Measurements

of Sizes up to 80 Inches, P. W. HARRISON. Instn Mech

Engrs Proc vl69 n47 1955 p 977-85 (discussion) 985-92. Need to formulate proposals for extension of Int Stand- ards Assn system of Limits and Fits above 500 mm has

required improved knowledge of accuracy of industrial measurement of such sizes ; in investigation by National

Physical Laboratory this information was obtained for diameters up to 2000 mm ; it was found that industrial measurements tend to be too small, especially at larger diameter. Combination Length Bar Standards, L. W. NICKOLS.

Machy (London) v89 n2284 Aug 24 1956 p 473-9; (Mach

Shop May-Sept 1956). Influence of screwed joints upon

overall length ; determination of torque used when screwing length bars together by hand ; measurement of changes

in overall length caused by screwing together length bars made in accordance with British Standard 1790 : 1952

development of new type of screwed connection where

change in length per connection is negligibly small and

is independent of assembly torque. Messdraht-Langenmesser, eim neues Gerate zum messen

grosser Abmessungen im Maschinenbau (Wire Length Measurement. A New Apparatus for Measurement of Large Dimensions in Machine Construction), M. BOGUS- LAWSKI, L. K. KAYAK (Moscow). Feingeriitetechnik vo nlO p 431 Oct 1956. Designs for both external and in- ternal measurements are described. Errors are from 10

to 2X10"7 parts. How to Measure Large Dimensions, H. W. SCHMIDT. Am Mach vlOO n26 Dec 3 1956 p 145-7. Large bores, long dimensions, and other large work can now be accurately measured without special single purpose gages ; long gage

blocks, or gage bars are combined up to 50-ft. length ; any wanted dimension split into 0.0001 in. can be built up by normal and long gage blocks, cutting gage costs. Eine Laengenmessmaschine fuer Messlaengen bis 6000 mm, G. DIETTRICH, K. KAATZ. Werkstattstechnik und Maschinenbau v48 n5 May 1958 p 276-81. Machine

for measuring lengths to 6000 mm ; construction and operation of optical machine to measure length of large inter- changeable dynamo parts at Siemens-Schuckert works,

Berlin ; critique of accuracy. Die Genauigkeit der Messung grosser Laengen in der Werkstatt, H. SCHMIDT. Werkstattstechnik und Maschinenbau v48 n6 June 1958 p 309-15. Accuracy in measuring great lengths (500-10,000 mm) in workshop; results of measurements made in England, Italy, and Germany

at request of subcommittee ISO/TC3/SC1 ; discussion of methods and instruments. Report on Accuracy of Measurement of Large Dimensions. Report read by I. H. FULLMER at meeting of Standards and Metrology Division, AOA, Jan 14 1959 11 p 9 figs 10

refs. Gives results and analysis of measurements of 30,

50, and 80 in. castings. Contents : Review of past practice, similar investigations abroad, measurement program,

sources of data, results of measurement, analysis of

results. How to Measure Long Pin Gages, F. H. ROLT, G. GODFREY, S. C. BOTTOMLEY. Am Mach vl03 nl8 Sept

7 1959 p 126-7. Machines developed by Hilger & Watts, London that are capable of measuring gages up to 30 ft. long ; design and operation of two machine types ; read- ings can be obtained to 0.00005 or 0.0001 in. Measurement of Large Dimensions, F. P. VOLOSEVICH,

Meas Techns 1958 n4 Dec 1959 p 396-9 10 figs. Translated from Izmer Tekhn n4 July-Aug 1958 p 12. Article de- scribes equipment developed for measuring dimensions,

including: lightweight external dial micrometers with widened anvils ; minimeter with an extended column ; gage

block with foot; horizontal optical comparator for 3.5 m range ; device for measuring by means of gage blocks

internal micrometer ; scribing slide gage.

Specification for Length Bars and Their Accessories. Brit Stand Instn—BS 1790 1961 33 p. Standard relates to length bars of cylindrical type, in inch sizes up to 48 in. and metric sizes up to 1200 mm, having parallel end faces

finished by lapping, while longer bars are to conform to certain clauses ; provision is made for 2 designs, one with

complete plane faces and other with annular faces sur- rounding internally threaded hole at one end or both ends of bar ; 4 grades of bar accuracy are reference, cali- bration, inspection, and workshop.

Universal Measuring Comparator Type IKU-2, N. F. DELYUNOV, E. I. ROZENBERG, E. P. SMIRNOVA.

Meas Techns 1961 n8 Feb 1962 p 601-4 2 figs 2 refs. Translated from Izmer Tekhn n8 p 1-3 Aug 1961. A comparator having a mm scale with range up to 500 mm.

The instrument is intended for direct and differential measurements of internal and external linear dimensions

of various articles. The differential dimensions are measured by comparing the measured article with block gauges, templates or reference details. Utilization of Wood for Making Large-Size Measuring

Devices. I. P. VAGANOV. Meas Techns 1961 n8 Feb 1962 p 607-10 1 fig 6 refs. Translated from Izmer Tekhn n8

p 7-9 Aug 1961. Wood diameter-measuring caliper gauges

are convenient to use, provide more efficient and accurate measurements as compared with the best metal gauges and micrometers, and the ambient air temperature vir- tually has no effect on measurement results. Wooden

measuring equipment has a number of advantages as eoin- 96
pared with metal equipment, providing the peculiarities

of wood are taken into account. Parallelism of Length Bar with End Load, D. C. WILLIAMS. J Sci Instrum v39 nl2 Dec 1962 p 608-10. Flexure analysis of engineer's length bar standard sup- ported horizontally at 2 positions with flat wrung to one

end; formulas for support positions which do not intro- duce errors in parallelism of ends ; effect of flexure on

length of bar is shown to be negligible. Vertical Type Comparator for Measurement of End

Standards, P. HOLMES, E. R. HARRISSON. Microtecnic vl7 nl Feb 1963 p 8-14. Illustrated description of instrument constructed at Defense Standards Laboratories, Australia, for measurement of end standards up to 40 in. long ; measuring head employs electromagnetic pick- up which is rigidly connected to datum platen ; special attention was given to reduction of heating effects due to 3.3. Extern

presence of observer ; discrimination of instrument is 0.1,a in. ; method used to calibrate instrument is described. Long Range Measurements, R. KIMBLE. ASME

Paper 63—Prod-18 for meeting May 7-9 1963 7 p. Prob- lems of greater flexibility and range of measurement in gage manufacture to cope with environmental problems of

chips, coolant, and space limitations ; concepts of toler- ances and repeatability, readability and response in meas- urement techniques are reviewed ; use of system incor- porating optical/electronics is reported to offer potential

in long-range measurement field. Gauge Blocks for Large Sizes, I. P. VAGANOV, N. M. SHCHIPACHEVA. Meas Techns 1963 n8 Feb 1964 p

649-50. Translated from Izmer Tekhn n8 p 15-6 Aug 1963. Gives results of various experiments to evaluate several parameters. Diameters

See also Subsection 3.5 New Measuring Machine, F. GOPEL. Zeit InstrumKde

v34 June 1914 p 180-3. Communicated from the Phys

Techn. Reichsanstalt. This is to measure the diameter

of a cylinder carrying a coil of wire. The measuring parts

are light and, being provided with slide movements, can

be easily moved to various parts of the cylinder. The

latter is so mounted that it can be rotated on its axis when

between the contacts of the measuring machine. Microscopes are used to measure the position of the contact

rods, which have pointed ends. Mesure Mecanique d'une Aire Spherique. Les Spheri-

: metres (Mechanical Measure of a Spherical Surface;

; Spherometers), P. VANET. Genie Civ v74 Feb 1919 p 96

J 6 figs. Principle of planimeter applied to measurement of area of closed figure drawn on a spherical surface.

. Zwei Schnellvergleicher fur zylindrische und platten- formige End-masse (Two Rapid Comparators for Cylindrical and Flat Gage Blocks), F. GOPEL. Werkstattstechnik vl4 Dec 15 1920 p 625-9 10 figs. Describes comparator designed by author for rapid and very accurate

relative measurements of cylindrical gage blocks, and one based on same principle for measurement of flat gage

! blocks up to 100 mm.

Pratt and Whitney "Super-Micrometer." Machy (N.T.) v29 Sept 1922 p 68-9. Also Am Mach v57 Aug 31, 1922

;

. I p 355. Has a capacity up to 8 in. diam. and settings are made by use of standard inch blocks. Head is graduated to 0.0001 in., and is driven by a belt connected to a knurled handwheel, slippage of which indicates proper contact

pressure. Work supports of various forms are provided. Federal Dial Comparator. Am Mach v58 May 24 1923 p 782. Dial indicator mounted on an arm extending over

a base. Supplied with a fixture for holding round work.

Societe Genevoise Bench Micrometer. Am Mach v59 Nov 29 1923 p 823-4. Equipped with test comparator

tube which serves as pressure indicator. Can be read

to 0.00005 inch. Carl Zeiss Optimeter. Am Mach v61 Oct 2 1924 p 560.

I Incorporates optical method of measurement that elimi- nates all moving parts except a small mirror. Optical system is housed in a right-angle tube, adjustably mounted

in an arm on a sturdy column. Vertical optimeter is shown in fig. 1 and optimeter with horizontal measuring

attachment is shown in fig. 2. The Measurement of Fine Wires, G. A. TOMLINSON.

J Sci Instrum v4 Dec 1926 p 74-5. A mechanical method

of measuring fine wires is described. The measurement

is made at a point and with a very light pressure so that no deformation occurs. The accuracy of the measure- ment is 0.00001 in. Measurement of Very Fine Quartz Suspension Fibers, G. A. TOMLINSON, H. BARRELL. J Sci Instrum v4 Oct 1927 p 410-3. The paper describes two indirect methods of measurement. One is purely mechanical and

involves a measurement of the elastic strain under a known tension, from which the mean cross-section can be

found. The other method depends on the observation of certain diffraction phenomena produced in white light. In

a set of fibers measured, the diameter varied from 3.3 to

0.6/i. The optical method is found to become unreliable when the diameter falls below about three wavelengths. Mikrotast-Feindrahtmesser (Microtast Fine Wire Measurer), M. BARTHOLDY. Zeit fur Feinmech und Prazi- sion v35 Oct 12 1927 p 250-1. Microtast mounted on column for measuring diameters of small wires. New Zeiss Projection Optimeter. Instrum vl May 1928 p 257-8 4 figs; Am Mach v68 1928 p 123. Outstanding

feature is visible reading of scale by both eyes instead

of by microscope ; more valuable in mass inspection ; table has serrated surface; range of scale to plus and minus

0.005 in. ; scale gradationed 0.00005 in. Uber die genaue Messung grosser Durchmesser (Accurate Measurement of Large Diameters), H. SCHMIDT.

Maschinenbau v7 nl5 Aug 2 1928 2 figs. Comparison be- tween direct measurement with a micrometer and indirect measurement (height of arc). Demonstration of large

errors of the indirect method. English translation available. Ein optisches Mikrometer (Optical Micrometer for Measuring Fine Threads), I. RUNGE. Zeit fur Techn Phys

v9 nl2 Sept 28 1928 p 484-6 8 figs. Describes an optical system in which the distance between diffraction bands

produced by the thread, related to the dimensions of the apparatus, gives the diameter of the thread with an ac- curacy of above 0.25% when the diameter is of the order

of 10 to 80 microns.

Inspection of Micrometer Spindles at the Zeiss Works, H. SIMON. Am Mach v70 n4 Jan 24 1929 p 175-6 3 figs. Testing lead of Zeiss micrometer spindle thread to 0.00005

in. by combined linear and angular measurements is de- scribed ; Zeiss micrometers are guaranteed not to vary more than 0.000125 in. in 1-in. length ; details of Zeiss

lead-testing machine. 97
New Amplifying Comparator. Instrum v2 n8 Aug 1929 p 281-2 1 fig ; Am Mach v69 Nov 29 1928 p 866. Ames

amplifying comparator described eliminates horizontal

stresses and strains and consequent differences in read- ings on same piece of work when shifted about under measuring point; all readings are positive and positively

repeat, regardless of direction in which work is passed under point. Elektromechanisches Messgeraet fuer Feindraehte (Elec- tromechanical Measuring Equipment for Fine Wires), M. BARTHOLDY. Kruppsche Monatshefte vlO Nov 1929 p

184-5 1 fig. Equipment has been designed in order to overcome disadvantages of measuring with calipers by which errors result from deformation and motion of measuring spindle ; wires can be measured from 0 to 0.05 mm

size is indicated electrically on scale graduated in 50 sections, each representing 0.001 mm with 0.0001 mm ex- actitude. Optical Measuring Machines, Eng (London) vl29 n3344 Feb 14 1930 p 236-7 11 figs. Measuring machine made by

C. Zeiss, of Jena, dispenses with use of micrometer screws and gage blocks, which are subject to slow molecular

changes, and of hydraulic feelers, which must exert some

pressure, and is based upon comparator principle ; optical system of optimeter is explained by diagram. Bauseh and Lomb Optical Comparator. Am Mach v72 Mar 20 1930 p 508. Accuracy to within 0.00005 in. is embodied in the optical comparator for comparison and

measuring purposes on parts with flat surfaces, balls, or

cylinders. The instrument is built into a strong steel casing. The optical comparator is supplied in two models,

the first of which has an eyepiece which is inclined 60

deg. to the measuring axis, and the other with a 90-degree

eyepiece. It is also possible to supply an instrument with

a projection attachment. The range of the calibrated

scale is plus or minus 0.004 in. Objects up to 6 in. in height can be compared.

Societe Genevoise Micro-Indicator Stand. Am Mach

v72 Apr 24 1930 p 706-7. A stand to make use of the

micro-indicator tube is being manufactured by the Societe Genevoise d'lnstruments de Physique, Geneva, Switzerland. By its use the micro-indicator tube can be con- verted to a comparator. The base and column of the stand

are of very heavy construction, the total weight being 48

lb. The table for supporting the pieces tested is 5 x 7 in., and is made flat within 0.0001 in. This table is provided with six T slots, which serve for securing two angle plates

in any position or a V-block for the support of cylindrical

pieces. The micro-indicator itself is supported in a heavy arm secured to the column by a strong clamp. The axis

of the indicator is 3% in. from the column. It is possible

to measure flat pieces as large as 12 in. in width. The

vertical capacity of the apparatus is 6 in. when using a

spherical contact point. Beitrag zur Methodik der Fasermessung (Fiber Measurement), B. SCHULZE. Papier-Fabrikant v29 nl Jan 4 1931 p 4-5 1 fig. Easily constructed apparatus employed

for direct determination of dimensions of fibers by meas- urement of projection. Societe Genevoise Model U-3 Micro-Indicator Stand. Am

Mach v74 May 28 1931 p 843. This stand is designed

for use with the fanshaped micro-indicator. It has an

oval-shaped base 10 in. long x 7V2 in. wide and rests on

three rubber feet. A socket is bored to provide for the interchangeable mounting of different types of lower

anvils or tables. The table is hardened and lapped opti- cally flat. It is 1% in. in diam. Arm movement is 6 in. The micro-indicator unit itself is mounted in the arm

through an adjustment ring on the upper part of the

supporting arm. The stand is 13% in. high and weighs

32 lb.

Tables for Societe Genevoise Micro-Indicator Stand U-3. Am Mach v75 Sept 10 1931 p 435. A modification of microindicator stand U-3 comprises a V-block as the table adapting it to the support of small cylindrical pieces from % to 2 in. Pieces up to 6 in. can be checked on a large flat table

of 4% in. diameter. An adjustable square is also furnished

for attachment to the column of the stand and serves as

a stop. Pratt & Whitney Electrolimit External Comparator. Am

Mach v76 Jan 28 1932 p 151. The "Electrolimit" external comparator provides fast and accurate means for inspection of production. Maximum distance between anvil and

spindle is 4 in. The anvil has a serrated surface IV2 x

3M> in. The anvil can be removed easily, and on the reverse side is a V-block. This equipment can be plugged

into a 110-volt, 60-cycle line. Standard magnification of the circuit will cause the needle to travel about %6

in. for each 0.001 in. variation in size. Measurement of Fibre and Yarn Diameters by Diffraction Method, J. A. MATTHEW. J Textile Inst v23 n3 Mar 1932 p T55-T70 1 supp plate. Introduction and sum- mary; theory, method, calibration and performance of

diffraction method ; details of other applications. Bibliography. Standardization of Micrometers, A. KUTAY. Vestnik Standardtizatziyi n2 (50) Mar-Apr 1933 p 43-8 in Russian. Micrometer standards developed by Gage and

Measuring Instrument Board of U.S.S.R. ; micrometer

errors; methods of determining deviations of surfaces from level and parallel ; factors affecting micrometer

errors, particularly scale graduation.

British Standard Specification for Micrometers (External). Brit Stand Instn—BS Specification n870 1939 18 p. Specification applies to: external micrometers having frame holding micrometer spindle and nut on one side opposite anvil on other with individual measuring ranges

of 1 in. up to 11 to 12 in., and 25 mm up to 275 mm to 300 mm ; setting gages for micrometers above 1 in. or 25 mm.

O.M.T. Omtimeter. Eng vl50 n3909 Dec 13 1940 p 477

Mech Wld vl09 n2819 Jan 10 1941 p 21-2. Illlustrated description of Omtimeter, particular feature of which is projection attachment permitting instantaneous viewing

at normal reading distance; range of scale of instrument

is 0.005, and graduation in divisions of 0.00005 ; greatest height of work that can be accommodated is 7 in. and

largest diameter is 6 in. Draft Specifications for External Measuring Comparators. Eng vl51 n3929 May 2 1941 p 358. Specification issued by British Standards Institution being circulated

for technical comment ; comparator is defined as measuring tool, consisting of measuring head on rigid stand over work table. Engineers' Comparators for External Measurement. Brit Stand Instn—BS nl054—1942 9 p. General construction ; work table ; adjustments for size of work and for zero

setting ; measuring contact ; operating pressure ; stops to mechanisms ; pointer ; scale ; accuracy of performance ; protection during transport ; marking.

Optical Comparators. J Sci Instrum vl9 p 141-2 Sept

1942. Two models of the "optigage" are described. Both

are for direct visual comparison of work with a standard, employing mech. and optical magnification. In one model the magnification is X 1,000, with a range of 0.001

in. ; estimations to within 0.00002 in. are claimed. The

second model has a magnification of X100, with a scale of ±0.01 in., allowing estimations to 0.0001 in. A pivoted

lever engages a fixed prism, rotation of which is shown

optically. Drawings and details are given. 98
Accessories for Mechanical Comparator. Eng vl56 n4044

July 16 1943 p 47-8 ; Engr vl76 n4565 July 9 1943 p 37-8. Illustrated description of some new attachments for use with "Sigma" vertical comparator ; first type is adjustable

locating stop designed to facilitate placing of cylindrical work with its diameter exactly in line with plunger ; sec- ond attachment is designed to facilitate cheeking of diameters of internal bores. Mechanical Comparator. Eng vl61 n4190 May 3 1946 p 414. Illustrated description of comparator manufactured by Sigma Manufacturing Co., intended for finer measurement; it has reading range of 0.002 in., or 0.001

in. on each side of zero line. Large Cylinder and Taper Comparator for Gauge Measurement, R. H. FIELD. Can J Res v25 n3 (sec F) May

1947 p 238-41, 3 supp plates. Illustrated description of comparator for accommodating cylinders or cones with maximum diameters of 12 in. and lengths up to 48 in. designed and constructed during war at National Research Laboratories, Ottawa. Le Comparateur. son Emploi son Fonctionnement, B. HUMBERT. Microtecnic vl n5, 6, Oct 1947 p 241-4, Dec

p 290-9. Comparator, its use and operation ; illustrated description of various types, including some recent in- struments manufactured in Switzerland. ( In French and

English.

)

Measuring Diameter of Fine Wire, R. W. CARSON.

Wire & Wire Prod v22 nl2 Dec 1947 p 967-71, 995 (dis- cussion) v23 nl Jan 1948 p 63. Discussion of advantages and limitations of various types of diameter measuring

instruments ; analysis of effect of anvil pressure on ac- curacy of measurement; electronic micrometer is illus- trated and described. Before Wire Assn.

Electronic Inspection. Aircraft Prod vlO nll2 Feb 1948 p 52—4. Principles and applications of Cornelius comparator. Tool for Measuring Large Diameters, C. BARNES. Eng

Inspection vl4 nl Spring 1950 p 36-9. Difficulty of measuring diameters of large gear blanks during process of turning with giant calipers or large vernier gages ; principles of instrument devised to simplify such measurements, which comprises, essentially, accurately constructed welded frame mounting dial gage and contact blocks

maintenance and use of gage. Reprinted from Machine

Shop Magazine. Dimensional Control on Automatics, Machy (London) v76 nl966 June 29 1950 p 925-6. Method developed by Sigma

Instrument Co. Ltd., Letchworth, employing one vertical comparator in conjunction with range of suitable fixtures

of simple design and so constructed that all dimensions

on component can be measured, as distinct from being

gaged, without resetting comparator; instrument and in- spection sequence are described and illustrated. The Diffraction of Electromagnetic Wave on a Dielectric Cylinder as a Method of Thickness Measurement for Quartz Threads. E. EBERHARDT. Zeit Angew Phys v3 n7 1951 p 242-6 in German. Theory is developed and ex- perimental apparatus described for a comparative method

of measurement of quartz threads. An experimentally

obtained group of curves gives the relation between dif- fraction phenomenon and thread diameter. The ac- curacy and usefulness of the method is verified by data

obtained with an electron microscope. The measuring ac- curacy of 7% is claimed for threads in the range 10-0.5^. A Simple Method for the Measurement of the Thickness

of Very Thin Fibres and Threads, W. VOIGT. Optik vll

nil p 509-10 1954 in German. A microscope attachment

is described which allows the diameter of a fibre to be

calculated. The fibre is in contact with another fibre or foil, whose movement is determined as the test piece

is rotated. Examples of the method are given. How Optics Replace Costly, Time-Consuming Inspection,

J. P. WRIGHT. Am Mach v98 n8 Apr 12 1954 p 168-9. Application at Brown & Sharpe Mfg. Co. of optical method of measuring alignment errors in micrometers

interpretation of spindle relationship to anvil by relative position and motion, of their images on collimator reticle

operation with angle comparator can be carried out by

unskilled inspectors more accurately in less than 2 min

micrometers can be manufactured more accurately than

before. Precise Measurement of Diameter of Fine Wires, I. G. MORGAN. Engr v200 n5206 Nov 4 1955 p 646-7; Eng

vl80 n4686 Nov 18 1955 p 703; Machy (London) v87 n2242 Nov 4 1955 p 1097-9. Apparatus for measuring

diameters of wires to within 0.00001 in. ; angle of tilt is measured by mirror and autocollimator and diameter of wire may thus be determined; apparatus developed in Metrology Division of National Physical Laboratory. Comparator for Measuring Average Diameter of Work

Which Has Nominally Circular and Uniform CrossSection, L. W. NICKOLS. Machy (London) v88 n2251 Jan 6 1956 p 43-5; Engineer v200 n5214 Dec 30 1955

p 933-4. Comparator enables rapid measurements to be made and is particularly suitable for work in which de- partures from circular cross section may be appreciable, provided that these departures do not include any re- entrant curves; construction of comparator ; its setting and operation ; range of measurement is from 1 to 2 in. diam ; under favorable conditions error may be about plus

or minus 0.001 in. Communication from NPL.

Measurement of Diameter of Opaque Cylinders by Scan- ning Microscopy, J. A. DOBROWOLSKI, W. GODFREY,

P. N. SLATER, W. WEINSTEIN. J Opt Soc Am v47 n2 Feb 1957 p 186-90. Experiments show that for cylinders

of diameter near optical resolution limit, scanning micro- scope gives too large size estimate ; variation of error with aberrations and numerical aperture of scanning objective, and with wavelength and state of polarization of

light were determined.

Precision Comparator for Small Cylindrical Work, J. C. EVANS, W. F. ATKINS. Engr v203 n5285 May 10 1957 p 716-7; Machy (London) v90 n2321 May 10 1957 p

1074-6 ; Eng vl84 n4770 Aug 9 1957 p 182-3. Simple comparator designed at National Physical Laboratory, to en- able diameters of small cylinders to be measured by simple technique to accuracy with plus or minus 0.00001 in. ; by

use of wedge, effect of errors of micrometer screw are reduced tenfold. New Instrument for Precise Measurement of Fine Wire

Diameters, L. WALTER. Wire & Wire Prod v33 n5 May

1958 p 543, 583-5. Equipment developed in National

Physical Laboratory in Great Britain provides means of measuring wire up to about 0.01 in. diam to accuracy of 0.00001 in. or better; principal design feature is use of very light contact load at measuring anvils, thereby re- ducing to minimum errors of measurement due to compression of wire. Messunsicherheit beim Messen von Durchmessern fiber 500 mm (Measurement Uncertainty in the Measurement of Diameters over 500 mm), L. WIZENEZ. Werkstattstechnik v49 n6 1959. 99
Measurement of Fibre Diameter Variation by Optical

Diffraction, W. J. ONIONS, B. ELLINGHAM. Brit J App Phys vlO n7 July 1959 p 328-32. A theory is de- veloped relating the intensity of light refracted at any

given angle by a parallel array of opaque fibres of un- equal diameters with the mean diameter and the coefficient of variation of fibre diameter. The ratio of the intensities of the first minimum and the first maximum is shown to depend upon the coefficient of variation of fibre diameter. This affords an opportunity of measuring fibre diameter variation. The possibilities and limitations of the method in practice are explored. Beriihrungloses Messen grosserer Aussen und Innen- durchmesser (Contaetless Measurements of Large

External and Internal Diameters), K. RANTSCH,

E. LEPPER. 4 FOKOMA Munich Oct 6-7 1959 p 1959-10. Contaetless measurement is an acute problem of the

progressive finishing technique to the metrologist. This problem is solved electrically, pneumatically, and optically. The explanations of this paper are concerned only with optical contaetless measurements, especially for external and internal diameters. Next the demands placed on new equipment are set forth for large measurements. An especially remarkable such measuring equipment is the

flawless, contaetless indication response of the cylinder

surface. For this the field of surface indication is especially treated. Optical indicators of known and of newer

kinds are systematically arranged and closely elucidated. Two principal groups of indication responses are thus

developed. These chief groups are further classified. Thereby the application possibilities of the single in- dicators may be recognized. From this knowledge con- clusions are derived for practical application in metrology. The already obtained experimental information presents

a prospect of future flawless measuring methods. An Image-Splitting Microscope for Accurate Measurement, J. DYSON. Nature (London) vlS4 Nov 14 1959

p 1561. Describes how, by fitting in the eyepiece a suit- able image splitting device, the two images may be sheared across each other until edge-to-edge contact is obtained. By reversing the shear until edge-to-edge contact is again obtained, the diameter of the object may be measured. The technique is illustrated by application to blood corpuscles. Systematik und Kennwerte von Laengenniessgeraeten

fuer Bohrungen und Wellen mit Durehmessem ueber 500 mm (Systematic and Characteristic Values of Length Measuring Equipment for Holes and Shafts with Diameters over 500 mm) , L. WIZENEZ. Werkstattstechnik v50 n8 Aug 1960 p 424-30. Design equipment, construction and materials employed for principal components of length measuring instruments for bores and shafts with diameters of over 500 mm ; physical and technological characteristics ; it is proposed that system of classification of instruments according to their measuring accuracy be

established. Tentative Methods for Measuring Diameter or Thickness

of Wire and Ribbon for Electronic Devices and Lamps.

American Society for Testing and Materials, ASTM Stand

Part 2 F16-61T p 1495-501 5 figs. Describes procedures

for measuring the diameter or thickness of round and flat wire (ribbon) 0.060 in. (1.524 mm) maximum, used in electronic devices and lamps. Mechanical measuring methods are based on the use of a sensitive measuring head with calibrated force settings, shaped measuring

anvils to reduce errors caused by material curvature or waviness, and a method for presetting the anvil spacing by means of gage blocks or cylindrical master standards. Fehlermogliehkeiten beim Messen Zylindriseher Teile mit

Kugeligen Messfliichen (Possibility of Errors in the Meas- urement of Cylindrical Parts with Spherical Measuring

Surfaces), O. NIEBERDING, S. TROST. Zeit fur Practische Metallbearbeitung v55 p 163 1961. Optische Praezisionsgeraete fuer die Drahtmessung

(Optical precision instruments for measurements on

wire), A. METZ. Draht vl2 n4 Apr 1961 p 153^. Description of following Leitz instruments and their use: "Tolerator" for checking thickness tolerances within 1/i; two types of "Ultra-Projectometer" for checking toler- ances with l/i and 0.1/t, respectively ; measuring microscope, for instance, for determination of wall thickness of insulation of cable. A Machine for the Precise Measurement of External Diameter, I. G. MORGAN, F. R. TOLMON, NPL. Machine Shop Mag v23 p 463 Aug 1962; Maehy (London) vlOl n2595 Aug 8 1962 p 295-301. Machine constructed at NPL has capacity from 0.2 in. to 3 in. and employs pneu- matic measuring system ; design requirements ; principle

of operation ; mechanical details and pneumatic system

described ; method of use ; performance results ; new machine is capable of reproducing comparison between

cylinder and slip gage to accuracy of about plus or minus

2/i in. New Method of Measuring Diameters of Balls to High

Precision, S. P. POOLE, NPL. Machy (London) vlOl n2605 Oct 17 1962 p 904-7 ; Am Mach/Metalworking Mfg

vl07 nl2 June 10 1963 p 159-61 ; Machine Shop Mag v23 nil Nov 1962 p 618-21 3 figs 2 refs. Equipment described was designed to improve accuracy of measurement for

balls of sizes below 0.2 in. in diam. by eliminating errors introduced through imperfect measuring faces; measure- ments are made under very small measuring loads and

true sizes of balls, i.e., diameters in uncompressed state, can therefore be accurately derived ; equipment, method of measurement and measuring force described. It is used in conjunction with the NPL-type slip gage interferometer and embodies a 5 mm parallel faced quartz block as the standard of reference. The sizes of balls below 0.2 in. diameter are measured by reference to the quartz block standard in terms of wavelengths of monochromatic light. A Machine for the Precise Measurement of External

Diameter, I. G. MORGAN, F. R. TOLMON, NPL. Quality Engr v26 n4 1963 8 p 6 figs 1 ref. The machine is de- signed for the measurement of diameter of standard

cylinders from 0.2 to 3 in. to an accuracy of ±5/j. in. The

cylinder is compared with gage blocks by means of a

caliper having spherical steel anvils whose displacements

are detected by a pneumatic measuring system. The anvils exert contact forces of only 3 g so that elastic deformation is negligible. The cylinder and gage blocks rest in close proximity and are not handled during measurement. Compensated Electrical Instrument for Remote Measure- ments of Displacements, M. I. BELYI. Meas Techns 1962 n8 Feb 1963 p 641-2 1 fig 2 refs. Translated from Izmer Tekh n8 Aug 1962 p 17-9. Instrument uses a method of compensating two emfs for direct measurement of linear displacements over large distances with an error not exceeding 10/i. Instrument for Automation of Large Diameter Testing,

V. A. TRUTEN'. Meas Techns 1963 n6 Nov 1963 p 465-70

2 figs 7 refs. Translated from Izmer Tekh n6 p 9-13 June

1963. From examination of existing methods it was

found that instruments based on the decimal system and

the rolling principle meet the requirements for precise and objective measurements, high efficiency, easy handling, and mechanical strength. 100
3.4. Internal Diameters

The Measurement of Large Internal Diameters, G. W. BURLEY. Prac Engr Jan 30 1913. Describes the rod gage and its use. Length Gage. D. R. GALLAGHER. Machy (N.T.) v26

Sept 1919 p 74; also May 1920 p 849. Describes a pin gage comprising a wooden handle and two wood screws. Gages of this type have been used successfully on work

up to 60 inches in diameter. Tapered Ring Gages, V. E. AYRE. Machy (N.Y.) v26 June 1920 p 971. Gives formulas for measuring tapered

ring gages by means of balls. Xew Light on Internal Measurements, J. BATH. Am

Mach v54 June 30 1921 p 1110-4 4 figs. Forms of contacts for measuring cylindrical surfaces. Results induced

by presence of oil on surfaces in contact. Holes measured by line contact. Measuring surfaces cleaned with

soap and water. The holding film as a detector of ir- regularities. Interference bands in a ring produced by

oil film. Xeue Optische Messverfahren fur den Werkzeug and

Maschinenbau (Zeiss Internal Measuring Machines), A. STEIXLE. Maschinenbau v3 Jan 24 1923 p 244-9 15

figs. Description of Zeiss measuring machines and applications. Measuring the Internal Diameter of Transparent Tubes.

J. S. AXDERSOX, G. BARR. J Sci Instrum vl Oct 1923 p 9-15. Two methods : (1) Immersing the tube in a suit- able liquid and varying the wavelength of the illuminating beam until equality of refractive index is attained so that, the system now being homogeneous, the diameter can be measured directly; (2) taking an X-ray shadow photo- graph of the tube and measuring the image found. Be- tween the two methods accurate measurements can be

effected no matter what the outside shape of the tube may be. "Zeiss" Inside Measuring Attachment for Horizontal

Optimeter. Am Mach v65 Aug 5 1926 p 264. To facili- tate the work of measuring bores, both absolute and relative. Accuracy of 0.00004 in. claimed.

Societe Genevoise Comparator for Small Internal Diameters. Am Mach v66 Mar 3 1927 p 389-90 1 fig. Made

by Societe Genevoise d'Instruments de Physique of Geneva. Switzerland, for use in measuring internal diameters of small size. Range 0.16 to 0.24 in. Comprises a rectangular table and a comparator tube. •Standard" External and Internal Comparators. Am

Mach v74 June 11 1931 p 925. The external gage is avail- able with a dial indicator or a fan-shaped scale. The dial- scale is graduated to 0.0001 in. in widely spaced divisions, whereas the fan-shaped scale is graduated to 0.00005 in., and may be fitted with tolerance markers. Optically flat 4-in. tables with serrated surfaces are furnished with the external gages. Pieces up to 6 in. in height can be ac- commodated under the direct-acting dial plunger. The

internal gage is for exploring holes for bell mouth, taper, and out-of-roundness. Ball racings and bushings can be

quickly checked for the above conditions. The dial is graduated to 0.0001 in. The work is slipped over two

arms projecting from the body. Comparators for bores from % to 3 in. and up to 3 in. in length are available. Internal Attachment for Zeiss Vertical Optimeter, G. SCHERR CO. Am Mach v76 Aug 31 1932 p 983. Measure- ment of bores from % to 4 in. to within 0.00005 in. ac- curacy can be done with an adjustable internal attachment, which is now available for the Zeiss vertical optimeter, an optical precision amplifying gage. Means

are also provided for determining taper and for finding both minimum and maximum diameter of the bore. The

attachment slips over the vertical post of the optimeter. Optische Pruefung von Hohlraeumen und langen Bohrungen (Optical Testing of Hollow Spaces and Long Bores),

G. ZIEHER. Maschinenbau vl6 nl3/14 July 1937 p 347-50. In order to obtain required exactness of modern production methods special measuring tools have to be designed

equipment for measuring bores, wall thickness, tapering,

parallel alignments, etc., described.

Electric Indicator Gauge. Machy (London) v54 nl397

July 20 1939 p 504-6 and v55 nl416 and 1417 Xov 30 1939 p 213-7 and Dec 7 p 241-3. Illustrated description of gage or comparator developed by AEG, Berlin in cooperation with Bauer & Schaurte, which can be used for both

external and internal measurements ; gage comprised mechanical and electric units, together with indicating equipment. Rachenlehrenpruefung mit Innenmessgeraeten, H. SCHORSCH. Werkstattstechnik und Werksleiter v34 n2 Jan 15 1940 p 21-5. Testing of jaw type gages by aid of

internal measuring disk according to DIX and ISA specifications, described. Internal Micrometers. Brit Stand Instn—BS n959—1941

15 p. Specification applies to internal micrometers comprising measuring head, extension rods with or without

spacing collars, and in smaller sizes, handle ; provision made for three sizes of measuring heads in both inch and

metric units. "Three-point method" of Measuring Bores, C. C. STREET.

Instrum vl4 ptl nl Jan 1941 p 6-7. Principle of method

is that of determining change in altitude of isosceles tri- angle that can be contained in bore under inspection

mathematical discussion shows manner in which such gage can give true difference in diameter between master

setting ring and bore under inspection. Bohrungsmessung mit Zwei- und Dreipunkt-Geraeten, G. BERXDT. Zeit Instrumkde v 61 n3 Mar 1941 p 69-82. Second part of discussion on principles, methods, and ad- vantages of "two-point" and "three-point" instruments for measuring bores ; formulas for evaluating required dimensions from measured values for point, ball and

rounded gages. Method for Measuring the Internal Area of Section of a Glass Tube, D. J. BEHREXS. Phil Mag v31 Mar 1941 p 199-203. The external and apparent internal radii at the section are determined from 3 microscope readings and the determination repeated at intervals at 30° around

the section. The author gives the theory, which is applicable whether the internal or external sections are

concentric or not, so long as the external section is cir- cular and the internal section is everywhere concave.

Electrical Tube Gauge, E. FAWSSETT. Eng vl56 n4057 Oct 15 1943 p 301-2. Illustrated description of electro- mechanical instrument for measuring internal diameter

of long tubes, which is capable of being used by semiskilled labor, particularly women, in quickly checking

internal diameter of air heater tubes in position. Electric Gaging to High Accuracy, W. F. ALLER. Elec Mfg Feb 1944. Describes Sheffield internal-external measuring instrument.

Electrolimit Internal Comparator. Western Machy &

Steel Wld v35 n3 Mar 1944 p 108-9. Some applications

of Pratt & Whitney Electrolimit internal comparator are presented ; series of photos and brief description given. 101
Size Control. Automobile Engr v34 n454 Oct 1944 p 397-

400. Reasons for use of end standards are discussed, with

special reference to end standards produced by Pitter Gauge and Precision Tool Co. ; description also given of two devices developed by this Company, stick micrometer

for internal measurements and Universal Measuring

Block. Bore Inspection, A. E. THOMAS, T. E. JONES. Aircraft Prod vlO nll6 June 1948 p 187-8. Fine measurement of interrupted and soft surfaced bores ; new method evolved

at AID Test House, Harefleld; application to measure- ment of rotor subassembly for high pressure fuel pump;

method gives accuracy to within 0.00002 in. and with

appropriate modification of anvils and stylii, it might

satisfactorily be applied to other problems of internal measurement. Comparator Gauge for Internal Measurement®, L. SANTER. Commonwealth Engr v35 nil June 1 1948 p

435-6. Principles of dial instrument developed during

investigations on creep in timber at split ring and shear

plate connector joints; based on Scott-Russell straight

line motion, gage eliminates personal error in setting, allows much greater number of readings to be recorded

in limited time, is much easier to read and requires less skilled operators. Rings and Plugs Checked to Hundredth of a Thou, M. J. PUTTOCK, NPL. Mach Oct 16 1948. Describes method of using an electric gage for the precision measure- ment of circularity, concentricity, and straightness of plain and tapered rings and plugs. Comparator for Measuring Diameters of Small Holes.

E. R. DYMOTT, W. O. JENNINGS. Machy (London)

v73 nl878 Oct 21 1948 p 590-1. Experimental apparatus

assembled for measuring diameters of ring gages and

holes from 0.5 in. (13 mm) down to 0.1 in. (2.5 mm)

by comparison with slip gages; comparator gives results accurate to plus or minus 0.00003 in (0.0008 mm).

Bore-Measuring Micrometer. Eng vl67 n4339 Mar 25 1949 p 272 ; Engr vl87 n4860 Mar 18 1949 p 312. Matrix Micro- Maag internal micrometer introduced by Coventry Gauge

and Tool Company is suitable for measuring bores be- tween 1 and 2 in. diam and up to 15 in. deep, to within

0.0001 in. ; photographs, drawings. Odd-Sized Holes to Millionths, E. J. TANGERMAN. Am

Mach v93 n24 Dec 1 1949 p 77-80. Steps taken at Bryant

Chucking Grinder Co., Springfield, Vermont, toward

achieving superprecision finishing of odd sized holes by

grinding ; special electronic gage produced by company

correct assembly of gage blocks, and new developed heavy

duty clamp considered as most important factors in attain- ing standard within ±0.000002 and in transferring dimension to hole within 0.000008. Measurement of the Internal Diameters of Metallic Capil- lary Tubes, C. T. COLLETT, J. C. HUGHES, F. C. MOREY. J. Res. NBS v45 p 283-8 Oct 1950. The uni- formity of the internal diameters of some metallic capil- lary tubes was studied by means of a small thread of mercury, using X-ray technique, following the method of Fisher. Eight tubes out of a group of twelve were selected as suitable for use in an absolute viscosimeter, and flow constants were computed. The tubes studied were about

15 ft long, with an internal diameter of about 0.015 in. Maximum deviation from the average diameter in most

cases was about 1.5% or less. Matrix Micro-Maag as Internal Gauging Standard, M. MAAG. Microtecnic v6 nl 1952 p 26-9. Set of gages comprising internal micrometers, and assortments of reference rings, measuring needles and various adjuncts ; internal micrometer is three-point contact instrument with accuracy of 1 micron permitting detection of out of

roundness; particulars of various types of Micro-Maag

sets for use as workshop reference standards.

- r New Precision Internal Measuring Machine, C. O. TAYLERSON, A. TURNER, NPL. Symposium on Engi- neering Dimensional Metrology Proc. 1953 p 73. Measures

ring gages from 0.1 to 1.5 in. to ±0.0001 in. by comparison

with gage block combinations.

Diffraction Patterns in Circular Aperture Less Than One

Wavelength in Diameter, S. L. ROBINSON. J App Phys

v24 nl Jan 1953 p 35-8. Measurements of diffraction patterns from 0.2 to 1.0 wavelength in diameter with

plane polarized electromagnetic wave incident normally

microradiation relative to that of unperturbed beam

determined at points along electric and magnetic diameters of apertures; data disagree with calculations from

Young's circuited form. Shardlow Imicro Internal Micrometer. Machy (London)

v82 n2112 May 8 1953 p 879-80. Micrometers introduced by Tesa, S. A. Renens-Lausanne, Switzerland, are pro- duced in many ranges by British company ; construction

of micrometer and method of operating anvils described. Pneumatic Gaging Applied to the Measurement of the Bore of Tube, R. CHITTLEBURGH, E. F. POWELL, G.

F. MORTON. J Sci Instrum v31 p 20-2 Jan 1954. A

method is described which enables the bore of a tube to be measured accurately at all positions along the length

of the tube. The method is particularly suited to the measurement of the bore of tube manufactured to close tolerances. With a method of amplification incorporated ! into the system, it is possible to determine whether the bore of tube having large tolerances, e.g., % in. bore with i a tolerance of +V32 in., lies within those tolerances. A

steel ball is placed within the tube and held in position by an electromagnet. The ball serves as the second constriction in a pneumatic system, air at constant pressure being supplied to one end of the tube through a first constriction of fixed size. The pressure developed between

j the two constrictions is a measure of the gap between

the steel ball and the inner wall of the tube.

P Measurement of Small Holes, I. A. GRIGOR'EV. Dept

of Sci and Indust Res. Her Majesty's Stationery Office,

( !

' London 1956 137 p. Discusses contact devices and

methods as well as contactless methods.

1 t Measurement of Small Holes, L. A. GRIGOR'EV. GB

Dept Sci & Indus Res 1956 137 p. Study of possibility of applying limit plug gages in sizes below 1 mm; series I « of tolerances for holes between 0.1 and 18 mm diam ; contact devices and contactless methods; application of ^

j internal gages with taper pin, spring type internal gage, and other mechanical means of measuring small holes. Translated from Russian.

Internal Measuring Machine. Engr v203 n5274 Feb 22

1957 p 304. Machine made by Coventry Gauge and Tool

[ Company stated to be capable of measuring diameters of

finely ground or lapped bores to accuracy of plus or minus

0.00001 in. or less; it is basically comparator using high \ precision slip gages as reference standards. Prototype Instrument for Measuring Diameters of Very , Small Bores, P. W. HARRISON, G. M. SEVERN. Machy

(London) v94 n2428 May 27 1959 p 1210-3. Instrument

developed at National Physical Laboratory is capable of measuring bores down to 0.03 in. diam, with lengths up

to 1% in. to accuracy of about 0.00002 in. ; principle of operation ; contact sensing device ; measuring stylus ; ap- I ; paratus described ; observational procedure. Machine for Precise Measurement of Internal Diameter, \ 1. G. MORGAN, F. R. TOLMON. Machy (London) v95 n2451 Nov 4 1959 p 941-6. Prototype machine built by

National Physical Laboratory ; existing equipment, pri- marily Zeiss universal measuring machine, was used to I j 102
save initial expense, and measuring range is therefore limited to diameters between 1.5 in. and 3.5 in. ; diameter of ring to be measured is established by comparison with known size of reference standard of box form built up

from slip gages and lapped steel endplates ; measuring

equipment and procedure ; performance tests. Machine for Precise Measurement of Internal Diameter.

I. G. MORGAN, F. R. TOLMOX. Microtecnic vl4 nl Feb

1960 p 14-20. Prototype machine for precise measure- ment of internal diameter: machine was developed for confirming performance of existing machines for diameters up to 6 in. (150 mm) and investigating possibility

of improving upon accuracy of measurement at present obtained ; comparative tests show agreement between machines and that accuracy of plus or minus o/x in. (plus or minus 0.125/i ) can be obtained. Minutes of Meeting No. 3 on Internal Diameter Calibrations and Measurements of the Measurements Research

Conference. XBS June 15 1960. Contains schematic drawings of various commercial measuring devices. Verfahren zum Erfassen der Umkehrpunkte Beim Messen

grosser Bohrungen und Wellen, L. WIZENEZ. Werkstattsteehnik v50 n7 July 1960 p 363-70. Methods for determining •reversal points" in measuring large bores and shafts; errors occurring in sensing of cylindrical bodies : three different sensing methods, their advantages and disadvantages described. Measurement of Dimensions in Inaccessible Places, I. A. KUPTSOV. Meas Techns 1959 nl2 Sept 1960 p 939 1 fig. Translated from Izmer Tekh nl2 Dec 1959 p 13. The

universal lever instrument with dial gage is being widely used in measuring the deviation of holes from a common

axis, the thickness of walls at a considerable depth in small holes, the direction of teeth and internal grooves of small diameters, and other similar dimensions. Instrument for Measuring Very Small Bores, P. W. HAR

RISOX, G. M. SEVERX. Engr v210 n5460 Sept 16 1960 p 467-9. Modifications and additions made to prototype

at Xational Physical Laboratory ; electric motor now

drives worm shaft and relay halts stylus : smaller stylus, 0.014 in. ball on tungsten stem, extends range down to bores of 0.02 in. diam : holes down to 0.0008 in. diam have

been made.

Further Development of XPL Prototype Instrument for Measuring Very Small Bores. P. W. HARRISOX, G. M. SEVERX. Machy ( London ) v97 n2497 Sept 21 1960 p 699-

700; Quality Engr v24 n6 Xov-Dec 1960 p 181. Refer- ence made to instrument previously described by authors

( see Engineering Index 1959 p 665 ) ; circuit for instru- ment modified; construction of even smaller stylus comprising ball of 0.014 in. diam mounted on tungsten stem. A Method of Measuring Internal Diameters of Pipes by Means of an Electrical Hole Gauge, D. E. ROKHMAX.

V. R. TYR. Meas Techns 1960 n2 Xov 1960 p 94-5 1 fig. Translated from Izmer Tekh n2 Feb 1960 p 6. The in- strument here described is intended for measuring pipe diameters over their entire length for research purposes

yet, a further improvement of its design and, in particular, its equipment with a centering device, will convert

this instrument into an engineering tool for checking the

internal diameter of pipes. If required, the variations

of the internal diameter values can be recorded on an

oscilloscope film. End-Pieces for Internal Measurement Devices, I. S. VASILEXKO. Meas Techns 1960 n2 Nov 1960 p 95 2 figs. Translated from Izmer Tekh n2 Feb 1960 p 7. In the case of internal grooves or stepped diameters it is often

difficult to measure dimensions accurately. For such measurements attachment IZO-1 to micrometer UIM-21,

with an end-piece which has a large diameter sphere, can

be used. Measurement of the Internal Cell Length of Glass Measuring Cells, H. MORET. Rev Sci Instrum (USA) v33 n2

p 241-3 Feb 1962. The paper describes a novel method, which would appear to be of general application. An

accuracy of a few microns is claimed. A brief description indicates how the method can be extended to deter- mine the cell length over the whole cell window area. Measuring Small Internal Dimensions on an Optimeter,

P. U. MARKOV. Meas Techns 1961 nlO Mar 1962 p 790-1

5 figs. Translated from Izmer Tekh nlO p 16-7 Oct 1961. A measuring method was developed based on the utiliza- tion of a horizontal optimeter and brackets redesigned

for the purpose of measuring small holes. Eine neue Messmaschine fuer Innendurchmesser, W. KIRCHNER G. BRAUNE. Werkstattstechnik v52 n6 June 1962 p 291—4. Xew measuring machine for inside diameters ; design and construction of machine used in particular for bores of ring gages : it operates according

to principle by Abbe and has range from 3 to 120 mm

measuring inaccuracy is only plus or minus 0.1/x in. Some Inside Facts on Inside Measurement. L. O. HEIXOLD. JR., ISA Proc Preprint 2.4.62 for meeting Oct 15-8 1962 6 p. Xew standards for equipment performance, ring geometry and laboratory reporting are sug- gested which must be acted upon before state of art can move forward. Measurement of Small Holes by Means of the "Magic

Eye," B. Ya. VERKHOTUROV. Meas Techns 1962 n9 Apr

1963 p 726-8 4 figs 1 ref. Translated from Izmer Tekh n9 p 12-4 Sept 1962. "Magic eye" is a tube 6E5 attachment

to a universal microscope. When the probe touches the measured hole the shadow in the tube spreads, thus in- dicating a contact. The component with the hole under

test is placed on the microscope stage. The probe is in- serted to a certain depth into the hole, the position of the diameter plane is found and the diameter of the hole d=Ij+dP is determined, where L is the difference in the readings of the microscope scale, dP is the diameter of the

probe. Een nieuwe meetmachine voor het Meten van Inwendige

Diameters. (Xew machine for measuring internal diameters), J. M. MULLER. Polytechnische Tijdschrift vl9 nil May 27 1964 p 464-7. Design and operation of machine developed by Kugelfischer Georg Schaefer & Co, Schweinfurt, West Germany ; special design features which were made necessary by high requirements to be met by measuring machine ; illustrated description of some

components which are particularly important for accuracy

of machine. 3.5. Measuring Machines and Bench Micrometers

The Whitworth Measuring Machine. Proc Inst Mech Standards of Length as Applied to Gage Dimensions, G. M.

Engrs 1856 ; Am Mach v47 1918 p 189. BOXD. J Franklin Inst 3d ser vll7 p 318-86 May 1884. Illustrates end standard. Whitworth measuring machine. Measuring Machines, Cornell. Am Artisan Xovember bench micrometer, etc. Discusses accuracy, tolerances, etc. 1874 ; Am Mach v29 May 17 1906 p 655-6. Standard Measurements in Machine Construction, F. J. The Whitworth (Millionth) Measuring Machine. T. M. MILLER. Am Mach vl5 9 Jan 7. 21 1892 14 figs. Prof. GOODEVE. C. P. B. SHELLEY, 1877. Sweet's bench micrometer is shown in Fig. 5. 103

771-846
The Army Gun Factory Comparator, J. E. HOWARD.

Notes on the Construction of Ordnance n63, Ordnance Office, Washington Oct 13 1893 10 p 10 figs. Describes a

transfer comparator, designed for laying off the distances

defined on a line standard bar, and establishing definite distances between or over the ends of contact points for

the adjustment of end measures, either for interior gage

rods and measures or for exterior diameter calipers. Its capacity is from 0 to 70 in. for gage rods and from 5 to 75

in. for exterior calipers. Automatic Recording Instrument for End Measurements,

L. HARTMANN. CR Acad Sci vl20 1895 p 1024-9.

Briefly describes (without illustrations) an instrument which measures to 0.001 mm. lengths by comparison with end standards. Instrument records measurements. Can

be used for measuring diameters of cylinders, etc. An Electric Micrometer for Laboratory Use, P. E. SHAW.

Phys Rev vl6 Mar 1903 p 140-57 6 figs. An instrument

of considerable adaptability having delicacy of 0.0001 mm

or less, accuracy, and great length of scale. A New English Measuring Machine. Am Mach v26 July 2 1903 p 964-5 5 figs ; Eng vl08 p 104-5 July 25 1919. A

description of the Newall Measuring Machine, having a tilting level indicator. The Improved Electric Micrometer, P. E. SHAW. Proc Roy Soc A v76 Aug 4 1905 p 350-9. Limits to its practical sensitiveness (4X10"8 cm) have been reached. Paper

states in detail the form, peculiarities, and limitations of the apparatus. First used for the measurement of the amplitude of a telephone diaphragm. Recent Improvements in the Newall Measuring Machine. Am Mach v28 Nov 30 1905 p 734-5 3 figs. Illustrates and

describes the new features recently introduced and the

increase in size, the latest machine having a capacity of

six feet. Discussion, J. E. STOREY, Am Mach v29 Feb 8 1906 p 183, Applications of the Newall correcting device

to precision lathes. Six-foot Measuring Machine. Constructed by the Newall

Engineering Co. Ltd. Eng v81 Jan 19 1906 p 78-9 6 figs

Am Mach v29 Apr 12 1906 p 488-9. Designed for use with

contact or line standards. Has spirit-level indicator. The English Precision Lathe and the Newall Measuring

Machine, J. E. SWEET. Am Mach v29 Feb 8 1906 p 172-

3 5 figs and discussion, J. E. STOREY, April 12 p 488-9, and J. E. SWEET, May 17 p 655-6. Design of screws and nuts for precision work. Includes description and

illustration of the Cornell measuring machine with

references. An Electrical Measuring-Machine for Engineering Gages and Other Bodies, P. E. SHAW. Eng v81 June 29 1906 p 865-8 13 figs. Abstracted from the Proc. Roy. Soc. A

v77 Dec 1 1905 p 340-64 10 figs. Describes a method

having the advantage of being more sensitive than the

old method, and giving an illustrated description of the machine. See also Sci. Am. Supplement Apr 7 1906. Transverse Comparator, W. KOSTERS. Wissenschaftliche Abh der Kaiserlichen Normal-Eichungs Commission,

v8. Julius Springer, Berlin, 1908. A Measuring Machine of Simple Construction, O. E. PERRIGO. Am Mach v31 Aug 20 1908 p 271-2 6 figs. A

work gaging machine with sliding contact plunger and

multiplying levers for moving the indicator pointer over

a graduated arc.

The Picard and Colomb micrometer, Am Mach v32-2 Oct 7 1909 p 620-1 2 figs. Report of the Committee of Economic Arts of the French Society of Encouragement

for National Industry on micrometer measuring machine,

for measurement of objects with parallel sides or the diameters of cylinders. Has hydraulic indicator. An Electro Micrometer, G. J. MURDOCK. Am Mach v32 Dec 16 1909 p 1025-7. Illustrated description of a tool for accurate measurements, general testing, and comparison. Especially adapted for obtaining accurate measure- ments of the inside diameter of bushings and other work when held in a chuck, where the hole is so small that the common inside micrometer cannot he used. Messmaschine von H. Hommel, D. GOPEL. Mech Ztg

1910 p 1-5. Automatic Micrometer Calipers. Mech Engr (GB) v26 Aug 26 1910 p 248-51 17 figs. Illustrated description of a

series of automatic calipers made in England. Fig. 1, auto

calipers, 1 inch between jaws, divided in .01 in. and Vu in. to Vi28 in. Fig. 2, do. Fig. 3, large auto calipers with from 6 to 38 in. reach. Fig. 4, large auto calipers, with

base to screw to bench, for measuring leather or large metal, etc., sheets. Figs. 5, 6, 7, types of graduated dials. Fig. 8, autocalipers, divided to 0.001 inch. Fig. 9, Imperial auto wire gage, to give direct readings in W.G. Nos. 1 to 30. Fig. 10, Vulcan patent plate gage. Fig. 11, auto sliding

calipers, to measure up to 6 in., dial marked every 1 mm.

Fig. 12, Auto sliding calipers with one dial in mm and 1 in inches. Fig. 13, large auto micrometer with 5 in. dial to measure % in., marked in 0.0005 in. Fig. 14, large auto micrometer with handle. Fig. 15, large auto micrometer.

Fig. 16, large auto micrometer with 7 in. dial for quickly measuring large quantities of samples. Fig. 17, auto micrometer with large reach of frame for measuring thick- ness of sheets of felt or similar materials. A Standard Measuring Machine, P. E. SHAW. Roy Soc Proc Ser A v87 Oct 31 1912 p 385-90. Gives an outline of the scope of an improved type of machine constructed by the author on the principle of electric touch (Science Abstract No. 1116, 1906) and now installed at the NPL.

Details and results to be given later. The Reinecker Measuring Machine, A LEMAN. Zeit In- strumkde Beib4 Feb 15 p 33-9 and Mar 1 1913 p 45-8 ; D

Mech Ztg ( Berlin) 1913 p 33 and 45. Communication from

the Phys-Techn Reicchanstalt. The peculiarity of this machine as compared with the usual mechanical touch machine invented by Whitworth, is the indication of contact shown by the rise of a dilute solution of alcohol in a capillary glass tube. Sectional drawings are given and some methods of adjustment are indicated. Electrical Measuring Machine, P. E. SHAW. Inst Mech Eng Proc v2 Mar-Apr 1913 p 579-629 ; Elect Rev v73 July

25 1913 p 127 ; Electrician v72 Oct 10 1913 p 9-11. A new

measuring machine is described founded on the principle of electric touch (See Sci. Abs. 1116-1906 and 718-1911). Applicable to measurement of cylindrical, spherical, or

parallel-faced bodies. The present machine embodies

improvements. Unit of measurement is 0.0001 mm.

Large Measuring Machines Constructed by Societe Genevoise. Eng v98 Sept 11 1914 p 323-6. One of these is adapted to measure a gage of even 3 m long. One new

feature in the machine is a rolling foot, allowing that change in temperature shall produce no strain along the length of the bed. The most accurate of the machines

described measures to 1 micron. The reference scale, in- stead of being fixed, is placed at the horizontal level of the micrometer screw and moves with it. The advantage

here is that a cosine error, instead of as usual a sine

error, is introduced. 104
Slocomb Bench Micrometer. Machy (N.Y.) v21 Mar 1915 p 591. Range 0 to 6 in. Graduated to 0.0001 inch. Methods of Measurement, D. T. HAMILTON. Machy

(N.Y.) v22 Oct 1916 p 100-8 18 figs. A survey of measuring machines and comparators. The following

types of universal measuring machines are shown : Fig. 8, Brown & Sharpe measuring machine, Figs. 12, 13, Slocomb

standard measuring machine; Figs. 14, 15, Societe Genevoise measuring machine ; Figs. 16, 17, 18, Newall stand- ard type of measuring machine ; Fig. 20, Reinecker measuring machine. A Length Comparator for Determining Linear Coefficients of Expansion, W. L. DE BAUFRE. J Am Soc Naval

Engrs Nov 1916. Construction and operation with method

of calculating. Mikroskop Fuhlhebel fur Schrauben-Messmaschinen

(Microscopic Indicator on Measuring Machines), F. GOE- PEL Zeit InstrumKde v37 July 1917 p 142-5. From

the Phys Techn Reichsanstalt. The anvil end of the measuring machine is controlled as usual by a spring. On being pressed back, when a gage is being measured, the

far end of the anvil bears against a sensitive lever by which any movement is multiplied 30- or 40-fold. The end

of the long lever-arm carries an illuminated index mark, which is viewed by a low-power microscope. The unit is 0.0001 mm.

The Taft-Peirce Measuring Machine, E. J. BRYANT. Am Mach v47 Nov 22 1917 p 913-4; Inspector, vl p 9 and 17 Aug 15 1919. A Simple Form of Measuring Machine. Engr vl25 Apr

5 1918 p 302 1 fig ; Iron and Coal Trades Rev, March 8, 1918. Measuring machine made by Armstrong. Whit- worth and Company, Ltd., is adaptable to a variety of gage measurements. Cylindrical feeler is used. Specially shaped anvils are provided for various classes of work.

Major, pitch, and minor diameters of screw thread gages can be measured.

Coats Precision Fluid Gage. Am Mach v49 Sept 5 1918

p 451. Describes Prestwich amplifying comparator having a diaphragm which actuates fluid in a capillary tube. A Universal Measuring Machine. Am Mach v53 July 8 1920 p 49-53 14 figs. Engr vl29 May 7 1920 p 472-3 and

p 476 9 figs partly on 2 supp plates. Construction and method of operation of universal measuring machine made

by Societe Genevoise and designed for accurate measure- ment of pieces of all shapes. Machine is intended as primary standard of measurement for use chiefly for measuring gages or parts of all descriptions, for measuring screw threads and as a rapid comparator. All meas- urements are made with reference to a standard scale mounted in a case, shown at the left side on top of the

bed, it being read by means of a microscope, never coming

in contact with the object being measured. The axes of the scale and of the work being measured are directly in

line, thus reducing the chance of error. The headstock

at the right contains an indicator to enable the obtaining

of the same pressure for each measurement. The fixture

in the center is for use when measuring screw threads. Precision Measuring and Inspection Devices, R. J. WHIBLEY. Machy (N.Y.) v27 Oct 1920 p 135-9 10 figs. Optical methods developed at British National Physical Laboratory, for facilitating inspection. Leonard Optical Comparator, 12 in. Am Mach v53 Oct

1920 p 88. The machine is intended to register accurately length measurements up to 12 in. within a limit of

0.0005 in. It has a heavy-section box bed, on the machined top surface of which are mounted two headstocks, one fixed and one adjustable. Each headstock carries an

anvil, the measurement being made between the anvils.

The fixed headstock carries a light box and the optical element, also the amplifying mechanism. The amplifying mechanism is so designed that any slight movement of the main body adjusts the ratio between the two sides of the first lever, maintaining the ratio of 7 to 1. The

smallest lever is the most important feature of the whole

unit, as any slight error on this causes considerable

alteration to the scale. A total magnification of 1,000 can

be obtained. Neure Feinmessgerate fur die technische Liingenbestim- mung (Modern Measuring Instruments for the Technical Determination of Lengths), G. BERNDT. Zeit VDI v65 June 18 1921 p 639-43 19 figs. Discusses improvements

in comparative measurements with gage blocks and measuring machines. Almost the same accuracy can be ob- tained with mechanical and optical lever gages, such as minimeters, optimeters, microscopic lever gages, etc., which are described. Details of Gopel and Kosters inter- ference comparators, used for finer measurements. Sum- mary of all measuring machines in which the order of fineness has been changed from 0.00001 to 0.000001 inch. Describes the following briefly and critically : 1 Pratt and

Whitney, 2 the German form which employs a liquid indi- cator, 3 Geneva Society with microscope and later for use with indicator, 4 machines with indicators by Eden

and Sears, 5 machines using indicators by Gopel, 6 Zeiss optimeter, 7 Shaw's electric micrometer, 8 the interfer- ence comparator of the Reichsanstalt, 9 other less well known forms. An Extensometer Calibrating Device, R. L. TEMPLIN.

Chem and Met Eng v25 Aug 10 1921 p 248-51 5 figs. Describes various instruments and methods of operation. Accurate End Measurement on Measuring Machines Using

a Screw, H. BAKER. Engr vl34 July 28 1922 p 81-3 6 figs. Experiments relating to attempts to measure correctly to one ten-thousandth of a millimeter. Description of machine used and methods. Using a machine of the Societe Genevoise make, with the endeavor to attain consistent work to .1 micron the author finds many precautions nec- essary, which are enumerated. Experiments with oil film

in micrometer screw, with dry screw, high tension, etc. The Pratt and Whitney Supermicrometer. Am Mach v57 Aug 31 1922 p 355 ; Machy (N.Y.) v29 Sept 1922 p 68 ; Am

Mach v66 Mar 31 1927 p 552 ; Eng vl24 Dec 9 1927 p 747. Instrument which occupies position intermediate between

ordinary micrometer calipers and an elaborate measuring

machine, is intended for general use by tool makers, in- spectors and mechanics, in shops where measurements of 0.0001 in. are required. Has a capacity of 8 in. and settings are made by use of gage blocks. Has controlled measuring force and work support of various forms. Messmaschinen und ihre Bedeuting fur den modernen

Betrieb, H. SCHULTZ. Prazision v2 May 1923 p 104. Transversal und Longitudinal—Komparatoren fur Langen- masse (Transverse and Longitudinal Comparators for Length Measurements), W. KOSTERS. Prazision v2 1923 pl68. The Wickman Gauge Measuring Machine. Engr vl35 Mar 9 1923 p 266-8 8 figs. Machine for verification of workshop gages, to be carried out quickly and accurately. Measurement of Thin Elastic Plates, C. CHENEVEAU,

J. CALLAME. CR Acad Sci vl77 Nov 5 1923 p 872-1. Describes a form of apparatus devised to measure accurately the thickness of a thin plate of elastic material. A

vertical rod, bearing a fiducial mark, rests on the plate so that the pressure is constant and as small as possible. The

height of the mark is measured by means of a microscope. The pressure may be altered, if desired, by placing weights on a pan carried at the top of the rod. 105
Bethel-Player Measuring Machine and Comparator, Am

Mach v61 nl3 Sept 25 1924 p 521 1 fig. Uses gage blocks as standards and a tilting level as an indicator. Technische Messgerate (Technical Measuring Instru- ments), W. BLOCK. Maschinenbau v3 Nov 13 1924 p

1036-8. Discusses basic difference of scientific and

technical measuring, independence of foreign instruments,

simplification of existing instruments, etc. Universal Measuring Machine. Machy (N.Y.) v31 Jan

1925 p 387-8 5 figs. Improved machine known as Hanson- Whitney universal type, which is in part a comparator and

in part direct measuring machine using precision screw and large graduated measuring wheel and vernier for ob- taining accurate measuring. Two multiplying lever in- dicators are embodied in the machine. End Measuring Machine at the National Physical Laboratory. Machy (London) v26 Apr 28 1925 p 113-4 2 figs. Special micrometer head stock and indicating tailstock form essential parts of machine. Measurement of short gages and of thermal expansion of short gages by inter- ference methods. High Precision Measuring Machines, T. TODD, Am Mach

v63 Sept 10 1925 p 420. Discussion of article by J. K. WOOD, Am Mach v62 p 945. Deals with measuring pres- sures of workmen. An Electrically-Controlled Micrometer Caliper, C. MOON.

J Opt Soc Am and Rev Sci Instrum vll Oct 1925 p 453-8. A description of a special micrometer caliper fitted with

electrical control for remote operation. The headstock and tailstock are supported by a heavy ring frame. The

headstock screw is driven by a very small electric motor, and in the tailstock there is a mechanism which auto- matically stops the motor by opening a set of electric contacts when the critical measuring pressure is reached. The caliper was designed for measuring the diameter of a

precision single-layer inductance coil while both coil and

caliper were in a constant temperature enclosure. Thickness Measurements of Compressible Materials, R. W. BROWN. India Rubber Wld v76 July 1 1927 p 197-8 5

figs. It is believed that appreciable increase in accuracy

of measuring compressible materials will be realized with more general recognition of effect on such measurements

of linear accuracy, foot size, foot pressure, and parallelism

of feet ; standardization of these factors would eliminate confusion existing at present. The Hilger "Tenthou" Comparator, C. F. SMITH. Machy

( London ) v31 Dec 1 1927 p 263 2 figs. Brief account of optical gage or comparator which measures differences to accuracy of 0.0001 in. (0.00254 mm) ; designed to measure depressions in rubber ; projects bright line on white

scale 10 in. length, divisions of which measure to 0.05 in.

total difference of 0.02 in. measured directly to 0.0001 in., and by estimation to 0.00005 in. ; small constant pressure

applied to object by contact point ; only one moving part. Motor Micrometer of Glasgow Transit-Circle, L. BECKER.

Monthly notices Roy Astron Soc v88 May 1928 p 604-6. An electrically driven micrometer, running 280 rev. per

sec. without appreciable variation by means of which

greater accuracy could be obtained than by another mode

of observation. The Calibration of Extensometers, R. K. TEMPLIN. ASTM Preprint v96 for mtg June 25 1928 8 p 3 figs. Details of new design of calibration device suitable for cali- brating extensometers arranged for measuring deformations on gage lengths varying from % to 10 in., inclusive

device indicates total deformations to nearest 0.000002

in. ; errors due to temperatures, design, workmanship, and

manipulation are discussed; calibration data pertaining

to micrometer screw are included together with results

obtained on few different types of commercial extensometers. Carl Zeiss Precision Measuring Machine, G. SCHERR.

Instrum vl Nov 1928 p 483^1 2 figs ; Am Mach v69 Oct 4

1928 p 561-2 ; Machy (London) v27 Mar 18 1926 p 815-6 5

figs; Western Mach Wld v20 329-30 Sept 1929 4 figs. Construction is based on entirely new optical principle, whereby micrometer screws as well as devices for controlling their rather excessive measuring pressure have

been eliminated entirely; in their stead only glass scales are being used together with optical indicator ; these

glass scales will not wear and therefore retain their orig- inal accuracy indefinitely. Scale is accurate to 0.00005 in. An Instrument for the Measurement of Thickness of Compressible Solids, M. C. MARSH. J Sci Instrum v6 Dec

1929 p 382-5 4 figs. Instrument combines sensitivity and

robustness, for measurement of thickness of compressible

fabrics over very wide range of pressures. Ames Dial Gage for Thin Materials. Am Mach v73 Aug 7 1930 p 266. Rapid and accurate measurement of thin materials can be effected by the dial gage illustrated. The

dial reads to 0.000025 in. Any size of contact points can

be furnished. The gage is finished in black crystalline lacquer. Grid-Glow Micrometer, R. W. CARSON. Electronics v4 June 1932 p 191 and 204. Hand micrometer with electri- cal means of indicating instant of contact between mi- crometer and center of ribbon failed; satisfactory measurements of elastic hysteresis effects were finally made by using Westinghouse DKU-612 grid-glow tube. Microlux Optical Micrometer. Eng vl34 July 15 1932 p 79. Micrometer manufactured by Fritz Werner, Berlin, for gaging finished parts within fine limits ; fundamental

features are that manual touch is replaced by constant mechanical pressure, reading is very greatly magnified, and it can be distinguished without aid of eyepiece. Van Keuren Light-Wave Micrometer, VAN KEUREN CO. Am Mach v76 Aug 3 1932 p 920. An accurate bench micrometer, the instrument has a 6-in. measuring wheel graduated in 0.0001 in., permitting readings of 0.00001 in. An optical flat is held in contact with a 3-in. steel flat with spring pressure and is connected by a tension rod

to the arm supporting the micrometer head. Bending of the arm is detected by movement of the light-wave inter- ference bands. Messmaschinen, G. BERNDT. Archiv fuer Tech Messen

v2 nl7 Nov 1932 p T167 (2p). Layout and operating

characteristics of length and thickness measuring machines with particular regard to designs by Societe Genevoise d'Instrunientes de Physique and Zeiss. Screw Micrometer Gages for Rubber Specimens, W. L. HOLT. J Res NBS vlO RP549 May 1933 p 575-82. Screw micrometers combined with an electrical contact

indicating device have been adapted to measuring the dimensions of soft rubber parts. Three types of gages have been built. Two of these are vertical gages for thickness measurements and the other is a horizontal gage

for dimensions, such as the width of test specimens and

the diameter of cylindrical or spherical parts. Measure- ments made with the micrometer gages are compared

with (1) the thickness or diameter computed from the volume and (2) those made with the usual type of dial gages. The micrometer gage measurements agree very

closely with the computed values due to the precision of the micrometer screw and the fact that there is little compression of the rubber at points of contact. Extensometer Comparator, A. H. STANG, L. R. SWEETMAN. J Res NBS vl5 n3 Sept 1935 (RP822) p 199-203, 106
1 supp plate ; Mech Wld v98 n2550 Nov 15 1935 p 473-4. Comparator for calibration of extensometers, compressometers, micrometer dials, and strain gages described

comparator has given satisfactory results in calibrating length-measuring instruments used for materials testing. Jig Borer Measuring System. Engr vl64 n4255 July 30

1937 p 135. Method of measurement used for setting

table of Newall jig boring machine; illustrated description of micrometer device, known as "Micro Locator,"

lsed for positioning table and trains of rollers with

micrometer attachment in position for setting longitudi- nal slide. Societe Genevoise Measuring Machine. Machy (London)

v53 nl369 Jan 5 1939 p 429-31. Universal measuring machine developed by firm in Geneva, Switzerland; ar- rangements permit of great diversity of operations on

single unit ; weight of carriage supported on ball bearings, with result that wear of guideways is eliminated ; in addition to two micrometer microscopes, goniometric micro- scope is provided. Neuere optische und elektrische Geraete und Verfahren

zur Laengenmessung, F. MUELLER. Maschinenbau vl8 nl3/14 July 1939 p 339-40. Recent optical and electric equipment and methods for measurement of lengths

illustrated description of equipment. Convenient Electrical Micrometer and Its Use in Mechanical Measurements, R. GUNN. Trans ASME (J App Mech)

v7 n2 June 1940 p A-^9-52. Simple micrometer of mechanical and electrical stability ; electric current out- put from micrometer is accurately proportional to im- pressed mechanical displacement. Zero drift, hysteresis, temperature, and pressure variations reduced to less than 1%. Special circuits described which permit indication

of sums, differences, ratios, or products of mechanical

displacements. Measuring to 0.000025 in. Without Pressure, R. W. CARSOX. Elec Mfg v40 Oct 1941 p 80-4 164-70 9 figs. Describes micrometer in which contact at the micrometer

produces operation of a relay which lights indicating lamps. Unit responds to changes of no more than 4/i" at the contact point. Unit makes consistently repeatable measurements of soft, flexible or compressible materials

as well as hard metal parts. Calibrator for Strain Gauges and Extensometers, D. A. MORRELLI. Commonwealth Engr v29 nl2 July 1 1942

p 290-1. Instrument evolved by author has proved very

satisfactory in use being robust, steady and easy to use

it involves no close clearances, or exceptionally precise machine work, and will handle large or smallest extensometers with equal ease. A Note on Electromagnetic Induction Micrometers, In- cluding a Novel Circuit, Incorporating Metal Rectifiers, R. J. COX. J Sci Instrum vl9 Aug 1942 p 117-20. Utilizes changes in inductance of iron cored coil produced

by changes in lengths of air gaps in its magnetic circuit. Verwendung ueblicher Messgeraete zu Sondermessungen

(Use of Ordinary Measuring Instruments for Special Measurements), L. TSCHIRF. Werkstattstechnik und

Werksleiter v36 n23/24 Dec 1942 p 491-4. Illustrated description of test apparatus for control of small calipers

measurement of surface thicknesses and symmetries ; control of spaces between holes. Proving-in Paper Micrometer, J. M. FINCH. Bell Lab

Rec v21 Jan 1943 p 121-2. It has been proposed that a

dial micrometer would be a satisfactory alternative in- strument to pressure-adjusted machinists' micrometers and more easily manipulated ; to determine the comparative merits of these devices, tests were undertaken and

the results are discussed.

Precision Measurement. Automobile Engr v33 n434 Mar

1943 p 123-5. Developments exhibited by E. H. Jones (Mach Tools) Ltd; various new designs for making some

form of measurement comparison ; trend is towards evolution of fine precision apparatus that is not too complex

or too delicate for use by comparatively unskilled

operators. Micrometer for Long End-Measurements. Eng vl58 n4109

Oct 13 1944 p 286 ; Engr vl78 n4619 July 21 1944 p 52-3 ; J

Sci Instrum v21 n9 Sept 1944 p 163-4. Brief illustrated description of PVE stick micrometer for making measure- ments of this kind, manufactured by Pitter Gauge and

Precision Tool Co. "Microptic" Vertical Measuring Machine. Eng vl59 Mar

30 1945 p 246-8. A new type of vertical measuring machine is described in which no multiplying devices are employed, the actual movement of the measuring contact be- ing read directly by means of a microscope. Its normal

capacity covers measurements from zero to 4 in., the read- ing being made directly to within 0.00005 in. and by esti- mation to 0.00001 in. For consistent and accurate readings, temperature control is necessary. The main scale is engraved on a block of glass and a graticule scale gives readings to 0.01 in., a micrometer scale, visible in one half

of the microscope field, giving the figures in the next 3 decimal places. Das Komparatorprinzip und sein optisches Aequivalent, K. RAEXTSCH. Optik v2 n3 Aug 1947 p 235-42. Principle of comparator and its optical equivalent; Abbe's comparator principle applied to sliding gage, micrometer

screw and apparatus for longitudinal measurements; de- scription of "Zeiss" apparatus built on Eppenstein's opti- cal principle ; photographs, diagrams. Improved Ultramicrometer According to Dowling's Method, G. GUSTAFSSON. Aeronautical Res Inst Sweden— RSAB (Roy Swedish Air Board—Translation n6) 1948

6 p. Principles of length measurement by determining

variations in capacity from corresponding changes in anode current of electron tube ; though requiring only one tube and very simple components this type of ultra- micrometer offers comparatively high degree of sensitivity and shows good reproducibility ; design details and sensi- tivity data. English translation from Ann Phys 1935. Zeiss Measuring Machine. Machy (London) v75 nl908 May 19 1949 p 660-2. Standard of reference and optical compensating system employed on new 2m measuring

machine. Abstract from BIOS Report No. 1809. Der Perflectokomparator (The Perflectocomparator )

, R. SCHULZE. VDI Zeit v93 n2 p 41-4 Jan 11 1951. Very

accurate measuring instrument for calibration of gages and workpieces. Very wear resistant ; photographs, dia- grams.

Micro-Inch Micrometer of One-Tenth Inch Range, E. B. BAKER. Rev Sci Instrum v22 n6 June 1951 p 373-5. It

is pointed out that many instruments exist which will magnify small displacements to almost any degree desired but always at expense of range ; while micrometer screw is notable exception, it does not give electrical output

construction details of device which combines lever, mi- crometer screw, sensing element, and servomotor to achieve

desired purpose. Machine for Testing Dial Gauges, D. C. BARNES, C. BARNETT. Engr vl98 n5150 Oct 8 1954 p 496-7. Continuous machine developed at National Physical Laboratory to speed up testing of gages and to give more detailed record of their errors ; if errors are present, they are shown by movements of indicating pointer, and magnitude

of errors may be observed by relation to two fixed refer- ence lines. Communication from NPL.

107
New Comparator for Measuring Pitch Errors of Root Ser- rations on Gas Turbine Blades, L. W. NICKOLS. Machy

(London) v86 n2218 May 20 1955 p 1085-8; Aircraft Prod

vl7 n6 June 1955 p 212-4. New comparator constructed at National Physical Laboratory measures pitch of pressure

flanks of serrations, and may be easily adapted to measure

pitch of centers of grooves ; principle of operation ; workholder, turret, setting fixture and other components de- scribed; setting and operating comparator. Gerat fur die Priifung von Zeigerlehren (Apparatus for the Testing of Dial Gages). Feingeratetechnik v5 nlO p

436-7, 471. In the National Physical Laboratory, Teddington, a continuous working apparatus was developed, which makes possible a quick calibration of dial gages. Some Instruments Developed Recently by Carl Zeiss, Jena. Machy (London) v89 n2291 Oct 12 1956 p 851-4. Instruments described include large toolmakers' microscope, 3-meter capacity length measuring machines, Zeiss recording hob testing machine, and electrolytic polisher, which incorporates microscope whereby progress of polish- ing operation can be observed. A Critical Evaluation of High-precision Electromechanical Linear Measuring Systems, F. BROWER. Elec Mfg

Aug 1957 p 128-41 28 figs 8 refs. Summarizes the advantages and limitations of commercially tried approaches to closed-loop machine tool position-measuring, some conventional, some off-beat and some proprietary, with a frank discussion of the accuracy, linearity, resolution, and

sources of error of each. Untersuchungen an handelsublichen Feinmessgeraten, D. LOBELL. Werkstattstechnik und Maschinenbau v48 n2 Feb 1958. Gives results of experiments relative to the de- pendence of measuring force on measuring travel; the

relationship between measuring force and scatter of mi- crometer instruments ; also result from rambles. Technische Feinmessgeriite, Weg und Ziel ihrer Gestaltung

(Technical Fine Measuring Equipment, Manner and Aim

of Their Design ) , H. PLESSE. Fourth Res and Construction Colloquium. Mach Tools and Factory Sci, Munich

vl p B67 Oct 6-7 1959. Electronic equipment, independent or as construction elements. The article gives a specific description of electronic fine measuring equipment

with a classification according to the different methods of work, whereby single processes are accurately set forth. Technische Feinmessgerate, Weg und Ziel ihrer Gestaltung

(Technical Fine Measurement Apparatus, Manner and Aim of Their Design), H. SCHORSCH. Fourth Res

and Construction Coloquium. Mach Tools and Factory

Sci, Munich vl p B63 Oct 6-7 1959. Recently the economy

of measurement has been added to the previously deter- mined technical viewpoints as to the design of measuring

apparatus. Proceeding from this the necessary measuring

times and automation are simultaneously investi- gated as to the relative positions of absolute and comparative measuring equipment and the action of these rela- tive changes appraised on the future relative positions of

single and multiple purpose equipment. Komparatorsystem und Werkzeug Maschine ( Comparator

System and Machine Tools), K. RANTSCH. Fourth Res and Construction Colloquium, Mach Tools and Factory

Sci, Munich vl p B55 Oct 6-7 1959. The comparator

principle in its classical form is in general not satisfac- tory with machine tools. A few possibilities for the less- ening of measuring errors of the first order with length measuring machines are presented. Finally its translation to machine tools is discussed, and indeed takes place

for machines with which the workpiece may be measurably shoved in one direction as well as for such with which the measurable displacement is in two crossed

directions. The described knowledge may give stimulation for the measuring technique of practicable equipment

of modern machine tools. Length Measurement Using Dynamic Technique, R. G. N. HALL, V. W. STANLEY. Machy (London) v97 n2502 Oct 26 1960 p 959-64. Principle of linear measurements

as function of time which is of particular value where dynamic calibration of scale or machine is required

description of apparatus and of technique which has many applications; its use in calibration of particular lathe which has servo-control system, using grating as reference scale. SIP Type CLP-10 Photo-electric Longitudinal Comparator, A. W. ASTROP. Machy (London) v99 n2554 Oct 25 1961 p 944-62. Details of new length measuring and

comparing equipment of outstanding accuracy and design

recently developed by Societe Genevoise d'Instruments

de Physique, Geneva, Switzerland; theoretical metrology on which instrument is based ; mechanical, electrical and

optical design features; special premises which are re- quired to house comparator and its associated equipment. What Makes a Good Gage Block Comparator? J. H. WORTHEN. Quality Assurance vl nl Oct 1962 p 45-7. Discusses gage block calibration, repetitive accuracy, test technique, calibration accuracy, and other considerations. Slow-Motion Micrometer Drive, F. R. TOLMON. Machy

(London) vlOl n2607 Oct 31 1962 p 1016-7. Prototype

"4-in. drum" micrometer with slow motion drive developed by NPL in Great Britain ; design and operation of instru- ment which has now been in constant use for more than

year for calibrating various types of displacement sensi- tive devices of high magnification and short range ; graph shows result of calibration of pneumatic measuring system

using slow motion micrometer drive. A Slow-Motion Micrometer Drive, F. R. TOLMON, NPL. Mach Shop Mag v24 nl Jan 1963 p 35-7 2 figs. Designed

for calibration of displacement sensitive devices. Vertical Type Comparator for Measurement of End

Standards, P. HOLMES, E. R. HARRISSON. Microtecnic vl7 nl Feb 1963 p 8-14. Illustrated description of in- strument constructed at Defence Standards Laboratories,

Australia, for measurement of end standards up to 40 in. long ; measuring head employs electromagnetic pickup which is rigidly connected to datum platen ; special atten- tion was given to reduction of heating effects due to pres- ence of observer; discrimination of instrument is 0.1/iin.

method used to calibrate instrument is described. A New Instrument for Measuring Radial Internal Clear- ance of radial ball bearings, S. AOKI, M. YOSHITSUGU.

Bull Japan Soc Prec Eng vl nl Oct 19«3 p 9-12 10 figs. Contents : causes of errors involved in conventional measuring methods and methods for minimizing such errors

GML's proposal ; development of the new instrument. 3.6. Manual Measuring Tools

3.6.1. General

Small Instruments of Measurement, J. HORNER. Cassier's Mag May 1905. Illustrates and describes various

small instruments of precision, giving some account of the care needed in their manufacture and their uses.

Note sur Quelques Jauges et Calibres (Notes on gages and measuring appliances), G. RICHARD. Rev Mecanique vl9 n2 Aug 1906 p 124-51 65 figs. With illustra- tions of a variety of micrometer and vernier cali- pers, and a discussion of precise measurements in the

shop. 108
Calipers and the Art of Calipering, F. A. STANLEY.

- Am Maeh v30 Mar 7 1907 p 327-62. Contributed and

- editorial articles dealing with various phases of the

subject.

: Evolution of the Spring Caliper. Am Mach v30 Mar 7 1907 p 327-8. Some interesting particulars regarding

-• this tool. Aids in Setting Calipers to a Steel Scale. Am Mach v30 Mar 7 1907 p 358-9. Accurate results obtained by means

j of adjustable stops on steel scales for setting calipers. The Side Play of the Calipers. Am Maeh v30 Mar 7 1907

p 359-61. Making allowances when boring holes for running, shrink, and press fits. au ,

to Gages and Interchangeability in Small-Scale Manufac-

;i ture, F. A. HALSEY. Am Mach v32 June 10 1909 p 960-1.

Illustrates and describes applications of the indicating beam caliper, explaining its advantages.

a- j 23 New Machinists" Tools. Am Mach v32-l June 3 1909

nd p 943-4 10 figs. Describes machinists' tools brought out

- recently by the Brown & Sharpe Mfg. Co., including a

*i universal surface gage, tempered steel rules with beveled

" edges, tempered steel rules with figure graduations, test indicator, tubular inside micrometer gages, height gage * attachment, heavy micrometer calipers, improved tool- makers' clamp, hardened square with beveled edges, and

heavy automatic center punch.

E j

; Measuring Tools. Machinery's Reference Book n21 1910. History and development of standard measurements

calipers, dividers, and surface gages ; micrometer measuring instruments, miscellaneous measuring tools gages. *:

'

- - Height Gages for Inspecting, A. C. LINDHOLM. Machy

' N.Y.) vl7 Sept 1910 p 51-2 2 figs. An indicating height

0» gage having two columns is shown in Fig. 1. An instru-

: ment for measuring the height gage settings is shown in

Fig. 2, which consists of a vertical series of notched size

; blocks and a micrometer suitably mounted on a base. m

Pioneer Steps Toward the Attainment of Accuracy, L. D. BURLINGAME. Am Mach v41 Aug 6 1914 p 237-43.

;^ I Work done at Brown & Sharpe plant in developing accurate machinists' tools including standard rules, wire gages,

cylindrical and caliper gages, and micrometer calipers.

-

I Also machine tools and shop methods.

Aji Exact Method of Setting Dividers. A. L. CONATY.

Machy (N.Y.) v25 May 1919 p 859. Describes vernier

caliper provided with holes for setting calipers.

tap i Shop Use of Octaval Notation in Shop Measurements, A.

.1 WATKINS. Meoh Eng v41 Nov 1919 p 870-1 and 905

4 figs. Advocates adoption of octaval notation to denote

British binary inch fractions in workshop and on workshop measuring instruments. Octaval rule, simple vernier calipers, double vernier calipers, single-screw micrometer, and two-screw micrometer using octaval notation

i?- t are described and discussed. Use of Precision Balls for Accurate Measurements, R. L. RANKIN. Machy (N.Y.) v26 Nov 1919 p 236-8 6 figs. Machy ( London ) vl5 Nov 27 1919 p 273-4 7 figs. Practice

of U.S. Bureau of Standards in use of precision balls as attachments for machines and for taking direct measure- ments in inspection of gages. Xew Precision Measuring Device. Machy (N.Y.) v27 Mar

1921 p 657-8 2 figs. Device for measuring within hundredthousandth part of an inch by use of only six precision measuring blocks, designed by B. M. W. Hanson, Hartford,

Conn. Sliding parallels actuated by micrometer.

Steel Balls as an Aid in Measuring, R. H. KASPER. Am

Mach v54 Apr 21 1921 p 696-7. Describes applications in finding center line of hole, locating position of hole, measuring depth of hole having rounded bottom, measuring

thickness of bushing wall, measuring thickness of double concave web. Schoop "Out Slide Mikes" for Measuring Diameters. Am

Mach v58 Mar 22 1923 p 462. A tape having special grad- uations and vernier, which is wrapped around the object whose diameter is to be measured. Modern Precision Measuring Instruments, W. L. WHIT- MARSH. Army Ordnance v4 May-June 1924 p 381-4, 400

8 figs. Describes standard types, including micrometer

caliper, vernier calipers, vernier beivel protractor, fluid gage, etc., and their functioning and use. Zeiss Fine Measuring Tools. Machy (London) v26 Apr

30 1925 p 144-8 12 figs. Describes measuring tools placed on market by Carl Zeiss, Jena, Germany, including depth

gages, micrometers, dial indicator, passameter twist drill gage, geartooth caliper, and optical dividing head. See

also p 334. The Development of Automatic Measuring Devices and the Use of Optical Methods, E. BUCKINGHAM. Am Mach

v69 nl8 Nov 1 1928; ASME Trans v51 n4 Jan-Apr 1929 p 5-6. Development of Measuring Devices, Primarily Manual,

J. A. HALL. Machine-Shop Practice (ASME Trans) v51 n4 Jan-Apr 1929 p 13-6 and discussion 16-7. History of development of devices for making linear and angular measurements ; go and not go gages ; length standards

Johansson and Hoke gage blocks ; use of comparators

difficulties in fine measurements ; discussion by E. Oberg

covered practical use of measurements. Am Mach v69 nl8 Nov 1 1928. Circumstantial Evidence from Hairs and Fibers, C. A. MITCHELL. Chem and Industry v49 May 30 1930 p

451-4. For purpose of evidence in criminal courts, it is necessary that any evidence given should be capable of

verification ; very useful measuring instrument is Kew

micrometer; for accurate measurement of width of hairs and fibers, Zeiss standard measuring glass with glass mi- crometer in circular or linear measurements will be found

trustworthy ; identification of isolated hairs ; distinctive human hairs ; hairs of animals ; fibers of furs ; vegetable

fibers. Grundlagen, Mittel und Beispiele zweckmaessiger Werkstattmessverfahren, T. DAMM. (Berichte ueber betriebs- wissenschaftliche Arbeiten. bd. 6.) Berlin. VDI Verlag, 1931 31 p Illus. Principles that underlie various measuring instruments used in machine shops, accuracy of these instruments and proper methods of using them. Eng. Soc. Library, N.Y. "Crescent" Tape-Rule. Am Mach v74 June 25 1931 p 997. This 6-ft. tape-rule has an accurate steel tape that auto- matically winds into a sturdy case 2 in. in diameter and

yet when completely withdrawn is rigid because it is of tempered steel, stiffened by special forming. The rule is nickel-plated and has prominent dark markings in inches

to 16th for the No. 696, and in lOths and lOOths of a foot (engineers' measure) for the No. 696D. The rule blade

is returned automatically by pressing the center button. Stanley Flexible Rigid Steel Rules, Stanley Rule and Level

Plant, New Britain, Conn. Am Mach v76 May 19 1932 p

656. These pull-push rules with a 6-ft. steel blade, coiled

in a watch-size case, are graduated in sixteenths. The

rule is a concave steel strip that may be bent as desired and yet is ordinarily rigid. 109
Messen von Bohrungen, G. BERNDT. Werkstattsteehnik

v28 nil June 1 1934 p 217-9. Shortcomings of fixed bor- ing calipers with respect to control of forms and their

efficiency ; for this reason they are supplanted by test indi- cators and micrometers; fundamental design principles; advantages and disadvantages. Beitraege zur Bestimmung der Masse von Rachenlehren,

G. BERNDT. Werkstattsteehnik und Werksleiter v29 nl8 Sept 15 1935 p 359-63. Contribution to determination

of dimensions of micrometers ; rules for design and shaping of micrometers and test calipers. Improved Equipment for Toolroom. R. HARRIES. Machy

(London) v64 nl647 May 4 1944 p 477-83. Illustrated de- scription of some designs for measuring equipment and

methods of construction ; extending range of micrometer

built-up sine bar ; radial setting arms ; vernier height gages from steel rules ; bench micrometers for long measurements.

Precision Instruments and Their Application, J. TITSGH.

Technique vl9 n6 June 1944 p 390-3. Discussion of cali- pers, micrometers, verniers, indicators and other com- mon precision instruments.

Size Control. Automobile Engr v34 n454 Oct 1944 p 397-

400. Reasons for use of end standards are discussed, with

special reference to end standards produced by Fitter Gauge and Precision Tool Co. ; description also given of two devices developed by this Company, stick micrometer

for internal measurements and Universal Measuring

Block.

Braille Instruments Aid Blind Inspectors. Iron Age vl57

n21 May 23 1946 p 56-7. Brief description of special braille marked gaging instruments developed in Great Britain as aid to rehabilitation of war wounded ; instruments now

available include vernier calipers and height gages, and

micrometers reading to 0.0001-in. ; operating and setting procedures explained. Pitch-Checking Instrument and Micrometer Slip Gauges. Eng vl68 n4367 Oct 7 1949 p 380. Matrix screw thread

pitch checking instrument and set of slip gages for checking micrometers, known as "Matrix Mikechex" introduced by Coventry Gauge & Tool Co. Srodki Zwiekszajaco Dokladnosc Odczytan na Wzorcach

Kreskowych, A. TOMASZEWSKI. Mechanik vl22 nl2 Dec 1949 p 461-3. Means of increasing accuracy of linear

scales ; diagrams. Know Your Measuring Tools, H. E. LINSLEY. Am Mach

v95 n7 Apr 2 1951 p 101-12. Common measuring tools used

at bench, layout table and machine, are discussed ; scales and tapes ; simple and vernier calipers ; micrometer cali- pers ; squares and protractors ; height and surface gages

miscellaneous gages ; how to read vernier and micrometer. Common Gage Types, R. H. WILCOX. Mill & Factory v51

n2 Aug 1952 p 97-101. Details of main gaging devices cur- rently in industrial use ; with exception of pneumatic, elec- tronic and electrical ; rules and tapes ; calipers ; height, depth, and surface gages ; micrometers ; thread gages. Linear Measurements—Instruments & Apparatus. ASME

Power Test Codes PTC 19.14 1958 Supp ASME, New

York, 1958 14 p. Types of instruments and methods of

linear measurement likely to be required by ASME Power

Test Codes; instruments which determine their range of

application. A Set of Measures and Instruments for Mobile Automobile

laboratories, B. N. VORONTSOV. Meas Techns 1959 nil

Sept 1960 p 849-51 2 figs. Translated from Izmer Tekh nil Nov 1959 p 13. Describes a set of measuring devices con- veniently portable and especially suited for mobile laboratories. These are designed for checking universal linear measuring instruments, instruments for measuring the hardness of metals, and for checking dial inside calipers. , Universal Measuring Block, R. D. PURVIS. Machy

(Lond) vl03 n2662 Nov 20 1963 p 1154-7. Equipment j described, meeting requirements of accuracy and also those of full utilization of instrument, consists basically of block of close grained cast iron which has accurately ma- '! chined central vees and locating pads on base, sides and

ends ; these pads allow block to be set in any of 5 positions while maintaining squareness, parallelism and symmetry

with central vees to high degree of accuracy ; applications ; . indicated ; equipment was found to be extremely useful for j . toolroom and experimental machine shop applications.

Classification and Comparison of Measuring Instruments,

T. BUSCH. Tool & Mfg Engr v54 nl Jan 1965 p 53-5. Tabulation of linear measuring instruments ordinarily used in manufacturing gives range, precision, sensitivity linearity and reliability for scales, vernier, micrometer, gage blocks, indicators, comparators, flat and squares. 3.6.2. Micrometers

i

1 New Brown & Sharpe Measuring Instruments. Iron xVge tj i Sept 27 1900. An illustrated description of micrometer

calipers and gages. The Use of Micrometer Calipers for Regular Machine Shop Gages, J. T. SLOCOMB. Am Mach v24 May 2 1901 p 494-5. An illustrated article explaining the uses made 5j [ of the micrometer caliper in the machine shop. New Micrometers, W. WEICHOLDT. Zeit InstrumKde I 1 v6 Mar 15 1902 p 53-5. These are made with wheel and ! i lever motions, and the length is given by the reading of a pointer on a circular scale, the instruments reading di- j, J rectly to from 0.02 mm to 0.0001 mm.

i Periodic Errors of Micrometer Screws, H. ROSENBERG. '< [ Zeit InstrumKde v22 Aug and Sept 1902 p 246-54 and I » 269-75. Mathematical treatment. Instruments de Mesure de Haute Precision (Measuring | Instruments of High Precision), A. GALASSINI. Rev I'i g Mecanique vl3 July 31 1903. Especially describing the \ j micrometers of Bariquand and Marre, as adapted for j j precise measurements in the workshop. Micrometer Gages, A. L. MONRAD. Am Mach v26 [ p Oct 29 1903 p 1524-6. Convenient tools described, includ- t

fl ing micrometer surface gage, micrometer height gage and i 5 micrometer beam caliper. The Improved Electric Micrometer, P. E. SHAW. Proc Roy Soc A v76 Aug 4 1904 p 350-9. Limit to its practij j cal sensitiveness (4X10-8 cm) has been reached. States 1 \ in detail the form, peculiarities, and limitations. First j

[j used to measure the amplitude of a telephone diaphragm, i i Some Micrometer Measuring Instruments, A. L. MON- 1 f RAD. Machy (N.Y.) vll Sept 1904 p 41-4, Illustrated

j >| description of the writer's own designs of micrometer | j surface gage, micrometer square, micrometer lathe tool, , small inside micrometer, micrometer depth gage, and

micrometer lathe stop. A New Type of Micrometer, W. C. DURFEE. Harvard [ J Eng June 1906. Describes what is called a rolling lens * micrometer and its chief merit is said to be its ease of [

" manipulation. Accuracy of Modern (Optical) Micrometers, M. D.

j EWELL. Proc Am Phil Soc v46 Jan-Mar 1907 p 187-90.

j J Eight modern scales on glass by different makers have i been compared, and two older ones (of 25 years ago). No

[j 110
advance in precision is shown, the results not even equalling those of the early period. Exceptionally good re- sults are, however, shown by a glass scale by Leitz and a photograph by Moller. On the other hand the maximum

4- and — divergence in a glass scale by Watson is 4.6/i in

0.1 mm, and in one by Bausch and Lomb 2.8/i. Some Gaging and Measuring Methods in American and

British Shops. Am Mach v30 Mar 7 1907 p 328-32. Large micrometers and other calipers ; their use by inspectors and machinists ; gaging big work. Standard Gages and Micrometers in the Shop. Am

Mach v30 Mar 7 1907 p 332-^. Micrometers of special design are illustrated. Discussion regarding fits. Micrometers. Am Mach v30 Mar 7 1907 p 351-6 361-2. Early history of the micrometer caliper; calibration of two Brown & Sharpe micrometer screws ; a micrometer made in a Chinese shop,- the use of micrometer calipers for regular shop gages, some modern micrometer calipers. Radius Micrometer, W. A. FARRAR. Machy (N.Y.) vl4

Sept 1907 p 56-7 5 figs. Two forms of radius micrometer

for setting turning or boring tools are described. Two

micrometer heads are so mounted that the ends of the

spindles just coincide with the axial line joining the centers when the barrels register zero. Micrometer Attachment for Reading Ten-thousandths.

P. L. L. YORGEXSEX. Machy (X.Y.) vl4 Feb 1908 p 399. Disk mounted on barrel having 250 graduations.

Sensitive Indicating Micrometer. Machy ( X.Y. ) vl5 Sept

1908 p 31. Uses a mercury column in a glass tube and

supported by a diaphragm as an indicator. An Electro Micrometer. G. J. MURDOCK. Am Mach v32 Dec 16 1909 p 1025-7. Illustrated description of a tool for accurate measurements, general testing, and comparison.

Especially adapted for obtaining accurate measurements

of the inside diameter of bushings and other work when

held in a chuck, where the hole is so small that the com- mon inside micrometer cannot be used. Ball Point versus Anvil Type Thread Micrometers. Machy (X.Y.) vl6 Mar 1910 p 564 3 figs. Points out that the anvil type detects drunken threads whereas the ball type does not. Plant Inside Micrometer Caliper. Machy (X.Y.) vl7 Xov

1910 p 237-8. A set of two inside micrometers for meas-

' urements from % to 2 in., each of which is provided with

I handle perpendicular to the micrometer axis which may

be rotated to lock the setting of the instrument. Some Uses of the Micrometer, G. W. BURLEY. Mech Wld Feb 23 1912. Explains the value of this precision

tool and describes uses to which it can be applied. An Electric Micrometer. B. THIEME. Zeit InstrumKde

v32 Oct 1912 p 322-5. A fine micrometer screw is mounted

on a rigid frame and can be rotated by gearing. Readings

of O.l/i can be obtained. Electrical contact is employed

using a galvanoscope as indicator. Slocomb Direct-reading Micrometer. Machy (X.Y.) v21 Dec 1914 p 326-7. Micrometer caliper for measuring the

size of wire, having a deep frame provided with a disk

dial at the end of the thimble on which the size of wire is given in steel wire gage, decimal equivalent of an inch, and iron wire gage. Howe We Came to Have the Micrometer Caliper, L. D. BURLIXGAME. Machy (X.Y.) v21 June 1915 p 778-88. Development of fundamental principles and improved

features.

How We Came to Have the Slocomb Shop Micrometer,

J. T. SLOCOMB. Machy (X.Y.) v21 Aug 1915 p 999-1000. Account of the designing of the micrometer caliper. Common and Special Micrometer Calipers, F. SERVER.

Machy (X.Y.) v21 Xov 1917 p 231-5 16 figs. Describes and illustrates tube micrometer, thread comparing mi- crometer (cone anvil and spindle), plate micrometer, paper micrometer, ball anvil-micrometer with relieved frame, heavy type micrometer, micrometer with inter- changeable anvils for large work, beam micrometer, mi- crometer for measuring three-sided piece, micrometers

with special points, depth micrometers, thread micrometer. The Micrometer Head in Tool Work, H. F. PUSEP. Am

Mach v48 Jan 10 1918 p 59. Cites examples of lathe work, measuring equipment for the milling machines, boring a

jig leaf, etc. Ten applications are illustrated. Ball Point Attachments for Micrometer, G. C. HAXE- MAX. Machy (X.Y.) v25 Mar 1919 p 645. Describes some methods of attaching balls to the contact points of micrometers. Micrometer Height Gage, H. KIEHXE. Am Mach v51 Aug 7 1919 p 258. The Effect of Finger-Heat upon the Micrometer Gauge,

L. PYLE. Sci Am Supp v88 Sept 20 1919 p 185 3 figs. Illustrates right and wrong ways to handle a micrometer

caliper and gives curve showing expansion with time as

the micrometer is held in the hand. The Davenport-Slocomb Direct Reading Micrometer. Am

Mach v52 Mar 4 1920 p 528-9. Counting wheels are mounted on a sleeve that runs concentric with the spindle. Reads from 0 to 999 thousandths.

Brinnell Indentation Micrometer. Am Mach v52 Apr 29

1920. A micrometer for measuring the diameter and

depth of the indentation made in applying the Brinnell

test. As may be noted from the illustration the instru- ment will register both horizontal and vertical measure- ments as separate graduations are provided. The dimensions of the impression can be read to 0.01 mm and the hardness value quickly determined by reference to tabulated data. Testing the Accuracy of Micrometers in Common Use, C. A. HUBBELL. Am Mach v53 July 29 1920 p 209-10. Sum- mary of results of test carried out on large number of micrometers in commercial use. Ueber die Messgenauigkeit von Schublehren und Mikrometern (The Accuracy of Sliding Gages and Micrometers),

O. KIEXZLE. Werkstattstechnik vl4 Aug 1 and 15 1920 p 426-8 and 442-5 13 figs. Points out that faults occur- ring in all measuring instruments are inaccuracy of construction, wear and tear on measuring surface, faults due

to different temperatures, to different pressure when

measuring, and to faulty readings. Xormung der Mikrometer (The Standardization of Micrometers), R. P. SCHRODER. Betrieb v3 Xov 25 1920 p 97-100 4 figs. Discusses gradation of size, accuracy, and

gap. Xotes on limit gages. Bath Internal Micrometer and Master Ring Gages. Am

Mach v54 Mar 31 1921 p 578-9. Micrometer is provided with four jaws fitted to inclined dovetail grooves in the body, and movement of the jaws is controlled by an accurate micrometer screw. Bath Micrometer Plug Gage. Machy (X.Y.) v27 Apr

1921 p 795-7 5 figs. The gage has four measuring jaws

provided with true cylindrical contact surfaces and held

in perfect alignment with the sliding member by means

of closefitting dovetailed slots. The measuring jaws are 111
expanded or contracted when the slide is moved back and

forth through the operation of a micrometer screw. It is claimed that, as the movable jaws fit tightly in the dovetailed grooves of the slide and are controlled by an accurate screw without backlash, an instrument is obtained which is as rigid as a solid plug. Die Aufbiegung von Schraubenmikrometern (The Spreading of Micrometer Frames), G. BERNDT. Betrieb v3 June 25 1921 p 574-81 12 figs. Results of experiments with a number of screw micrometers by different firms. Formula for calculation of semi-circular frames. Tables

of permissible amounts of spreading of frame and

weights for rectangular cross-section frames. Checking the Accuracy of Micrometer Measurements, E. SHELDON. Am Mach v55 Oct 6 1921 p 562HL. Notes on

close measurements with micrometer ; possibilities of error due to mechanical defects. Genauigkeitsanspriiehe an Mikrometer und Fiihlebel (Ac- curacy Requirements of Micrometers and Lever Gages),

G. BERNDT. Betrieb v4 Feb 11 1922 p 280-4. Relation between measuring and reading accuracy of screw micrometers. Suggestions for increasing accuracy of lever gages. Inside Micrometer and Height Gage (Comb.). Iron Age

vllO July 13 1922 p 84. Tool made by Reed Small

Tool Works. Combination set comprises a micrometer

head, adjusting wrench, 5 rods and % in. spacer for capacity 2 to 7 in., 5 additional 5 in. spacers, and height- gage base attachments of two different forms. Slocomb Inside Micrometer. Am Mach v58 Apr 5 1923 p 532b. Provided with an auxiliary cap for measuring

large diameters. Measuring Threads Accurately with Micrometers. Can Machy v«il May 1 1924 p 31-2 and 51 6 figs. Hints on

accurate use of micrometers. Proper Care Essential to Micrometer Accuracy. Can Machy v32 July 24 1924 p 25-6 6 figs. Hints on use and

care of measuring instruments. Slocomb Tube Micrometer. Am Mach v61 Sept 18 1924

p 480. Micrometer caliper of standard construction ex- cept frame is designed to support a stud extending at a

right angle to the spindle and forming the anvil. Mikrometer und Messapparate (Micrometers and Measuring Instruments), P. DUCKERT. Zeit InstrumKde v44

Oct, Nov and Dec 1924 p 443-53, 483-94, and 547-55; and v45 Apr 1925 p 176-85. A description, with numerous

illustrations and diagrams, of various types of micrometers. For a comprehensive treatment of the theory of the various instruments the author refers to the treatise by E. Becker in Valentiner's Dictionarv of Astronomy, 3, Sec 1. Brown & Sharpe Direct-Reading Micrometer No. 26. Am Mach v63 Oct 1 1925 p 567; Eng vl21 Jan 8 1926 p 60. Direct reading feature consists of a set of numbered dials which are actuated by the movement of the measuring screw through steel indexing gears. Wear of Micrometer Screws. Machy ( London I v27 Jan 14 1926 p 521-22 2 figs. Report of series of experi- ments made at Zeiss plant. Screw Thread Micrometer Calipers, H. BENTLEY.

Indus Mgmt (London) vl3 June 1926 p 261-2 2 figs. Application of micrometer calipers to measuring V-type screw threads. Brown & Sharpe No. 11 Micrometer. Am Mach v67

July 28 1927 p 173. Has enlarged opening in frame and

small size of the frame at its anvil end, designed to : measure odd-shaped pieces. The Meter-Inch Micrometer. Model Engr & Light Machv

Rev v57 Sept 1 1927 p 202-3 3 figs. Combination of : metric and inch micrometer instrument which as a whole -M

is considered accurate within satisfactory limits ; calibra- tion of screw for progressive error at intervals of 0.1 in. over its 1 in. of length showed it to be within 0.0001 of inch total, and within 0.003 mm by metric measure. Brown & Sharpe Nos. 90, 91, and 92 Micrometers. Am

Mach v68 Apr 26 1928 p 714. Combined range 12 to 24 in. Each tool is provided with four interchangeable anvils of - different lengths. Micrometer for Measuring Diameter of Quartz Fibers. Eng vl25 June 1 1928 p 655 2 figs. Capacity .020 mm.

Galvanometer serves as an indicator. Brown & Sharpe Micrometers. Am Mach v68 June 28 \ 1928 p 1063-4. Nos. 60 and 62 micrometer calipers, range S 1 to 2, and 2 to 3 in. Inside micrometer No. 276 provided j with 10 changeable anvils. Brown & Sharpe Blade-and-Disk-Anvil Micrometers. Am

Mach v69 Sept 27 1928 p 521-2. Special micrometers for i| measuring forming tools. Thin blades on the ends of anvil and spindle permit them to enter the narrow slots i and grooves of forming tools. Starrett No. 210 Micrometer for Comparing Screw ' Threads. Am Mach v69 Oct 25 1928 p 668. Lufkin Direct-Reading Micrometer. Am Mach v73 July ! !! 24 1930 p 187. This direct reading micrometer gives the j si total measurement without difficult and often incorrect ' i additions. This reading is shown at a glance by an in- genious arrangement of the figures on the sleeve. The 11 P hub markings are the same as on the regular type of micrometers. Hundredths of thousandths are indicated by j S a long line. The three shorter lines indicate 0.025, 0.050, i 1 and 0.075, and are arranged so that they appear as a I group of three. Mischker Square-barrel Micrometer. Am Mach v73 I I Nov 13 1930 p 796. Quick setting by means of a ratchet i I to within 0.025 in., and then final measuring by means of '] ji a graduated barrel, are features of this square-barrel '\ \ micrometer. The measuring stem with its square barrel

is removable and is intended for use with a set of frames -j I of varying sizes. The stem is provided with a short \ f thread sufficient for one complete turn or 0.025 in. move- [ ° ment. An inside stem is provided with the set. Neo-Mierometer. Eng vl31 n3413 June 12 1931 p 775 2 figs. Instrument is made in two forms, smaller instrument having range of from zero to 12 in. between gage points, j j and corresponding range for larger instrument being ( p from zero to 40 in. ; each can be used for both internal j f, and external measuring.

Starrett Thimble-Friction Micrometer Caliper. Am Mach j v75 Dec 10 1931 p 909-1. A friction-stop mechanism ' eliminates the inconvenience of reaching beyond the I 1 thimble to operate the stop. Since the stop disengages at ' • exactly the same pressure each time, the operator is as1 I sured of uniform contacts. Range of the instrument is 0 to 1 in. by thousandths or, for an extra charge, by i j ten-thousandths.

Starrett Micrometers with Tungsten-Carbide Tipped An- ; vil and Spindle. Am Mach v76 Jan 28 1932 p 150. The , anvil and spindle of micrometers are now available with [ facings of cemented tungsten carbide to give greater wear resistance. The frame is cut away to facilitate use 112
in places where

inserted. the ordinary micrometer cannot be Brown & Sharpe Micrometer Calipers with T. C. Surfaces. Am Mach v76 June 23 1932 p 800. Micrometer calipers

(1-in. size) in several styles have the ends of the spindle and anvil faced with tungsten carbide, useful where the micrometers are subjected to unusual wear. Laengenmessung mit Schraublehren, G. BERNDT. Archiv

fuer Technisches Messen v2 nlo Sept 1932 p T137 (2 p). Principal factors contributing to errors in length meas- urements with screw calipers. Starrett #700 Inside Micrometer Caliper. Am Mach v76 Xov 23 1932 p 1175. Dimensions between 0.200 and 1 in. can be measured directly in thousandths. The micrometer

combines the sliding jaws of a slide caliper and the easy reading thimble and sleeve arrangement of a micrometer

caliper. One jaw is fixed and the other is attached to the sleeve. Micrometers. Mech Wld vl04 n2712 Dec 23 1938 p 611-2.

Specification applying to micrometers having bow-shaped frame holding micrometer spindle and nut on one side opposite anvil on other with individual measuring ranges

of 1 in. to 11 to 12 in., and 25 mm up to 275 mm to 300 mm and to setting gages for micrometers above 1 in. or 25 mm. One of series of Brit Standards Instn. Specifications in course of production for engineers' precision

tools. Take Good Care of Micrometers. Mill & Factory v32 n3 Mar 1943 p 108-20. Tool craftsmanship charts pointing

out some of more common abuses to which micrometers

are subjected ; preventive measures. Improved Micrometer Allowing Lateral and Rotary Adjustment. Indus Power & Prod v21 n232 Feb 1945 p 90. New micrometer head comprises easily operated means

of locking thimble in new rotary and lateral positions on

spindle, after insertion of shim or shims between flange on spindle and internal flange on thimble. Micrometers and How to Use Them, G. W. DAWSON.

Motor Service July 15 1946 p 124, 154, 157, 218. Micrometer measurement reading and interpretation explained, including recommendations for care and handling. Multi-Purpose Micrometer. Engr vl82 n4729 Aug 30 1946 p 196. Brief description of new form of micrometer

introduced by E. H. Hones (Machine Tools), Ltd. designed

for use on wide range of work not adapted to measure- ment by standard type of instrument; consists of stand- ard micrometer barrel at base of sleeve on which is mounted block instead of usual frame. How to Read Micrometers and Verniers, J. FOSTER.

Power Generation v52 n3 Mar 1948 p 81-3. Instructions

for use of typical micrometer as used in machine shops

principle of operation ; English type micrometer ; metric

type micrometer ; vernier micrometer ; vernier caliper

universal bevel protractors. Measurement of Close Tolerance Parts. Matls & Methods

v29 n4 Apr 1949 p 79, 81. Method of correcting observed micrometer readings to obtain actual dimensions of part

of standard temperature (68 °F)

External Micrometers. Brit Stand Instn—BS n870—1950

19 p. Provisions for micrometers with measuring ranges

of 0 to y2 in. and from 12 to 24 in. (with their corresponding metric equivalents) ; requirements relating to micrometers with interchangeable anvils and various measuring

ranges up to 24 in. (600 mm)

Measurement of the Thickness of Capacitor Paper, W. SOUDER, S. B. NEWMAN. NBS Cir n532 10 p 1952.

The definition of thickness must be carefully analysed

before choosing an instrument for such measurements. Three methods are available: (1) by direct observation

across an edge section by means of a micrometer microscope, (2) by measuring the separation of two geometric

surfaces between which one or more specimens are placed, and (3) by determining the mass of a definite area of sample and computing the thickness, using the density parameter. Measurements have been made on some

commercial thin capacitor papers, using the interferometer, micrometer microscope, mechanical micrometers, and the surface analyser. These data have been analysed.

It has been found that the precision dial micrometer or the precision screw micrometer may be used for such measurements. The size and type of contact and the load to be applied will depend on the needs of the manufacturer and user of the paper. Micromaster. TESA, Ltd., Switzerland, Bui 28 Nov 1952

3 p 7 figs. Micrometer giving a partial digital readout with graduations on thimble and sleeves arranged side by

side. Longitudinal play is eliminated by use of differential screw threads. Micrometer with Setting Shown Numerically. Eng vl77 n4590 Jan 15 1954 p 87. "Micromaster" micrometer de- veloped by Tesa, Ltd, Switzerland, is similar to normal

micrometer, but divisions are more widely spaced and

setting is indicated by numerals. New Design of Height Gauge, H. A. CHIVERTON.

Machy (London) v87 n2235 Sept 16 1955 p 695-6. Gage

developed by author is based on micrometer principle in- stead of usual vernier scale, and affords number of advantages, including low cost of manufacture, and exceptional robustness ; design details. A Universal Test-Piece for Use with Micrometers of Throat over 100 mm, A. N. DOLGUSHEV. Meas Techns

1959 n2 Feb 1959 p 97-8 1 fig. Translated from Izmer Tekh n2 Feb 1959 p 14. A test piece having ball tips for checking parallelism of faces. Modern Measuring Instruments*—Electric and Electronic Gages, F. W. WITZKE. ASTME Tech Papers v60. book 1, paper No. 245. Electronic gage heads now pro- vide extreme precision and accuracy for standards labora- tory use. Performance specifications are listed. A Device for Checking Micrometers for Dimensions over

100 mm, YU. F. AKSYUK, YA. P. VOLOSIN. Meas

Techns 1959 n5 June 1960 p 311 1 fig. Translated from

Izmer Tekh n5 May 1959 p 9. The proposed device per- mits the checking of micrometers with a wide measure- ment range (over 100 mm) by means of length standards with the maximum size of the block equal to 25 mm,

thanks to the presence of an auxiliary adjustable stopper. Evaluation of the Measuring Efforts in Micrometer Instru- ments, A. I. SUVOROV. Meas Techns 1962 n4 Sept 1962 p 278-9 2 figs. Translated from Izmer Tekh n4 p 8-9 Apr 1962. Relates measuring effort to stability of mi- crometer readings and methods of its measurement. An Improved Precision Height Gage, L. B. VALE, Ames

Research Center. NASA SP-5001 Nov 1963 12 p 3 figs 4 patent refs. For sale by Office of Tech. Services, Dept.

of Commerce, Washington, D.C., 20230, price 50 cents. Describes a wedge parallel actuated by a micrometer which yields performance and accuracy superior to those

of previous devices. It may be accurately set to a desired height without auxiliary measuring devices, there is no

lost motion in the movement of the upper block, and the

resolution is improved. 113
3.6.3. Vernier Instruments

See also subsection 4.2 The Reading of Verniers. Am Mach v25 Apr 3 1902 p

474-5 5 figs. An explanatory article. The Reading of Verniers. Am Mach v30 Mar 7 1907 p

349-51 5 figs. Explains the reading of verniers. Inside and Outside Caliper Gage, H. E. CURTIS. Am

Mach v32-2 Nov 4 1909 p 786. A vernier beam caliper having inside measuring jaws. Vernier Height Gage, Machy (N.Y.) v23 Feb 1917 p 546. Slide Gage. Jeweler's Circular Jan 7 1920 p 143. A vernier

caliper having special features is described. Brown & Sharpe Nos. 465A and 465B Height Gage In- struments. Am Mach v69 Aug 30 1928 p 374-5. Die Genauigkeit der Ablesung an einem Nonius bei feinen Kreisteilungen (Exactitude in Reading of Vernier on Small Circular Divisions), K, LUDEMANN. Zeit In- strumKde v49 n5 May 1929 p 238-48. Tabulation of observations on reading with and without magnifying

glass ; summary of existing literature. Bibliography.

British Standard Specification for Vernier Calipers. Brit Stand Instn—BS Specification n887—1940 14 p. Specifica- tion applies to calipers, with internal and external measuring faces, and having ranges of measurement in inch

units up to 48 in., graduated to read 0.001 in., in metric

units up to 1 mm, graduated to read 0.02 mm, and in both

inch and metric units with above graduations. Choix et Determination d'un Vernier, A. LABORDE,

C. TURLAN. Technique Mod v38 n9-10 May 1-15 1946 p 106-11. Study of theory of vernier, its intervals and

method of observation; circular verniers; charts and

tables presented. Some Variables Influencing Vernier Acuity, I. Illumination and Exposure Time. II. Wave-length of Illumination, K. E. BAKER. J Opt Soc Am v39 p 567-76 July 1949. Functions relating vernier acuity to illumination have

been obtained for two different exposure times and at 3

regions of the visible spectrum. An apparatus providing

the necessary stimulus controls has been described in detail and the procedure is fully explained. Single Element Verniers Reading Two or Three Dimensions, R. E. LEWIS. Rev Sci Instrum v21 p 647-9 July

1950. By superimposing concentric radial elements on

rectangular co-ordinate rulings, vernier systems may be

constructed reading in two or three dimensions without

the necessity of any particular angular orientation. A

two-dimensional vernier may consist of one transparent element ruled with concentric circles. The observed tan- gencies of the circles, with regard to a rectangular grid placed in contact, provide the reading of the additional decimal of the co-ordinates of the fiducial centre of the

circles on the grid. A three-dimensional vernier system may be established by means of a binocular optical system

presenting images of spheres concentric with the locating point and images of co-ordinate boxes in the same space. The tangency of a vernier sphere and co-ordinate plane

indicates the last decimal of the reading. Angular orien- tation may be indicated by radial lines near the points

of tangency.

Precision Vernier Calipers. TESA, Ltd., Switzerland Bui

21 Feb 1951 4 p 15 figs. Discusses important factors in manufacture and use of vernier calipers, including accuracy of graduation, thickness of lines, errors of

interpretation, influence of the measuring pressure, deformation of beam and jaws, and objective and subjective

influences on measuring accuracy. Modernized Slide Gauge. L. D. SHCHUKIN. Meas

Techns 1962 nl June 1962 p 18 2 figs. Translated from

Izmer Tekh nl p 15 Jan 1962. Modified vernier caliper

for measuring internal dimensions. Making Parts for Vernier Calipers, P. A. SIDDERS.

Machy (London) vlOl n2604, 2606 Oct 10, 1962 p 800-8, Oct

24 p 924-32. Methods employed for production of new

instrument, type 600 calipers, developed by James Chester- man & Co., Sheffield ; it was designed to meet need for

relatively inexpensive calipers with acceptable standard

of accuracy ; operation ; induction hardening jaws ; grind- ing external measuring jaw ; finish broaching operation

milling operations on beam ; surface grinding operations

operations on triggers ; inspection trolley specially built to facilitate inspection work ; grinding ends of scales and

ends of depth gage blades. Chesterman-Sogenique Electronic Height Gauge. Machy

(Lond) vl05 n2706 Sept 23 1964 p 761-2. Gage described has dial indicator to ensure predetermined stylus pressure and digital indicating equipment ; it is designed to enable accurate measurements to be made rapidly, and to elimi- nate possibility of slight errors in reading instruments of vernier type. 3.6.4. Dial and Test Indicators

See also subsections 5.2.3 and 5.3 New Micrometers, W. WEICHOLDT. Zeit InstrumKde

v6 Mar 15 1902 p 53-5. These are made with wheel and

lever motions, and the length is given by the reading of a pointer and circular scale, the instruments reading

directly from 0.02 mm to 0.0001 mm.

The "Just It" Lathe Test Indicator. Machy (N.Y.) vl3 Dec 1906 p 225 2 figs. Pivoted-finger type of test indicator. Toolmakers Universal Test Indicators, J. D. STRYKER, Am Mach v30 Sept 19 1907 p 411-2 9 figs. A test indicator

of the plunger-pin type. Inspecting Tools with the Test Indicator, J. H. BOULET. Am Mach v30 Oct 17 1907 p 537-41, Nov 14 1907 p 773. Illustrates and describes a number of methods of testing and measuring various classes of tools by means of indi- cator of the author's invention. Dial Gages for Accurate Measurements. Machy (N.Y.) vl4 Dec 1907 p 264-5 3 figs. A Test Indicator and Some of Its Applications. Am Mach

v31 Aug 27 1908 p 303-5 9 figs. An instrument of plunger- pin type, for setting and testing lathe, miller, shaper, and

surface plate work. Made by Henry Koch and Son. Various applications are illustrated. Compact Form of Dial Indicator, L. HAAS. Machy

(N.Y.) vl5 Aug 1909 p 966-7. Plunger-pin type indicator using spiral and multiplying lever combinations. Dial Indicators. Zeit Practische Maschinenbau v45 1910 p 2059-60. A Novel Fine-Measuring Machine—"Hirth Minimeter",

A. GRADENWITZ. Am Mach v33-l Apr 14 1910 p 696-7

8 figs. Various adaptations of "Hirth" Minimeter for gaging are illustrated. Fig 1, the minimeter lever, pointer, and scale ; Figs. 2, 4, and 8, the minimeter mounted as an

amplifying comparator ; Figs. 3, 5, 6, and 7, the minimeter mounted to gage rings. 114
Automatic Micrometer Calipers. Mech Engr v26 Aug 26 1910 p 248-51 17 figs. Describes a series of dial micrometers, or auto calipers, made in England. A Test Indicator and Comparator. H. F. ATKINS. Am

Mach v34 Aug 31 1911 p 407-9 19 figs. Illustrated de- scription of a simple indicator of almost universal applicability. The principle on which the indicator depends is the magnifying of the movement of a plane surface by

transferring it to a roller, held between the movable plane and a fixed plane, and causing the roller to swing a pointer over a graduated sector. Test Indicators and Their Uses, G. W. BURLEY. Mech Wld Dec 1 1911. Explains uses to which they are applied and illustrates and describes types. A Universal Indicator. H. V. PURMAN. Machy (N.Y.) vl8 Jan 1912 p 341-2 4 figs. Diagrams and descriptions of indicator of pivoted-finger type, designed by F. A. Turner.

Test Indicator. Machy (N.Y.) vl8 Apr 1912 p 648-9. Pivoted finger type of indicator made bv American Watch

Tool Co. Universal Test Indicator. Machy (N.Y.) vl8 July 1912 p 898. Pivoted-finger type of indicator made by Alvan

Mfg. Co. Lowe '-Last Word" Indicator. Machy (X.Y.) v20 Mar

1914 p 610 2 figs. Fig. 1 shows Lowe test indicator carried on ball-joint toolpost shank ; Fig. 2 shows Lowe indicator mounted on the needle of a surface gage. Also Machy

(X.Y.) v22 Xov 1915 p 248 3 figs. Contact point is pro- vided with a friction joint at the pivot. Toolmakers' Test Indicator, D. BAKER. Machv (X.Y.) v23 Xov 1916 p 246-7 3 figs. Pivoted finger type of indi- cator designed by Warren Dunbrack. Ausbau der Fiihlhebelmessung (Development of Lever- Gage Measurement), M. KURREIX. Werkstattstechnik

vl6 Oct 15 1922 p 613-6 8 figs. Describes new measuring

tools of the Fortuna Works, Stuttgart-Cannstatt, Ger- many, exhibiting at Leipzig Exhibition. A Study of Commercial Dial Micrometers for Measuring

the Thickness of Paper. P. L. HOUSTOX. D. R. MILLER.

Tech Papers XBS n226 Dec 29 1922 p 125-52. For abstract

see Subsection 5.4. Federal Micrometer Dial Gage. Am Mach v58 Apr 26 1923 p 643. See also p 889. Consists of a bench stand for holding dial indicator at any desired angle and a pair of micrometer jaws. Federal Dial Indicators. Models D and DD. Am Mach

v58 June 14 1923 p 889. Show 0.04 in. per revolution. D-10 -'Last Word" Test Indicator. Am Mach v61 July

31 1924 p 211. For specially accurate work. Range 0 016

in. Magnifies 300 times. Toleranzmesser, Flachen und Winkelpriifer (Tolerance Measurer, Surface and Angle Measurer). W. EWALD.

Deutsche Opt Wochenschrift vl2 n36 Sept 1926 p 466 4 figs

vl2 n34 Aug 1926 p 441 1 fig. Describes mechauical indi- cating instrument for measuring thicknesses and angle deviations. Produced by Askania. A Convenient Indicating Device for Dividers, Calipers and

Compasses. Instrum vl Mar 1928 p 165-6 1 fig. Device

designed to eliminate tiresome and slow operation of tak- ing measurements directly from scale or rule ; disk is grad- uated in Vtn and %oo in-; dial performs function of ver- nier ; can be provided with dial for direct indication of any

desired units.

Ames Dial Micrometer. Am Mach v72 Feb 6 1930 p 281. Easier reading to thousandths by means of widely spaced

dial graduations is the chief feature of this dial indicator micrometer. Two dials are employed. The smaller indi- cates the revolutions of the larger pointer, each graduation

of the small dial representing 0.1 in. The large dial has

100 widely spaced graduations around the dial, each rep- resenting 0.001 in. The range is to 1 inch. By operating

the spindle lock, the tool may be used as an adjustable snap gage. Apparatus for Measurement of Very Small Displacements, H. WHITAKER. J Sci Instrum v8 n8 Aug 1931 p 251-8

6 figs. Apparatus consisting of accessory device, which

can be fitted to standard type of microscope ; method consists in using fine quartz pointer as lever which multiples small displacement to be measured. Japanese Scientists Develop Simple Optical Indicator, P. X. HELDT Automotive Industries v70 n26 June 30 1934 p 813-4. Details of optical indicator developed by F. Nakanishi, M. Ito, and K. Katamura.

Frictional Forces in Dial Gauges, C. F. BRUCE. Eng

vl67 n4335 Feb 25 1949 p 169-71. Investigation of "sticki- ness" in movement of plunger on anvil of gages for dial indicators of type which are mounted on surface gage and

used mainly for leveling of surfaces ; frictional forces in gage may amount to as much as 50% of max operating

force on gage, as measured when gage is lightly tapped

photographs, charts. How to Get Your Money's Worth Out of Dial Indicators,

I. A. HUXT. Am Mach v93 nl2 June 12 1949 p 93-100. Construction and maintenance recommendations includ- ing standard dimensions and types of dials ; checking of indicators : their correct mounting : when and how to use

indicators. Les Defauts des Comparateurs a Cadran. G. MICHALET.

Pratique des Indus Mecaniques v32 n9, 10. 11, Sept 1949 p 279-87, Oct p 318-21, Nov p 359-63. Defects in dial comparators of %oo mm; results of study conducted at Laboratoire Central de l'Armement ; discussion of differ- ent defects, their causes and remedies : degree of accuracy which can be expected ; different types of comparators

illustrations. The Deming Test Indicator. Precision Measurement in the Metal Working Industry. 1952 ed. Syracuse Univ.

Press. Described on p 108 and illustrated in Figs. 164 and

165. (No other published description has been found, but

it was very popular during the First World War and subsequently. ) Is graduated to 0.0005 in. It has a spring- pivoted compound lever system and a number of replace- able ball points for reaching into small holes, slots, and

recesses. Messuhren, G. BERNDT. Dresden. Technische Hochschule Wiss Zeit v3 nl 1953-4 p 63-70. Dial gages ; formulation of standards and determination of errors. New Dial Indicator Design Features Only Four Moving

Parts, R. C. SOUERS. Machine & Tool Blue Book v49

no May 1954 p 193-200. 202. Nilcoid indicator now in stage of production at Nilsson Gage Co.. Poughkeepsie,

N.Y. will reduce disadvantages of gear train indicator without sacrificing any of advantages ; design details of indicator which is claimed to retain its accuracy longer than gear train type. Stable Wide-Range DC Amplifier, F. F. OFFNER. Rev

Sci Instrum v25 n6 June 1954 p 579-86. Versatile high

gain amplifier for biological applications ; features include

differential push pull operation with rejection ratio greater than 1000; response from zero to beyond 30 kc has maximum gain of about 2.5 X 10s

; optical control of 115
high and low frequency cutoff is provided ; other features

circuit diagram.

Dial Gauge, H. W. BAKER. Eng vl86 n4841 Dec 19 1958 p 804-6. Investigations carried out to obtain precise information about reliability of both new and nearly new

gages, and to shed light upon factors which should re- ceive special attention from manufacturers or users. Fully Transistorised Frequency Modulated Indicator for Field Tests, R. S. ROBSON, A. GOODIER, R. G. PENN.

Engr v207 n5380, 5381 Mar 6 1959 p 374-7, Mar 13 p 412-14. Indicator for translating mechanical parameters into elec- trical ones, developed by Thornton Research Centre, Chester ; thermionic valves have been replaced by transis- tors and crystal diodes ; it will replace most indicators used by Shell Research. The Accuracy of the Dial Indicators of D-Type Shore Hardness Testers, K. YAMAMOTO, K. IIZUKA. Report

of the Central Inspection Institute of Weights and Measures, Japan, vll nl report 28 1962 in Japanese. A method

for testing the accuracy of the dial indicators of D-type Shore hardness testers is devised. By means of this meth- od 10 indicators are inspected : two made by Shore In- strument & Manufacturing Co., U.S.A. and eight by do- mestic manufacturers. The results show that one division of the scales of the indicators does not correspond to the height of rebound of 0.1238 mm which would be the stand- ard value when the same definition as C-type testers is applied for the scale of D-type testers but corresponds

to about 0.13 mm, and show that most of the indicators have a periodic deviation of 0.020-0.045 mm and random

deviations of 0.025-0.040 mm from the mean pitch of the graduation. The cause of the periodic and random

errors is investigated and it is concluded that the former

error arises from the eccentricities of both the scale plate and the pinion to the center of rotation of the pinion and

can be cancelled out by adjusting the magnitudes and

phases of two eccentricities, whereas the latter one is due

to the error of teeth form of the rack and pinion and deter- mines the ultimate accuracy of the hardness readings, which is assumed to be 0.2-0.3 units in Shore scale for the

testers. 4-m-Endmasskomparator (4-Meter End-Measure Comparator), M. DUHMKE in collaboration with G. GEORGI

and W. FISCHER. Feinwerktechnik v66 1962 p 369-72 3

figs 4 refs. With this comparator parallel end measures

over 200 to 4000 mm in length are compared with stand- ards of equal length by mechanical contact. The measures lie on two-dimensionally applied ball bearings and are

hydraulically controlled from the outside of a temperature

shield surrounding the measuring apparatus. Device for Checking Dial Gauges and Indicating Hole

Gauges, E. M. EVICH. Meas Techns 1962 n6 Dec 1962 p 463^ 1 fig. Translated from Izmer Tekh n6 p 15 June

1962. Equipment was made from an old height gage ; its measuring device consists of a zero class micrometer, and

a collet chuck is used for fixing the dial gauge or bending

limiter of a hole gauge tubular stem. More Reliable Testing of the Precision of Dial-Type

Gauges, A. N. KARTASHOVA. Meas Techns 1963 n.3 Sept 1963 p 185-8 1 fig 5 refs. Translated from Izmer Tekh n3 p 4-7 Mar 1963. Describes a newly-developed

testing technique for dial gages which provides higher

reliability of testing with lower expenditure of labor. Addendum to Section 3

3.2. End Measuring Rods and Measurement of Long Lengths

Combined Micrometer and Sensitive Indicator Unit, W. F. ATKINS. Machy (London) vl05 n2697 July 22 1964

p 271-2 ; Machine Shop v25 n8 Aug 1964 p 398-400. To

overcome difficulty when measuring work pieces of large diameter, design was produced at National Physical Laboratory in which micrometer and fiducial indicator are combined in single unit that can be mounted on machine

external and sectional views of unit are described ; unit was fitted to diameter measuring machine used at NPL

for checking API screw plug gages. 3.3. External Diameters by Mechanical Methods

Superposition Spherometer Type IZS-8, S. D. GOLOD,

V. A. NIKITIN. Meas Techns n8 Mar 1965 p 679-81 2 figs. Translated from Izmer Tekh n8 p 19-21 Aug 1964. The new superposition spherometer IZS-8 is suitable for measuring convex and concave spherical surface radii in the range of 80 to 40 000 mm. As compared with spherometers made abroad the IZS-8 spherometer has several advantages which are : high precision provided by large- diameter carrier rings for measuring the radii of curvature in large components, the replacement of supporting- bands used in foreign spherometers by ball bearings over which the carrier rings can be turned as they become

worn, direct measurement of the spherical segment curvature deflection by comparing it with a certified instrument

scale, as against indirect measurement used in foreign spherometers which require reference glass spheres.

A Study of Errors in the Measurement of Microscopic

Spheres, C. P. SAYLOR, NBS. App Optics v4 n4 Apr

1965 p 477-86 11 figs 6 refs. Uncertainties in the microscopical measurement of small spheres as influenced by

index of refraction of the mount, focus, aperture, and

resolution have been variously reported and denied. The

present study was conducted with large spheres in order

to disclose the basic phenomena, but with such optical conditions as would ordinarily be used for much smaller

objects. The reality of each reported error is verified. The principal uncertainties originate in the geometrical

optics of thick bodies, but these effects tend to be confused by limitations in resolving power. See also F. Ehrenhaft,

p. 10. 3.4. Internal Diameters by Mechanical Methods

Investigation of Contact Methods for Measuring Internal

Sizes of Components with Stationary Instruments, G. B. KAINER. Meas Techns nil Apr 1965 p 945-9 4 figs 1 ref. Translated from Izmer Tekh nil p 8-11, Nov 1964. The

research revealed the basic components of the error pro- duced in measuring internal sizes with stationary instruments. The process was investigated by means of a recorder with induction transducer which was mounted

on an instrument with a metering device (for instance, an optimeter) in such a manner that all the displacements

of the component together with support table could be recorded in the course of measurements.

(Continued on p. 151) 116
Section 4. Calibration of Line Standards of Length, Including Tapes

CONTENTS

Page

4.1. Line standards, general 117

4.2. Calibration of subintervals 120

4.3. Calibration of tapes 122

4.4. Measuring microscopes and line comparators 123 Addendum to Section 4 128 4.1. Line Standards, General

Comparaisons des Metres dans L'Air a la Temperature

Ambiante ( Comparisons of Meters in Air at Ambient

Temperature), M. J. PERXET. Trav et Mem du BIPM

v4 1884 273 p 10 figs. Description of Brunner transverse comparator ; measurement of temperatures ; calibration of thermometers: measurement of lengths; calibration of optical micrometers ; method of comparisons and reduction

of data ; results ; tables ; observations. Standard Measures, E. A. GIESELER. J. Franklin Inst Aug 1888 p 115-33 ; Eng News Sept 8 1888. Gives brief history of the development of standards of length, de- scribes the present standards of the United States, and

methods adopted to compare them with other standards. The New Standards of Weight and Measure. The Nation Oct 24 1889. An interesting letter from Paris, de- scribing the methods used in preparing the standard meter

bars and standard kilograms for the International Bureau

of Weights and Measures.

Nouvelles Determinations des Metres Etalons du Bureau

International (New Determinations of the Meter Standards of the International Bureau), J. R. BENOIT, C. E. GUILLAUME. Trav et Mem du BIPM vll 1895 87 p. Discusses comparisons of several standards made in 1884,

1892, 1894 and other years by various observers ; derives equations for their temperature coefficients ; defects of the microscopes of the Brunner comparator ; observations. On the Comparison of Line and End Standards, L. A. FISCHER. Bui Phil Soc Washington vl3 p 241-50. Read

before the Phil. Soc. of Washington May 28, 1898. Precision in Determinations of Length, J. R. BENOIT.

Int Phys Congress at Paris Rept 1 1900, p 30-77. A re- sume of the practice and progress in different countries as

to the standard and measurement of length. France, England. Russia, and Germany are dealt with, and the ex- tension of the metric system noted. The best form for standards of length is discussed and the tests they should

bear are described. The probable error of a single comparison in comparing 30 standard meter bars is calculated

to be ±0.12/i. The permanence of the standards and their variations with temperature are also treated. Methods of Testing Flat-End Gages and Standards. Great

Britain NPL Rept 1906 p 39-42. Flat-end gages are tested by an optical method, involving the reflection of light from

them. A method of measuring an end standard by means

of a line standard is to apply two or more end standards

(preferably flat ends) and draw a line near the middle

of each. All possible combinations with a line standard

are measured.

Standards of Length, H. T. WADE. Sci Am Mar 10 1906. Information concerning the two meter bars in the custody

of the National Bureau of Standards at Washington, and

the care given them. Also the uses to which they are

applied. Methods of Comparing Standard Measure Bars, L. A. FISCHER, NBS. Am Mach v29 Oct 25 1906 p 547-8. Describes a simple process for deriving the yard from the meter bar. Verification of International Meter Standards, C. E. GUILLAUME. CR Acad Sci vl73 Dec 27 1921 p 1438-43. Results of recomparison of various national standard meters with the international protype meter.

fiber Metermassta.be mit Strichteilung und ihre Genauigkeit (Regarding Meter Measures having Line Division and

their Accuracy) , K. LUDEMANN. Der Betrieb v4"n9 Feb

11 1922 p 292-8 13 figs. Proposal for a standard meter measure with line divisions required in mechanical

metrology. Matters of Special Interest in Precision Metrology, A. PERARD. Rev Opt v2 Dec 1923 p 506-11. Precise defini- tion of the exact method of making a setting with a micro- scope on a line graduation might be "to set the microscope

so as to obtain equality of the luminous area between the

line of the microscope graticule and the edges of the line upon which the setting is made". Discusses personal er- rors, fogging of objectives and torsional forces on bars. Testing of Line Standards of Length. NBS Cir n332 May

13 1927 22 p 2 figs. Method used in comparison and stand- ardization of line standards of length and basis of such measurements in United States ; apparatus used and pre- cautions necessary for precise work ; information regarding testing of line standards and of metal tapes, includ- ing shipping directions. Optical Instrument Demands Unusual Precision, H. SI- MON. Am Mach v68 Mar 8 1928 p 421-3 6 figs. Scribing and checking of half-inch line on blade used in Zeiss measuring microscope; accuracy within plus or minus 0.00002

in. must be maintained ; high-precision dividing engine and apparatus used to check its work ; testing device per- mits readings to be made correct within limits of about

0.000008 in., plus or minus. Skalen fuer Messgeraete (Scales for Measuring Instru- ments), G. KEINATH. Archiv fiier Tech Messen v3 n32 Feb 1934 p T20-1 (4 p) . Scales for measuring equipment

comparative study of various standard types ; illustra- tions. 117
Gestaltung von Instrumenten zum Zwecke der Verein- fachung Messtechnischer Aufgaben (Design of Instru- ments for the Purpose of the Simplification of Technical Measurement Problems), R. SEWIG. Zeit Instrumkde

v56 n9 Sept 1936 p 349-57. Design of instruments with view to simplifying practical problems of measurements

psychoteehnieal and phototechnical form and character of

scales discussed. Homogeneous Scales for Pointer Instruments, H. MAURER. Zeit InstrumKde v57 Jan 1937 p 26-9. In certain types of pointer instruments it is necessary to read the

position of the pointer in terms of divisions of a non-homogeneous scale, owing to the mode of operation of the measuring device. Thus a similar change of the measured

quantity a at different parts of the scale corresponds to dissimilar changes of angular position w of the pointer, where w is some non-linear function of a. It is possible

to find curves on which the lengths of the intercepts be- tween two positions of the pointer are linearly proportional

to the difference between the corresponding indicated

quantities, so that accurate linear interpolation between

scale divisions becomes possible. For practical purposes a scale of circular form is retained but the fiducial marks

are shown on a zig-zag line. Improvements in Definition of International Standards of Length and in Comparison of Standards, A. PERARD, C. VOLET. CR Acad Sci v208 Jan 23 1939 p 263-5. An ac- count of the state of certain copies of the standard metre.

It was decided to renew the scales on five of these, and

this was done satisfactorily as regards definition, thick- ness of the lines reduced to 3.5/t and other points of im- provement. There has taken place also an improvement

in the observing instruments. The redrawn standards

will be compared, with the international metre and its latest copy. Permanence of Standards of Length, T. H. FIELD. Can

J Res vl7 Sec A May 1939 p 71-6. A few reasons are

presented for believing that the fundamental standards

for the metre and the yard, and also the legal Dominion

standards of length, are not changing appreciably. On

the other hand, measurements of a number of laboratory

nickel-iron rules show progressive shortening which is still taking place, through periods up to 20 years. Comparaison au Prototype metrique de ses Temoins et des Metres d'Usage du Bureau International des Poids

et Measures, A. PERARD, C. VOLET. CR Acad Sci v212 n2 Jan 13 1941 p 71-3. Comparison of metric stand- ard with its reference replica and with meters used by

International Bureau of Weights and Measures ; report on

comparisons made by four independent observers, with improved optical comparator. Comparison of Etalons of Length, C. VOLET. Rev Opt

(Theor Instrum) v21 1942 p 168-75 in French. Analyses

the systematic errors liable to be encountered in the comparison of standard metres, etc., when observations are made on grooves or scratches. The effects of the shape

of the groove and of the illumination are discussed. The

method of comparison by means of reversible microscopes

is advocated and a Societe Genevoise instrument of this type is described. Premiere Verification Periodique des Metres Prototypes Nationaux et Determination de Quelques Nouveaux Proto- types (The First Periodical Verification of the National Prototype Meters and Determination of some New Prototypes), A. PERARD, L. MAUDET, C. VOLET. Trav et Mem du BIPM v20 1944 86 p 7 figs. 7 refs. Characteristics

of the Prototype Meters ; revision of the early measures,

actual values of dilatations and equations; instruments and methods,—Brunner comparator, thermometers and

temperature, manner of checking a line, organization of the measurements ; periodic verification,—the prototype of the Bureau, the national prototype meters, prototype meters

verified several times, table of results, conclusions ; deter- mination of changing prototype meters. An Adjustable Scale for Measuring Instruments, W. KOCH. J Sci Instrum v22 May 1945 p 94-5. A method

is described for constructing and using a scale which

compensates for calibration errors. The principle in- volves the use of 3 fixed points ; the appropriate scale read- ing is determined by the intersection of a movable line with an arc passing through each point of the scale. The

line is adjusted by reference to the fixed points. Metres and Comparators, C. VOLET. Microtecnic v2 n4 Aug 1948 p 138-43. Comments on substitution and dis- placement methods used for comparison of graduated

length standards ; description of improvement which made

it possible to avoid instrument errors when using substitution method ; construction principles and choice of good standard discussed. Measuring Instruments—the Division on Glass of Graduated Areas of Instruments, F. DELHOMME, J. MARTIN, CR Acad Sci Paris v227 Aug 2 1948 p 335-7 in French. The technique of making scales on glass by depositing by

evaporation of thin homogeneous layer of Pb or Al, ruling with a dividing engine, and coating with a protecting layer

of varnish is fully described. New Method for the Calibration of Line Standards. Soc Gen dTnst Phys May 31 1950. Micrometer Eyepieces, H. BECKER. Microtecnic v5 n2, 3 Mar-Apr 1951 p 59-65, May-June p 108-13. Limitations of eye in respect to its optical resolution in reading very fine scale division ; problems connected with use of magnifying eyepiece or microscopes on micrometer in- struments ; reference made to some German patents in

this field ; typical optical systems for precision readings

factors important in manufacture of micrometer eyepieces. Human Factor in Instrument Design, L. S. BEALS, JR. Instrum v24 nil Nov 1951 p 1290-1, 1337-9. How aviation

or other instrument dials and control knobs can be im- proved and made more useful by careful analysis and

design of size, resistance to motion, grouping, direction

of motion, numbers, letters, pointers, and scale division. Bibliography. New Comparator of High Precision for Measurement of Line Standards of Length, J. S. CLARK, L. O. C. JOHNSON, V. W. STANLEY. J Sci Instrum v28 nl2 Dec 1951 p

357-64. 1-m comparator having two heat insulated tanks

designed to contain line standards of length and to bring them in turn under pair of micrometer microscopes rigidly fixed at distance apart equal to nominal length of stand- ards to be compared ; instrument can be used to compare

lengths of two standards or to determine their coefficients of thermal expansion. Les Metres Prototypes du Bureau International. Notes

Historiques. Renovation. Etude. (The Prototype Meter

of the International Bureau. Historical Notes. Restoration. Study), A. PERARD, C. VOLET. Trav et Mem du BIPM v21 1952 156 p 36 figs. 46 p of historical notes. Re- view of measurements prior to 1937. Study of new sources

of errors. Restoration of the meter and the Brunner comparator. Determination of the meter retraced. Examination of the progress realized. Conclusion. Note on a

study of the subdivisions. Graticules for Engineer Optical Measuring Instruments,

A. G. THOMSON. Mech Wld vl33 n3402 Jan 1953 p 26-7. Processes developed by Brit Sci Instrum Res Assn, which

have enabled graticules for optical instruments to be made

with accuracy which, in general, enhances precision of instrument ; graticules are produced by photography and

etching on glass, and by vacuum evaporation of films of chromium, aluminum, platinum, palladium, rhodium, etc. 118
The Possibility of Comparing Line Standards of Length

Photographically. A. H. COOK. Proc Roy Soe A v219

_ I Oct 7 1953 p 500-15. Line standards can be compared

visually to about one in ten millions. It seems possible

that in a photographic comparison appreciably higher

- precision could be attained with less labour. Photographs

: of the lines on some line standards have been examined

" with a densitometer to determine the accuracy with which

i"* the distance between two photographic images of such

-'- lines could be measured. "With suitable definition of line position a single measurement of this distance should have

a standard deviation corresponding to less than 0.05/t. Provided the temperature of the bars is known with sufficient accuracy it should be possible to compare two line standards to much better than one in ten millions in less han half the time taken by present visual methods. A

* machine for measuring the photographs is suggested. The

• characteristics of photographs of some lines are given in an appendix.

:' Novel Devices for Checking Graduated Scales and Tapes,

C. HOFFROGGE. Microtecnic v9 n5 1955 p 247-52 7 figs. - Devices are described which make possible the checking

if graduated scales and tapes with an uncertainty of some

-' =0.01 mm. The standard can be moved longitudinally in order that coincidence readings can be carried out on the graduations to be compared. The displacement is given by a dial comparator or a micro-indicator. The devices can be used with particular advantage for tolerance measurements.

- Calibration of Meter Line Standards of Length at the National Bureau of Standards. B. L. PAGE. J Res NBS v54 —' nl Jan 1955 p 1-14. The results of the intercomparisons

of the total lengths of several meter bars and of ealibra-

' -• tions of the subintervals of some of these bars for the

- past twenty years are reported. Information both on

the degree of stability of these standards and on the preci-

- sion with which such measurements can be repeated was

obtained. The results are critically analyzed and com-

- ments made as to the precautions necessary in the preci-

>a» sion comparisons of line standards of length.

ai Machine Tool Scales with Optical Reading Devices, C.

' i GODFREY, S. C. BOTTOMLEY. Microtecnic vl3 n4 Aug

- 1959 p 154-61. Use of precision scales on machine tools. especially when viewed by optical projection, has many

advantages ; they are unaffected by wear, can be magnim - fied, and permit subdivision of main scale ; review of variff1-

. ous types covers micrometer projectors, vernier projectors,

P circular scales, and "microptic" scale reader ; photographs.

"A , The Manufacture, Testing, and Application of Precision

fiJ

( Glass Scales, G. MEISTER, J. CICHON. (Zeiss, Jena)

as* 1960. An example of automation in precision-measuring

technology by means of photoelectronic methods. Contents : On the state of dividing techniques : basic methods

for the objective photoelectronic localization of graduation marks ; instrument technology ; application of glass scales ; automation of photoelectronic reading of glass scales. De l'lmportance de la Quality d'une Regel-Etalon, P. MARTIN. Optics in Metrology, P. MOLLET. Pergamon Press

| 1960 p 57-62 8 figs. The coming change in the definition

of the meter and its consequences ; line standards on glass and on metal, advantages and disadvantages ; factors of

, errors : precision ; definition of the line ; factors influencing

the good definition of the line ; appropriate materials for good scales ; lines with round edges ; the Volet effect ; the

retracing of the prototypes.

; Survey of Development of Line Standard Metrology, J.

i PETAVEL. Microtecnic vl4 nl Feb 1960 p 1-13. Methods used by Bureau of Weights & Measures, and standards

1 Laboratories for intercomparison of line standards and

their comparison with international standard ; micrometer

microscopes enable meter to be defined with relative uncertainty of one part in 107

; photoelectric microscopes have

enabled uncertainty to be reduced to one part in 10s

. Calibration of Line Standards of Length and Measuring Tapes at National Bureau of Standards, L. V. JUDSON. NBS Monogr nl5 May 1960 11 p. Methods used in cali- brating line standards of length and measuring tapes sub- mitted for standardization ; equipment used is described

briefly; there is discussion of some considerations that should be given as to whether or not standard should be submitted to Bureau; instructions are given for submitting items to Bureau for calibration; appendix contains

useful information on use of steel tapes. Unmittelbarer Anschuss von Strichmassen an Liehtwellen- langen (An Instrument for Direct Comparison of Line Standards with Wavelengths of Light), C. HOFFROGGE.

Amtsblatt PTB 1961 n2 p 192-5. See abstract under 2.4.6. An Automatic Fringe Counting Interferometer for Use in Calibration of Line Scales, H. D. COOK, L. A. MARZETTA. J Res NBS v65C n2 Apr-June 1961 p 129-40. A

reversible fringe counting interferometer is described in which mechanical, optical and electronic adjustments are maintained stable by servomechanism control or by balancing. An electronic fringe counter and interpolator per- mits recording of the count in digital form to 0.01 fringe. Design factors and details are discussed. On an Instrument for Calibrating Graduated Scales up to

1 Meter in Terms of Wavelength of Light, Y. SAKURAI.

Global Technol Apr 1961 (Digest of original Japanese article). Description of an interferometric line standard

comparator. The principal components are a photoelectric microscope and an interferometer employing a Koester's double prism and corner-cube reflectors. A reversible fringe counter and interpolator is used to determine the order of interference. Interference Comparator for the Calibration of Line Standards Directly in Terms of Standard Wavelengths,

K. M. BAIRD. Rev Sci Instrum v32 n5 May 1961 p 549-54. An interference comparator for routine calibration of line standards or scales by direct reference to the vacuum

wavelength of Kr86

. Principles of construction and per- formance characteristics are given. Method of exact frac- tions used to determine the order of interference. Case Histories of Methods to Achieve Cost Reduction Through Optical Tooling, A. W. YOUNG. ASTME Creative Mfg Seminars Tech Paper SP63-120 Feb 1963 7 p. Eleven examples are described dealing with alignment of machine tools, checking out rotational error of rotary

tables, transfer of angular measurement in shops, use of

telescope and clinometer mounted in one fixture, etc. The Calibration of Linear Scales by the Method of HansenPerard. E. G. THWAITE, R. T. LESLIE. Austral J' Phys vl6 nl Mar 1963 p 82-107. The exact least-squares

solutions are obtained by matrix inversion. These sets of equations correspond to the "simple calibration" and the

"cross calibration," of linear scales by the method of Hansen-Perard. Tables are given of the inverses of the coefficient matrices of the normal equations for most practical cases and expressions are derived for the variance to be associated with any interval between calibrated scale graduations. Positioning System Spaces Lines to Within Vio Microinch,

E. G. LOEWEN. Control Eng vlO n5 May 1963 p 95-8. Author, associated with Bausch & Lomb Inc., explains op- eration and control of ruling engine that scribes up to 100,000 uniformly spaced lines per inch on diffraction grating. Magneto-Optic Positioning, R. J. MELTZER. IEEE Trans

Indus Electronics vIE-10 nl May 1963 p 46-56. For accurate production of scales and grids it was necessary to 119

771-846 O—66 9
develop device which could locate lines with precision better than 1/dn. ; system is described that accomplishes

this by forming image of line with polarized light, whose

angle of polarization varies with position of line. High-Precision Linear Scales. Firm of Dr. Johannes

Heidenhain, Traunreut. Oct 1963 19 p 21 figs. Describes advantages of scales manufactured by the patented Diadur

process. Describes detail features of high-precision glass

rules, metal rules, grating bars, and coded rules.

Recommendations for Design of Scales and Indexes. Brit Standards Instn—Brit Standard 1449 pt 1 1964 44 p. Rec- ommendations in this part are intended to be generally

applicable to quantitative instruments of bold presentation and designed for rapid reading, intended to be read

to resolution of about 1 to 2% of scale range and are particularly concerned with relating scale dimensions to max- imum reading distance; they are only applicable to single

scale instruments having dials with full circle, part circle or straight scales as defined.

4.2. Calibration of Subintervals

Note. The more important articles are indicated by an

asterisk (*) Traite de Thercnoinetre (Treatise on Thermometry), HENNERT. 1758 (Book.) Chwolson in his Traite de Physique v3 p 42 states that the method generally ascribed

to Gay-Lussac was first given by Hennert. Gay-Lussac is credited by very many writers on this subject with having

given the first method of calibration. Some have, however, given evidence to prove that he did not originate the method. An outline of the method of Gay-Lussac is given

in many treatises on experimental physics and in books on thermometry but without reference to Gay-Lussac's de- scription of his method. Anmerknlngar angaende thermometrars fortfardigande och Bruk. Hallstrom, G. GABRIEL, Abo, 1823 Akad Dissertation. A very early method of calibration, concerning which there seems to be considerable difference of opinion, although the Hallstrom method is often referred to in the

literature. In a footnote to an article by Hallstrom in the Ann Phys Chem in 1836, Poggendorf states that, as the method is the same as that already published by Bessel,

to save space it is not repeated, although included in Hall- strom's manuscript of the article. Rudberg later pointed

out some slight differences. The committee of the British Association (see under Stewart) put the method in an

entirely different classification from that of Bessel. The

original dissertation unfortunately has not been available

for consultation in the preparation of this bibliography. Methode die Thermometer zu berichtigen ( Method of Correcting the Thermometer) , F. W. BESSEL. Pogg An Phys

v6 1826 p 287-308. A method of calibration in which the various lengths used are not multiples of the smallest or

unit interval. Untersuchungen fiber das Thermometer : V. Die stereo- metrischen Verhaltnisse der Glassrohre (Investigations

of the Thermometer: V. The Stereometric Proportions of the Glass Tube), P. N. C. EGEN. Pogg An Phys und

Chemie vll p 529-36 1827. A method of calibration which

is a slight modification of that of Bessel. Allusions are sometimes found in the literature to Egen's method without any journal reference being given. Uber die Konstruktion des Thermometers (Regarding the Construction of the Thermometer), F. RUDBERG. Pogg An Phys v40 1837 p 562-82. A method of repeated subdivision ; for instance, first divide the total length in half, then compare the three-thirds of the total length, then

divide the total into twelfths, etc. *Bestimmung der Teilungsfehler eines gradlinigen Massstabes (Determination of the Graduation Errors of a

Rectilinear Scale), P. A. HANSEN. Abhandlungen der Mathematisch-Physikalischen Klas.se der Koniglich Saehsischen Gesellschaft der Wissenschaften vl5 1879 p 525-

667. The basic memoir on which present-day methods of

calibration of scales are founded. It discusses the cali- bration of a single scale. Methods of double calibration are a later development.

t'ber das Kaliibrieren von Thermometern (Regarding the Calibration of Thermometers), M. THIESEN. Carl's Repertorium fiir Experimental-Physik vl5 1879 p 235-99. The author points out that Lambert in his "Pyrometrie"

published in 1779 had used (p 31, 43) the method of cali- bration commonly attributed to Gay-Lussac, and that it was known even earlier. An application to thermometry

of this method is briefly outlined by Thiesen. It is stated that Rudberg's method is only a special case of Hallstrom's, but that it has the disadvantage that the corrections to the divisions obtained in the component parts of the calibration are not well coordinated to make a unified system of corrections.

*I T ber die Anwendung der Methode der Kleinsten Quadrate auf die Kalibrirung der Thermometer (Regarding the Application of the Method of Least Squares to the Cali- bration of the Thermometer), W. J. MAREK. Carl's Re- pertorium fiir Experimental-Physik vl5 1879 p 300-19. Method of calibration of a thermometer (applicable also

to a scale) for cases of division into 2, 3, 4, 5, and 6 parts with a brief statement of the general case. Corrections

to the intervals are obtained by the solution of the normal

equations obtained by least squares methods. These equations are given a form especially applicable for ready numerical solution. Numerical examples exemplifying

the method in the calibration of thermometers are given, together with formulas for obtaining the probable error

of the results. See also reference to article by Benoit,

li 121. t'ber das Kalibrieren von Thermometern, inbesondere

fiber die wahrscheinliehen Fehler der Kaliberkorrektion (Regarding the Calibration of Thermometers, Especially Regarding the Probable Error of the Calibration Correction), M. THIESEN. Carl's Repertorium fiir Experi- mental Phys vl5 1879 p 677-81. By a consideration of the probable errors, the feasibility of an abbreviated method

of calibration is shown. There is a saving of time compared with the rigorous least squares method proposed by Marek. The artifice used by Thiesen had been pro- posed by F. E. Neumann in the case of another set of equations similar to those involved in this work, and the method

of calibration is sometimes known as the NeumannThiesen method. Report of the Committee Appointed for the Purpose of Reporting on the Methods Employed in the Calibration of Mercurial Thermometers. B. STEWART; RUCKER

T. E. THORPE. Report of the Brit Assn for 1882 p 145-204. Discussion with illustrative examples using

the following methods : Gay-Lussac, Hallstrom, Rudberg,

Thiesen, Marek, Bessel (as modified by von Ottingen and

improved by Thorpe and Riicker). These methods are

also applicable, with certain modifications to the cali- bration of divided scales. Four classes of methods are

distinguished by this committee. (1) "Step by step," ex- ample, Gay-Lussac's method; (2) "Principal points," ex- amples, Hallstrom, Thiesen, Marek; (3) "Repeated divi- sion," example, Rudberg; (4) "Distributed points," examples, Bessel and the modification by von Ottingen. 120
^Calibration of Thermometer Green 5280 by Hansen's

Method, C. C. BROWN. Van Nostrand's Eng Mag v29

1883 p 1-7. One of the few expositions in the English language of Hansen's method. Mesures de Dilatation et Comparaisons de Regies Metrique.

13 Thermometres-Corrections de Calibrage (Measurement

of Dilation and Comparison of Metric Scales. 13 Cali- bration Corrections of Thermometers). J. R. BENOIT.

Travaux et Mem du BIPM v2 1883 p C35-C48. Method

of Marek as used in the calibration of thermometers. This

article is in French ; Marek's original article was in German. Etudes Thermometriques (A Study of Thermometry).

C. E. GUILLAUME. Trav et Mem du BIPM v5 1886 92

p 5 figs. Comprises study of thermometers, variations of thermometers, and concordance of thermometers. Note sur l'Etalonnage des Sous-Divisions d'une Regie, sur

l'etude des Erreurs Progressives d'une Vis Mierometrique,

et Sur le Calibrage des Thermometres (Note on the Cali- bration of the Subdivisions of a Scale, on the Study of Progressive Errors of a Micrometer, and on the Calibration of Thermometers), O. J. BROCH. Travaux et Memoires du BIPM v5 1886 p 1-82. Development of the method of Hansen for the calibration of a single scale. Computation

forms. Applications to calibration of line standards, micrometer screws, and thermometers.

Weinstein Handbuch der Physikalischen Maasbestimmung

v2 1888 p 274-82. Method of Hansen for single scales and

method of Thiesen for a double calibration. On the Determination of Errors of Graduation Without

Cumulative Errors and the Application of the Method to the Scales of the Cape Heliometer, D. GILL. Monthly notices of the Royal Astron Soc v49 1889 p 105-18. ( See also the errata on p 241 of the same volume.) A method is outlined of calibrating two scales simultaneously. This method is essentially that of Lorentzen. No general for- mulas are given and no computation system outlined. It

is to be noted that Gill considered all intervals to be cali- brated with the same weight, whereas, as Jacoby pointed

out, weight factors given by Lorentzen must be used. Traite Pratique de la Thermometrie de Precision (Treatise on the Practice of Precision Thermometry), C. E. GUILLAUME. Gauthier-Villars et Tils, ImprimeursLibraires 1889 336 p 4 plates 45 figs refs. Methods of cali- bration of thermometer scales with illustrative examples

are given on p 43-99 : Gay-Lussac's method ; NeumannThiesen method ; complete least squares method. The Cumulative Errors of a Graduated Scale, W. A. ROGERS. Proc. ASME vl5 1893 p 127-46. The method of Broch and the method of summing the corrections found

for the unit lengths are each discussed and illustrated. Rather undue emphasis is placed on the possibilities of simple summing the corrections found for the individual

intervals ; Mr. Rogers was an experienced and careful ob- server ; repetition of length measurements to a certain precision is no proof of their accuracy to that degree.

' *t'ber die Untersuchung der Scalen eines Heliometers I (Regarding the Investigation of the Scales of a Heliometer), G. LORENTZEN. Astron Nachr vl31 n3134 1893

p 217-38. This is a method of double calibration which

differs only slightly from a least squares solution. Uber die Untersuchung der Scalen eines Heliometers II (Regarding the Investigation of the Scales of a Heliometer), G. LORENTZEN. Astron Nachr vl35 n3236 1894

p 353-66. This is an application of the method of double

calibration described by the same author in a previous paper to the calibration of two heliometer scales, each a decimeter in length.

Note on the Division Errors of a Standard Scale, H. JA- COBY. Astron Nachr vl37 n3285 1895 p 357-60. Jacoby

points out the advance made by Lorentzen over Hansen

and also the practical identity of Lorentzen's method with

that used and described by D. Gill. The fact that Lorent- zen gives a weight factor for the several intervals is emphasized. Jacoby suggests repeating the observations on

the first and last comparisons of the two scales in the usual

order of measurement four times. The final results would

then be more uniformly weighed. The possibility of computing the number of times to repeat each separate ob- servation in order to produce a weight of unity for all points is suggested by Jacoby as of some possible theoretical importance. On the Determination of the Division Errors of a Straight

Scale, H. JACOBY. Am J Sci vl51 May 1896 p 333-42.

Gill's method, an improvement on Hansen's and Lorentzen's formula, are both explained and discussed. A modification of Gill's method, by the author, follows, whereby

accuracy within 0.00002 inch is obtained. A method of calibration of two scales in which the various observations are repeated such number of times as to secure a

unit weight for the final result for the correction to each

interval. An application to the calibration of screws is included, whereby the nonperiodic errors of a screw are determined without assumption of any law of error. Uber die Ermittelung der inneren Theilungsfehler zweier Masst&be nach der Methode des Durchschiebens (Regarding the Investigation of the Inner Division Errors of Two

Scales by the Method of Translation), DZIOBEK. Wiss Abh der Kaisarlichen Normal-Aichungs-Kommission v4

1903 p 1-56. A least squares solution for a double calibra- tion with comparisons with the method of Thiesen ; numerical examples. Uber die gleichseitige Bestimmung der Theilungsfehler zweier Maszstabe durch die Methode des Durchschiebens (Regarding the Congruent Determination of the Division Errors of Two Scales by the Method of Translation), A. LEMAN. Wiss Abh der Kaisarlichen Normal-Aichungs- Kommission v6 1906 p 1-75. A method of double calibration. Standardization of Divided Scales, C. E. GUILLAUME.

Ann des Poids et Mesures, vl3 1907 p 1-54. There are three factors in a complete determination: (1) The for- mula of thermal expansion; (2) the total length; (3) the

calibration of the divisions, i.e., the differences in the dis- tances between successive divisions. The theory is fully investigated and certain examples are given. The author

considers that the third factor above need not introduce a greater error than 0.1m throughout the meter scale, but

uncertainties in temperature and in the expansion formula

bring up the error to 0.2/* or 0.3/*. Both a method of single and one of double calibration are given, each with ex- amples. Note sur le Calcul des Etalonnages de Grandeurs en Progression Arithmetrique (Note on the Calculation of the

Calibration of Size by Arithmetical Progression), A. PERARD, Trav Mem du BIPM vl6 1917 p 1-77. A method

of single calibration and a method of double calibration. The method given in this circular is a variation of the method of single calibration described by Perard.

Calibration of a Divided Scale. NBS Cir n329 May 13 1927 15 p 1 fig. Method used at NBS for calibrating equal

subintervals of length on a line standard ; apparatus, ob- serving procedure, and mathematical reduction of data. Bibliography.

Calibrations of Line Standards of Length of National Bureau of Standards, L. V. JUDSON, B. L. PAGE. J Res NBS vl3 n6 Dec 1934 p 757-72. Results of intercompar- 121
ison of total lengths of meter and of decimeter bars, and

results of calibrations of subintervals of several of them

are given. Instrument Scale Distribution and Its Effect on Observational Errors, R. G. JEWELL. Instrum v8 n3 Mar 1935 p 58-60, 79. Certain electric indicating instruments have

uniformly divided scales while others have scales which

are open over one portion and constricted over another

portion ; purpose of paper is to show what factors affect distribution and to determine what effect distribution has upon observational errors. Bibliography. The New Graduated Prototype of the International Bureau of Weights and Measures for the Subdivisions of the Metre, H. MOREAU, N. CABRERA. Rev Opt (Theor In- strum) v23 Oct-Dee 1944 p 255-60 in French. The difficul- ties originally encountered in working with Pt-Ir (poor

polish, difficulty in marking, etc. ) meant that some of the

older prototypes were not entirely satisfactory. One of these (T4) has now been renovated, markings removed,

surface planed and repolished, and regraduated. Two in- dependent examinations have now been made of this new

prototype and it is found that the error for any graduation rarelv exceeds a micron. The length is given as 1 m

1.14/1 atO°C,

Adjustable Scale for Measuring Instruments, W. KOCH.

J Sci Instrum v22 n5 May 1945 p 94-5. Method described

for constructing and using scale which compensates fairly well for calibration errors ; principle involves use of three

fixed points; appropriate scale reading is determined by

intersection of movable line with arc passing through each

point on scale ; line is adjusted by reference to fixed

points. Choix et Determination d'un Vernier, A. LABORDE, C. TURLAN. Techn Mod v38 n9-10 May 1-15 1946 p 106-11. Study of theory of vernier, its intervals and method of observation ; circular verniers ; charts and tables presented. Manufacturer's Viewpoint on Instrument Calibration, H. BERRING. ISA J vl n4 Apr 1954 p 32-4; Steel Processing v40 nl Jan 1954 p 33-7, 51. Problems relating to correct positioning of pointer on calibrated scale, from

viewpoint of manufacturer responsible for original dial calibration ; extent to which manufacturer's equipment,

required for calibration of large numbers of instruments, may differ from that employed by testing laboratories and

industrial instrument departments ; mechanics of calibration ; scale division and layout. Photoelectric Microscope for Measurement of Linear

Scales, J. S. CLARK, A. H. COOK. J Sci Instrum v33 n9 Sept 1956 p 341-7. Apparatus for accurate measure- ment of scales of high precision; real image of graduation line, formed by microscope objective, is caused to

oscillate across fixed slit in front of photocell ; phase

sensitive rectifier determines when mean position of line image coincides with center line of slit ; short scales were measured directly in wavelengths with standard deviation

of about 0.1/i. Automatic Measurement of Small Deviations in Periodic- Structures, H. T. CLOSSON, W. E. DANIELSON, R. J. NIELSEN. Rev Sci Instrum v29 nlO Oct 1958 p 855-9. Special optical, mechanical, and electronic techniques have

been combined in a new instrument, the microdeviometer

originally developed for measuring and recording the pitch uniformity of helices in travelling wave tubes—in which a beam of light and two optical gratings are used to obtain

a very accurate scale of distance. The location, with re- spect to this distance scale, of the salient periodic fea- tures in the structure being measured is established through the interception of a second light beam by the

structure. Electronic circuitry automatically stores and

processes the position information and feeds the processed

information, in the form of deviations from the corresponding ideal structure, to a pen recorder. A measuring accuracy of ±lfi has been consistently obtained, and

measurements which formerly required nearly 2 man-days

are accomplished in less than 10 min. Wiederholbarkeit und Richtigkeit der Messwerte beim Zusammenwirken von Optischen Ablesegeraten und Stri- chteilungen (Repeatability and Accuracy of Measured

Values with Coordinate Action of Optical Reading Apparatus and graduations) , K. RANTSCH, Optics in Metrology, P. MOLLET. Pergamon Press 1960 p 50-6. Proposes

the proportion of the scale value to the average error

of the individual measurement as the reading quality

characteristic, for which a simple formula is indicated. Calibration of Line Standards of Length and Measuring Tapes at the National Bureau of Standards, L. V. JUDSON. NBS Monogr 15 1960 p 11. See 4.1 for abstract. General Theory of Verniers ; Verniers for Nonuniform

Scales, P. M. PEPPER. Ohio State Univ—Eng Experi- ment Station—Bui v30 n2 Mar 1961 55 p. Novel means

of applying verniers to nonuniform scales : mathematical

principles on which vernier depends are treated ; rudi- mentary error theory for verniers ; and approximate methods for construction of generalized verniers ; concept

of acceptability for approximate verniers is defined and

employed in treating several examples of generalized

verniers. Selection of the Number of Check Points on an Instru- ment Scale, A. S. NEMIROVSKII, V. A. VOLKONSKII.

Meas Techns 1961 nl Sept 1961 p 6-13 1 fig 3 refs. Translated from Izmer Tekh 1961 nl p 5-10 Jan 1961. Article describes the selection of an optimum number of check

points on an instrument scale. This solution could be

applied to developing or improving methods of checking

a wide range of instruments.

Calibration of Linear Scales by Method of Hansen-Perard,

E. G. THWAITE, R. T. LESLIE. Austral J Phys vl6 nl Mar 1963 p 82-107. See 4.1 for abstract. 4.3. Calibration of Tapes

Measuring a Steel Tape, W. GRIBBEN. Am Mach Mar

19 1896. A good illustrated description of a job quite out S & of the usual run of machine shop work.

tlber eine Anreihevorrichtung fiir Genaure Messungen mit 1 I] dem Stahlbande (Details of a Series of Precise Measure- ments with Steel Tapes). Zeit Oesterreichische Ing und

Architektonische Verein Feb 12 1897. An account of a

series of experimental measurements to determine the probable error and limit of precision of steel tape measurements. Gives useful practical details. Steel Measuring-Tape Apparatus, A. E. BURTON, J. F. HAYFORD. Eng Record v45 Jan 25 1902 p 80-1. Outline

is given of the development of this instrument at M.I.T.

since 1888 and of tests to which it was submitted by the US Coast Survey. The Bureau of Standards and Its Relation to the United

States Coast and Geodetic Survey, S. W. STRATTON. Reprinted by the Government Printing Office from the "Centennial Celebration of the United States Coast and Geodetic Survey" Apr 5-6 1916 18 p 11 figs. This is largely a review of F. R. Hassler's work in procuring instruments

for a coast survey and in providing and comparing physical standards. The Measurement of Tapes and Wires at the Reiehsanstalt, P. A. THOMAS. Zeit InstrumKde v39 Nov 1919 p

321-32. A description of the 30 m. measuring track used

for the most accurate measurement of invar and other

tapes and wires. A description is given of the sledge 122
carrying the travelling microscope and of the procedure

| involved in a complete test of length. Standardization of Measures of Length at the Laboratory

of the Dominion Land Surveys. Bui 44, Dept of the Interior, Canada, Topographical Surveys Branch 1921 33 p

'32 figs. Description of equipment for calibrating tapes.

Effect of Concentrated Loads on the Length of Measuring

Tapes, L. V. JUDSON. Sci Papers NBS v21 nS-534 Apr

15 1926 p 385-93. Formulas are given for computing the change in length of a tape when concentrated loads such

as thermometers are added to the tape. Experimental

data confirming the formulas are given. Testing of Measuring Tapes at the Bureau of Standards,

L. V. JUDSON. NBS Cir n328 Mar 1927. Description of

steel tape and invar geodetic tape calibration at NBS.

Nomographic Chart for Steel Tapes, C. D. SHEPARD.

Civ Eng v2 July 1932 p 440-2 4 figs. Elimination of cor- rections to tape measurements made possible by determination of tension of accuracy. The 24 m interference comparator of the Potsdam Geodetic

Institute, F. MUHLIG. Deutsch Akad Wiss Berlin. Verbff Geodat Inst Potsdam n2 50 p 1949 in German. An

instrument for standardizing invar tapes for geodetic base measurements in terms of the red Cd line. The distance between mirrors 12.5 cm apart is compared with the dis- tance between the mirrors of a Fabry-Perot etalon by es- tablishing interference between white-light beams which

have undergone one reflection at the 12.5 cm mirrors and

two reflections at the etalon. A wedge is inserted into the combined beams to produce white-light fringes and the

difference between the longer interval and twice the

shorter interval is equal to the thickness of the wedge at the point where the white-light fringes occur. Similarly

the 12.5 cm interval is compared with aim interval, that with a 6 m interval and the latter with the 24 m interval. The length of the etalon and the thickness of the wedge are

obtained in terms of the red Cd line. The apparatus is arranged so that for convenience in field work the comparisons between the different stages can be made simultaneously, and with two observers the etalon can also be standardized at the same time. The influence of optical aberrations is discussed, the use of the instrument is de- scribed and some measurements are reported. 50-Metre Mural Comparator at N.P.L., J. S. CLARK. Engr.

vl89 n4908 Feb 17 1950 p 201-3, Feb 24 p 228-30. Method

used at National Physical laboratory to standardize precision tapes and wires used by geodetic surveyors and for other measurements of length ; micrometer microscopes and other equipment are attached to brick wall 164 ft long, whole forming comparator of sufficient short term

stability for comparisons of necessary accuracy ; description of improved equipment and technique supplements article in "Glazebrook's Dictionary of Applied Physics",

Vol. 3, 1923 ; illustrations. Standardisation of Steel Surveying Tapes, J. S. CLARK,

I L. O. C. JOHNSON. Empire Survey Rev vll n81 1951 p 118-28 4 figs 7 refs. Surveying tapes of steel are much

more satisfactory mechanically than those of invar, and

are less subject to secular changes of length, but the magnitude of their coefficient of thermal expansion demands a

closer knowledge of their temperature than can be obtained

with ordinary thermometers suspended near the tapes. The measurement of steel tapes in terms of their electrical resistance has therefore been investigated. The history of

this work is traced. The use of resistance methods has

proved satisfactory in the field, and under Laboratory conditions at the NPL the accuracy of 1 part in 2 millions in the measurement of the lengths of 24-metre and 100-foot

tapes of steel is attained. Such steel tapes appear to have

remained stable on the average within about 2 parts in a

million in 25 years. A New Method for Determining Linear Thermal Expansion of Invar Geodetic Surveying Tapes, P. HIDNERT,

R. K. KIRBT. J Res NBS (RP-2407), v50 n4 Apr 1953 p 179-85. An electrical method for measurement of linear thermal expansion is described. A direct current is passed through the tape for heating. Observations of changes

in length and electrical resistance are taken at different constant temperatures of the tape. Temperature of the tape is determined from its different resistances and the temperature coefficient of resistance. This method has

several advantages over the old method of measuring the change in length of the tape at different ambient temperatures of the laboratory. Neues Prufungsverfahren fur die Eichung von

dern (New Testing Method for the Calibration of Tapes),

C. HOFFROGGE. Special reprint from the Amtsblatt n

4/56 of PTB, Deutscher Eich-Verlag, Berlin W 30 1955 p 320-1 2 figs. Meteransehluss von Invardrahten fur Basismessungen

(Meter Reference of Invar Wires for Base Line Measurements), C. HOFFROGGE, H. RUMMERT. Veroffentli- chung der Deutschen Geodatischen Kommission, ser B n71

1958 11 p 7 figs 6 refs. A part of 1958 was spent by the PTB in the calibration against the prototype meter of the invar wires used in the measurement of the 8-km baseline

in the Ebersberger Forest near Munich. The arrange- ments and measuring methods applied are described and

the possible sources of error are quantitatively investi- gated. Berechnung der Messlange bei frei durch hangenden Band- massen (Calculation of Length of Freely Suspended

Tapes), M. GARY. Zeit fur Vermessungswesen v84 n6

1959 p 188. Discusses calibration of tapes. Universal Device for the Inspection of Direct-Reading

Gages, M. A. ADADUROVA. Meas Techns 1959 nl Mar

1960 p 7 1 fig. Translated from Izmer Tekh nl Jan 1959 p 6. Describes a comparator having a 1 meter base with which every meter division of measuring devices of any

length are compared with it in turn. In checking a tape measure its free front end is connected to the lead tape

of the right-hand reel, passed over the guide rollers and, together with its case, placed onto the left-hand reel. Thus

placed, the divisions of the tape being inspected are opposite the divisions edge of the master tape. The error of each meter is determined after placing the first graduation of the tape being inspected against the corresponding mark of the master tape, by reading the error on the other

end. Calibration of Line Standards of Length and Measuring

Tapes at the National Bureau of Standards, L. V. JUDSON. NBS Monogr 15 May 20, 1960. Description of tape

calibration methods at NBS. Appendix on the use of steel tapes including Young's Modulus of Elasticity, corrections

for sag, and tension of accuracy. 4.4. Measuring Microscopes and

Line Comparators

See also Subsection 1.2.3 Measuring Objects in the Microscope, F. E. IVES, J Franklin Inst vl54 July 1902 p 73-6. The image of an illumi- nated scale is projected in the plane of the object by means

of the substage condenser. In the author's arrangement

a Welsbach light, with ground-glass chimney and hood,

illuminates a jeweller's saw set up, on a block of wood,

at a suitable distance from the condenser. The distance between two teeth was equivalent to 0.02 mm on the stage micrometer. 123
A Microscope for Measuring Screw Threads. Eng v76 Nov 13 1903 p 660 9 figs ; Am Maeh v27-l Jan 21 1904 p

78-9 7 figs; Machy (N.Y.) v24 Feb 1918 p 494-5 4 figs. The instrument was made by the Cambridge Scientific In- strument Co. for the Small Screw Gage Committee of the

British Association by whom it was placed in the custody

of the National Physical Laboratory. Figures show dif- ferent views of the instrument and the arrangement of cross wires and various adjustments. Comparator, A. J. COX. Zeit InstrumKde v22 Nov 15 1907 p 229-31. Bureau of Science, Manila, Philippines. A solid base carries two vertical guide bars rigidly con- nected at the top by a cross piece, from the middle of which two scales to be compared are hung. The suspensions for both are provided with an adjusting screw, so that the

scale zeros can be set together. The bottom of each scale

is secured to the base by a suitable clip. The reading microscope (magnifieation=60 diams.) has horizontal traverse on the edge of the plate, capable of adjustment, which is carried on a slide having vertical motion on the guide bars. With the aid of a scale in the eyepiece of the microscope, readings can easily be obtained correct to 0.01 mm. For greater accuracy the most costly method of the German Imperial Commission of Standards is recom- mended. See also Deutsche Mech Ztg 1907 p 230-1 and

Phil J Sci v2 Manila 1907 p 139-43. The Transversal Comparator, A. BLASCHKE. Zeit InstrumKde v27 Dec 1907 p 361-9. Communication from

the Phys Tech Reichsanstalt. Improvements in the comparator, including details as to thermostats.

tiber einige Neueinrichtungen fur Langen- und Kriestei- lungen mit Mikroskop-Ablesung (New Length-measuring

Instrument), C. PULFRICH. Zeit Instrumkde v27 Dec

1907 p 369-73. Communication from the Optical Workshops of C. Zeiss. The instrument is called the stereo- comparator. Rough readings are taken by the eye alone

to 0.1 mm on a metal scale. Fine readings are taken on

a glass scale to .01 mm. A series of mirrors is used to send

the light onto the scale and then horizontally to the eye. The principle is also applied to the measurement of angles. The Microscope in the Tool Room, F. A. STANLEY. Am

Mach v30 Dec 12 1907 p 887-92 and 916. An illustrated

article showing how a great variety of operations in con- nection with tool work may be facilitated by the use of the microscope. A comprehensive article. The Microscope in the Manufacturing Plant, F. A. STANLEY. Am Mach v31 Jan 16 1908 p 77-8. Illustrates and

describes some of the advantages of the microscope in connection with manufacturing processes. Includes the

description of a microscope having two micrometers at

right angles to each other mounted in the base of the instrument and actuating the work-supporting table. Registration Micrometer for Spectra, O. LOHSE. Zeit InstrumKde v30 June 1910 p 169-73. Description of a new measuring micrometer for spectra, with a series of registration keys for recording the readings directly as

observed. Der grosse Komparator der Kaiserlichen Normal-Ei- chungs-Kommission (Large Line Comparator of K. N. E. Komm), W. KOSTERS. Zeit InstrumKde v33 Aug 1913 p 233-47 9 figs. Describes a new comparator for the finest length measurements and for comparison of meter bars. Describes the room in which it is installed ; the system of interchange of the standards ; the pier and microscope

the rail, turntable, and carriage ; the troughs of the one- meter comparator and its length-standard supporting

table ; special features of the one-meter comparator ; and

the troughs of the four-meter comparator. Micrometer Microscopes, A. W. GRAY. NBS Sci Paper

215 Bui 10 1914 p 375-90. Discusses some errors affecting

measuring microscopes, methods of applying corrections

to a group of micrometers and of determining the correc- tions of micrometer microscopes. Measuring Templets and Screw Threads with a Microscopic Measuring Machine. Machy (N.Y.) v24 May 1918 p 791-3 5 figs; Am Mach v53 July 22 1920 p 187; Eng

Prod v2 Jan 13 1921 p 4-44 12 figs. Construction and ad- justment of Alfred Herbert design of measuring micro- scope and application for testing accuracy of templets or contour gages and screw threads. The machine has a

table capable of 12-in. longitudinal movement by accurate amounts by insertion and removal of hardened steel measuring rods between flat contact pieces. The table carries a pair of centers, one of which can be adjusted crosswise

to enable accurate alignment of work. A microscope fitted with two crosshairs, one rotating with the outside tube and the other rotating with the eyepiece, is mounted on

a compound slide controlled by micrometer screws. The

outer tube of the microscope has a dial reading to half de- grees and the eyepiece has a vernier reading to one minute. A light projector is fixed to the machine and will project parallel rays of light past the work. Use of Microscopes in the Gage Section, Bureau of Standards, R. L. RANKIN. Am Mach v51 Sept 18 1919 p 581-2. Discusses use of microscope in linear measurements on

gages, etc. Note on a Handy Form of Measuring Microscope, T. F. CONNOLLY. Opt Soc Trans v22 nl920-21 p 194-8. The

instrument comprises a microscope system of relatively low power ; a double-image prism traverses the object- space, and is controlled by the rotation of a milled band

operating a spiral slot. Exit pupil discs of telescopes or other optical instruments and Brinell impressions can

be measured by a single contact setting of the edges of the duplicated discs. The range is from 1 to 6 mm. and

the accuracy with fixed focus ±0.02 mm. The reading

scale is divided to 0.1 mm. No vernier is used. A New Ocular Micrometer, H. KELLNER. J Opt Soc Am

v7 Oct 1923 p 889-91 4 figs. Describes micrometer employing sliding measuring wedge in place of micrometer

screw. Presents the advantages but not the defects of both the micrometer screw and the glass scale. A glass

scale is adjusted by a sliding wedge and readings then taken to three places of decimals. On the Limit of Accuracy in Optical Measurement, A. A. MICHELSON. J Opt Soc Am and Rev Sci Instrum v8

321-8 Feb 1924. The limits of accuracy obtainable in observations with the telescope, microscope, interferometer, and spectroscope are discussed. Societe Genevoise Combined Measuring and Drilling Machine. Am Mach v66 June 30 1924 p 1112. Adapted for measuring in polar coordinates. Has circular table per- mitting angular measurements, table lead screw of 4 in. range, and a microscope.

Zeiss Thread-measuring Instruments. Am Mach v62 May

28 1925 p 861-2 5 figs. A toolmakers' microscope is shown

in fig. 5. Work may be mounted on V-blocks or centers that are placed on a compound table provided with a

swivel movement. For inspecting thread profiles the in- strument is provided with an accurate optical templet, containing the profiles of standard threads, as shown at

C, fig. 13, which is located at the upper portion of the magnifying lens and turned by hand until the desired

profile is brought into view. Microscopic Measuring Machine, C. M. GOOTSCHAU.

Machy (N.Y.) v31 June 1925 p 791-2 3 figs. A binocular measuring microscope for inspecting and measuring the

faces on type and embossing punches and for determining

their position relative to bodies and shanks. One micro- 124
scope is focused on a scale and the other on the work, the images being blended when seen through the binoculars. Principles and Advantages of Optical Methods for Measuring Machine Parts, H. F. KURTZ. Mech Eng v47 mid- Xov 1925 p 987-92 16 figs. Fig. 4 shows an erecting tool- makers' microscope, that is, one giving the image the same aspect and motion as that of the object. The crossslide stage is actuated by micrometers reading to 0.0001

in. Fig. 5 shows a special screw-measuring stage, and

Fig. 6 a goniometer eyepiece for the tool-makers' microscope. A New Measuring Micrometer, J. H. DOWELL. Opt Convention Proc. Part Hp 991-8 : Disc. 998-9 1926. A new

micrometer measuring up to 6 in. is described, and the

theoretical considerations controlling its design are dis- cussed. The main features are a carriage with geometric

bearings, which can be released from the nut to line up

the specimen, an enclosed screw and slide, and a microscope of geometric design adapted to take a wide range

of objectives. Societe Genevoise Measuring Microscope. Am Mach v64 Jan 28 1926 p 177-8. Measuring microscope suitable for the measurement of small machine parts, fibers, mesh of

textiles, pitch and diameters of small screws. Performs

both angular and linear measurements. The microscope

is mounted in a slide, the ways of which are part of the

rotating table. The angular position of the table is read

by means of a graduated circle and vernier. The slide

is moved by means of a micrometer. Ein Universalmessmikroskop (Universal Measuring Microscope), A. STEINLE. Maschinenbau v5 May 20 1926 p

445-9 16 figs. Discusses optical measurement of threads, and progress attained in increased precision with projection method. Bausch and Lomb Toolmakers' Microscope. Am Mach

v65 Oct 14 1926 p 652-3 2 figs. Microscope having base

with micrometer adjustment, illuminator attachment,

lead-measuring attachment, protractor eyepiece, etc. Zeiss Universal Measuring Microscope. Am Mach v66 May 26 1927 p 913-4. Has wider range than toolmakers' microscope and is designed to measure pitch diameter

of screw threads, using knife edges.

Society Genevoise Two-Coordinate Measuring Machine. Am Mach v69 Nov 1 1928 p 706-7. Also Machy (N.Y.) Nov 1928. The object to be measured is placed on a table which moves in one direction on V and flat ways under

the action of a precision micrometer screw which causes motion of the table through 16 in. The microscope is carried on a slide by which it is moved across the table by

a similar micrometer screw through a range of 4 in. Has

a variety of useful features.

Zeiss Improved lx3-in. Toolmakers' Microscope. Am

Mach v73 Nov 20 1930 p 832-3 2 figs. This model retains

the features of previous designs, such as : the dial templet

smooth table movement guided by balls ; a free swiveling

table top, and a quick-acting micrometer crank. The general design has been made more massive and sturdy, and

longitudinal movement of table of 3 in. permits the use of gage blocks. The cradle for the centers and V-blocks can

be clamped to the table. The box-type column can be

swiveled for bringing the microscope tube and illumination jointly into angular position for projecting the helix angle of a thread. Measurement of pitch diameter to within the limits of 0.0002 in. can be made. Specifications : Cross travel of table, 1 in. ; longitudinal travel of table, 3

in. ; magnification, 30 times ; range of micrometers, 1 in.

graduation of micrometers, 0.0001 in. ; reading of angles on universal ocular, 1 min. ; reading of angles on dial templet, 10 min. A special projection attachment, for converting the Zeiss toolmaker's microscope into a projector is available, making observation visible to both

eyes from an image on the screen. Societe Genevoise Micrometer Microscope. Am Mach v75

July 30 1931 p 221-2. Model 281-D may be used for check- ing the profiles of small gears or screw threads. The

micrometer screw is fitted and lapped into the bronze nut, while the thrust bearing of the screw is a sapphire ground

optically flat to eliminate periodic error. Micrometer- drum divisions permit estimates of a tenth of a division, or 0.000005 in. To obtain the complete reading it is merely

necessary to set down successively the numbers indicated on the turn counter and the micrometer head. The eye- piece can be placed over the center of the desired field to reduce the distortion of the image. Total magnification

is 41.5, 63 or 96 times. Optical Measuring Machine. Eng vl33 Mar 4 1932 p 294. Machine patented by R. Douglas, installed in Orthological

Institute, London ; measures small wire and like, to ac- curacy of 0.00005 in. ; method of measurement ; though

originally designed for measurement of very fine filaments or of very small holes, same method is applicable to ordi- nary workshop measurements. Measuring Microscope for Rubber Specimens, R. E. LOFTON. Indus and Eng Chem (Analytical Ed) v4 Oct 15 1932 p 439-40. Microscope provided with six-times mi- crometer eyepiece and objectives of 32 and 48 mm focal length is suitable for measuring cross-sectional dimensions

of rubber test specimens ; width of specimens is usually

greater than that of die with which they were cut ; thick- ness of soft compounds as determined by microscope is greater than that indicated by gage of plunger type. Improved Toolmakers' Microscope. Engr vl66 n4320 Oct

28 1938 p 477-8 ; Eng vl46 n3799 Nov 4 1938 p 547. Illus- trated description of Zeiss microscope for measurement

of gages, templets, form tools, screw threads, gears, and

similar parts. "Home-made" Toolmakers' Microscope, E. W. PENNINGTON, Am Mach v84 nl3 June 26 1940 p 460-1. Illustrated description of conversion job done on contour projector which widened its usefulness without sacrificing any of

its original functions. Direct-Reading Measuring Microscope, J. E. SEARS, JR., A. TURNER. J Sci Instrum v43 nl7 Feb 1941. The arti- cle describes a travelling microscope designed for measuring by direct readings Debye-Scherrer X-ray powder

photographs. With this instrument measurements are made by direct reference to a glass scale which can be

traversed, together with the photographic film, beneath

a low-power microscope in which the scale and film can be viewed together. A fixed vernier also of glass, is viewed

at the same time and readings may be made to 0.01 mm.

The scale and film are traversed by hand, enabling rapid movements to be made throughout the length of the film. A fine traverse is provided for adjusting the film image to the cross wire in the microscope. Measuring Microscope, G. H. WAGNER, G. C. MAILEY,

W. G. EVERSOLE. Indus and Eng Chem (Analytical Ed

)

vl3 n9 Sept 15 1941 p 658-9. Technique for measuring

vertical distances up to several centimeters with precision

of 0.00005 cm ; illustrated description of microscope which

has range of 16 cm and can be read to 0.000058 cm ; difficulties that were encountered and solved in construct- ing and calibrating instrument to this precision. Taylor, Taylor and Hobson Toolmakers' Microscope. Machy (London) v61 nl558 Aug 20 1942 p 217; Automobile Engr v32 n480 Nov 1942 p 497-8. Illustrated descrip- tion of microscope for use in toolroom and standards room, mainly intended for examination and measurement of screw threads, thread cutting tools and grinding wheels and for measurement of lengths and angles on small components, form tools, and

125
Cooke Toolroom Microscope. Machy (London) v61 nl559 Aug 27 1942 p 235-7. Illustrated description of micro- scope developed by Cooke, Troughton and Simms, intended

to serve as comprehensive measuring instrument in both

factory and laboratory. The Toolmaker Microscope as Optical Comparator, F. KOENIG. Screw Mach Eng June 1944 p 40-3 5 figs. Deals primarily with the adaptability of the toolmaker

microscope as a comparator.

Optical Locating System Takes Guesswork Out of Positioning, G. C. BECKER. Am Mach v90 nl Jan 3 1946 p

83-6. Developed for graduating curved gunsight elevating

bars, optical indexing fixtures use 40X toolmakers

microscope and specially engraved master scale; air clamps assure uniform pressure, permit operator to check

setting with microscope while applying pressure, and al- low quick release of work ; construction, operating details, performance and working results ; modifications of fixture discussed in which same principle is applied to other close tolerance machine work. The Measurement with the Microscope of Inaccessible Di- mensions of Macroscopic Bodies, G. SCHENDELL.

Archiv fuer Tech Messen nl78 (Ref. V1121-8) Nov 1950 p T120 in German. Two arrangements are described. They are suitable for measurements of, for example, elec- trode dimensions or spacings which are inaccessible due

to enclosure in glass envelopes or are at high potentials. Parasitic Vertical Movement of a Symmetrical System of Guided Rods, J. E. PLAINEVAUX. Nuovo Cimento vll June 1954 p 626-38 in French. A brief historical review

of mechanical arrangements for the rectilinear guidance

of elastic rods is followed by an approximate theoretical treatment of a particular compensation system which is used in microscope travelling stages. The treatment is based on the principle of the superposition of small de- formations. Das Mikroskop, A. METZ. Archiv fuer Tech Messen n223 Aug 1954 p 185-8. Microscope for length measurement

and contour control ; ocular micrometer ; measuring micro- scope with tube displacement ; applications. Semi-Automatic Recorder for Filar Micrometer Eyepiece and Its Application to Track Measurement, B. STILLER.

F. I. LOUCKES, JR. Nuovo Cimento (Ser. 10) v4 n3

Sept 1956 p 642-7. A differential transformer has been mounted on a filar micrometer eyepiece and has been

coupled to a recording circuit, to make possible automatic

recording of the hairline positions. The apparatus greatly reduces the time required to make measurements with a

filar eyepiece; e.g., as when measuring the multiple Cou- lomb scattering of tracks in nuclear emulsions. A Photoelectric Microscope for the Measurement of Linear

Scales, J. S. CLARK, A. H. COOK. J Sci Instrum v33 n9 Sept 1956 p 341-7. A description is given of a photoelectric microscope which is suitable for the accurate measurement of linear scales of high precision. A real image of a graduation line, formed by means of an ordi- nary microscope objective, is caused to oscillate across a

fixed slit in front of a photoelectric cell. A phase-sensitive

rectifier determines when the mean position of the line image coincides with the center line of the slit. When

this is so, the d.c. output of the rectifier is zero and for small displacements of the mean position of the line gage, the d.c. output—which is measured on a microammeter

is proportional to the displacement. The standard deviation of a single setting of the microscope is about 0.03/t and by associating the microscope with an interferometer, short linear scales have been measured directly in wavelengths with a standard deviation of about 0.1,u. It is thought that, with a properly designed interferometer to measure the displacement of a scale with respect to a

fixed photoelectric microscope a standard deviation of

0.05,u would be achieved. Measurement of the Diameter of Opaque Cylinder by Scan- ning Microscopy, J. A. DOBROWOLSKI, W. GODFREY,

P. N. SLATER, W. WEINSTEIN. J Opt Soc Am v47 n2 Feb 1957 p 186-90. Experiments have been carried out to determine the systematic errors in the measurement of the diameters of opaque cylinders by scanning microscopy. It was found that for cylinders of diameter near the optical resolution limit, the scanning microscope gives too large a size estimate. The variation of the error with aberrations and numerical aperture of the scanning objective, and with the wavelength and state of polarization of the

light were determined. Optimum conditions for size de- termination are suggested. Modifications to a Travelling Microscope Used for Measuring X-ray Powder Photographs, W. E. ARMSTRONG,

R. J. DAVIS. J Sci Instrum v35 n2 Feb 1958 p 59-61. The cross-hairs in the microscope eyepiece were removed and the reference mark was obtained from a light spot thrown on the photograph from a projector clamped to the barrel of the microscope. Cross-hairs seen in silhouette tend to obscure faint lines on the photograph and prevent

their measurement. The light spot eliminates this effect, allows change of magnification for measuring different

lines without moving the reference mark, eliminates paral- lax and allows the use of a binocular eyepiece. These

features reduce eyestrain while measuring a photograph, and improve the accuracy of measurement of faint or dif- fuse lines. The photograph is illuminated by a short

fluorescent tube, the light of which is cooler and "harder"

in quality than that of filament lamps. Means are de- scribed of adjusting the light intensity of the tube over

a wide range. Microscope Mechanical Object Stage for the Study of the Tracks of Charged Particles in Photographic Emulsions

or Other Objects in Transparent Media, H. SLATIS. Rev

Sci Instrum v29 nil Nov 1958 p 968-70. In addition to the usual arrangements for measurements of the x and y coordinates for nuclear tracks in photographic emulsions,

the stage is rotatable about the optical axis of the micro- scope as well as about an axis perpendicular to the optical

axis. The angles of rotation can be read off scales. Through these arrangements and by the use of an eye- piece micrometer the orientation and the length of nuclear

tracks can be measured directly. La Dispersion de Lecture dans les Microscopes Micrometriques, J. PETTAVEL. Optics in Metrology, P. MOLLET. Pergamon Press 1960 p 63-72 12 figs 2 refs. Dis- cusses measuring accuracy of micrometer microscopes having projection screens. The reading dispersion is the

sole factor affected by the design of the micrometer. Comparison of dispersion curves for different types. The

reading dispersion is less on projection screens than in microscope eyepieces provided that the surface is devoid

of granulation. Length Measurement at the Optical Resolution Limit by Scanning Microscopy, W. T. WELFORD. Optics in Metrology, P. MOLLET. Pergamon Press 1960 p 85-91 4 figs 6

refs. The image of an edge object in a scanning micro- scope with full-cone illumination is calculated, and it is shown that the half-intensity point does not occur at the

position of the geometric image, resulting in a systematic

error in determination of the position of the edge. A Precision Microscope for the Measurement of Small

Dimensions, V. E. KOSTIN. Meas Techns 1959 n6 June

1960 p 412-3 1 fig. Translated from Izmer Tekh n6 June

1959 p 18. The measurement of dimensions with the preci- sion measuring microscope is performed by absolute and

comparative methods. The first method is used with the ocular micrometer, and in the second, the measurements 126
are performed by comparison with a length standard

placed between supports. A Semi-Automatie Analyser for Bubble Chamber Photographs, O. R. FRISCH. A. J. OXLEY. Nuclear Instrum and Methods (Int) v9 nl Oct 1960 p 92-6. Photographs of nuclear particle tracks can be accumulated rapidly with

fast-cycling bubble chambers. This article describes a machine for measuring the photographs quickly so that

the subsequent computation can be done with an elec- tronic computer. The films are projected onto a ground

glass screen bearing a reference mark, and moved by hand

through a pantograph to bring interesting points onto

the mark. The pantograph carries a plate with a fine square lattice of dots, and four photocells serve to digitize

its X and Y coordinates. The two stereoscopic images of

a point can be merged by moving one of the projection

lenses; this motion also is digitized photoelectrically. After setting each point, the measured data are punched

on tape, to be fed later to an electronic computer. The

design, operation, and performance of the machine are

described in some detail, together with the principles of measurement and some proposed improvements. A Xew Micrometer Microscope, R. BARER. Nature (Lon- don) vl88 Oct 29 1960 p 398-9. Measurement of the size of particles in a microscope against an eyepiece scale is tedious and often inaccurate. A new system is described

in which two images are seen, sheared by a known amount.

Particles whose diameter equals the shear will just touch, those smaller will appear as two distinct objects, while

layer particles will overlap. An attachment to a standard

microscope is described. This allows the shear to be controlled in amount and direction, so allowing the meas- urement of irregular shaped objects. Photoelectric Microscopes for Comparing Graduated

Linear Measures. L. K. KAYAK, S. I. TOROPIN. Meas

Techns 1960 n2 Nov 1960 p 90-2 2 figs 3 refs. Translated from Izrner Tekh n2 Feb 1960. The developed experi- mental photoelectric microscope, applied to a four meter

comparator, is suitable not only for sighting graduations,

but also for direct measurement of length differences read

off a comparator by the objective method. Measurement of Object-Micrometer Type Scales, N. A. KLIENTOV. Meas Techns 1960 n2 Nov 1960 p 93^1 1

fig. Translated from Izmer Tekh n2 Feb 1960. A special- ized instrument for measuring object-micrometer type

scales has now been installed in a production shop. By

means of this instrument rapid and efficient measurements

of object-micrometers are made according to the specifica- tion of GOST 7513-55. Checking MPB-2 Measuring Microscopes, F. P. VOLOSEVICH. Meas Techns 1960 n2 Nov 1960 p 95-6. Translated from Izmer Tekh n2 Feb 1960. Describes a modified hori- zontal comparator IZA-2 for checking the readings of measuring microscopes MPB-2 used with hardness testers TSh. Modernized Horizontal Comparator, E. I. FINKEL'- SHTEIN. Meas Techns 1961 nl Sept 1961 p 16-20 4 figs 2

refs. Translated from Izmer Tekh 1961 nl p 12^, Jan

1961. Describes an improved comparator for testing ref- erence linear scales. Method for Determining Comparator Screw Errors with

Precision, J. M. BENNETT. J Opt Soc Am v51 nlO p

1133-8 Oct 1961. A method is described for determining

with precision the relative cumulative error and the

periodic error of a comparator screw. Measured curves of these errors shown for two comparators. The method

also gives the relative lengths of the intervals on the scales used in the measurements. The SIP Type CLP-10 Photoelectric Longitudinal Comparator, A. W. ASTROP. Machy (London) v99 Oct 25

1961 p 944-62 19 figs. Details of new length-measuring and

comparing equipment. The basic principle as proposed by M. Volet ; features of the mechanical design ; the travers- ing carriage ; traversing the carriage ; drive to the carriage and microscopes ; the photoelectric microscope ; measure- ment and comparison without interferometry ; the inter- ferometry equipment; using the Fabry-Perot etalon;

special permises. A Photoelectric Setting Device for a Measuring Microscope, H. GOLLNOW. Monthly Notices Roy Astron Soc

( GB ) vl23 no 1962 p 391-7. A photoelectric setting device

for the measurement of emission and absorption lines is described. Its special advantages for the case of ill-defined and asymmetrical stellar lines is discussed. The probable

error for one setting is well under half a micron and is independent of line definition; systematic errors between

different observers are practically eliminated. Setting Accuracy of Graduation Lines, W. LOTMAR.

Microtecnic vl6 n2 Apr 1962 p 55-60. Comparative in- vestigations concerning setting accuracy of graduation

lines between 2 straddling reference lines have shown

that method of image formation has no manifest influence on standard deviation, providing comparable optical equip- ment is used. A Device for Accurate Linear Measurements of Chart

Traces and Graphs, M. D. ROGERS. J Sci Instrum v39 n6 June 1962 p 317 1 fig. Measures to within 0.002 in. the position of x-ray diffraction peaks obtained on a chart

recorder. A Cathetometer with Automatic Levelling, J. GIELESSEN, K. STEINER. Zeit Angew Phys (Germany) vl4 nl2 Dec 1962 p 715-7 in German. An optical device elimi- nates the need for levelling the cathetometer telescope each time it is displaced. Microscope for Measuring Small Diameter Holes and

Their Concentricity, S. L. GONDIK. Meas Techns 1962 n8 Feb 1963 p 648-9 2 figs. Translated from Izmer Tekh

n8 Aug 1962 p 23^. See abstract in subsection 7.4. Test Measurements in Comparators and Tolerances for Such Instruments, B. P. HALLERT. Photogrammetric Eng v29 n2 Mar 1963 p 301-14. Comparator tests are as- sumed made with aid of measurements of grid coordinates

of high and known geometrical quality ; tolerances of regular errors, residuals and standard errors of unit weight are determined according to confidence limits from statistics

practical examples ; certain regular errors of grid coordi- nates can be distinguished from errors of comparator

tests of some different glass scales are shown. Magneto-Optic Positioning, R. J. MELTZER. IEEE

Trans Ind Electronics vIE-10 May 1963 p 46-56 27 figs. The system described permits production of accurate scales and grids, with a precision better than one //. in, by forming an image of the line with polarized light whose angle

of polarization varies with the position of the line. A

combination of position sensitive polarization of Faraday

modulation produces a signal whose phase depends on the sense and whose amplitude depends on the amount of dis- placement of the line image from the optic axis. Sensitivities of one microampere per microinch displacement can be achieved with unit magnification. Cathetometer KM-8, F. M. DANILEVICH, V. A. NI- KITIN. Measurement Techniques (English translation of Izmeritel'naya Teknika) n7 July 1963 p 544-6. Cathe- tometer described is intended for measuring vertical seg- ments up to 500 mm in length, at distance of 280-1810 mm

from protective glass of telescope (with lens attachments) and in range of 1810 to infinity (without attachments) : as compared to its Western counterparts, instrument is claimed to have higher precision in measuring vertical linear segments, smaller error in its reading device, and 127
higher efficiency and ease in operation, since image of

object, millimeters scales, and level bubbles are seen si- multaneously in eye piece field of vision. Measure to Millionths-in Seconds, C. STEAD. Am Mach/

Metalworking Mfg vl07 nl9 Sept 16 1963 p 109-11. Carl

Zeiss Universal Measuring Microscope employed 'by Taft- Peirce Manufacturing Co, Woonsocket, RI measures all kinds of contour gages, threads of any shape, cutting

tools, templets, chasing tools, and similar parts ; with attachment it can measure eccentricity and helix angle on

threads, worms, gear shaper cutters, and gear and

thread hobs; direct readings can be made to 50 millionths of in. and 1 min of arc ; measuring time cut 85%.

Development and Applications of Photo-Electric Microscopes, A. MOTTU, J. PETTAVEL. Proc Mach Tool Design and Res, Pergamon Press 1964 p 455-71 18 figs. Principle of photo-electric microscope is discussed, together with applications in calibrating divided scales, determining the position of a movable member of a machine or in- strument, and positioning manually or automatically a movable member of a machine or instrument. An Improved Temperature-Controlled Bath for the Comparison of Line Standards, E. G. THWAITE. Microtecnic vl8 nl Feb 1964 p 2-7 7 figs 3 refs. The interrelation- ship of uncertainty of temperature, material of standards, and inaccuracy of linear measurement is discussed to- gether with the special requirements of a temperaturecontrol system to allow temperature to be measured to the accuracy required in very precisely comparing reference

line standards. A description is given of a temperaturecontrolled bath, having a stability of ±0.003 °C at 20 °C

for periods of 15 minutes, developed for use on a 1-meter

line standards comparator.

Photo-Electric Microscope for Precise Setting on Scale

Lines, J. L. GOLDBERG, H. J. RITTER, Microtecnic vl8

n2, 3 Apr 1964 p 54-67, June p 117-24. Description of photoelectric miscroscope designed for use in transferring from optical wavelength standards to mechanical linear standards ; instrument provides indicator to permit impersonal settings to be made on line standard consistent

to 0.01 /i as compared with 0.2 /i for visual microscope ; de- viations of up to plus or minus 0.2 p from set position can

be measured; lineal magnification of displacement is 350.000 times; electronic system uses semiconductor cir- cuits which meet all requirements of stability for instru- ment of this type. Measurement of Microscope Magnification, D. H. FREE- MAN. App Optics v3 n9 Sept 1964 p 1005-8. Procedure of calibrating ruled scale and of measuring magnification of

visible light microscope is described ; measurement tech- niques include use of movable hairline micrometer, imagesplitting ocular, photoelectric scanning of photomicrographic plates, and photoelectric scanning of image plane

empirical treatment of magnification measurements, in- cluding effects of optical distortion, is employed, so that

residual errors are assigned to imperfections in measuring

screw plus random contributions.

Classification of Photoelectric Microscopes, A. M. DUBI- NOVSKII. Meas Techns n3 Oct 1964 p 205-8 8 refs. Translated from Izmer Tekh n3 p 13-5 Mar 1964. Photoelectric microscopes can be divided by the principle of

their conversion of the measured quantity into an elec- trical signal into three groups, of amplitude, pulse-position, and modulated types. Each type has a characteristic functional circuit from which it is easy to determine the

relationship between their measurement error and their

circuit component parameters. Pulsed photoelectric mi- croscopes are superior to others in their quality characteristics, such as stability of readings, range, etc. The

amplitude and modulated photoelectric microscopes are mainly used as null detectors, whereas it is possible by means of pulsed photoelectric microscopes to measure the

position of graduation lines, as well as distances between

them. An analysis made by means of the information

theory has shown that it is possible to evaluate the properties of photoelectric devices by means of information

characteristics, such as the flow of useful information and the capacity of the reading unit. These characteristics are suitable for finding such parameters of microscopes as precision and speed of operation. Addendum to Section 4

4.1. Line Standards, General

Untersuehungen und Maasregeln zur Herstellung der Einheit des preussischen Langenmaases (Experiments and Measurement Control for the Production of the Prussian Length Standard), F. W. BESSEL, Berlin 1839 148 p. On the Measurement of the Base Lines at Holton, Indiana and at St. Albans, W. Va., 1891-2, A. T. MO'SMAN, R. S. WOODWARD, O. H. TITTMANN. Appendix 8, Report

for 1892, U.S. Coast and Geodetic Survey, Government

Printing Office 1893 p 329-503. Contents : Description of iced bar base apparatus and its application to the measure- ment of base lines ; length of iced bar Bi7 ; measurements made with iced bar apparatus ; the metallic tape base apparatus ; measurements of bases made with the tape apparatus ; method of computing correction for flexure

of 5-meter bar Bw ; and mathematical theory of metallic

tapes, including changes in length due to variable parameters. (Continued on p. 173)

128
Section 5. Dimensional Measuring Instrument Design Features

CONTENTS

Page

5.1. Measuring instruments, design principles 129

5.2. Amplification 131

5.2.1. General 131

5.2.2. Electrical 132

5.2.3. Mechanical 138

5.2.4. Optical 139

5.2.5. Pneumatic 141

5.3. Dials and pointers 143

5.4. Optical features 143

5.5. Pivots 146

5.6. Slides, stands, and tables 146

5.7. Springs and suspensions 148 Addendum to Section 5 151 5.1. Measuring Instruments, Design Principles

The Parallel Motion of Sarrut and Some Allied Mechanisms, G. T. BENNETT. London, Edinburgh and Dublin

Phil Mag v9 June 1905 p 803-10. A link mechanism for exact parallel motion is described. See also Dunkerley's

Mechanics, page 386. Design and Construction of Scientific Instruments, R. S. WHIPPLE. Opt Soc Trans v22 1920-21 p 35-52; Eng

vlll May 27 1921 p 659-62. A general resume of the

principles underlying the design of scientific instruments. The Mechanical Design of Scientific Instruments, A. F. C. POLLARD, J Roy Soc Arts v70 Sept 29, Oct 6 and 13 1922 p 769-80, 783-94, and 797-808 43 figs ; Eng vll3 June 9 16

23 and 30 1922 p 729-30 763-64 794 and 828-9 24 figs. Consideration in design of qualitative and quantitative instruments used in many branches of physical, engineering and chemical sciences. Abstract of three Cantor Lectures delivered before Royal Soc of Arts. Notes Upon the Mechanical Design of Some Instruments Shown at the Exhibition of the Physical and Optical

Societies, 1928, A. F. C. POLLARD. J Sci Instrum vo Mar 1928 p 88-92 5 figs. Ross kinematograph projector

Maltese cross movement ; W. Ottway and Co. screw measuring machine ; Laby X-ray spectograph ; goniometer fit- ting of Muller's X-ray goniometer spectrograph. Konstruktionsgrundlagen der feinmechanisehen Technik

(Principles of Instrument and Apparatus Design), W. KNIEHAHN. VDI Zeit v72 n49 Dec 8 1928 p 1773-5

34 figs. Discussion of standard structural elements, joints, bearings, gearing, etc., of mechanical, electric, optical, and acoustic apparatus. The Geometric Design of Scientific Instruments, J. A. TOMKINS. Instrum Wld vl Dec 1928 p 229-31. Considers degrees of freedom and gives examples showing

the result of the imposition of successive constraints on a

rigid body, each constraint being imposed by causing one

point of the body to touch a fixed surface. Examples

of geometrical slides and geometrical clamps. Lists

authorities. Notes on Design of Measuring Instruments, F. H. ROLT.

Ch. 14 of Gauges and Fine Measurements, Vol. II. Macmillan and Co. Ltd, 1929. Discusses geometric location, geometric slides, the principle of alinement, form and

flexure of measuring machine beds, the thrust of micrometer screws, the use of flexible steel strips, micrometer

screws, and fine adjustments. Grundlagen und Geraete Technischer Laengenmessungen,

G. BERNDT. 2d ed. Berlin, Julius Springer 1929 374 p

illus diagrs tables. Survey of scientific principles of measurement and instruments for practical use ; evolution of usual standards is described, and methods by which

shop and control standards of length are made and cali- brated are discussed ; application of various types of gages and other measuring instruments ; physiological errors in measurement and reference of meter to wavelength of

light are discussed in appendixes. Eng. Soc. Library, N.Y. H. SCHULZ was coauthor of 1st ed 1921. Zwei Messtechnische Grundsaetze und ihre Befolgung (Two Fundamental Rules of Measuring Techniques and

Their Observation), G. BERNDT. Werkstattstechnik

v24 Sept 1 1930 p 461-7 22 figs and Sept 15 1930 p 495-8

10 figs. Sept 1 : Example of comparators shows that to avoid errors of first order, object and not measuring in- strument should be moved; it is further made apparent

that for longitudinal comparator standard and object must be located on same axis (Abbe's principle) ; observation of these rules in principal measuring instruments and methods is investigated. Sept. 15: Technical measuring methods and instruments based on principle of transversal comparator. Works of Messrs. Cambridge Instrument Co., Ltd., Eng

vl32 n3416 July 3 1931 p 1-5 21 figs partly on p 16 and supp

plate. In design of instruments, geometric principle, of which late Darwin was perhaps greatest exponent, is largely employed ; examples of effective application of geo- metric principle of instrument designs ; layout and equip- ment of works ; research ; work organization.

Zeiss Optical Cam Checking Device. Am Mach v75

Sept 3 1931 p 397. The outfit consists of a scraped sur- face plate with two parallel T-slots, an optical dividing head and tailstock and a measuring microscope. The

camshaft is taken between centers, and the angular set- ting secured from the optical dividing head. The readiug 129
may be taken directly to one minute of arc. Rise and

fall of the cam for each angular setting is secured by means of the measuring microscope. The reading is obtained directly from a scale. Distance between centers can be up to 60 in. Daempfung von Messgeraeten (Damping of measuring in- struments), W. HOFMANN. Archiv fuer Tech Messen

vl Mar 1932 p T38-9, and Apr p T54 ; Veroeffentlichungen aus dem Gebiete der Nachrichtenteehnik 2 n2 1932 p 103-6. Mar : Fundamentals, theory and determining values

theoretical mathematical analysis and curves. April

Calculation of air damping devices for measuring instru- ments. Bibliography. Luftdaempfungen fuer Messgeraete (Air damping of measuring instruments), F. EICHLER. Archiv fuer Tech Messen vl Apr 1932 p T55. Application and de- sign of air damping devices for measuring instruments. Some Industrial Applications of Metrology, M. F. TURRETTINI. Machy (London) v50 nl299 Sept 2 1937 p 692-5. Fundamental conditions that must govern design

of precision instrument or machine, in order to ensure

best chances of success ; example given of causes of error which may arise in operating screw cutting lathe. Before

Eeole Nationale Besancon. Measuring and Gauging Contacts for Modern Production,

F. HORNER. Can Machy v48 nl2 Dec 1937 p 192-5, 202 and 220. Production methods demand great accuracy which can only be obtained by suitable measuring devices equipped with surface of contacts of special design, some

of which are briefly described ; solid and adjustable gages

micrometer calipers ; internal micrometers ; screw gaging and measuring ; contacts for indicating. Design Factors Controlling Dynamic Performance of In- struments, C. S. DRAPER, G. P. BENTLEY. ASME Paper

n30 mtg Dec 4-8 1939 9 p. Generalized treatment of in- struments which have single movable index, controlled by magnitude* of single actuating quantity ; such instru- ments act as system with 1° of freedom ; properties can

be specified in terms of range, scale sensitivity calibration and environmental error and uncertainty ; definitions and

use of each of these quantities discussed. Bibliography.

Use, Care and Maintenance of Laboratory Instruments, H. N. HAYWARD. J Eng Education v30 n5 Jan 1940 p

506-10. If accuracy is to be maintained and known, fre- quent checking of test instruments with reliable working

standards is essential ; if possible, correct type of instru- ment should be used in every application ; cause of errors

in instruments ; calibration and checking of instruments. Instruments for Measuring Dimensions, O. W. BOSTON.

Metal Progr v48 n4 Oct 1945 p 991-6. Linear dimension measuring instruments and gages discussed in relation to design, principles and applications as quality control tools. General review, O. W. Boston ; Rules, Micrometers and

Calipers, H. D. Hiatt ; Comparators, W. H. Baker. Geometrical Measurement, C. H. H. FRANKLIN. Eng

Inspection vll n2 summer 1946 p 9-23. In principles set forth engineering production is considered mainly as art of controlled production of geometrical forms in agreed

relation to standard units of size and shape; standards of length measurement ; accuracy and limits ; systems of geo- metrical measurement ; complex measurements ; apparatus

characteristics ; geometrical construction of measuring

appliances ; sources of error in geometrical methods ; use

of interferometer. Before Instn Eng Inspection. Precis of a discussion on "Practical considerations in in- strument design"—London, 1948. J Sci Instrum Phys

Ind v25, Apr 1948, p 122-4.

New Optical Precision Measuring Instruments for the Workshop, A. METZ. Trans Instrum Meas Conf Stock- holm 1949 p 182-5 1950 in German. A brief illustrated de- scription of new Leitz instruments. These include an

instrument for the control of sizes of workpieces, a co- ordinate drilling machine with a precision measuring

ocular, a telescope with a magnification of 32 and a range

of 1-50 metres, and the "Perflektometer," an instrument

for the measurement of end gap and other gauges. Laboratory Instruments, Their Design and Application,

A. ELLIOTT, J. H. DICKSON. Chemical Publ Co, New

York, 1953 414 p. Principles of good design necessary for construction for instruments in laboratory workshop ; sep- arate chapters discuss properties, treatment, and use of various materials ; methods of construction to meet special requirements ; Kinematic design of instruments ; optical instruments and glass; use of photography in research. Eng Soc Library, N.Y. Discussion on Kinematic Design Applied to Instruments. Soc Instrum Technol Trans v6 n2 June 1954 p 66-82. Views of various participants on advantages of instru- ment design based on kinematic principles ; such practice

is of value in improvisation of research apparatus to be put together without specially good workmanship, con- struction of apparatus which is precise in function with- out imposing close dimensional limits, and design of equip- ment for metrology applications ; particular instrument

designs. Instrument Linkages, W. O. DAVIS. Soc Instrum

Technol Trans v7 nl Mar 1955 p 1-9. Design of linkages which have to operate accurately in indicating or computing instrument mechanisms under conditions of vibration and abnormal acceleration ; return springs and

counterpoises ; relationship of number of kinds of calibra- tion adjustment to number of null error points obtainable

in calibration curves ; examples of linkages for providing

linear, square-law, and log-law approximations in translation-to-rotation mechanism. Some Principles of Measurement and Control, J. F. COALES. J Sci Instrum v33 nl2 Dec 1956 p 457-64. Two classes of measurement are those which only have to be observed and recorded and those which are used to control; limitations from which all measuring instru- ments suffer, e.g. they all disturb physical system on which measurements are being made and they all have

inertia and damping to some degree, also no measuring

instrument is completely stable ; these limitations are dis- cussed; simple theory of linear control systems is developed. New Comparator for Measuring Pitch Errors of Fir-Tree Root Serrations in Gas Turbine Discs, L. W. NICKOLS.

Machy (London) vl9 nil Nov 1957 p 450-4. Comparator

described is complementary to instrument reported in Engineering Index 1955 p 202; new comparator rapidly measures pitch errors to desired accuracy by comparison

with composite slip gage standard, with errors recorded on chart ; design and principle of operation ; measuring head and turret ; workholder and indexing mechanism

setting comparator; interpretation of chart record. Aperture Corrective Systems, J. OTTERMAN. IRE

Trans Instrum vI-8 nl Mar 1959 p 8-19. Corrective networks for improving performance of certain instru- mentation systems ; desired correction serves to offset averaging effect common to such sensing devices as deflec- tion plates of oscilloscope, scanning beam of television camera, networks particularly useful when aperture small enough to provide essentially flat response up to desired frequency is not technically feasible. Mesure et Instrument de Mesure (Measurement and Measuring Instruments) , J. IDRAC, 4th ed. Dunod, Paris 1960 L30
125 p. Basic principles of measurement ; areas of measure- ment and sensitivity ; accuracy : velocity : statistical distributions. La Mesure dans l'Automatisme, l'Automatisation des Mesures (Measurement in automatization, and automatization of measurements), U. ZELBSTEIN. Genie Chini v83 nl Jan 1960 p 1-14. Automatization of measurement

is essential when manual observation and control is impossible (for example, at high speeds) or when standard arrangements have reached limit of their possibilities. Universal Mechanical Assembly for Laboratory Purposes,

Particularly for Optical and Semi-Automatic Measurements. J. BAKOS, Z. ERDOKURI, K. KANTOR Magyar

Tudomanyos Akad Kozponti Fiz Kutato Intezetenek Kozlemenyei (Hungary), v9 n3 p 171-80 1961 in Hungarian. Describes a versatile mechanical unit and driv- ing mechanism both easily assembled from universal ele- ments. The driving mechanism can be remote controlled. The two assemblies are suitable either for individual or

for joint use. The various elements are provided with

connections to optical and precision mechanical tools, and

in this way their usefulness may be considerably extended. Logarithmische Terstaerker mit VDR-Widerstaenden

(Logarithmic amplifiers with voltage dependent resistor resistances), R. ROEHLER, H. P. POPP. Zeit In- strumKde v70 nl Jan 1962 p 15-16. It is found that

certain ceramic resistances have logarithmic characteristic within wide range which is made use of in construction of logarithmic amplifier: deviation of amplifier- characteristic from logarithmic scale is maximum of 2%

within 3.5 decades ; amplifier is used for direct indication

of emulsion densities, but its range of application is much

larger. Grundbegriffe der Messtechnik (Fundamentals of Measuring Practice). DIN 1319 lop Jan 1962. German standard

available in both German and English from ASA. price

$2.50. Covers basic principles governing the use of measuring instruments and fundamentals of errors arising in measuring practice. Applies to measuring instruments

in which an index associated with the instrument is set, or sets itself, to a position on a scale belonging to the instrument.

Kontakteinrichtungen fuer empfindliche Zeigermessgeraete (Contact devices for sensitive indicating instru- ments), K. H. ZEITZ. Archiv Tech Messen n313 315 Feb 1982 p 33-6, Apr p 87-90. Principles of operation and design of devices for wide range of instruments used

for chemical processes, industrial temperature measurement, etc., 23 refs. Non-Contact Dimensional Measurements by Optical and

Electronic Techniques, C. D. BRYANT. IRE Trans on Indus Electronics vIE-9 nl May 1962 p 1-6. Accurate

dimensional measurements of. products during processing are major requirement in many industries; because of high heat radiation, rapid motion, or other factors noncontact measurement system is desirable; systems which have been developed using combination of closed circuit television and special optical techniques together with

special purpose computers and associated readout devices. Some Uses of Elasticity in Instrument Design, R. V. JONES, J Sci Instrum v39 n5 May 1962 p 193-203. Dis- cussion of anti-distortion instrument mountings, elastic movements for rotation and translation, movement magnifying and reducing devices, elastic averaging schemes,

simple harmonic force and constant force systems, elastic energy stores, and slow relaxation device for transmitting rapid displacements only. 45 refs. Graticules and Fine Scales : Their Production and Appli- cation in Modern Measuring Systems, E. BOVEY. J Sci Instrum (GB) v39 n8 Aug 1962 p 405-13. After a histori- cal survey an account is given of a wide range of proc- esses employed for graticule manufacture. Optical, photographic and mechanical requirements together with

their respective limitations are discussed. Finally, some

special high-quality graticules and scales employed in modern measuring systems are described.

Classification of Automatic Measuring Instruments, V. M. SHLYANDIN. Meas. Techns 1962 n6 Dec 1962 p 456-7. Translated from Izmer Tekh n6 p 9-11 June 1962. Devel- ops the definition that an automatic measuring instrument

is a device which evaluates objectively the measured

quantity by balancing it automatically with a compensating quantity, and which uses for this purpose an

auxiliary power source.

5.2. Amplification

i 5.2.1. General

Measurement of Small Displacements, A. RIGHT N

Cimento v6 1897 p 349-52 in Italian. The author describes

a simple method of measuring small displacements, such

as the motion of a point on an expanding bar. It consists

essentially of a short lever supported at two close points on the same side of its centre of gravity by two very fine stretched fibres, one of which runs in an upward direction, and the other downward. The directions of the fibres will intersect on the vertical through the centre of gravity of the lever. The lower end of the lower fibre is fixed, and

the upper end of the upper one is attached to the moving

point. When the point moves upward or downward, the

lever is tilted, and the angle of tilt is measured by a tele- scope, or lamp, and scale. In the actual instrument the suspension is bifilar; a thread of three cocoon-fibres is formed into a rectangle, the two upper corners of which

are fastened to a rod connected with the moving point, and

the two lower corners to a similar rod connected with the

fixed point. The thread passes between two jaws at each end of a crosspiece attached horizontally at right angles

to the lever. By this means errors due to torsion of the

fibre are avoided; and by using short fibres changes in length due to humidity of the air do not cause any appreciable error. The author has succeeded in magnifying

a small motion twenty thousand fold by this apparatus. Empfindlichkeit von Instrumenten, G. KEINATH.

Archiv Tech Messen vl Feb 1932 p T22. Sensitivity of measuring instruments ; rules outlined are applicable pri- marily to electric instruments and also to great extent to other types ; definitions ; value of high sensitivity ; sensitivity of various types ; current, voltage and energy sensitivity ; numerical data. Bibliography. Recent Progress in Making of Precision Instruments, A. J. PHILPOT. J Roy Soc Arts v96 n4764 Mar 12 1948 p 213-22 (discusssion) 222-1; Mech Wld v 123 n3187 Feb 13 1948 p 193-4 ; Metal Industry v72 n8 Feb 20 1948 p 151-2 ; Machy Market n2474, 2475, Apr 16 1948 p 195-6. Apr 23 p 205. Discussion of means by which increased accuracy of instruments is obtained; examples of optical and surveying instruments accuracy of which has been

increased by magnification ; magnification by conversion

applied to conversion of small temperature changes into large pressure changes ; data on recently developed instru- ment in which small changes in linear dimensions are converted into changes of frequency ; discussion of magnification by electronics. 131
Primary Detectors for Measurements, E. B. LYNCH, A. J. CORSON. Elec Eng v67 n9 Sept 1948 p 849-59. Basic

elements of any measurement system may be classified into three functional groups known as primary detectors, intermediate means, and end devices ; by classifying pri- mary detectors for both electrical and non-electrical quantities, convenient selection of suitable detector may be made when quantity to be measured together with range

over which it will vary is known. Paper 48-104 before Am Inst Elec Engrs.

Is There a Science of Instrumentation?, E. U. CONDON.

Sci vllO n2858 Oct 7 1949 p 339-42. Rules governing

classification of instruments; characteristics of trans- ducer; transforming and amplifying elements of instru- ment; present demands for instrumentation improvement

are essentially higher sensitivity and faster response. Theory of Mechanical, Electrical, Electronics and Air

Gaging, W. P. ALLER. ASME Paper n52—A-S9 for meeting Nov 30-Dec 5 1952 16 p. Characteristics of mechanical, electrical, electronic and air gages that have made

possible separation of inch into smaller and smaller divi- sions ; descriptions of dial indicator, mechanical comparator, reed gage mechanism, electric transducers, gaging

circuits, limit type gage head, flow type gage, Venturi

type gage, back pressure gage and differential gaging

circuit. Sensitivity of a Vibrating Reed Null Indicator, L. J. SOMERVAILLE. J Sci Instrum v31 nl2 Dec 1954 p 439-

40. A simple vibrating reed null detector is described. The sensitivity of the instrument has been studied by two

methods. In each case consecutive readings were ob- tained within ±2X10"9 in. Mechanic-Electric Transducer, K. S. LION. Rev Sci Instrum v27 n4 p 225-5 Apr 1956. Description of a

transducer system which permits the conversion of mechanical displacements into electrical signals. The sys- tem is based upon a high-frequency discharge in a gas under reduced pressure. Different modifications permit

the detection of either very small movements ( <1 mm)

or large movements (several cm), or small changes of capacitance (fraction of a micro-microfarad). A Mechanical-Electric Transducer of Simple Design, M. MANZOTTI. J Sci Instrum v33 n8 Aug 1956 p 314-

15. A probe electrode plunged into a current field experi- ences a potential which is a function of its position in the field ; when it is moved, the variation of potential is also a function of the displacement. This principle makes

possible the design of mechanical-electrical transducers of simple construction and easy assemblage. An application

to pressure recording is here described. The sensitivity

(o cm of water per full deflection) and speed of response

(no distortion for variation of pressure up to 220 cm of water per second) can, if necessary, be easily improved.

Six Transducers for Precision Position Measurement, J. O. MORIN. Control Eng v7 n5 May 1960 p 107-12. Review

of high precision transducers, with measurement capabilities up to one part in quarter million, includes pin-and- pawl mechanism, magnetic bench-mark system, resolver- type transducers, electrostatic transducers, and diffraction gratings. A Recording Extensometer. A. D. MARTYNOV. Meas

Techns 1959 n3 May 1960 p 163-4 1 fig. Translated from

Izmer Tekh n3 Mar 1959 p 7. Discusses inclusion of elec- trical recorder into amplifying devices. Screening Micrometer—New Principle for Measuring

Small Movements. B. E. NOLTINGK. Brit Communications & Electronics v7 n6 June 1960 p 430-5. Limitations

of conventional resistive, capacitive, inductance, and

photoelectric pickups for measuring small movements are reviewed; new type of transducer is described in which

coupling between coils is varied by screen moving be- tween them ; sensitivity of device is such that movements

of lfi and less can be readily measured. Hydraulic Method of Measuring Length, V. 6. SHTEIN.

Meas Techns 1959 nl2 Sept 1960 p 934-8 3 figs. Translated from Izmer Tekh nl2 Dec 1959 p 10. The instru- ment described proves the possibility of using the hydraulic method for linear measurements and the production

of commercial instruments operating on this principle and capable of wide application in different devices, in- cluding those used in various methods of automatic

control. Electromechanical Transducer for Small Displacements and Forces, G. S. BERLIN. Pribory i Tekh Eksper (USSR) 1961 n5 p 152-7 Sept-Oct in Russian. The

design, characteristics, and parameters of an electro- mechanical transducer (mechanotron) for small displace- ments and forces, and of a simple, highly sensitive mechanotron micrometer and dynamometer with a potentiometer recorder are described. [Eng. translation

in : Instrum exper Tech (USA) n5 Sept-Oct 1961 p 973-7 ; publ. April 1962.] Investigating the Kinematic Error in a Hydraulic Comparator, V. V. MATVEEV. Meas Techns 1961 nlO Mar

1962 p 784-8 4 figs 6 refs. Translated from Izmer Tekh

nlO p 11^ Oct 1961. The kinematic error in hydraulic comparators plays an important part in, determining Lhe

final judgment on the advisability of using the hydraulic method and on selecting a suitable arrangement for the instrument. In order to eliminate the kinetic error and

raise factor, and hence raise the sensitivity of the instru- ment, it is necessary to use hydraulic comparators which

provide a constant pressure on the diaphragm due to the

liquid head independently of the displacement of the instrument's measuring rod. Barium Titanate Ceramics for Pine-Movement Control,

J. V. RAMSAY, E. G. V. MUGRIDGE. J Sci Instrum

v39 nl2 Dec 1962 p 636-9. Barium titanate transducers

are described for use in automatic control of Fabry-Perot

interferometer, to achieve parallel displacements of plate

to accuracy required in interferometry. High Precision Linear Electro-Mechanical Transducers,

F. BROUWER. Int Production Eng Research Conference Proc Sept 9-12 1963 p 592-600. Published by ASME.

Various types of transducers for linear positioning and

measuring problems in machine tool and gages are analyzed, including mechanical linkages and leadscrews, rack and pinion drives, diffraction graftings, digital scales, linear inductosyn. Steward-Warner linear position trans- ducer etc. of which only digital scale gives absolute machine position directly ; final choice of system for particular application depends to large extent on indi- vidual factors determined by environment in which measuring systems shall be used, and on magnitude of allowable

errors. Extensometer Calibrator, G. E. RICKWOOD, Canada, Nat

Research Council-Mech Eng Report MH-102 Aug 1963 p 3

plates. Arrangement suitable for producing and measuring linear extensions of order of 1 /tin. over range of plus or minus 0.0035 in. is described ; provision is made for referring measurements to gage blocks ; originally de- signed to permit calibrating vibrating wire strain gages,

it is readily adaptable to calibrating other types of exten- someters and strain gages by addition of suitable mounting

blocks. 5.2.2. Electrical An Electric Micrometer, P. E. SHAW. Proc Phys Soc London vl7 Mar 23 1900 p 431-59 16 figs; Phil Mag v50 Dec 1900 p 536-62 6 figs ; Abstract, Electrician v44 Apr 6 132
1900 p 854-5. Describes a method, said to be reliable, of measuring small distances by electric contact. Electric Contacts, H. ROHMANN. Phys Zeit v21 Aug 15

1920 p 417-23. A torsion arrangement is described by means of which displacements of the order of could

be determined. With this apparatus the variations of current, due to closer approach of the electrodes of a

contact, could be followed. The "contact distance" for

different materials was of the order of magnitude of

1-50/ifi. The results made it possible to produce an

efficient metal microphone and a reliable coherer. A Method of Measuring the Periodic Error of a Mechanism, G. A. TOMLINSON. J Sci Instrum v6 n5 May 1929 p 152-3 3 figs ; Mech Eng v51 nl2 Dec 1929 p 955. Simple apparatus devised in the Metrology Department of National Physical Laboratory for determining periodic

error in motion transmitted by kinematic pair; consists

of two similar electromagnetic markers connected in series so as to produce series of simultaneous kicks on smokedplate records attached to two components of kinematic

pair ; mechanism is allowed to move at very slow rate. The Electric Gage. A. V. MERSHON. J. W. MATTHEWS.

B. C. WAITE, JR. Gen Elec Rev v32 nl2 Dec 1929 p 674-

5 3 figs : West Machy Wld v21 nl Jan 1930 p 10 30 3 figs. Instrument is independent of human sense of touch

simple and rapid to manipulate; amplification factor is 10.000 : electric gage has been developed to meet need for accurate gaging device that has but minimum of moving

parts and that will permit routine gaging operations to be conducted with great rapidity. Electric Precision Gage of Great Accuracy. Machy

(N.Y.) v36 n6 Feb 1930 p 435-6 3 figs. Description of

electric gage designed to meet demand for accurate gaging

device that has minimum of moving parts and that will permit routine gaging operations to be conducted with

greater rapidity ; with amplification factor of 10.000. this gage, independent of human touch, makes possible meas- urements to 0.00005 in., gage may be used for both inside and outside measuring. General Electric Magnifying Electric Gage. Am Much

v74 Feb 19 1931 p 340. An electric gage that measures

one one hundred thousandth of an inch, and then magnifies that dimension 10.000 times, has been developed. This type of gage is suitable for almost any kind of meas- urement with certain changes in set-up. The gage consists essentially of a contact point supported to move

through a limited distance in the direction of measurement, say 0.0005 in. This movement causes a pointer to

1 travel 5 in. over a scale of an indicating instrument. The

diamond contact point is fitted in the gage spindle, which

is made to suit the work.

Piezo-Electric Gage and Amplifier, R. A. WEBSTER. J Franklin Inst v211 n5 May 1931 p 607-16 7 figs. Pressure gage using cartridge of pure bakelite : within this was

placed pile of 21 quartz crystals, each 0.69 in. sq. by

0.053 in. thick, being separated by platinum electrodes

screwed brass ends held them in cartridge which was

I then sealed with beeswax : gage has given good service, and although few of crystals cracked, no loss in sensitivity has been noticed. Grid Glow Micrometer, R. W. CARSON. Am Mach v75

nil Sept 10 1931 p 407 2 figs. Operating principles and

hook-up of instrument using vacuum tube to avoid errors

resulting from contact pressure. New Electric Arrangement for the Measurement of Small

Displacements, S. REISCH. Zeit fiir Hochfrequenztechnik v38 Sept 1931 p 101-11. A brief description is given

of various electric micrometer arrangements, with a full bibliography. The various arrangements are criticized, and then a new type of capacitative displacement measuring apparatus is described which is based on the potential distribution across condensers arranged in series. The theoretical capacity sensitivity is 2.5X10""8

. Precision Measurements of Mechanical Dimensions by

Electrical Measuring Devices, A. V. MERSHON. Gen

Elec Rev v35 Mar 1932 p 139-44. Electric gages for measuring diameters ; combination electric gages for making two or more measurements at same time; electric sizing control used to automatically machine parts to given dimension; electric matching control used to machine parts to existing masters ; strain gage used to measure change in length of structural member, etc. Korkeajaksointerferenssiin Perustuva Rekisteroeivae

Mitrometri, P. E. KUOKKANEN, A. BAECKSTROEM.

Teknillinen Aikakauslehti nl2 Dec 1934 p 388-95. High

frequency interference recording micrometer invented by authors for measuring and recording diameter variations

of thin wires used for manufacturing of glow lamps

variation of 0.0001 mm in wire diameter will cause deflec- tion of 1 or 3 mm respectively on recording paper of in- struments. (Brief abstract in English p 395.) Elektrisches Ultra-Mikrometer zur Messung des Waerrneausdehnungskoeffizienten keramischer stoffe (Electric micrometer for measuring coefficients of thermal expansion of various ceramic materials), A. HEINZ, H. KOTTAS. Sprechsall v68 n4 and 5 Jan 24 1935 p 49-51 and Jan 31 p 65-7. Details of procedure ; illustrations. Galvanomagnetic Measurement of Small Displacements.

S. REISCH. Akad Wiss Wien Ber vl45 2a 9-10 1S36

p 725-52. The method depends on the variation of the

resistance of Bi with the magnetic field in which it is placed. To obtain a high sensitivity and good temperature compensation four Bi resistance coils, connected so as to form a Wheatstone bridge, move in the gaps of two permanent magnets. In order that correction may be applied for the temperature of the whole network, this forms the arm of another bridge enabling the total resist- ance to be measured. Theoretical considerations lead to the calculation of a calibration curve and give information concerning the constancy of the zero, and the limit of sensitivity. Two practical designs are given, to- gether with their experimentally-determined sensitivities. These, expressed as fractional changes of resistance for

1 mm of movement, were 1.6 X10"2

. Measuring Millionths of an Inch, R. W. CARSON. Elec J v33 n2 Feb 1936 p 106. After several years of experi- mental work, entirely new method of measuring spring

deflections was developed, using electronic micrometer

device used electronic means of indicating point of contact between hand micrometer and test specimen in form

of small cantilever beam.

Electric Gage, C. M. HATHAWAY, E. S. LEE. Mech Eng v59 n9 and 12 Sept 1937 p 653-8 and (discussion) Dec 1937 p 963. Mechanical measurements involving displacements as small as 0.00001 in. and even 0.000001 in. can be made with electric gage described ; displacements

being measured can be amplified 10,000 or 100,000 times on

indicator without introducing frictional effects; four methods of electric gaging, capacitance, bridge, saturation, and eddy current, are described. Bibliography. Before Am Soc Mech Engrs.

Elektrische Messung kleinter Laengenunterschiede ( Electric measurement of small differences in length). E. FROBOESE K. SCHOENBACHER. Archiv fuer Elektro- technik v33 n5 May 12 1939 p 341-6. Fundamental operation of electric measuring gage discussed; special reference made to sources of error and their correction ; examples of practical application. Convenient Electrical Micrometer and Its Use in Mechanical Measurements, R. GUNN. ASME Advance Paper n34 133
meeting Dec 4—8 1939 4 p. Simple micrometer of mechanical and electrical stability developed ; electric current out- put from micrometer is accurately proportional to impressed mechanical displacement ; zero drift, hysteresis, temperature, and pressure variations reduced to less than 1% ; special circuits described which permit indication

of sums, difference, ratios, or products of mechanical

displacements and are useful in mechanical measurements. Note on Electromagnetic Induction Micrometers, Includ- ing Novel Circuit, Incorporating Metal Rectifier, R. J. COX. J Sci Instrum v 19 n8 Aug 1942 p 117-20. Convenient method of measuring displacements of order of few thousandths of inch is one which utilizes changes in inductance of iron cored coil produced by changes in lengths of airgaps in its' magnetic circuit; methods of

indicating these changes in inductance are discussed

new circuit is described which incorporates metal rectifiers and microammeter or galvanometer as indicator. Electric Gauges, H. P. KUEHNI. Gen Elec Rev v45 p 533-6 Sept 1942. The gage is an a.c. bridge circuit in which one or more impedance branches are acted upon

by the quantity to be measured. The calibrated amount

of brdige unbalance is indicated on an instrument which may be remotely installed at any convenient location. Detecting Small Mechanical Movements, J. C. FROMMER.

Electronics vl6 p 104-5 July 1943. A valve circuit for detecting movements of 10"° in. is described. These move- ments are converted into capacitance changes of the order

of 0.01/ijit F. Variations in oscillator and cable characteristics are nullified by the insertion of a displacement

unit between the oscillator and amplifier. The amplifier has been used successfully for measuring blood-pressure

curves. Elektrische Verfahren zur Messung kleiner Laengen

(Electrical methods of measuring small lengths), W. REDEPENNING. Archiv Tech Messen nl50 Dec 1943 p T145 (2 p) (J112-4). Illutrated description of electric methods at measuring short linear dimensions with aid of induction or contact instruments; both types described and illustrated. Measurement of Displacement and Strain by Capacity Methods, B. C. CARTER, J. F. SHANNON, J. R. FOR- SHAW, Engr vl77 n4602 Mar 24 1944 p 237-8. Account

of some developments for which aiithors and colleagues

at Royal Aircraft Establishment have been responsible

authors have found it advisable to employ electronic equipment that is adaptable to any class of pick-up, e.g., resistance, electromagnetic, capacity, or induction, with

associated pre-circuits. Abstract from Symposium before Instn Mech Engrs.

Electric Gaging Methods for Strain, Movement, Pressure and Vibration, H. O. ROBERTS. Instrum vl7 n4, 5, 6,

7, 8, 9, 10, 11, 12, Apr 1944 p 192-6, May p 260-5, 284,

286, 288, June p 334-9. July p 398-403, 414, 416, 418, 420,

422, 424, Aug p 475, 484, 486, 488, 490, Sept p 534-4, 544,

546, 548, 550, 552, 554, Oct p 603-5, 626, 628, Nov p 668-

70, 684, 686, 688, Dec p 742-4, 755. Apr-May : Principles

of operation ; auxiliary circuits and recording devices

operating techniques ; gaging methods based on variations of capacitance; sensitivity, stability, and accuracy

discussed. June-Aug : Gaging methods based on variation of inductance.' Sept-Dec : Gaging methods based on

variation of resistance. A Change-of-Capaeitance Method for the Measurement of Mechanical Displacements, E. BRADSHAW. J Sci Instrum v22 June 1944 p 112-4 2 figs 2 refs. Method is suitable for the measurement of static or alternating dis- placements. The circuit includes two radio-frequency

oscillators feeding a mixer valve. Variation in the fre- quency of one of the oscillators, and therefore in the frequency of the mixer output, is effected by the changing

capacitance. A frequency-amplitude converter circuit produces a direct voltage which is proportional to the change of capacitance. Use of Radio-Frequency Apparatus in Inspection, J. COR- NELIUS. Maehy ( London ) v66 nl699 May 3 1945 p 473-6. Details of construction and operation of apparatus which

measures such mixture variations as one thousandth part

of millionth of inch ; comprising measuring and indicating

units, physical units in inspection are translated into

electrical units which are amplified by external power on

indicator ; electronic arrangement and radio circuit employed are explained, and economics and advantages of

its application discussed. The Use of Frequency Modulation in a Sensitive Micrometer, G. M. FOLEY. Am Phys Soc Proc June 1945. Abstr.

in Phys Rev v68 p 101 Aug 1 and 15 1945. To measure

the unimpeded displacement of an object, one plate of a small air capacitor is attached to the object. The other

plate is fixed close to the moving plate, and the capacitor

is used to tune a r.f. oscillator. The change in frequency

resulting from motion of the object is converted into pro- portional d.c. voltage by a receiver similar to a radio

receiver. Voltages of ±300 V are obtained from small

displacements, and a magnification of the motion 10*-10° times can be obtained, permitting detection of displace- ment of 10"6 in. The apparatus is robust and stable and

requires no electrical connection with the object. Two

such micrometers were placed at rt. angles to measure the

rotation of a precision lathe spindle in its bearings, the outputs of the two micrometers being applied to two axes

of a c.r.o. A similar micrometer was used as a high-speed recording dilatometer to follow the allotropic transformation of steel on heating and cooling. Electric Gaging Methods, H. C. ROBERTS. Instrum vl8

n9, 10, 12, Sept 1945 p 616-7, 624, 626, 628, 630, 632, 634, 636, Oct p 685-9, 706, 708. Dec p 882-9, 912-4, 916-8,

920. Sept : Calibrating devices. Oct : Calibration checking circuits and oscillographs, Nov : Power supplies. See earlier parts of series listed above. Capacitance Micrometer, R. W. DAYTON, G. M. FOLEY.

Electronics vl9 n9 Sept 1946 p 106-11. Variations in oscillator frequency caused by minute movements of capacitive circuit element are converted to output voltage changes in electronic gage ; using principle which has been

successfully used for dilatometer, monometer, roughness gage and hardness testing apparatus ; device uses limiting amplifier to free instrument from errors which might be caused by amplitude variations ; design details. Electronic Gaging, P. H. HUNTER. Electronic Indus vo n9 Sept 1946 p 68-71. New standards of accuracy and

speed in dimensional inspection made possible by preci- sion electronic instruments, is exemplified by two mi- crometer developments ; Carson Electronic micrometer employs screw of high lead accuracy with electronic cir- cuit facilitating interpolations to 25 microinches or less

Wilmotte "Visi-Limit" micrometer features sensitivity not dependent on size of material being measured, and

accuracy of ±0.0002 in. Indicateur de Contact Electrostatique a Battements

(Electrostatic oscillating contact indicator), P. FAYOLLE. Rev Gen de Elec v56 n3 Mar 1947 p 124-8. Appli- cation to comparator for ultra-micrometric recording:

illustrated description of screw comparator combined with

electric contact indicator, claimed to give very accurate

results. Les Ultra-Micrometres Electrostatiques (Electrostatic

ultra micrometers), A. PARNET. Machines et Metaux

v31 n343 Mar 1947 p 107-9. Principle of apparatus and

comparison of two different solutions ; illustrated description of 150-mm and 250-mm comparator and micrometer

used for internal measurements. 134
A Variable Capacitor for Measurements of Pressure and

Mechanical Displacement ; A Theoretical Analysis and Its Experimental Evaluation. J. C. LILT. V. LEGALLAIS,

and E. CHEERY, J App Phys vl8 n7 July 1947 p 613-28. A variable capacitor is described for measuring small dis- placements, small volume changes, and pressure differ-

' ences. The capacitor consists of a deflectable diaphragm

i and a fixed electrode. The diaphragm is metallic, planeparallel, clamped at the edges, and at earth potential

the electrode, at an a.c. potential, has a plane surface

parallel to the undeflected plate across an air gap. For use

in displacement measurements, the diaphragm's center is deflected by a point contact from a mechanical link to the observed system, or by a uniform pressure load from a

fluid link to the system. The plate deflection results in a change in the air gap, and thus generates a capacitance

signal, which is measured by electrical methods. The

theory of the device is analyzed and sensitivity and

alinearity factors are derived. Cathode-Eay Eecording Micrometer and Force Gauge,

J. EWLES, C. CUEEY. J Sci Instrum v24 nlO Oct 1947 p 261-5. Features of device using oscillograph with moving coil system to record and measure rapidly varying movements of order of 3 mm to accuracy of 0.0025 mm;

bv attaching moving coil to specially designed force gage

of natural period of about %ooo sec, device has been applied

to record and measure rapidly varying forces and prelimi- nary study of rapid shear. Electronic Gauges. J. SCHWAETZ. Microtecnic v2 n5, 6 Oct 1948 p 199-206, Dec p 267-74, v3 nl Jan-Feb 1949

p 10-8. Systems for transformation of mechanical dimen-

, sions into voltages such as piezoelectric gaging heads for measurements of pressure, resistance extensometers for measurements of strains and stresses; study of types of gaging heads suitable as sensitive part of electronic comparators; gaging heads utilizing variations of capacity or

of selfinductance can be adapted for accurate measurements of lengths. Mesure et Amplification de Faibles Deplaeements par Modulation de Frequence (Measurement and amplification of small displacements bv frequenev modulation),

P. BEICOUT, M. BOISVEET. *Eev Gen de l'Elec v58 nlO

Oct 1949 p 402-4. Use of manometric capsule as variable gap in capacitor in tuned circuit; frequency modulation

resulting from pressure changes are determined using Bradley discriminator and output is read on calibrated milliameter; equipment is suitable for manometer,

vibronieter, or seismograph.

Electronic Developments in Instrumentation, D. ED- MUNDSON. Soc Instrum Techn Trans vl no Dec 1949 p 8-17 (discussion) 18-9. Use of amplifiers for indicat- ing instruments applied to measurement of physical quantities; consideration of a-c amplifier in instrument form,

a-c bridge detector, negative feedback amplifier, d-c amplifiers, chopper amplifier, self balancing potentiometers and photoelectric amplifiers ; questions of reliability and

maintenance. Measurement and Amplification of Minute Displacements

1 by Frequency Modulation, P. A. BEICOUT, M. BOIS- VEET. Eev Sci Instrum v21 p 98-9 Jan 1950 2 figs. All functions are performed using only two tubes, an oscillator and a discriminator. Describes apparatus and discusses

principle, characteristics, and applications of same. Kleinstwegmessung mit induktivem Geber (Measurement

of Very Small Movements by Means of an Inductive

Pickup), F. STEJSKAL. Electrotech Zeit v71 no Mar 1 1950 p 115-6 6 figs 5 refs in German. Mechanical vibrations, as they occur in the testing of vehicles or station- ary machines are converted by means of small pickup

coils into a compensation circuit in electrical voltage

fluctuations and shown on a loop oscillator. The pickup

elements and circuits are described.

Differential Transformer as Applied to Measurement of Substantially Straight Line Motion, W. D. MacGEOEGE.

Instrum v23 n6 June 1950 p 610-4. Methods for deter- mining displacement of bellows or diaphragm, motion of

float, tip travel of Bourdon tube and tilt of weigh beam

discussion of basic design of differential transformers and

circuits which permit their application to measurement

of instrumentation variables such as pressure, flow, force,

etc. ; schematic diagrams. A Micro-Inch Micrometer of One-tenth Inch Eange, E. B. BAKEE. Eev Sci Instrum v22 p 373-5 June 1951. Many

instruments exist which will magnify small displacements

to almost any degree desired but always at the expense of range. The micrometer screw is a notable exception, but does not give an electrical output nor will it measure

distance directly and continuously without extra equip- ment. The present device combines a lever, a micrometer

screw, a sensing element and a servometer to achieve this purpose. Improvements in Null Indicator Electromagnetic Gauges,

E. B. BROWN. J Sci Instrum v28 p 272-4 Sept 1931. The conditions for elimination of errors due to mains fluc- tuations are discussed, and an improved form of null setter

is described, which in itself is a useful piece of laboratory equipment since it may be used as an a.c. potentiometer, having a small and nearly constant phase defect less than %°. The null setter was originally designed by the au- thor for use as a counterbalance for a diaphragm oper- ated moving coil gauge, but in this paper its application

is shown to an a.c. mains operated gauge for remote

indication with magnification of small angular deflections. Inductance-type Transducer and its Applications, J. YAMAGUCHI, Y. SAKUEAI. Tech. Eept Osaka Univ

vl p 201-12 Oct 1951. The "variable-gap" inductance- type transducer is used as the pick-up in measurement of

length, pressure and mechanical vibration. In this paper fundamental considerations and practical applications of

this transducer are described. The sensitivity of source which is applied to the transducer and the acting current

of inductance coil, and the adequate values of these are shown in the case of a micrometer. Next, in the meas- urement of dynamic pressure or acceleration the relation between these mechanical quantities and gap length is discussed theoretically. As practical applications the ultra-micrometer, pressure recorder and acceleration meter are described. By the ultra-micrometer the diameter of a steel ball can be measured with sensitivity Vioii. The pressure recorder is applied to the measurement of dynamic pressure between pantograph and trolley wire and as an acceleration meter for vehicles. These instru- ments are stable, use light transducers of small size and

robust construction, and are suitable for telemetering. They are thus suitable for field testing. Micrometer Dilatometer, E. J. VANDEEMAN. Eev Sci Instrum v22 Oct 1951 p 757-60. The construction, cali- bration, and use of a dilatometer that is ideally suited for use with radioactive materials is described. Expansion measurements are made electrically with a linear variable transformer.

Electronic Ultramierometer, W. ALEXANDEE. Electronic Eng v 23 n286 Dec 1951 p 479-80. Micrometer uti- lizing single octode tube and particularly adapted to measuring small changes of length ; circuit makes use of change of anode voltage when resonant frequencies of two grid oscillator circuits are separated progressively from common value; change of length measured is applied to capacitor plates in one grid circuit. Electronic Measuring Instrument for Small Displace- ments, L. A. GONCHAESKII. Elektrichestvo 1952 n6

p 62-5 in Eussian. The theory of the input diode of a thermionic measuring instrument for small mechanical

displacements using a moving electrode is presented. A

771-846 (>—66 10
method for determining the current and voltage sensitivities of the instrument is found. It is seen that a diode with flat parallel electrodes is the most sensitive input element for such purposes, as far as current sensitivity is concerned, whereas the possibilities for improving voltage

sensitivity are rather limited. Die Electronic im Dienste der Messtechnik (Electronics

in the Service of Measurement Technique), F. TURRETTINI. Ind Organisation v21 n6 1952 p 166-72. Electronic Device for Measuring Small Transient Dis- placements, J. J. TROTT. J Sei lustrum v29 n7 July 1952

p 212^1. Micrometer device for measuring displacements down to 10 micro in., being suitable whenever it is possible

for equipment to be mounted on stable support ; use for measuring relative and absolute movements of concrete road slabs under wheel loads of vehicles; device is based upon variation of output of h-f oscillator due to movement

of metal disk near tuning coil. A Linear Transducer for the Electrical Measurement of Displacement, M. J. TUCKER. Electronic Eng v24 Sept

1952 p 420-2. This device depends upon the change in coupling between two coils with linear displacement. The

primary is wound round the centre limb of a stack of Permalloy gate stampings. It extends almost halfway up

this limb and above it is located the movable secondary

coil. This latter coil is connected through a bridge rectifier to a d.c. indicating instrument. Over the linear oper- ating range, corresponding to a displacement of approx.

1 cm, the output current varies from 1.3 to 2.7 mA. Accordingly, sensitivity can be improved by backing off some

of this current, and two circuits intended for this purpose

are shown. The circuit as used has to work off a 250c/s

supply, but the advantages of a high frequency, e.g. 2 kc/s, are pointed out. Over the 1 cm range, linearity within the accuracy of measurement, approx. 0.005 cm, is achieved.

Electronic Dimensional Gaging, C. W. WILLIAMS. ASME Paper n52 A-98 for meeting Nov 30-Dec 5 1952 12 p. Features of gaging devices where displacement of measuring tip which engages piece to be measured is magnified by vacuum tube or amplifier to permit user to read dis- placement on scale, or to furnish impulse to control auto- matic gaging and handling equipment, use of recorders driven by amplifier where permanent records are useful. Electronic Circuitry for Instruments and Equipment, M.

H. ARONSON. Instrum Pub Co, Pittsburgh, 1953 310 p. Nonmathematical presentation of basic circuits and funda- mental techniques with examples and application covering broad scope ; resistance, capacitance, inductance and sig- nal shaping, vacuum tube and gas tube fundamentals,

amplification, rectification, and oscillation circuits dealt

with. Eng Soc Library, N.Y. Comparateur Eleetromecanique (Electromechanical Comparator ) , J. HUETZ. Techn Mod v45 n2 Feb 1953 p 47-50. Principles and characteristics; apparatus described has

characteristics of strain gage, such as high degree of stability and fidelity. The Photodianode, G. DELOFFRE E. PIERRE, J. ROIG. CR Acad Sci [Paris] v237 pl507-9 Dec 9 1953 in French. The use of the two anodes in a vacuum photo- tube with siiitable geometry enables the relative anode

currents to be used as a measurement of the displacement

of a light spot on the cathode. The tube is of use for the precision measurement of small displacements or

rotations. Direct Reading Instrument for Measurement of Small

Displacements, W. C. CORNER, G. H. HUNT. J Sci Instrum v31 nl2 Dec 1954 p 445-7. Arrangement whereby

different hi] condenser forms part of a-c bridge network;

displacement of central plate causes proportional off balance voltage; small displacements can be measured to accuracy of 10"7 cm ; applicability to measurement of magnetostriction of small crystals of nickel, maximum change

in length being 85 X 10"° cm. A Simple Circuit for Use With Condenser Strain Gauges,

D. M. MAURICE. J Sci Instrum v31 nl2 Dec 1954 p

4,42-A. A one-valve circuit operating at 200 Mc/s is de- scribed which gives a stable output proportional to the

strain and sufficient to drive directly a low-impedance

recording milliammeter. It may be used, with a wide

range of recording capacitance down to 3pF. The con- necting cable to the recording condenser acts as a trans- mission line and may be long without affecting seriously the working of the circuit. Electronic Indicators of Mechanical Quantities, L. A. GONCHARSKII. Uspekhi fiz Nauk v55 nl 1955 p 81-100

17 refs in Russian. A survey, including material on

the electronic micrometer, vibrometer, dynamometers,

manometers.

History of Electrical Devices for Measuring Strains and

Small Movements, B. E. NOLTINGK. J Sci Instrum v32 n5 May 1955 p 157-8. The development of apparatus for measuring strains and small movements by transduction

into electrical signals is traced over the past hundred

years. Instruments depending on resistive, capacitive, inductive, piezoelectric, acoustic and photoelectric systems

are considered, and the chief contributors to the introduction of different techniques are enumerated.

Electronics : New Answer to Shop Gaging Problems, D. M. GASKILL. Am Mach v99 n25 Nov 21 1955 p 134-6. Design and functioning of electronic gaging system; gages can be made sufficiently sensitive to measure deviations in dimensions as small as 0.000010 in., 0.000001 in., or even

0.0000005 in. ; other applications ; examples of checking dimensions on lapped hydraulic motor pistons, high pre- cision gears and armature shafts. Apports de l'Electronique a la Metrologie (Contributions

of Electronics to Metrology), J. AVRIL. Soc. Francaise

des Mecaniciens Bui v6 n20 1956 p 22-4. Different methods enabling physical quantities to be transformed into

electrical variables, irrespective of use made of them;

examples. A Magneto-Resistance Displacement Gauge, I. M. ROSS,

E. W. SAKER. Nature (London) vl78 Nov 24 1956 p

1196. The displacement to be measured causes a small

strip of InSb to change its position relative to a permanent magnet the poles of which are shaped to give a strong

field gradient in the direction of movement. The mean

field over the crystal and hence its resistance are then a

function of position. In practice two crystals rigidly connected are used to overcome temperature errors. Instrument Transducers, J. THOMSON. J Sci Instrum

v34 n6 June 1957 p 217-21. After dividing the problems

of instrumentation into two categories (1) the determination of what is to be measured, and (2) the investigation

of how to make the measurements, the importance of en- ergy transformations to problems in the second category

is established. The attempt is made to define the forms

of energy in a manner suitable for instrument research and a chart is presented showing important physical and

chemical phenomena as transformations between these forms of energy. Particular attention is paid to those transducers which provide an electric signal. In conclusion, recent developments of transducers are consid- ered from the point of view of instrumentation and the

significance of solid state science is underlined. Use of Piezoresistive Materials in the Measurement of Displacement, Force, and Torque, W. P. MASON, R. N. THURSTON. J Acoust Soc Am v29 nlO Oct 1957 p 1096- 136
101. The use of piezoresistive materials as strain gauges and in the measurement of displacement, force and torque

is discussed generally. A torsional transducer, which was

constructed from n-type Ge. is described, and the experi- mentally obtained voltage-torque characteristic is given. Der heutige Stand der Entwicklung elektrischer Messgeraete fuer mechanische und waermetechnische Grossen

i Present status in development of electric instruments for measuring mechanical and thermotechnical values), G. BECK. Werkstattstechnik und Maschinenbau v48 n3 Mar

1958 p 169-78. Survey of indicating, amplifying and

recording instruments. A Sensitive Micrometer for Measuring Small Displace- ments, J. XORBURY, D. SHEWRIXG. J Sci Instrum

v35 n6 June 1958 p 217-20. A variable parallel-plate ca- pacitor associated with an oscillating circuit forms the

basis of an apparatus which can measure displacements

of the order of 200A. The apparatus is so designed as to combine robustness with sensitivity, ease of calibration and reproducibility. The use of a diode pump integrator

circuit makes the sensitivity independent of the gain of

, the a.c. amplifier. The capacitor is of simple construction and standard electronic components are used throughout. The Measurement of Small Displacements by Electrical Screening. B. E. XOLTIXGK. Inst of Phys Stress Analysis Group Conf, Delft, 1959. A conducting screen inter- posed between two coils affects their electrical coupling.

It is shown how the dependence of this effect at the exact

position of the screen can be made the basis of a trans- ducer converting mechanical displacements to electrical

scale. Such a system needs only a small element attached

to the moving part to be measured ; it is insensitive to movements in directions other than those studied ; and it can allow an indefinite travel of the moving element. A

< small instrument is described, used on this principle, which

has a linear range of 10 mm and a stability of a fraction

of. a micron, allowing displacements to be observed on any

scale between millimetres and hundreds of Angstrom units. Inductance Bridge for Sensitive Displacement Measurements Over Long Periods, D. MURRAY. J Sci Instrum

v36 n7 July 1959 p 312-15. An application of linear dif- ferential transformers in an ac. bridge that provides

reproducible displacement measurements over long periods, extends the linear response while retaining high

, sensitivity, and can be readily adapted for automatic re- cording of displacement.

, Modern Measuring Instruments—Electric and Electronic

, Gages, F. W. WITZKE. ASTME Tech. Papers 60 book 1 paper n245. Electronic gage heads now provide extreme

precision and accuracy for standards laboratory use. Performance specifications are listed. Application of Electronics to Industrial Metrology, J.

1 QUEXTIX. Microtecnic vl4 n3 June 1960 p 125-35. Roles

of electronics in solving metrological problems are re- viewed ; applications to high and low resolution instru-

( ments, equipment for remote measurements, and for auto-

, matic control based on small dimensional variations are

Application of Continuous Secondary Electron Multipli- cation for Amplifying Small Currents. P. K. OSHCHEPKOV. B. X. SKYORTSOV. B. A. OSAXOV, I. V. SIPRI- KOV. Instruments & Experimental Techns (English

translation of Pribory i Tekhnika Eksperimenta ) n4 July- Aug 1960 p 611-14. Electron multiplier developed at Metallurgical Inst of Acad of Sciences, USSR, operates on

principle of continuous secondary electron amplification without central focusing electrode ; approximate calculation of multiplying system ; production technology and

composition of one of versions of emitter material.

Xovel Displacement Detector and its Application in a Recording Thermobalance, J. C. VAX DER BREEGGEX,

H. J. WOUTERLOOD. J. Sci Instrum v37 n8 Aug 1960

p 297-300. A transducer has been developed to detect changes in position of a balance beam. Its operation is based upon a differential capacitor. Variations in capaci- tance are made to produce directly a d.c. voltage corre- sponding in sign to the sense of deflection of the balance beam. The construction of the transducer is described, and its application in automatic apparatus for thermogravimetric analysis is illustrated by results obtained on

the dehydration of copper sulphate and the decomposition

of quinoline phosphomolybdate. The sensitivity of the instrument can be varied in nine steps to give full-scale deflections from 10 to 500 mg. An accuracy of about 1.5 mg or 0.75% of full scale was obtained for the 200 mg

range. Unicom Measuring System, S. RIGBY. Automatic Control vl3 n6 Dec 1960 p 31-8. Mechanical inspection sys- tem developed by Adage, Inc., which employs linear vari- able differential transformers as input transducers to sense contours, and electronic system for processing trans- ducer outputs and producing printed inspection reports;

basic resolution of automatic gaging system of various

types of components, is 0.001 in. Sensitive Output Indicator for Differential Transformer

Displacement Determinations, D. WOBSCHALL. Rev

Sci Instrum (USA) v32 nl Jan 1961 p 71-3. A transistor- ized circuit particularly designed as an output indicator

for linear variable differential transformers for the meas- urements of small displacements is discussed. Resolution

of the unit is about 0.05/i ; the linearity is about M%.

Refining Measurements by Capacitance Techniques. F. K. HARRIS, R. D. CUTKOSKY. ISA J v8 n2 Feb 1961 p 63-

6 8 figs 1 ref. Through recent advances in the art of capacitance measurement, capacitance may be determined

solely by a length, and vice versa. Accordingly capacitance bridges will be useful for measurement of mechanical displacement, film thickness, and dielectric constant, both as a spot check and as a continuously recording

quality control technique. Design and Construction of Device for Recording Small

Displacements, P. R. JAMES. Mag Concrete Res vl3 n37 Mar 1961 p 37-9. Design and construction of electrome- chanical device for remote, continuous recording of dis- placements of order of one mm in concrete structures ; elec- tronic potentiometer recorder is used in conjunction with

bridge circuit of four resistance strain gages, variation in out-of-balance potential being used as measure of displace- ment ; instrument developed to measure movement of sec- tions of concrete road on either side of expansion joint. Method for Adjusting Xominal Inductance of Transducers,

B. E. KOSTICH. Meas Techns 1962 n3 Sept 1962 p 187

1 fig 2 refs. Translated from Izmer Tekh n3 p 9 Mar 1962. Describes a method for a smooth adjustment of the trans- ducer's inductance by varying the reluctance of a hollow

core by means of displacing inside it a screw of a high

permeability. Compensated Electrical Instrument for Remote Measure- ments of Displacements, M. I. BELTI. Meas Techns 1962 n8 Feb 1963 p 641-2 1 fig 2 refs. Translated from Izmer Tekh n8 p 17-9 Aug 1962. The author has developed an

electrical instrument which uses a method of compensating two emfs for measuring large displacements with an

error not exceeding 10/i. This instrument can be used as a transducer in devices for automatic control of displace- ments, especially of carriages and tables of metal-working

machines. Computation of an Inductive Transducer with an Adjustable Short-Cireuited Turn, V. YA. EDUSH, M. A. XABIEV. Meas Techns 1962 n8 Feb 1963 p 684-90 3 figs 2 137
refs. Translated from Iziner Tekh n8 p 50-3 Aug 1962. An inductive transducer of linear displacements whose

sensing element consists of a moving short-circuited turn. Displacements Transducer with Electrical Recording, V.

V. NIKIFOROV. Meas Techns 1962 n9 Apr 1963 p 733-4

1 fig. Translated froin Izmer Tekh n9 p 17-8 Sept 1962. A transducer on the basis of a clock type indicator, pro- vided with an electric-spark paper recorder for registering displacement of tenths or hundredths of a mm. New Electrical Contact Head Type GK-3, F. M. DANILEVICH, V. A. NIKITIN. Meas Techns 1963 nl Aug 1963

p 19-21 2 figs. Translated from Izmer Tekh nl p 14-6 Jan 1963. Describes an improved electric contact head

used as an attachment to measuring or gaging devices for measuring 1 to 13.5 mm diameter holes either directly or by a differential method. A Automatic Recording Differential Dilatometer, J. BAR- FORD. J Sci Instrum GB v40 n9 Sept 1963 p 444-5. The

apparatus is suitable for the study of the kinetics of phase

transformations and precipitation processes in the solid

state. Relative length changes between a specimen and

a control are measured by means of a variable inductance

transducer. The differential system works to better than 1%, over temperature ranges of up to 1000°C.

Indicating Instrument for Measuring Very Small Dis- placements, K. I. ZABLONSKII, V. I. NASSAL'. Meas

Techns 1963 n5 Nov 1963 p 381 1 fig. Translated from

Izmer Tekh n5 p 13-4 May 1963. Describes a resistance wire transducer by which it is possible to record displace- ments of the order of O.l/i by means of ordinary amplifying equipment.

Application of Induction Transducers for Measuring Dis- placements at High Temperatures, M. I. KORSUNSKII,

A. S. LAGUNOV, L. P. BAIVEL. Meas Techns 1963 n8 Feb 1964 p 651-4 5 figs. Translated from Izmer Tekh n8

p 16-9 Aug 1963. The transducer can be used as a basis

for designing an instrument for automatic checking and

control of the starting and operating of powerful steam

turbines. The temperature-compensated transducer can

also be used for remote contactless measurements of clear- ances in other machines which operate at high temperatures. The method of temperature compensation can be used for induction transducer measurements of other

quantities. There exists the possibility of increasing the temperature operating range of the transducer. However,

for this purpose it may be necessary to use magnetic materials with higher Curie points, for instance, cobalt. 5.2.3. Mechanical

See also Subsection 3.6.4 The Minimeter for Fine Measuring, F. C. PERKINS.

Can Machy v20 Nov 21 1918 p 592-93 5 figs. Principle and

forms of Hirth apparatus for measuring threads, balls, cylindrical parts and grooves, also for inside measuring

of various diameters. The Determinateness of the Hysteresis of Indicating In- struments, F. J. SCHLINK. J Washington Acad Sci v9 Jan 19 1919 p 38-45 2 figs. Hysteresis determinations of non-integrating mechanical measuring instruments require no unusual care, and are fully reproducible. The Concept of Resilience with Respect to Indicating In- struments, F. J. SCHLINK. J Franklin Inst vl87 Feb

1919 p 147-69 2 figs. Deals particularly with instruments

of index-and-seale and value-controlling types of class of non-integrating instruments, as distinguished from inte- grating instruments and those used for comparison pur- poses strictly.

Die Genauigkeit mehrfacher Fuhlhebel (The Accuracy of Multiple Lever Gages), G. BERNDT. Werkstattstechnik

vl5 June 15 1921 p 347-50 2 figs. Comparison of accuracy

of single and multiple levers. States that, when possible, : instead of using several levers with smaller gear ratios,

it is better to use a double or single lever with gear ten j

1 times as great. A Study of Commercial Dial Micrometers for Measuring

the Thickness of Paper, P. L. HOUSTON, D. R. MIL- LER. Tech Papers NBS n226 Dec 29 1922 p 125-52. The a mechanisms were studied to determine the effect of the ; ?' various designs on the contact pressure, the variation in i contact pressure, and the accuracy and variance of the '; 1 instruments. Specifications are given for a standard \ instrument.

| J Das Reibungsfreie Minimeter ( Frictionless Minimeter),' 8 N. PFLEIDERER. Zeit fur Feinmech v32 Feb 20 1924 p ; 38-9. Description of Hirth minimeter, with a sectionals J view showing the construction. New Soeiete Genevoise micro-indicator. Machy (London) j v36 Apr 3 1930 p 19-20 2 figs. Embodies rocking plate and ; knife edges to give max amplification of 500. Spindle^ - travel is approx. 0.03 in.

!? Precision Measuring Instrument. Eng vl31 n3404 Apr .10 ' 1931 p 500 2 figs. At Leipzig Fair, Fortuna-Werke Spe- : zialmaschinen-fabrik A-G., of Stuttgart-Cannstadt, exhib- j ited number of examples of their precision measuring ! instruments, many of which embody Hirth minimeter ; \ interesting application of minimeter is shown in combina- j - tion instrument for testing distance between gudgeon-pin j

1 hole and piston head or pistons of internal-combustion -; engines, as well as whether axes of this hole and of piston ; 1 are truly at right angles. Recent Developments in Design of Precision Measuring [ Instruments, M. A. ROBBIN. Mech Wld v91 Feb 5 1932

J

j

:- p 123-5. Operating principles and accuracy of Hirth- Ij I Minimeter, Krupp's Mikrotast gage, Zeiss optimeter andj

~

l Werner's Microlux indicator.

U Mechanische Fuehlhebel, G. BERNDT. Archiv fuer Tech 1 I Messen vl May 1932 p T71 (2 p.). Operation of lever 1 ] I mechanisms of precision gages with data on accuracy and £ I use of German and Swiss makes.

i » Fuehlhebelmessgeraete ( Contact Lever Measuring Instru- ' S51 ment), ALBRECHT. Werkzeugmaschine v40 nl2 June ' « 1936 p 299-304. Application of contact lever to various 1 « types of movements for mechanical, optical and electric* « measuring instruments.

» k Mechanical Amplification of Small Displacements, A. F. C. j I POLLARD. J Sci Instrum vl5 n2 Feb 1938 p 37-55. De- | a scribes a number of the more satisfactory methods of| |i amplifying small displacements and of accurately reducing j "< large movements to small and corresponding displace- j S ments. The mechanisms described and discussed include i |

levers, combined with optical means of increasing their ; i| sensitivity, the rolling cylinder of small diameter, gear

trains of various types, the differential screw mechanisms, f | mechanisms depending on the bending, twisting or sagging j ; i( of flexible elements, hydraulic and liquid indicating de- 1 | vices, including spirit levels, and a pneumatic micrometer, s L The paper concludes with a discussion of the natural limit | |

to the sensitivity of all measuring instruments, and a short

,

Bibliography. Die Messeigenschaften der Messuhr und ihre Berueck- \, a sichtigung in der Werkstatt (Characteristics of clock dial ., g micrometers and consideration of their use in work shops) , | |

E. BARZ. Werkstattstechnik und Werksleiter v32 nl2 ; June 15 1938 p 287-9 and 291-5. Study of measuring | * errors and underlying fundamentals of standards for this [ f type of micrometer. 138
Draft Standard Specification for Dial Gauges. Machy

i London) v54 nl400 Aug 10 1939 p 594-5. Specification prepared under authority of Mechanical Industry Committee of British Standards Institution, in response to request received from Institution of Production Engineers ; main purpose is to set up standard of accuracy for commoner types of dial gages now in use. Dial-Gauge Research, G. SCHLESINGER. Eng vl38 n

3859 Dec 29 1939 p 725-7. Review of report on dial gage and its use issued by Institution of Production Engineers,

giving account of researches carried out at Loughborough

College ; examples of employment of instrument in accept- ance tests for machine tools illustrated. British Standard Specification for Dial Gauges for Linear Measurements (Excluding Back Plunger Type). Brit Stand Instn BS Specification n907 1940 19 p. Specifica- tion applies to gages having axis of plunger movement

parallel to plane of dial ; with dial diameters of 1*4 in- to 2 in. and having ranges of movements of plunger up to

V2 in- or 12 mm and measuring by steps of 0.001 in., 070005 in. and 0.01 mm.

Levers of Constant Ratio, R. S. CLAY. J Sci Instrum vl7

n3 Mar 1940 p 49-55. Theoretical discussion of simple

lever, bent lever, and lever with connecting link ; applications of levers of constant ratio. A Fine Mechanical Adjustment of Variable Sensitivity, D. S. PERFECT. J Sci Instrum v21 p 123-4 July 1944.

It was desired to adjust to a specific setting the tilt of a mirror to an accuracy of the order of 0.1 in. or better. A

spring was encastered. at one end and also constrained on

one side near this end by an adjustable fixed ball. Near

this ball a second ball presses against the other side of the

spring, and is given minute displacement when the spring

is flexed by a screw controlling the free end. The dis- placement can be used to give linear or angular adjust- ment to a suitably constrained body linked to the second

ball. Adjustment of the longitudinal separation of the two balls controls the minification factor. A Mechanical Arrangement for Measuring Small Changes

in Length. G. LEIBFRIED. Zeit Phys vl27 n5 p 580-7

1950 in German. An apparatus for measuring length changes such as are observed when plastic deformation

begins in a single crystal is described. The linear move-

• ment is taken up by two fine wires rolling between plane

-. . surfaces, and the angular movement of the wires is re- corded optically. A magnification of 3X105 is achieved,

j i and an accuracy of about 10 A is claimed. Some results

•

; j for single Al crystals are discussed.

I New Johansson Measuring Instruments. Machv (Lon-

:

. don) v83 n2144 Dec 18 1953 p 1217-9. Feature of Mikropj . kator comparator, designed by Swedish Co., is that fric- ionless drive to pointer is provided by twisted metal strip

;

i two designs of surface finish indicators developed which

, also employ twisted metal strips for operating pointers

. Deltameter air operated automatic sizing unit which is £ available with measuring heads of various designs,

tff

I T'ltra-Sensitive Mechanical Comparator. Eng vl77 n4588

. fan 1 1954 p 23. Comparator with magnification of 200,-

- • 000 is production model from range of "Mikrakators" made by C. E. Johansson, Ltd ; special Mikrakators made

- with range of plus or minus 0.00002 in. and graduations

for each 0.000001 in. Din Neues Verfahren zur Messung klelner Laengenaen- * derungen (New method for measuring small changes in length), D. KUHLMANN-WILSDORF. Zeit fuer Angew

Ihys v6 n4 Apr 1954 p 171^. Differential method of measuring length by means of horizontal roller having two

• sections of different radii; movable bands attached to w length being measured are fastened to perimeter of each

roller section; rotation of roller is determined by mirror arrangement ; apparatus construction and applications are

included. Basic Principles of Link and Lever Adjustment, N. A. ANDERSON. ISA J v3 nl Jan 1956 p 10-12. Calibration steps for link and lever recorder or indicator which

has pen or pointer connected to element or other power

source by 4-bar linkage ; adjustments for zero, multiplication and angularity ; first covers angle between pen and

pen lever ; second, ratio of total pen or pointer motion to

total element motion ; last, unequal rates of pen or pointer

travel for equal increments of rotation. CEJ Mikrokator. Machy (London) v92 n2366-67 Mar 21 1958 p 658-66, Mar 28 p 713-6. Mikrokator produced by

Aktiebolaget C. E. Johansson, Eskilstuna, Sweden is shock

resistant, dial type measuring instrument capable of high

amplification, which incorporates thin twisted metal strip design ; its application to diameter, load and surface finish measurement ; operations in production of Mikrokator methods employed in assembling amplifying mechanisms.

Adjusting Device Incorporating an Ultrafine Movement,

H. M. KING, J. B. WEIR. J Sci Instrum (GB) v39 nl

p 31 Jan 1962. The primary screw thread is on the out- side of a shaped hollow bar with a necked extension in which two slots are cut. A lapped contact button is at the

end. The secondary screw is inside the bar and has a

tapered extension. When this is pushed into the neck the

outer bar expands and contracts. A maximum shrinkage

of 0.0006 in. is obtained and a one-hundredth turn of the secondary screw gives a movement of two millionths of an

inch. New Instruments for Linear Measurements, G. B. KAINER, N. N. MARKOV, V. YA. EIDINOV. Meas

Techns 1962 n3 Sept 1962 p 184-7 5 figs. Translated from

Izmer Tekh n3 p 6-8 Mar 1962. Describes several types

of mechanical indicators including an optical spring head

spring head having a bronze tape twisted helically from

the middle ; two gear and lever indicators ; a head having moving electric contacts ; waviness instrument for checking gears ; and an indicating hole gage. 5.2.4. Optical

Photographic Registration of Sounds, D. C. MILLER.

Phys Rev v28 n2 Feb 1909 p 151 ; Sci v29 p 471 1909 ; Eng

v94 p 550 1912. A small steel cylinder, 1 mm in diameter,

is arranged to receive angular motion, with a minimum of reaction effects, which is proportional to the displacement

of a sensitive diaphragm. A minute mirror, with its plane

parallel to the axis of the cylinder, reflects light to a special camera, and at a distance of 30 cm gives waves 15 cm

wide which show great detail. See also The Science of Musical Sounds, D. C. Miller, Macmillan Co. N.Y. 1916, The Phonodeik p 78-88. The National Physical Laboratory—Optical Lever Comparator. Eng vllO July 9 1920 p 56-8. Apparatus for measuring thermal expansion by tilt of a glass or quartz

Optical Strain Gages and Extensometers, L. B. TUCKERMAN, NBS. Proc ASTM v23 pt II 1923 p 602-10, 10 figs 7

refs. Describes three optical lever observing and four mirror systems. A Sensitive Optical Lever Method for Measuring the Thermal Expansion of Small Specimens, J. GUILD. J Sci Instrum vl Apr 1924 p 198-204 3 figs. Method employed

is comparative one in which two specimens of suitable form stand close together on flat reflecting surface and

support second reflecting surface approximately parallel

to first ; inclination between two surfaces is measured by

auto-collimating telescope system. Optical lever system 139
employed, magnification 390, corresponding to measure- ment of change in length of approximately X/20 for green

light. Molecular Measurements by Optical Lever, W. N. BOND.

Nature vl22 Aug 4 1928 p 169-70. Optical lever giving very large magnification to test the accuracy with which a

steel-to-steel contact will return after separation, and

whether the thickness of a mica sheet can be detected as varying in multiples of the "molecular" length. Preliminary results are given. Molecular Length Measurement by an Optical Lever, W. N. BOND. Phil Mag v7 June 1929 p 1163-82. Used in a

series of penetration experiments on mica and steel. A

periodicity is shown, viz, 10X10"8 for mica, and 6.8 Xl0"8 for steel which agree with the lengths of the unit cells of mica and of cementite as determined by X-rays. Optisehe Fuehlhebel (Optical Contact Levers), G. BERNDT. Archiv Tech Messen v2 July 1932 p T100

(2 p. ) . Optical systems by which limitations in length of mechanical feelers are extended by application of frictionless ray of light ; details of Zeiss optometer, Sears feeler, Mikrolux, Optotest and interference feeler. Bibliography. Der Lichstrahl als Zeiger in Technischen Messgeraeten

(Light beam as pointer in technical measuring equip- ment), K. H. SIEKER. Zeit fuer Fernmeldetechnik vl3 Dec 15 1932 p 186-90. Application of pointer is shown

in series of examples ; selection of examples made from

practical standpoint and no critical analysis is given. Bibliography. Geometry of Optical Indicators, K. J. DE JUHASZ. J

Franklin Inst v229 nl Jan 1940 p 53-80. Article describes term "optical indicator," embracing all kinds of instru- ments in which one or more optical levers are incorporated

classification of optical indicators; optical lever; kine- matic considerations ; optical levers with one degree of freedom of rotation ; application of theorem to particular

cases; effect of deviations from assumed conditions; nonspherical screens ; convergent light beams ; mirror support. A Multiple-Reflection Optical Lever, H. O. HOADLEY.

Rev Sci Instrum v20 Jan 1949 p 30-41. A detailed description is given of an optical lever which secures increased

sensitivity by means of multiple reflections from a single small mirror. It is of particular use where space is limited, or where the mirror must have minimum size and

mass. Its limitations are an inherent restriction of the measurable range, and a comparatively rapid loss of light with increasing number of reflections. A model system was constructed, which demonstrates that no special

difficulty is met with in making an optical lever according

to these principles up to 7 reflections. Tests made with

the fifth-order reflection proved the model to be quite

satisfactory. An Apparatus for Measuring Small Changes in Linear

Dimensions, D. G. R. BONNELL, A. WATSON. J Sci Instrum v27 Jan 1950 p 10-12. During the study of the

effect of freezing on certain building materials, it became

necessary to develop an apparatus to measure small linear changes in two dimensions. In the apparatus described, movement of the specimen is magnified by the change in the angle of reflection of a beam of light incident on a system of rotating mirrors. A device is incorporated to translate horizontal movements of the specimen into vertical movements on the extensometer. Some Points in the Design of Optical Levers and Amplifiers, R. V. JONES. Proc Phys Soc London B v64 June 1951 p 469-82. The design of optical levers with photoelectric

amplifiers is examined and sources of instability are

traced. Convection currents causing refraction variations are found in some circumstances to affect the light balance in the optical lever ; they may be minimized by properly designed shrouds around the optical path. The better known causes of instability are discussed, and the appropriate remedies are described. The discussion is extended

to the stability of galvanometers. The design of an optical lever and amplifier is given which can detect a change

of 10~9 radian in a mirror 5 mm in diameter with an indi- cation time of 1 sec and with a long-term drift, of the order

of 10~8 radian/hour.

Deflection Multiplier for Reflecting Galvanometers, T. M. DAUPHINEE. Rev Sci Instrum v26 n9 Sept 1955 p 873-5. A very simple multiple reflection system is described by which the effective sensitivity of a reflecting galvanometer

can be increased by a factor of five or more without in- creasing the mirror-to-scale distance. The full width of

the galvanometer mirror is used for each reflection, so that with a good quality mirror there is little reduction in the sharpness of the hairline image and only moderate reduction in the brightness of the spot. Use of a 2 m path dis- tance and four or five reflections makes it possible to ex- tend the useful sensitivity of a sensitive galvanometer

close to the limit set by Brownian movement. The princi- ple of this amplifying system can be applied directly to most forms of optical lever. On a Light-Pointer Arrangement for Null Instruments, H. HAAS. Optik vl5 n2-3 Feb-Mar 1958 p. 135-7 in Ger- man. The use of a porro-prism permits the light beam re- flected from a mirror to be split into two beams which

deflect in opposite directions for a mirror rotation. Thus

the null position is shown as the only position for which

there is a single beam. Recording Optical Lever, R. V. JONES, J. C. S. RICHARDS. J Sci Instrum v36 n2 Feb 1959 p 90-4. A

small optical lever is described which can detect a change

of 10"10 rad in orientation of a 2 mm2 rairror, with a re- sponse time of about 0.25 sec. A differential cadmium

selenide photocell is used with a standard optical grid technique to detect the displacement of the reflected light beam from a 4V, 3.2W lamp. Transistors are used to stabilize the lamp current and to amplify the signals for a pen recorder. "Noise" arising from convection currents

in the light beam and from the photocells appears not to exceed greatly the photon fluctuations in the light beam. Records illustrate the performance of the lever and amplifier in detecting changes in dimension of a crystal of a few

times 10"10 cm and changes in refractive index of a gas by a few times 10~9

. The system has also been applied to an

infrared detector using the linear expansion of a metallic

strip, where the Limit for a 5 x 0.2 mm strip is about 10-11 W for a 1 c/s bandwidth. For this purpose the signal can

be differentiated with respect to time, and velocities of down to 30/i/annum can be observed. It appears that a displacement of 10"12 cm could be detected. Some Developments and Applications of the Optical Lever,

R. V. JONES. J Sci Instrum (GB) v38 n2 Feb 1961 p 37-

45 22 refs. The history of the optical lever is briefly re- viewed from its invention by Peggendorf in 1826 to the

recognition by Ising in 1926 of Brownian fluctuations of a galvanometer in the records obtained by Moll and Burger

in 1925 with their thermoelectric relay. The design of

optical levers and amplifiers by the author and his collab- orators is outlined ; these give sensitivities of the 10"10 ra- dian for a mirror 2.00 mm x 2.0 mm, and an observation bandwidth of 10 c/s. The effects of convection currents and photon fluctuations are indicated. The applications of

optical levers to a range of measurements, including Brownian fluctuations, radiation pressure, linear expansion and infra-red detection are described. Optical and

photoelectric systems similar to those developed for the

optical lever can be used for alignment measurement ; applications include refractometry for refractive index changes of order 10~9

, and a test of the constancy of the

velocity of light in a transverse magnetic field. 140
An Optical Lever Gauge for Local Thickness Measure- ments on Fragile Crystal Plates, W. E. SPEAR, A. R. ADAMS. G. A. HENDERSON. J Sci Lustrum (GB) v40

n6 June 1963 p 332. The design and use of a simple and

inexpensive gauge is described which is suitable for thick- ness probing on fragile crystal platelets between 10/j. and

500/a thick. It employs a miniature optical lever which

gives an optical magnification of 103

, and the local crystal thickness can be determined to within 0.5/i. Ultraoptimeter IKP-2, V. A. NIKITTN, E. P. SMIRNOVA.

Meas Techns 1963 n6 Nov 1963 p 461-3 2 figs. Translated from Izmer Tekh n6 p 6-8 June 1963. A new model of an

ultroptimeter IKP-2 was developed in 1961 by the Lenin- grad association of optical-mechanical plants. The instru- ment is intended for contact measurements of external

linear dimensions, and uses a relative method by comparing the measured article with block gauges, jigs, or sample

components. The instrument's optical system is based on

the autocollimation principle in combination with repeated

reflections. 5.2.5. Pneumatic

High-Precision Measurement of Lengths and Thicknesses, M. MENNESSON. CR Acad Sci vl94 Apr 25 1932 p

1459-61. The method consists essentially of a measure- ment of change of pressure in air when flowing through an orifice whose section is a function of the length or thickness to be measured. A supply of air at constant

pressure, regulated to within 1 mm of water, flows through

a calibrated orifice into a vessel and thence through a second orifice whose size has to be found. The object whose dimensions are required is placed on a movable base whose distance from the second orifice is known. The

air pressure between the two orifices is a function of their

sectional areas and is measured by a water manometer. The sensitivity can be varied by a suitable choice of the

orifice diameters and the initial air pressure. Groupe "Mecanique de Precision et Metrologie." Mechanique v21 n271 Mar-Apr 1937 p 69-83 ; English review

in Engr vl64, n4254 July 23 1937 p 106. Symposium

before Soeiete Francaise des Mecaniciens, as follows

Metrological Instrument of French Make, DUMANOIS

Pneumatic Amplification, L. WATTEBOT; Application

of Solex Micrometer in Industrial Metrology, J. OUTIN

Application for Measuring Strength of Materials, H. DE

LEIRIS ; Application in Study of Metals Cutting, R. BEN- SIMON ; Application in Measurement of Surface Conditions, P. NICOLAU.

Die praktische Verwendung des Solex-Messverfahrans

< Practical application of Solex measuring method), O. N'lEBERDING. Werkstattstechnik und Werksleiter v36

n23/24 Dec 1942 p 498-504. Air is used as measuring medium ; testing of small nozzle openings and bores ; early form of Solex plug gage ; testing of calipers and external diameters : multiple test apparatus ; testing of pistons. Solution of Instrumentation Problems by Pneumatic Null Balance Method, C. B. MOORE. Instrum vl8 n9 Sept

1945 p 598-603. Principal characteristics of pneumatic

null balance method ; description and summary of design

factors including nozzle characteristics, effective area of

flexible member, and materials of construction ; typical examples of utilization of pneumatic null balance principle

in solving instrumentation problems; automatic control. 'Reprint with additions available from Moore Products

Co.) Nozzle Flow Characteristics in Pneumatic Force-Balance

Circuits, D. B. KIRK. Moore Products Co. Outline of an

illustrated lecture before Industrial Instruments and

Regulators Div., ASME.

Pneumatic Gauges, H. NIEPEL. Mech Wld vll9 n3098 May 17 1946 p 545-50. Principles and applications for

measuring instruments. Translated from German journal Feinmechanik und Praezision v50 1946 p 255-60. Pneumatic Length Measurement Principles, E. GOTHEL.

Archiv fur Tech Messen Issue 152 (Ref. V1121-6) T3

July 1947 in German. The "Solex" pneumatic method of length measurement, invented by Marcel Menneson, gives an accurate indication of small length differences by using gas flow. Constant-pressure compressed air flows through an orifice into a closed chamber and through a second

orifice, where it impinges on a surface at distance d. The

pressure in the closed chamber then ozd. The incoming

air pressure is kept constant by an air-bubble overflow and the chamber pressure is measured by a water mamometer. The theoretical air flow relations are deduced. Owing to moisture and orifice-bore roughness these rela- tions are very approximate, and the instrument must be

empirically calibrated. Air Jets . . . Their Characteristics for Gaging Devices, R. S. ELBERTY. Maeh Design v20 nl Jan 1948 p 111-4. Discussion of air jets used for ultrasensitive gages ; characteristics of air jet gaging devices are revealed in tests relating to pressure drop across air jet, sensitivity of pres- sure type air gage, sensitivity of air jet, and zone of greater sensitivity of pressure type air gage; data on

pressure regulators and air gage circuits. Evolution de la Metrologie Pneumatique (Evolution of pneumatic measuring apparatus), R. TRIBARREN. Machines et Metaux, v32 n356 Apr 1948 p 123-7. Principles

self control and quality control ; pneumatic control of micrometers, internal cylindrical gages, "Solex" pneumatic

vernier, and vertical scale; illustrations. A New Pneumatic Method for Measuring Small Variations

in Length and Some Applications of It. C. G. HARD.

IVA, Stockholm, v20 n3 1949 p 107-19 in English. After

a brief survey of other pneumatic measuring methods the

principle and theory of the Delta system are described. The device consists of two measuring chambers fed with

air at constant pressure through an intermediate chamber,

the air passing from the intermediate to the measuring chambers and then out into the atmosphere through

valves, all mounted on the same spindle, and designed for greatest sensitivity. The relation between the ratio of the chamber to the applied constant pressure, and the

spindle position, is shown to be approximately linear. The merits of the system are listed. The Delta meter, a commercial form of instrument, utilizing the Delta sys- tem, and generally used as a comparator, is fully illus- trated and described. Les Lois de la Metrologie Pneumatique (Laws Governing Pneumatic Metrology), R. MOLLE. Rev. Gen de Mecanique v 34 nl3 Jan 1950 p 26-30. Laws governing pneu- matic metrology and their application to development of new apparatus in laboratories of Faculte Polytechnique

de Mons ; principle of Solex apparatus and various other

types of pneumatic gages described and illustrated. Versatile Pneumatic Instrument Based on Critical Flow, W. A. WILDHACK. Rev Sci Instrum v21 nl Jan 1950 p 25-30. Principles of instrument for measurement and

control of pressure, temperature, flow, humidity, gas composition, or mechanical displacement ; in simplest form,

critical flow is maintained through two nozzles in series; variation in flow through first nozzle, occurring with

changes of pressure, temperature, etc., are reflected as change in absolute pressure at entrance to second nozzle. Pneumatic Comparator of High Sensitivity, M. GRA- NEEK, J. C. EVANS. Machy (London) v79 n2016 July 5 1951 p 33-6 ; see also Engr vl92 n4981 July 13 1951 p 62-

4; Eng vl72 n4470 Sept 28 1951 p 414-5. Comparator,

having good speed of response, consists essentially of hol- 141
low double piston which is air tight sliding fit inside cylinder of % in. bore ; calculation of force exerted on

surface under measurement; example of use of comparator for fine measurement. Maximum Sensitivity in Pneumatic Gauging, N. R. WYNN, N. STOLOW. Letters in J Sci Instrum, v32 n4

p 55 Apr 1955. The first author points out with reference

to the paper by the second that the condition for max.

sensitivity when a null-point method is used in pneumatic

gaging is obtained when He tt= l/2H. The second author

argues, however, that this is correct for one application

of the gauging method but not for the practical operation

of his apparatus.

Application of Pneumatic Gauging to High Precision Linear Measurement, J. C. EVANS, I. G. MORGAN. J Sci Instrum v33 nlO Oct 1956 p 388-90. Pneumatic system employed in precise measurement of variation in thickness,

in each of three principal directions, of nearly perfect cube

recently used at National Physical Laboratory ; theoretical

basis of method, and details of experimental arrange- ments; advantages of pneumatic gaging techniques for

linear measurement.

Schlag- und Fluchtungsmessung mit Luftmessgeraten

(Twist and alinement measurement with air measuring

instruments), O. NIEBERDING. Zeit fur Maschinenbau

und Fertigung v90 n3 p 181-3 1957 13 figs 1 ref. Cites 5 advantages of pneumatic measuring apparatus for twist and alignment measurement. Discusses deviation from

perpendicularity to axis of the end faces of bores and

shafts, alignment of coaxial holes, and alignment of

parallel bores. Pneumatische Gerate Zum Messen von Achsabstanden (Pneumatic Instruments for Measurement of Eccentricities), O. NIEBERDING. Werkstattstechnik und Maschinenbau v47 nil 1957. Pneumatic Gauging Technique in Its Application to Di- mensional Measurement, J. C. EVANS. Inst Prod Engrs

J v36 n2 Feb 1957 p 110-20, 140 ; see also Inspection Engr

v21 n3-4 May-June 1957 p 50-54, July-Aug p 79-86. Work described was carried out as part of research pro- gram at National Physical Laboratory dealing only with

type of gaging in which displacement or change of size

is determined by measuring change of pressure which it is made to produce; theoretical and practical considerations ; calibration and performance ; applications. Eigenschaften pneumatischer Feinmessgerate (Properties

of pneumatic precision measuring instruments), O. NIEBERDING. Industrie-Anzeiger n20 Mar 8 1957 3p 11

figs. The problem of establishing finest dimensional dif- ferences with the necessary reliability is better solved with pneumatic measuring equipment than with usual and known means. The article discusses the manner of op- eration of fine pneumatic measuring equipment, air pres- sure requirements, contactless measurement, influence of surface roughness sensitivity against dirty surfaces, ad- vantages of the pneumatic caliper, advantages of the jet in yielding numerical values, distance transmission of meas- urement values, measuring units yielding average values, pneumatic means for amplification, damping. Dynamic Air Gaging Reduces Cycle Time in Precision Measurement, A. H. JOYCE, K. E. RUGG. Gen Motors Eng J v5 n4 Oct-Nov-Dec 1958 p 29-32. In study of dynamic gaging characteristics, analog computer was used

to simulate dynamic air gaging; mathematical relation- ship between pressure, time, restrictor size, jet size, circuit volume, and distance established ; diagrams of electronic

circuitry and air gaging circuit ; example. Kennzeichnende Eigenschaften pneumatischer Messgerate

(Characteristic Properties of Pneumatic Measuring Equipment ) , R. CARL. Four FoKoMa Oct 1959 p B81 Munchen.

In the scope of the investigations of measuring equipment and controls organized by Prof. Eisele this report is a compendium of the extensive theoretical and practical

results. Contents: Introduction and systematik; the

feeler ; transducer and indicator ; experimental investigations, conclusions, bibliography. Bauarten und Eigenschaften pneumatischer Messgerate (Types and Properties of Pneumatic Measuring Equip- ment), O. NIEBERDING. Four FoKoMa Oct 1959 Munchen, p B77 ; Maschinenma'rkt v66 nl9 Mar 4 1960 4 p

10 figs. The author characterizes the types and properties

of pneumatic measuring equipment, elaborates the com- mon characteristics, and characterizes the individual

peculiarities in their advantages and disadvantages.

Electrification of a Pneumatic Micrometer with a Liquid Manometer, B. D. KOSTROV, S. P. IUDIN. Meas Techns

1958 n5 Feb 1960 p 509. Translated from Izmer Tekh n5

Sept-Oct 1958 p 10. The authors have electrified a manometric pneumatic micrometer which used a 1.5%

solution of sodium bicarbonate. Owing to the minute

currents used and a polarity of connection in which the reducing agent, hydrogen, is produced on the small sur- faces of conductors, the harmful electrolytic action was

eliminated. Pneumatic Gauges for In-Pile Measurements, J. PEFHANY. Nuclear Eng (GB) v6 p 77-9 Feb 1961. A

description is given for the development of a pneumatic

gauge for in-pile measurements of very small movements. Work done suggests that accurate results can be expected

at temperatures in excess of 400 °C. Pressure Stabilizers for Pneumatic Instruments Used in Linear Measurements, A. P. KUROCHKIN, F. V. TSI- DULKO. Meas Techns 1961 n8 Feb 1962 p 604-7 3 figs. Translated from Izmer Tekh n8 p 4-7 Aug 1961. The special work carried out by the Interchangeability Bureau in establishing the relation between the operating pressure

error, and hence, the error of measurement, has made it possible to specify the requirements for various measuring

systems with respect to pressure stabilizer accuracy. Knowing the actual accuracy characteristics of stabilizers,

it has been made possible to specify their ranges. Pneumatic Self-Balancing Systems, A. P. KUROCHKIN,

I. YU. OKUN*. Meas Techns 1963 nl Aug 1963 p 14-5 1

fig 3 refs. Translated from Izmer Tekh nl p 10-1 Jan

1963. Describes development of a bridge schematic, namely a self-adjusting balanced pneumatic bridge, which was successfully utilized in an automatic machine for

selecting balls by the differences in the ball bearing races. Errors in Pneumatic Linear-Measurement Systems, A. P. KUROCHKIN, E. L. NOSKIN, F. V. TSIDULKO.

Meas Techns 1963 n2 Aug 1963 p 108-11. Translated from

Izmer Tekh n2 p 14-6 Feb 1963. The error of a pneu- matic measuring system produced by the instability of the

operating pressure H is one of the components of the

system's total error. The degree and nature of the effect produced by this error on the readings of the system de- pends on the type of the latter, its parameters, design, etc. The error is conveniently represented as a ratio of the absolute error to the corresponding measurement range

expressed in linear or pressure units, provided the measuring range does not exceed the linear portion of the

characteristic. Les Capteurs Pneumatiques (Pneumatic Pickups), C. RENET. Automatisme v8 n9 Sept 1963 p 305-10. Basic

structure of measuring instruments using pneumatic servomechanisms is reviewed ; operation of various types

of pressure-sensitive elements and pneumatic pickups is 142
described ; relative merits and shortcomings are compared. Precision of Pneumatic Instruments for Linear Measurements, A. YA. ROSTOVTKH. Meas Techns 1963 n5 Nov

1963 p 376-9 2 figs 4 refs. Translated from Izmer Tekh

n5 p 10-2 May 1963. Analyzes and evaluates the factors which affect the precision of measurements made by the

"solex" instrument based on a pneumatic method for

measuring dimensions, and examines the problem of elim- inating the causes which lower this precision. Principles of Pneumatic Gauging, J. C. EVANS, I. G. MORGAN. NPL Notes on App Sci n34 1964 32 figs 19

refs. Discusses scope of pneumatic method, range of

linear measurement, pneumatic sensitivity, overall magnification, basis for design, practical considerations, and

pneumatic equipment developed at NPL.

5.3. Dials and Pointers

See also Subsection 3.6.4 A Set of Proposed Standard Numerals for the Scales of Measuring Instruments, A. P. TROTTER. Inst Elec Engrs J Feb 1 1916. CoL A. Strange's designs and pro- posed changes in interests of simplicity. Pointers of Low Inertia for Measuring Instruments, R. MIELICH. Zeit fur teclm Phys vl7 nl 1936 p 27-31. It

ia shown experimentally that glass is superior to alumi- num as a material for constructing low-inertia pointers

for measuring instruments. This is mainly because glass can be drawn down into the form of tubes with extremely

thin walls, and a suitable method of performing this op- eration is described. Rigidity in the pointers can be maintained by combining together tubes of different thick- nesses ; at the same time, low moments of inertia are

achieved. Designing Instrument Dials for Quick, Accurate Reading, W. F. GRETHER. Machine Design v20 n6 June 1948

p 150-2 208-9. Review of psychological findings which

underlie first steps toward design of aircraft or other instruments for maximum ease and accuracy in reading. Based on paper before Soc. Automotive Engrs. Machine Dials and Scales, W. R. GARNER, J. W. GEB- HARD. Machine Design v21 n8 Aug 1949 p 98-105. Design of dials to insure quick, accurate reading ; dial uses can be classed into three groups ; check, directional, and

quantitative readings; factors affecting reading precision and speed of reading as related to dial numbering and

markings, kind of pointer, dial grouping, etc. ; other design

data. Bibliography.

Indicators and Controls. A. CHAPANIS. Machine Design v27 n4 Apr 1955 p 212-4. Designing for maximum

readability and efficiency. From "Some Applications of Experimental Psychology to Machine Design" in Office of Naval Research, Research Reviews. June 1954. Tensator Spring as Force Transmission System in Instru- mentation, C. PERNETTA. Machy (London) v91 n2344

Oct 18 1957 p 927-31. Results of preliminary survey of

possible applications of Tensator constant force spring as force/transmission element in field of instrumentation

dial gage incorporating Tensator springs; use of spring

for avoiding hysteresis effects ; Tensator employed in con- junction with metal band; suggested design for direct reading gage and caliper gage.

On a Light-Pointer Arrangement for Null Instruments, H. HAAS. Optik vl5 n2-3 p 135-7 Feb-Mar 1958 in Ger- man. The use of a porro-prism permits the light beam

reflected from a mirror to be split into two beams which

deflect in opposite directions for a mirror rotation. Thus

the null position is shown as the only position for which

there is a single beam.

Design of Visual Indicators, J. SPENCER. Eng Matls &

Design v4 n9-10 Sept 1961 p 572-6, Oct p 672-5. Sept

Design characteristics of indicator dials and scales for general industrial purposes requiring accuracy of plus or minus 1% of maximum scale values ; examples of good and poor design. Oct : Design of qualitative and repre- sentative indicators. Quality and Quantity of Information, K. F. H. MURRELL. Soc Instrum Technol Trans vl5 n2 June 1963 p 96-9. Progress review of instrumental displays and

design of their use in Great Britain ; it is concluded, from

instruments still being manufactured, that not enough

thought is yet being given to suitability of instrument to needs of operator. Mechanische Schwingungen erschuetterter Messwerke in Spannbandlagerung. (Mechanical vibrations of taut- suspension instrument movements subjected to shock).

F. WEIDENHAMMER. Frequenz vl7 n8 Aug 1963 p 302-

11. Motional equations for low-amplitude vibrations about finite, electrically established deflection of pointer; 6 degrees of freedom are considered ; equations show that compliance with certain decoupling condition generally

yields maximum possible mechanical stabilization of movement ; otherwise, pointer extremity will perform amplified forced vibrations in plane of indication ; such vi- brations are approximately calculated for almost-satisfied decouping condition. Recommendations for Design of Scales and Indexes.

Brit Standards Instn—Brit Stand 1449 pt 1 1964 44 p. Recommendations in this part are intended to be generally applicable to quantitative instruments of bold presentation and designed for rapid reading, intended to be read to resolution of about 1 to 2% of scale range and

are particularly concerned with relating scale dimensions

to maximum reading distance; they are only applicable

to single scale instruments having dials with full circle, part circle or straight scales as defined.

5.4. Optical Features

Optische Hilfsmittel an Messgeraten (Optical Aids to Measuring Apparatus), W. BLOCK. Betrieb v4 n9 Feb

11 1922 p 285-9 6 figs 2 refs. The object is not to form

experiments regarding optical methods of measurement

but to form about their convenient application a few considerations regarding optical auxiliaries to measuring

equipment of each kind and to completely exploit and

increase their measuring accuracy. Quelques Points Particuliers de Metrologie (The Setting

of Microscope Cross Wires), A. PERARD. Rev Opt v2 Dec 1923 p 506-11. On the Limit of Accuracy in Optical Measurement. A. A. MICHELSON. J Opt Soc Am and Rev Sci Instrum v8 Feb 1924 p 321-8. The limits of accuracy obtainable in observations with the telescope, microscope, interferometer, and spectroscope are discussed. Optical Measurement in the Workshop ( Optische Messverfahren in der Werkstatt), C. von HOFE. Praktischer 143
Maschine-Konstrukteur v58 Mar 10, June 16, July 14, and Aug 11 1925 p 187-89, 382-84, 446-^8, and 507-11 14 figs. Discusses methods of optical measuring, especially those used in optical shops, covering spectrometers, measuring

thickness and radii. Bibliography.

Principles and Advantages of Optical Methods for Measuring Machine Parts, H. F. KURTZ. Mech Eng v47 Mid-Nov 1925 p 987-92 16 figs ; Machy v63 Dec 3 1925 p

894 for abstract. Outlines four classes of optical instru- ments namely, interference apparatus, imaging systems,

optical scale reading, and optical levers; and describes measuring instruments already designed for machine- measuring purposes. Measurement of Fiber Diameters by Diffraction Method,

H. J. McNICHOLAS, H. J. CURTIS. Rev Sci Instrum

v2 n5 May 1931 p 263-86 6 figs. New construction of Young's instrument (eriometer) ; critical study of accu- racy and adaptability of instrument in averaging of wide

range of diameters as distributed in group of fibers

sources of error and limitations of method. A Mirror Comparator for Production Inspection, O. P. VAN STBEWEN. Am Mach v75 Sept 10 1931 p 417-8

4 figs. Unit works with combined optical and mechanical

magnification. Quantitative Thermo-electric Magnifier for Optical Pointers, J. H. JEFFREE. London, Edinburgh and Dublin

Phil Mag and J Sci vl4 Sept 1932 p 366-72. Simple

device for magnifying deflections of optical pointers, giv- ing large magnification which is independent of fluctua- tions in illumination intensity. Xeue Erfahrungen mit dem Ultra-Optimeter (Recent ex- perience with ultra-optimeters), C. BUETTNER. Werkstattstechnik und Werksleiter v29 n4 Feb 15 1935 p 65-6. Usefulness in measurements of high precision ultra-optimeter made by C. Zeiss, in Jena. Durchmessermessgeraet fuer lange Bohrungen (Diameter measuring equipment for long bores), Werkzeugmaschine

v40 nl6 Aug 31 1936 p 394. Detailed description of equip- ment using optical methods of observation. Ueber eine einfache Anordnung zur parallaxefreien Able- sung von Zeigermessageraeten (New type of mirror ar- rangement free of parallax error in reading of scale indicating instruments), H. BUMAN, G. RITZOW. Zeit fuer Techn Phys vl9 n4 1938 p 97-8. Method of Dimensional Gaging with Photoelectric Cells,

C. TUTTLE, W. BORNEMANN. Instrum vl2 n2 Feb

1939 p 67-70. Notes on procedure and equipment ; photoelectric photometry applied to gaging; optical magnification in photoelectric gage; accuracy of method. Some Applications of Optics to Engineering, M. H. TAYLOR. Inst Production Engrs J v20 nil Nov 1941 p 439-65

(discussion) 466-70. Types of measurement to which

optics can be usefully applied ; notes on optical measure- ment to which optics can be usefully applied ; notes on

optical measurement of lengths, angles, and irregular con- tours ; screw thread projection ; measurement of some

irregular shapes which cannot be projected by conventional means. Uber die optischen Grundlagen der technischen Feinmessgeraete (Optical principles of technical precision measuring apparatus), K. RAENTSCH. Werkstatt und Betrieb v74 nil 12 Nov 1941 p 295-9, Dec p 315-22. Nature of

light ; law of reflection and refraction ; survey of physiological optics ; various optical instruments described

single lens microscope and telescope ; protection devices

multi-lens microscope and telescope; photographs and

diagrams.

A Long Optical Path in a Restricted Space, H. R. DRATZ,

J. E. MACK. J Opt Soc Am v32 p 457-64, Aug 1942. An

instrument is described for attaining a long optical path

by repeated traversal between a concave spherical mirror and a totally reflecting prism. Its properties are outlined and compared with those of other devices for similar purposes. The number of traversals is in principle unlimited but the angular spread of the final beam is less than that of the first traversal. The final image, which

is almost free of aberration, is as large and almost as

bright as the source. The optics of the instrument is considered in detail. The Measurement of Small Linear Motions by Optical Methods, R. W. G. HUNT. J Sci Instrum v23 p 119-21 June 1946. Two optical methods for measuring small

linear motions have been used, and some results obtained thereby are reproduced. The first makes use of two

microscope objectives and depends on lenticular magnifi- cation for high sensitivity; the second uses a concave

mirror and two prism systems, high sensitivity being ob- tained by means of prismatic magnification. Engineering Optics, K. J. HABELL, A. COS. Sir Isaac Pittman & Sons, London, 1948 411 p. illus diagrs charts

tables, 35s. Critical survey of most important optical methods and instruments applicable to engineering practice ; properties of ideal optical systems and actual systems

discussed ; light and illumination, microscopes, telescopes, optical projection and profile microscopes considered. Eng Soc Library, N.Y. Die Optik in der Feinmesstechnik, K. RAENTSCH. Carl Hanser Verlag, Munich, Germany, 1949A 317 p illus diagrs

charts tables. Book describes measuring instruments and

their optical principles ; fundamentals of technical optics discussed ; various instruments for fine measurements

considered. Bibliography. Eng Soc Library, N.Y.

Optical Tools for Shop Precision, C. EMERSON. Am

Mach v93 n25 Dec 15 1949 p 91-8. Optical flats and their applications ; optical projection discussed including light- ing and lenses, screens and charts, staging and surface

projection ; shop microscopes and microscope attachments

collimation, optical systems for boring and grinding machines, and small optical tools described. An Interference Micrometer for Diameter measurement

of textile filaments in moisture-controlled atmospheres,

P. DENTON. J. Sci Instrum v29 Feb 1952 p 55-7. An

instrument is described for determining minute dimensional changes on a specimen enclosed in atmospheres of

different but pre-determined moisture condition. Localized Fizeau fringes, formed by reflection from a pair of aluminized glass plates that correspond to the fixed and

movable jaws of a normal micrometer, are used as sensi- tive fiducial indicators for the appropriate setting of a micrometer head. One edge of the movable plate is laid

in contact with the specimen and the other rests on a lever, the longer arm of which lies in contact with the micrometer head. This is adjusted until the fringe formation, which is viewed through the eyepiece of a Fizeau inter- ferometer, indicates parallelism of the aluminized surfaces

in a direction set by the line joining the ends of the lever ; specimen thickness is then derived from the lever reduction ratio. Air of standard moisture condition moves

past the specimen in a glass cell which is fitted with a flat roof to transmit the light. The instrument applies a

small known force on the specimen and is especially appli- cable to measurements on compressible bodies. Data on

the variation in diameter of cellulose filament with mois- ture condition are presented to illustrate the performance

of the instrument. A New Instrument for Measuring the Thickness of Glass Tube Walls, K. BERNOLAK. Exper Tech der Phys vl n2 1953 p 91-2 in German. A simple optical device is 141
described whereby the direct measurement of the thick- ness of glass tube walls may be made to an accuracy of

0.01 mm ; the latter depends on the regularity of the tube

thickness. Ultrasonic Microscope. S. T. SOKOLOV. Radio & Television News (Radio-Electronic Eng) v49 n2 Feb 1953 p

S-9. How obtaining of very short ultrasonic waves of order of wavelength of visible light, has led to develop- ment of microscope with which it is possible to view object

in magnified scale, image is seen directly on cathode ray

tube screen: calculations show that magnification ap- proaches order of tens of thousands of times ; design and

operating details of various versions. Translated from

Russian journal, Progress in Phys Sci v40 Jan 1950. Design of Graticules and Reference Marks, and Some

Factors in Operation of Scientific Instruments, R. T. LESLIE, L. D. ARMSTRONG. Austral J App Sci v6 n2 June

1955 p 167-82. Experimental study of factors affecting accuracy of combinations of graticules with reference marks, effects of line thickness, separation of fixed line

pairs, angle between crossed transverse lines, width of

light gap between central and outer elements, illumination, ambient temperature and other factors. A Large Optical Slit Mechanism Employing Spring Movements. R. V. JONES. J Sci Instrum v33 n5 May 1956 p 169-73. A spring layout is described for producing

symmetrical movement in an optical slit 10 em long, and

capable of operating at any width between 5 and lOOOjt. Such factors as the parallelism and separation of the jaws

are made independent of gravity by suitable arrangement

of spring strength and disposition of centres of gravity of the moving members. The jaw edges are optically worked

to confine width variations along the slit to about

±0.15;i r.m.s.. and the jaws can be set parallel by eye and

hand to within about 0.3^ variation in the 10 cm length. Measurement of Small Displacements of a Plane Surface

with a Semi-Virtual Slit Modulator, P. BARRET. J Phys Radium vl7 n6 June 1956 p 29 S in French. This method

is suitable for measuring the displacement of a polished or

plated surface. A metal plate, such as a razor blade, is mounted parallel to and about 0.01 mm away from the

surface. Observation of the slit at grazing incidence shows a real and a virtual (reflected) edge. Variations

in the magnitude of this "sem-virtual slit" are used to modulate a beam of light falling on a photocell for recording static or dynamic displacements of the surface. Optical Probe for Accurately Measuring Displacements of

Reflecting Surface. K. W. T. ELLIOTT. D. 0. WILSON.

| Sci Instrum v34 n9 Sept 1957 p 349-52. Displacement

of plane reflecting surface along its normal can be accurately measured by probe without making mechanical contact with it ; successive settings of probe relative to fixed surface indicate that standard deviation of single setting

of probe is about 0.4/i(1.6X10~3 in.) when probe is used

with calibrated line standard, displacements may be measured with standard deviation of 0.7yn(2.8X10-5 in.). Precision Measurements on the Z-Axis of a Microscope,

D. HEUGHEBAERT, J. HEUGHEBAERT. "Particle Photography" Conf, Montreal, 1958 in French. A considerable increase in the accuracy of measurements in the

vertical plane is obtained if the relative distance between

the objective and the eyepiece is made variable, the dis- tance between the objective and the plate remaining un- changed. A device based on this principle is described,

its use and the attainable accuracy are illustrated for a number of cases. Considerations Regarding Possible Use of Some Optical Elements, N. BARANY. Periodica Polytechniea—Elec Eng v.3 n3 1959 p 183-96. Review of known adjusting devices for optical and precision instruments with examples

of unduly neglected control mechanisms ; mechanical constructions in military instruments adaptable to civilian

uses. A Recording Scanning Micrometer, V. R. REGEL', V. G. GOVORKOV. Pribory i Tekh Eksper (USSR) 1959 n4

p 133-6 July-Aug in Russian. This displacement micrometer is based on the photoelectric measurement of a lumi- nous flux which passes through a system of two rasters moving with respect to each other. A laboratory model of

the instrument permitted the measurement of displace- ments of up to 10 mm with an accuracy of 0.1/*. [English

translation in: Instrum Exper Tech (USA) n4 p 654-7 July-Aug 1959; publ. June I960.] Beriihrungloses Messen grosserer Aussen-und Innendurch- messer (Contactless Measurements of Large External and

Internal Diameters), K. RANTSCH, E. LEPPER. 4 FoKoMa Munich Oct 6-7 1959. Contactless measurement

is an acute problem of the progressive finishing technique

to the metrologist. This problem is solved electrically, pneumatically, and optically. The explanations of this paper are concerned only with optical contactless measurements, especially for external and internal diameters. Next the demands placed on new equipment are set forth

for large measurements. An especially remarkable such measuring equipment is the flawless, contactless, indication response of the cylinder surface. For this the field of surface indication is especially treated. Optical indicators of known and of newer kinds are systematically ar- ranged and closely elucidated. Two principal groups of indication responses are thus developed. These chief groups are further classified. Thereby the application

possibilities of the single indicators may be recognized. From this knowledge conclusions are derived for practical application in metrology. The already obtained experi- mental information presents a prospect of future flawless- measuring methods. An Image-Splitting Microscope for Accurate Measurement,

J. DYSON. Nature (London) vl84 Nov 14 1959 p 1561. Dsecribes how, by fitting in the eyepiece a suitable image

splitting device, the two images may be sheared across each other until edge-to-edge contact is obtained. By

reversing the shear until edge-to-edge contact is again ob- tained, the diameter of the object may be measured. The

technique is illustrated by application to blood corpuscles. Adjusting Your Point of View, J. R. SULLY. Eng Matls & Design v3 nl Jan 1960 p 13. Description and diagram

of optical instrument developed to eliminate distortion often found when viewing small-scale models with naked

eye ; instrument can be used for models of various scales by adjusting distance between reflectors or prisms. Precise Measurement of Small Objects, J. DYSON. AIE

Eng (formerly AEI Eng Rev) vl nl Jan 1961 p 13-17; Maehy (London) v92 n2520 Mar 1 1961 p 503-8; Quality Engr v25 n2 Mar-Apr 1961 p 41-5. Optical principle of and apparatus associated with new method based on

application to microscope of "image splitting principle"

method enables measurements to be made with precision about 10 times better than resolving power of microscope

allows, and is particularly suitable for rapid and precise measurements of repetitive nature, such as are required

in inspection department. Device for Adjusting Universal and Measuring Microscopes, N. K. KRASNOPEROV. Meas Techns 1961 nl

Sept 1961 p 21-2 2 figs 1 ref. Translated from Izmer Tekh

1961 nl p 15-6 Jan 1961. A device was made for eliminat- ing the displacement of the optical axis of a type UIM-21

and BMI microscope tube with respect to the axis of rota- tion of the supporting column. 145
Development and Application of Fiber Optics Techniques

to Precision Measuring Devices, Transducers and Auto- matic Transducers and Automatic Control Systems, E. D. GRIM. Electronic Components Conference-Proc 1962 p

137-40. Application of techniques using fine filament of glass of circular cross section and high index of refraction surrounded by thin jacket of lower index glass as basic element in design of transducers, distance and angle measuring devices, automatic position control systems, card and tape readers, light operated relays, function generators, and other similar devices. Quality and Quantity of Information, K. F. H. MURRELL. Soc Instrum Technol Trans vl5 n2 June 1963 p 96-9. Progress review of instrumental displays and

design of their use in Great Britain ; it is concluded, from

instruments still being manufactured, that not enough

thought is yet being given to suitability of instrument to needs of operator.

Optimum Operating Conditions for Scanning Devices in Photoelectric Recording, M. G. MIKHAILOVA. Meas

Techns 1963 nl Aug 1963 p 22-5 4 figs 6 refs. Translated from Izmer Tekh nl p 16-8 Jan 1963. Scanning photo- transducers are widely used in systems requiring precise focusing on a graduation. Scanned phototransducers with a small scanning amplitude can be used under the same conditions as similar transducers based on the meas- urement of the duration of adjacent pulses, since the parameters of the former do not depend in a zero measuring method on the amplitude of vibrations or the width

of the graduation image. Modern Optics in Machine Tool Technique. Firm of Dr. Johannes Heidenhain, Traunreut. Mar 1964 46 p 36 figs. Discusses advantages of optical measuring methods, fun- damental terms in metrology, and principles of measuring

system employing transverse step vernier chart. Presents a survey of standard instruments.

5.5. Pivots

Instruments Pivoting, C. E. FOSTER. Wld Power vl4 Aug 1930 p 116-9 6 figs. To grasp nature of problems which face manufacturer of electrical instruments, it is necessary to study conditions under which pivoting sys- tem works ; each modification or extension of existing standard specifications is in direction of greater sensitivity, smaller forces, and higher accuracy. Important Points on Pivot Bearing Design, P. H. WHITE.

Machy (N.Y.) v37 n6 Feb 1931 p 450 1 fig. Application and care of pivot and center bearing ; construction details. New Method of Pivoting on Instruments, A. J. LUSH.

Instrum v4 n2 Feb 21 1931 p 106-8 4 figs. Position of pivots within their jeweled bearings is of vital importance ; any other position taken up by movement than that

in which it was calibrated will very obviously affect con- stancy of calibration. Die Drehzapfen-Aufstellung (Pivot Mounting), K. LUE- DEMANN. Zeit fuer InstrumKde v51 n9 Sept 1931 p

449-63 10 figs. Historical review ; test results on meas- urement of small-size pivots; avoidance of centralizing error was so complete that remaining error could be dis- regarded ; results of various measurements given in tables. Bibliography.

Friction of Pivots and Journals. Machy (London) v39 n995 Oct 29 1931 p 142-4 7 figs. Mathematical investigation of conditions obtaining in flat, conical, truncated

conical, hemispherical and Sehiele pivots and journals.

Static and Clinging Friction of Pivot Bearings, M. C. HUNTER. Proc Inst Mech Engrs London vl51 n3 1944 p 274-84 ; Abstract in Eng vl57 p 117-20, Feb 11 and p

138-40, Feb. 18, 1944. Describes special apparatus used in the investigation carried out to determine the static fric- tion of various combinations of metals, including stainless

steel and duralumin, under several conditions of dry and

viscous lubrication. The paper gives data showing the rapid growth of the coefficient of friction during the first 24 hr at rest, and the subsequent increases over a period

of 5 days. A series of long-term tests of 30, 60, and 90

days, on a selected number of specimens, provides a direct comparison from which the relative merits of the various combinations of materials is drawn. Evidence is provided

suggesting advantages to be derived from the use of graphite as a preventive of clinging friction. Apparatus for Measuring Static Frictionail Torques of Instrument Jewels, W. H. PEARSE. J Sci Instrum v25 nlO Oct 1948 p 344-6. Device which can be used to ob- tain measure of surface quality of synthetic sapphire "V"

jewels and hence enable their performance as jewel bear- ings for precision indicating instruments to be expressed

quantitatively ; pivoted element rests on jewel to be ex- amined and is deflected by air jet, flow of which is gradually reduced and element allowed to return to position of equilibrium ; results of tests given. Physical Basis of Mechanical Factors of Merit in Pivoted Measuring Instruments, L. MERZ. Archiv tech Messen

Issue nl6 (Ref. J011-2) T3-T4 Jan 1950 in German. The

Keinath mechanical factor of merit, given by Fm =10

(torque for 90° defection) /(weight of moving system) 15

, is discussed. The view that this factor of merit is empirical is concluded to be unjustified, and that the index

1.5 has a real physical basis. Design and Manufacture of Jewels and Pivots for Instru- ments and Meters, G. F. TAGG, E. A. HOWELL. Soc Instrum Technol Trans. v3 n3 Sept 1951 p 124-33. Pivots and jewels employed in indicating instruments and meters i are subject to considerable stress in normal usage, during

transport, etc. ; theoretical considerations necessary in de- sign of bearings to give satisfactory performance under

static and impact conditions; design nomograms for de- termining whether safe operating conditions prevail. Gas Bearings in Precision Instruments, G. B. SPEEN.

Electromechanical Components & Systems Design v8 n4 Apr 1964 p 40-3. Use of gas bearings in instruments, such as gyroscopes, accelerometers, giiribal bearings of

inertial platforms, space simulators, and test tables, is dis- cussed, along with methods of avoiding their improper

application.

5.6. Slides, Stands, and Tables

Micrometer Leveling Table, J. H. DOWELL. J Sci Instrum v9 July 1932 p 234-6. Levelling table designed to give precise adjustment in three directions. Particularly valuable for interferometers. The construction is robust and its geometrical design ensures that wear is taken up

autohiatically.

Standard Dimensions of Bail-Bearing Slide Races and Derived Kinematic Constraints, A. F. C. POLLARD. J Sci Instrum vll n6 June 1934 p 173-83. Construction and di- mensions for ball-bearing slide races suitable for slides with single degree of freedom as well as for certain bear- ings of spherical contacting elements peculiar to kine- 146
matic design, are discussed ; table of dimensions for use of

designers, in inches and millimetres included. Precision 60° V-Block, A. N. APPLEBY. Machy (Lon- don) v66 nl706 June 21 1945 p 675. Author presents several additional uses for V-block applications : providing

block is made with 60° included angle and distance from

apex formed by angular sides to base of block is known,

precision measurements can be obtained by aid of height

gage, clock indicator or any two point measuring instru- ment ; exemplary application is defined. Ball Bearing Slides, C. JOBST. ASME Advance Paper

n47 A-42 for meeting Dec 1-5 1947 6 p 2 supp sheets. Examples of progress made in reducing friction in sliding movements of machinery to minimum with addition of pre- loading of slide mechanism so that higher operating

speeds, greater precision of product and longer life at lower cost are possible ; preloading produces high stability

in slide because operating loads merely modify total load, either increasing or decreasing it, in contrast with con- ventional slides in which live load changes from no load

to full load. Stander mit Tisch fur Messgerate (Stand with Table for Measuring Instruments). DIN 2223 Oct 1949 1 p, avail- able from ASA. Gives post diameters and lengths of support arms for various ranges. Surface Plates, Sizes, Dimensions, and Requirements. DIN 876 June 1950 2 p, German Standard available from ASA. Cast iron surface plates, design and bearing area

requirements. The Sliding Surface, G. I. FINCH. Proc Phys Soc London B v63 p 465-83 July also ibid A v63 Aug 1950 p 785-803. The 34th Guthrie Lecture delivered to the Physical Society. A review of the existing state of knowledge of what

actually takes place when one solid surface slides over

another, with or without intervening lubricant, a critical survey of past and current ideas, and an account of the

author's own work and that of his school on the subject

Particular attention is paid to the role of the oxide layer on the surfaces and to the lubricant as a carrier of oxidant

to the high temperature regions of solid-to-solid contact. Xine Types of Ball Slides for Linear Motion. Prod Eng

v21 n9 Sept 1950 p 128-9. Diagrams show construction

details of antifriction devices used for precision, straight

line motion. Three-dimensional Surface-table. Machy (London) v78

| n2000 Mar 15 1951 p 438-9. Surface table developed by

Fairey Aviation Co., Ltd. of Hayes Middlesex, permits measurement in three dimensions ; guide rails attached to two adjacent edges of table serve as means of supporting

vertical members : great accuracy of table noted ; details

of equipment and its use. Get More From Your Surface Plates, J. HYLER. Iron Age vl73 n5 Feb 4 1954 p 156-8. Requirements of cast

iron and granite surface plates employed for inspection and checking operations; selection and use of surface

plate ; their value for gaging, checking, and especially for layout work on small lots of parts where tooling is not economically practical. Wear of Cast Iron Machine Tool Slides, Shears and Guideways, H. T. ANGUS, D. MARLES, M. H. HILLMAN.

Brit Cast Iron Res Assn J Res and Development v6 n3 Dec

1955 p 72-82. 4 plates, 3-page chart, Appendix 83-135. Survey of slides of 30 machine tools, still in operation at

time of examination ; severity of wear indicated by gradings good, fair, poor and very bad ; influence of microstructure and phosphorus content on wear particularly considered ; case history of each examination, including

operating details, analysis, hardness, etc.

The Influence of Elastic Deformation Upon the Motion

of a Ball Rolling Between Two Surfaces, K. L. JOHNSON.

Proc Inst Mech Engrs (GB) vl73 n34 1959 p 795-810. When a ball rolls between two surfaces, in general, a tan- gential contact force and a relative angular velocity of spin are present at each point of contact. Both these

actions give rise to tangential frictional tractions trans- mitted across the contact surface which are shown to result in a velocity of creep of the ball in a direction per- pendicular to the nominal rolling path. The magnitude

of the creep velocity depends critically upon the magnitudes of the tangential force and the velocity of spin. If these actions are small there is negligible slip between the contacting surfaces and the creep motion is predominantly

a function of the elastic properties of the materials. At

larger spin velocities slip extends over a greater proportion of the contact area and the creep is influenced by the

frictional properties of the surfaces. Creep measurements

were made over a wide range of conditions of rolling. The

results are reduced to non-dimensional form, in terms of two parameters expressing the effect of tangential forces and spin respectively. The resistance to rolling was measured and is shown to control the axis about which the ball

rolls. The detailed mechanism of the rolling process is discussed. Cantilever Indicator Stand for Precision Inspection, D. C. K. PEARCE, F. R. TOLMON. Machy (London)

v95 n2452 Nov 11 1959 p 1002-4. New stand developed by

National Physical Laboratory is very much simpler than

previous designs and therefore less expensive to manufacture; very fine adjustment can be obtained by bending

vertical column through medium of cantilever and fine screw ; data showing sensitivity of adjustment provided by indicator stand ; specially devised steel band clamp for holding indicator. Anti-Distortion Mountings for Instruments and Apparatus, R. V. JONES. J Sci Instrum (GB) v38 nlO Oct 1961 p 408-9. Some principles for the mounting of instrument

platforms are discussed. For many optical and mechanical instruments, the working platform may best be pro- tected from external mechanical distortion by supporting

or suspending the platform by members, usually three, whose stiffness is much less than that of the platform. At the same time, these members can be stiff enough to give a fairly rigid location. Some possible arrangements

are outlined. The Design of Air Bearings and their Application to Measuring Instruments and Machine Tools, H. L. WUNSCH, NPL. Int J Mach Tool Design and Res vl n3 Nov 1961 p 198-212 14 figs 6 refs. Contents: Introduction ; general principles ; design data for flat air bearings

operating under steady load conditions ; same under alter- nating load conditions; application of pressurized air bearings for machine tool slideways, automatic lead screw measuring bench, pneumatic roundness measuring instru- ment, etc. Method for Slideway Error-Compensation on Measuring

Instruments and Machine Tools, C. HOFFROGGE. Microtecnic vl5 n6 Dec 1961 p 247-50. Slideway errors may

be compensated with respect to guided element by using simple lever system arranged between that element and

slideways, system of levers being controlled by means of compensation guidebar or rail ; this makes it possible to reduce angular errors of graduated scale carrying table

of longitudinal comparator 4.50 m in length from 3.5 to

0.3 sec of arc. Amelioration des Surfaces Planes de Glissement et Particulierement des Glissieres de Machines Outils par Differ- ents Procedes. et Notamment, par Trempe Haute Fre- quence et par Sulflnusation (Improvement of plane sliding surfaces, and of machine tool slides in particular, by vari- ous processes, especially by HF hardening and by Sulfinuz 147
process). Y. DE VILLEMEUR. Rev Universelle des Mines vl8 nl Jan 1962 p 102-9. Selection of materials for

slides and their hardening treatment considered. Raschet napravlyayusehikh kacheniya iipriehiny vykhoda

ikh iz stroya, Z. M. LEVINA. Stanki i Instrum n6 June

1962 p 8-12; see also English translation in Machines &

Tooling v33 n6 1962 p 10-15. Anti-friction slideway cal- culations and causes of failure ; as result of experiments and analysis of influence of manufacturing errors on magnitude of pressure, engineering calculation method has

been derived based on contact stresses ; calculations make

it possible to determine optimum slideway dimensions and

materials ; roller slideways can bear considerably greater

loads than ball bearing slideways, their load bearing ca- pacity being approximately 10 times greater. How to Stop "Stick-Slip" on Ways, H. E. TIFFANY. Am

Maeh/Metalworking Mfg vl07 n4 Feb 18 1963 p 102-3.

Difficulty of detecting and preventing stop-start motion

of table as it slides along machine ways is noted ; why

table sticks and slips as it slides along ways ; special lubri- cants can help to make it easier to start table; how to

select right lubricant. A Rotator to Study the Dimensions of Non-Circular Fila- ments, J. D. COLLINS. J Sci Instrum GB v40 n4 Apr

1963 p 198-9. An instrument is described which en- ables a fiber or filament to be rotated under a microscope so that the fiber profile diameter at any angle may

be measured. In particular, for elliptically shaped fibers such as wool, the major and minor axes and the angles

at which they occur may be observed. The instrument

uses a dial gage, which measures in 0.0005 in. intervals up to 1 in., and this enables accurate longitudinal move- ments of the fiber to be made. By the use of an adjust- able stop accurate movements may be made along the whole length of fibers up to six inches long. Crosssectional area variations and elliptieity along the whole

fiber length can thus be measured. Further, the mecha- nism enables the fibers to be extended by a known amount

so that dimensional changes may be studied. The in- strument was designed to be used with a projection micro- scope specially made for wool fiber diameter measurements. Universal Measuring Block, R. D. PURVIS. Machy

( Lond) nl03 n2662 Nov 20 1963 p 1154-7. Equipment de- scribed, meeting requirements of accuracy and also those

of full utilization of instrument, consists basically of block

of close grained cast iron which has accurately machined

central vees and locating pads on base, sides and ends

these pads allow block to be set in any of 5 positions while maintaining squareness, parallelism and symmetry

with central vees to high degree of accuracy ; applications indicated; equipment was found to be extremely

useful for toolroom and experimental machine shop

applications.

5.7. Springs and Suspensions

Reed Gages Guarantee Close Tolerance Under Shop Conditions, C. F. DREYER. Factory and Indus Mgmt v80 n4 Oct 1930 p 722-4 10 figs. Improvement in indicator gage which will permit its use in control of product toler- ances defined in ten-thousandths of inch ; limitations of

fixed gages and of usual forms of indicators ; construction

of fixed gages and of improved indicator gage ; advantages shown in number of successful applications. Flexure Pivots to Replace Knife Edges and Ball Bearings,

V. S. EASTMAN*. Univ Wash Eng Experiment Station- Bul n86 Nov 1935 47 p. Derivation of equations for simple

flexure pivot without fixed center of rotation, flexure pivots with fixed centers of rotation, self-compensating

flexure pivot; miscellaneous uses for flexure-pivot. Equations. Instrument Springs, J. W. ROCKEFELLER, JR. Wire

and Wire Prod vll Nov 1936 p 631-9. Considerations important in design and manufacture discussed, together with relative merits of extension under axial load, mechanical hysteresis, creep under load, temperature effect on modulus of elasticity ; Elinvar and related nickel- chromium steels, and approved methods of manufacture.

Bibliography. Measuring Elastic Drift, R. W. CARSON. ASTM Preprint nl07 meeting June 28-July 2 1937 10 p. Recording

electronic micrometer, sensitive to deviations as small as millionth of inch, developed to measure deflections of spring members of precision instruments without disturb- ing load deflection ; test strip specimens and actual elastic elements used in instruments. Bibliography. Ueber die elastische Nachwirkung (Theory of Elastic After action ) , SCHOLETZER. Zeit fuer InstrumKde v57 n9 Sept 1937 p 371-78. Theory of elastic after-action of instrument spring ; mathematical and graphical analysis. Utilizing Flat Spring in Accurate Mechanisms, A. M. WAHL. Machine Design vll nil Nov 1939 p 40-2. In- dicative of versatility of flat springs are some unusual

applications to two recently designed extensometers ; both

utilize flat strips of spring steel to serve dual purpose of guides to obtain straight line motion and as means of exerting definite pressure on contact points. Federgelenke im Messgeraetebau (Spring Suspensions in Measuring Instruments) , H. STABE. VDI Zeit v83 n45 Nov 11 1939 p 1189-96. Most important of numerous sus- pension systems discussed and illustrated; necessity for elimination of frictional defects pointed out. Instrument Springs Control Performance, P. MacGAHAN.

Elec Mfg v34 n4 Oct 1944 p 99-102, 174, 176. Compared

to springs in other mechanisms or even in watches, springs used in instruments may be very weak ; their strength is measured in "mili-metergrams" of force required to pro- duce certain angular deflection; measuring strength of springs ; proper mounting of springs. Bandaufhaengung fuer den beweglichen Teil bei Messgeraeten (Suspensions for moving parts of measuring instru- ments), J. BUBERT. Archiv fuer Tech Messen nl52 Oct

1947 p T29 2 p. Considerations concerning bearing fric- tion ; fiber suspensions in electric and other measuring

devices ; simple and fixed suspensions. Aufhaengebaender (Suspensions), J. BUBERT. Archiv

fuer Tech Messen nl52 Oct 1947 p T30 (4 p). Suspension

fiber materials ; applicability in galvanometers and like devices, of phosphor bronze, silver, gold and copper as well as silk or quartz fibers and steel wires ; torsional and other

characteristics of fibers as related to cross sectional shape. Theory of Symmetrical Crossed Flexure Pivots, W. H. WITTRICK. Austral J Sci Res Ser A vl n2 June 1948 p 121-34 1 supp plate. Use of pivots in scientific instru- ments in place of knife edge bearings ; general theory of symmetrical crossed flexure pivots under any combination

of vertical and horizontal loads is given ; theory used to derive set of curves presenting all information necessary

for design of such pivots. Parallel and rectilinear spring movements, R. V. JONES.

J Sci Instrum v28 Feb 1951 p 38-41. Discusses the design 148
of instrument movement in which the moving member is held by two equal and parallel leaf springs ; the member

can be moved parallel to itself by pushing it normally to the springs. In a constructed specimen the parallelism was maintained to within ±3.5 sec of arc over 6 mm of

travel by a simple method of balancing the springs. Ar- rangements are described for combining two or more

spring systems to develop a rectilinear movement. Per- formances are quoted for three constructions, the best of which held a straight line within about ±0.25/* over 5 mm

of travel, and ±l/t over 10 mm. In some applications spring movements are superior to kinematic slides. Suspension Strip, P. CHRISTOPH. Arch fur Tech

Messen Issue nl82 (Ref J013-5) Mar 1951 p T34 in Ger- man. Suspensions for comparatively heavy weights (e.g. gyros, torsion balances, torsional pendulums for clocks) are considered. Formulae are given for: (1) torsion moment for given dimensions of suspension, suspended

weight, torsion angle, and constants of suspension material; (2) width/thickness ratio of suspension to give minimum torsion moment for given cross-sectional area

(3) ratio of torsion moments of round wire and rectangular suspension of optimum width/thickness ratio, of same

cross-sectional area and material ; ( 4 ) time of swing as function of weight and amplitude. Instrument Springs and Spring Instruments, J. W. ROCKEFELLER, JR. Wire and Wire Prod v26 n9 Sept

1951 p 764—5, 802-7. Properties required in springs to make them suitable for precision instruments ; principle

of spring as measurement of force; attitude of Weights and Measures departments toward tolerances; Elinvar wire ; instrument spring ; improvement in scale springs

three charts showing errors in otherwise perfect 3-revolu- tion circular dial in scale, and effects of these errors. Design Characteristics of Cross-Spring Pivots, L. W. NICKOLS, H. L WUNSCH. Eng vl72 n4472 Oct 12 1951 p 473-6 ; Engr vl92 n4994 Oct 12 1951 p 458-61 ; Machy

(London) v 79 n2030 Oct 11 1951 p 645-51. Investigation

to provide information of use to designers wishing to in- corporate cross spring pivots in their instruments; sizes were kept within range usually employed for this purpose

work relates to type of cross spring pivot most commonly

used, in which cross strips intersect at 90° at midpoint

of their functional lengths to 90° symmetrical cross spring

pivot ; illustrations, graphs. Alignment by Suspension on Elastic Strip, J. E. C. PLAIXEVAUX. Note in Nuovo Cimento vlO Oct 1953 p 1451-60 in French. After a brief review of systems used

for the near rectilinear alignment of a suspended part on

elastic strips, a method is described for calculating these suspensions where the strips operate in flexure along the whole of their length. The method takes account of the

large deformation of the strip and enables the parasitic movement perpendicular to the principal movement to be determined. A New Method for the Measurement of Small Changes

in Length, D. KUHLMANN-WILSDORF. Z Angew Phys

v6 n 4 1954 p 171^ in German. The instrument described

consists of a horizontal roller which is divided into two

parts of different radii and which is supported by two vertical bands. The upper band is fastened at one end to the part of smaller radius and the lower band to the other

part. The other ends of the bands are fastened to the two points between which the changes in length are to be measured. The rotation of the roller is measured by means of a mirror attached to the roller. Details of suit- able properties and materials for the bands, the types of measurement and of Lhe practical application, range of use and sensitivity of the instrument are given. Flexure Devices, P. J. GEARY. Brit Sci Instrum Res

Assn 1954 44 p. Literature survey and bibliography. Discusses means of : supporting movable members, control

influencing scale shape, indicating recording, and influenc- ing sensitivity. Angle-Spring Hinges, R. V. JONES. J Sci Instrum v32 n9

Sept 1955 p 336-8. Features of hinges whose design is based on each of twisting L-section cantilever beam about

its corner edge ; simplest form is easier to make and is more compact than cross strip hinge; limitations of angle

spring are described and various designs of simply compensated hinges indicated ; such hinges can be useful components in instrument design, being free from friction and

backlash. Application of Spring Strips to Instrument Design. Notes

Appl. Sci NPL nl5 1956 25 p 22 figs 4 refs. This booklet provides designers with information about some of the various applications for providing pivoting and parallel motion, conversion of linear to angular motion. The uses

of buckling and twisting strips are described, and indi- cating mechanisms based on them. Miscellaneous uses

include support of counterweights, protection of precision

scales, biasing springs, and locking a carriage to a slide. Methods of attachment of spring strips are also described. Zur Berechnung von Torsionsbaendern und Torsions- sponnbaendern im Feingeraetebau, (Calculation of torsion suspension bars and prestressed torsion bars in precision apparatus), S. HILDEBRAND. Dresden. Tech Hochschule-Wiss Zeit v6 n4 1956-7 p 749-56. Calculation for rectangular cross sections according to L. Bubert-A. Foeppl formulas, and C. Weber method; comparison of these methods. Some Parasitic Deflections in Parallel Spring Movements, R. V. JONES, I. R. YOUNG. J Sci Instrum v33 nl Jan 1956 p 11-15. Some parasitic departures from parallel and rectilinear movement in simple and compound assemblies are analyzed. The following factors are considered : accuracy of construction, geometrical proportion, spring

variations, spring distortion, platform bending, clamp dis- tortion, and gravity effects. It is shown that the "ideal" height at which to drive a parallel spring element is at half the spring height, and it is concluded that while

spring tolerances are surprisingly "easy" care must be taken with the platforms and clamps if the highest per- formances are to be achieved. In compound movements,

the possibility of "slaving" the intermediate platform, sug- gested by Plainevaux has been tested in practice with

good results. Fundamental Behavior of Sensitive Springs, R. TOMASCHEK. J Sci Instrum v33 n2 Feb 1956 p 78-81. It is shown that by extending a flat spiral spring by a force acting at one of its ends perpendicular or at an angle to

its original winding plane, shapes of a special form, called serpent springs, can be obtained. Though capable of sup- porting relatively heavy loads, these springs respond under

certain conditions to small changes in the loads by con- siderable lengthening and twisting. The conditions for obtaining such springs of high sensitivity and their funda- mental behavior are described. Pitching Movement of an Elementary Suspension on Elastic Strips, J. E. PLAINEVAUX. Nuovo Cimento serlO v4 no Nov 1956 p 1133-^1 in French. A horizontal plate mounted on two identical vertical elastic strips, rigidly fixed to its ends and clamped vertically at their lower

extremities, tilts whenever it is moved laterally, through

a small angle of the second order in the horizontal dis- placement, unless the loading of the plate is symmetrical.

If such pitching is to be reduced to a minimum, there is an optimum position for the line of action of the horizontal

displacing force, which is approximately midway between

the plate and the fixed ends of the strips. But the appli- cation of the force in the plane of the plate may be 149
preferable, for this makes the system less sensitive to vibrations and involves only a third-order error in the

orientation of the plate. Elastic Aftereffect in Bronze Suspensions of Electrical Measuring Instruments, A. A. TIMOFEEVA. Meas

Techns 1958 n3 May-June 1958 p 342-6 6 figs. Translated from Izmer Tekh n3 Nov 1959 p 73. Investigation establishing certain regularities in behavior of suspensions, which provide possibility of determining stresses arising

in them and expected deviation from their return to zero, with error permissible in preliminary instrument calculations. Statics and Dynamics of a Helical Spring, R. GEBALLE. Am J Phys v26 n5 May 1958 p 287-90. The theory of the extension and twisting of a helical spring was given in a

recent paper by Krebs and Weidlich. This theory is re- viewed and its applicability as an experiment in advanced

mechanics is described. From measurements of extension and twisting under static load, and also from simple

observation of the coupled oscillations of these degrees

of freedom, it is possible to calculate Poisson's ratio and

the shear modulus. The two independent procedures give

consistent results. The experiment provides an excellent demonstration of the geometry and elastic deformation

of a helix, its static equilibrium and its coupled

oscillations. Improved Magnetic Suspension System, C. G. McIL- WRAITH, J. B. BREAZEALE, E. N. DACUS. Rev Sci Instrum v29 nil Nov 1958 p 1029-33. Magnetic suspension apparatus which supports ferromagnetic object free from contact with its surroundings and which is capable

of maintaining this support for any attitude or orientation

in space of apparatus as whole; applications as frictionless bearing and as force balance in various instruments, such as accelerometer, analog double integrator, differential pressure detector, long period pendulum, and fluid density instruments. Torsion Devices, P. J. GEARY. J Electronics and Control v5 n5 Nov 1958 p 483-96. Elastic connections are being used increasingly in measuring instruments for suspending or guiding moving parts which have to travel back and

forth through limited distances or angles; two types of torsion devices are described ; torsion suspensions and

torsion hinges; suitable types of material indicated and

problems in mechanical construction discussed. Dynamik der Spannbandlagerung (Dynamics of strap suspension systems), E. SAMAL. Archiv fuer Tech Messen n277 Feb 1959 p 3L4. Analysis showing advantages of such system for protection of measuring instru- ments against shock damage during transportation as well as other undesirable effects of shock and vibration during

operation. A Gauge for the Precision Measurement of the Thickness of Germanium and Silicon Wafers, D. BAKER. Proc

Inst Elec Engrs Paper 2891E [Int Conv on Transistors and Associated Semiconductor Devices], publ. May 1959

3 p. Some of the difficulties associated with the precision measurement of the thickness of thin germanium and sili- con wafers, together with several possible methods of measurement, are briefly discussed. A gauge which employs the optical-lever principle is described in which frac- tional restraint of the moving parts is reduced to that of a knife edge alone, thus ensuring good repeatibility of reading with probe pressures of less than 3 g. The gauge

covers the range 0.270 micron with an overall accuracy

of ±0.5 micron. Taut-Band Suspensions for 250-Degree Instruments, V.

S. THOMANDER, R. C. MACINDOE. AIEE Trans v 79

pt 1 (Communication and Electronics) n44 Sept 1959 p 379-83 (discussion) 383-4. New design of instrument

suspension containing moving element suspended by two

metal bands under tension which replace conventional

spiral springs, jewels, and pivot bearings, design is free from bearing friction, thus eliminating major causes of trouble experienced particularly with electrical measuring instruments. Paper 59-159. Torsion Devices, P. J. GEARY. Brit Sci Instrum Res

Assn Survey of Instrument Parts n3 1960 142 p. Review

of available information on design, construction and func- tioning of torsion devices as working parts of measuring

instruments ; torsion suspensions ; suspension ligaments ; bifllar and trifllar suspensions ; coiled torsion suspensions

torsion hinges; torsional magnifying devices, 207 refs. Magnetic Suspension for Low Temperature Studies, A. D. SHVETS, V. B. KASHIRIN. Instrum & Exper Techn

(English translation of Pribory i Tekhnika Experimenta)

n6 Nov-Dec 1961 p 1180-2 ; Cryogenics v2 n5 Sept 1962 p 276-8. Arrangement for connecting apparatus for studies both at normal and at low temperatures, to ferro- magnetic part of suspension ; portion at helium temperatures is electromagnet coil, control and ferromagnetic

core to which vessel with liquid helium is fixed; whole

system is brought into rotation by external rotating magnetic field ; such apparatus has been used for measuring moment of inertia of rotating liquid helium ; circuit and

apparatus diagrams. Taut-Band Suspension Instruments, G. STOLAR, C. B. STEGNER. Instrum & Control Systems v35 n2 Feb 1962 p

134-5. Advantages obtained in using taut band sus- pension, instead of pivot type suspensions, including elimination of friction in movement; suspensions devel- oped by Weston Instruments Div. Daystrom, Inc. especially for a-c and d-c indicating instruments. Instruments without Pivots. Eng vl93 n5005 Mar 23 1962 p 388. Dispensing entirely with jewels, pivots and

control springs, instruments are being manufactured by Crompton Parkinson Ltd, in which movement is suspended

on ribbon of heat treated beryllium cooper held taut by

tension springs mounted on bushes fitted to supporting brackets on movement frame; ribbon may be only 0.005

in. wide by 0.0005 in. thick, with latter held to within

0.00001 in. ; suspension is for ammeters, voltmeters, fre- quency and speed indicators, etc. Why Taut-Band Suspension, J. MEILI. ISA J v9 n4 Apr 1962 p 44-7. Advantages of taut-band suspension, use of which has been made economically feasible by modern manufacturing techniques; eventually, taut-'band sus- pension will replace pivot-and-jewel movements in electric instruments. Some Uses of Elasticity in Instrument Design, R. V. JONES. J Sci Instrum (GB) v39 n5 p 193-203 May 1962. The paper presents the text of a discourse delivered at the 1962 Exhibition of The Institute of Physics and The

Physical Society, which reviews anti-distortion instru- ment mountings, elastic movements for rotation and translation, movement magnifying and reducing devices, elastic averaging schemes, simple harmonic force and constant

force systems, elastic energy stores, and a slow relaxation

device for transmitting rapid displacements only. Accuracy of Parallelogram Spring Suspensions, A. S. VALEDINSKII. Meas Techn 1962 n4 Sept 1962 p 284-5

3 figs 1 ref. Translated from Izmer Tekh n4 p 13-4 Apr

1962. Determines the error in displacement in the direc- tion of the indicator tip movement which is placed at an

angle )3. Construction and Performance of Various Flexure

Hinges, D. M. MARSH. J Sci Instrum v39 nlO Oct 1962 p 493-7. Simple and yet precise clamp for strip hinges which facilitates construction of flexure hinges of fairly

J o<>
general application; merits of single strip hinge, which

becomes especially simple to construct by method pro- posed; it is shown that for limited rotations it is often superior in performance to cross strip hinge. Considerations in the Application of Flexural Pivots, H. TROEGER. Automatic Control vl7 n4 Nov 1962 p 41. Sensitivity, accuracy and repeatability are limited primarily by pivot friction and backlash where pivoted members

are used to transfer or algebraically operate upon forces

or displacements. Since many instruments, controls, and

measuring devices employ pivoted members the reduction

of pivot friction and backlash is consequential to the re- duction of their contributed error.

Spannband- and Spitzenlagerung (Strap and point sus- pension), S. GOETZE. Assn Suisse des Electriciens Bui

v53 n25 Dec 29 1962 p 1268-73. Relative merits of two

types of suspensions for measuring instruments are dis- cussed ; taking into account accuracy, robustness and other

characteristics of intruments involved. Guides with Flat Springs for Forward Displacements, TA. M. TSEITLIN. Meas Techns 1963 n9 Feb 1964 p 732-6

2 figs 11 refs. Translated from Izmer Tekh n9 p 11-5 Sept

1963. Deals with widely-known spring guides of the par- allelogram type for forward displacements, and certain

characteristics to be considered in design to prevent over- loading and premature failures. Addendum to Section 5

5.2.2. Electrical Amplification

The Ultra-Micrometer ; an Application of the Thermionic

Valve to the Measurement of very small Distances, R. WHIDDINGTOX. Phil Mag 6ser v40 n289 Nov 1920 P634-9 2 figs ; v46 n274 Oct 1923 p607-8, with A. HARE,

co-author; v49 n289 Jan 1925 pll3-21 3 figs with F. A. LONG, co-author. If a circuit consisting of a parallel plate condenser and inductance be maintained in oscilla- tion by means of a thermionic valve, a small change in the distance apart of the plates produces a change in the frequency of oscillations which can be accurately deter- mined by methods described. It is shown that changes

as small as one two-hundred millionth of an inch can be

easily detected. Sensitive Valve Method for the Measurement of Capacity ; Applications, J. J. DOWLING. Roy Soc Dublin. Proc

vl6 Dec 1920 pl75-84, Mar 1921 pl85-8 ; Eng vll2 Sept 9

1921 p395 ; Phil Mag v46 July 1923 p 81-100, Nature vlll June 2 1923 p 742-3. Describes arrangement of the apparatus and its application as an ultramicrometer for measuring minute movements, inasmuch as the capacity of a condenser varies with the separation of the plates. Electrical Apparatus for Measuring Small Motions, H. A. THOMAS. Engr vl35 Feb 9 1923 pl38-40 ; J Sci Instrum

vl 1924 p22-6 7 figs. Apparatus consists of a high- frequency oscillator and an inductance coil arranged in close proximity to the metallic body whose motion is to

be measured. It is applicable to the analyzing of the

transient conditions existing in all types of engineering

structures when subjected to live loads. The principle has been applied successfully to the operation and maintenance of a standard pendulum, without any contacts being required to operate the mechanism for inserting energy into the stroke. The "Ultramicrometer," a New Instrument for Measuring

very small Displacement or Motion, and Its Various Applications, J. OBATA. World Eng Congress, Tokyo, 1929

vo p79-84 12 figs refs. Distributed by Kogakkai, Marunouchi, Tokyo, 1931. The detailed construction together with various applications were published previously, else- where. The present paper contains the results of further

applications, namely : The recording of earth movements

direct recording of accelerations ; an electrical indicator

for high speed internal combustion engines ; precise recording of sounds, pressure variations, and various mechanical vibrations. Capacitive Displacement Transducers, A. V. FEDOTOV.

Meas Techns n7 Feb 1965 p 571-5 2 figs. Translated from

Izmer Tekh n7 p 15-6 July 1964. The necessity of extending the range of capacitive displacement transducers has

led to the theoretical and experimental investigation of certain systems of these transducers. A capacitive trans- ducer with a range of 200^ and a scale factor of l/i was

produced. It is stable in operation and insensitive to external interference. Addendum to Section 3 (continued from page 116) 3.5. Measuring Machines and Bench Micrometers

Thickness Gauge with an Antenna Transducer for Nonconducting Materials, B. M. SHLTAPOSHNIKOV, E. M. KON'KOVA. Meas Techns n7 Feb 1965 p 578-81 1 fig 3 refs. Translated from Izmer Tekh n7 p 18-20 July 1964. A device has been designed and built for measuring the thickness of glass plastics and similar nonconducting

materials by means of a metal backing. It is provided

with direct reading in units of length and can be used

at any distance from the edge of the tested sample, with- out destroying it and without first determining its physico- chemical properties. Extensive testing has shown that

the design is satisfactory and it is convenient to use. Its

electrical circuit is simple, and the number of control devices is small.

771-846 O—66 11 151
1
Section 6. Angle Measurement

CONTENTS

Page

6.1. Angle measurements, general 153

6.2. Alinement, straightness, and autocollimators 157

6.3. Angle gage blocks and polygons 162

6.4. Calibration of graduated circles, dividing heads, and protractors 164

6.5. Angle measurement by interferometry 167

6.6. Sine bars, plates, and fixtures 169

6.7. Spirit levels 170

6.8. Tapers 172 Addendum to Section 6 173

6.1. Angle Measurements, General

See also subsections 10.1.3 and 10.5. The Telescope-Mirror-Scale Method, Adjustments and

Tests, S. W. HOLMAX. John Wiley & Sons. N.Y. (re- printed from The Technology Quarterly), Sept 1898 39

p 11 figs 3 refs. This presentation is designed for putting

the method of measuring small angles into direct service.

It discusses the several sources of error. It describes the various adjustments and tests in the sequence in which

they should ordinarily be made and gives a numerical measure of the closeness with which each must be carried

out to secure a specified precision in the result. Some re- marks on the selection of instruments are appended.

Solid Angles, L. WEBER. Zeit fur InstrumKde v28 May

1908 p 129-36. Describes at length two new methods of measuring solid angles. In the first method, which is adapted to measuring areas on the surface of a sphere, use

is made of the pantograph to obtain (1) the projection of

a given area on some fixed plane and (2) the projection

of the central section parallel to this plane. From a comparison of these two the area on the sphere can be deter- mined. In the latter part of the paper a modified form

of Moritz apparatus is described.

Setting Angles for Milling Angular Cutters and Taper

Reamers, W. A. KNIGHT. Machy vl5 Nov 1908 p 161-8. Mathematical development of subject with numerous

tables. Bibliography. The Measurement of Angles and the Rectilinear Scale

of Constant Sensibility (La Mesure des Angles et L'echelle Rectiligne de Sensibility Constante), M. DUGIT.

Techn Mod vl2 n9 Sept 1920 p 353-61 14 figs. Advantages

and disadvantages of rectilinear scale as compared with

I circular scale. Construction of spiral protractors. The Measurement of Angles in Radians (Le Mesure des Angles en Radians )

, J. MAITRE. Genie Civ v78 n2003 Jan

1 1921 p 10-2 1 fig. Utilization of radians for measuring

angles by means of straight lines. Winkelmessung (Angle Measurement), F. GOPEL Chapter 3 of Handbuch der Physik, Verlag Julius Springer,

Berlin v2 1926 p 91-111 20 figs refs. Discusses the division

of the circle, and instruments and set-ups for angle measurement.

Determination of Angles by the Use of Microscopic Areas,

A. ARNULF. CR Acad Sci vl89 July 22 1929 p 152-3.

The object of the device is to determine to an accuracy of

1' the direction of the normal to a polished surface of small radius of curvature (e.g., 0.001 mm2 ). A luminous

point situated laterally is by means of an unsilvered plate

of glass placed at an angle of 45° in the optical axis of a microscope, reflected through the object glass on to the polished surface under examination, and thence back to the eye. The variations in the resultant illumination reaching the eye according as the tangent plane to the surface at the point of incidence of the pencil of light is, or is not, accurately perpendicular to the optical axis of the microscope, enable the direction of the normal to be

accurately determined. Accuracy in Angle Gaging, J. A. POTTER. Am Mach v72 June 26 1930 p 1024-5 8 figs. Procedure for proper meas- urement of angles, simple, double and compound.

Testing Safety Razor Blades, R. W. WOODWARD. Iron Age vl31 June 22 1933 p 981-3 22 figs. Measurement of cutting angle, testing edge with photoelectric cell, Woodward sharpness tester. Winkelverwandler und Winkeluhren (Angle Converters and Meters), H. MAURER. Zeit fur InstrumKde v55 Nov

1935 p 448-56 2 figs 4 refs. Disadvantages of various sys- tems of angular measurement, e.g., in terms of radians,

degrees, minutes, seconds, etc., are briefly referred to, the

application of such systems in military and naval science

being, inter alia, referred to. The advantages of a system

in which 2-n- radians is divided into 6000 units are pointed

out. The term "set" ( derived from sechs and tausend ) is suggested for the new unit. Devices for interconversion

of the various scales are described and their use exemplified. Simple High-Sensitivity Method for Optical Measurement

of Very Small Angles, A. PERRIER. Helvetica Physica Acta v9 n5 1936 p 332-4 in French. Details are given of

a method of measuring small angles in which the move- ment of a real image of a fixed object, formed by a concave mirror attached to the moving system, is measured with

a micrometer eyepiece. Messen von Winkeln mit Messcheiben und Lehrdornen (measurement of angles with disks and plug gages). Werkstatt und Betrieb v70 n% Feb 1937 p 33. Outline

of practice for measurements of angles by aid of disks and

cylindrical calipers ; practical examples given. 153
Alignment Projectors and the Precision Measurement of Angles, C. DEVE. L'Optique (Rev Opt Theor Instruin) v20 1941 p 115-48. Discusses the limitations of telescopes

for the measurement of small angles, then proceeds to analyse the advantages, and estimate the precision, of alignment projectors. Two types of work are discussed, the measurement of angles subtended by distant objects and the use of goniometric work in laboratories and workshops. Details are given of the instrument suited to each

type of work and the various methods of use and applications are considered. These include the manufacture of precision prisms, measurement of small angles between two reflecting faces, the variation of the refractive index

of the atmosphere, etc. Measuring and Inspection Instruments. Eng vl56 n4053

Sept 17 1943 p 227. Brief illustrated description of three instruments demonstrated by E. H. Jones (Machine

Tools), Ltd. London, namely, Sigma taper measuring machine manufactured by Sigma Iustrument Co ; Brisdon

inspection table made by F. Brauer; and universal sine table made by Papworth, Ltd. Projection Angle "Dekkor." Eng vl57 n4093 June 23 1944 p 487-8. Illustrated description of improved precision

optical instrument for checking angular relationship be- tween plane surfaces, manufactured by Adam Hilger, Ltd : scales are visible on screen on to which they are projected by optical system. Notes on the Use of Circular Dividing Apparatus for Angular and Linear Measurement, G. P. BARNARD, NPL.

His Majesty's Stationery Office July 1945 81 p 55 figs. Contents : Introduction ; main apparatus required ; divid- ing heads ; universal measuring block ; accessory ap- paratus ; introduction to measurement ; preparation for gauge inspection ; measurement of selected examples. Appendixes, note on location of center of small circular arc

note on pitch radius measurements ; rotation involving- translation, sources of error ; intersection dimensions and

gauging triangles ; principle of minimum rotation ; prop- agation of accidental error. Calibration of a Set of Master Wedges, D. H. RANK.

J Opt Soc Am v36 Feb 1946 p 116-9. Calibration of a Set of Master Wedges, D. H. RANK. J Opt Soc Am v36 n2 Feb 1946 p 116-9 2 figs. Discusses two

methods : ( 1 ) telescope and scale and ( 2 ) multiple beam

method. The latter permits determinations to better than

0.25". Describes experimental procedures and discusses quality of surfaces, measurement of index of refraction,

errors, and comparison of wedges with the Twyman

Interferometer. Standards of Length and Angle for Precision Engineering. H. BARRELL, NPL. Trans. Instrum and Meas Conf, Stockholm, 1947 p 182-90 7 figs. Discusses practical standards of length, measurement of longer distances, practical standards of angle. Precision Method of Checking • Compound Angles, J. AHEARN. Machy (NT) v53 n5 Jan 1947 p 178-81. Method involves use of angle block for supporting work

piece on sine plate which is elevated to bring compound

angle face into horizontal position : steel ball is placed in pocket formed by faces of included angle of angle block and supporting end plate ; largest size ball will give most

accurate measurements. A New Theodolite Goniometer. I. R. RAO, and S. V. S. RAO, J Sci Industr Res v6 Dec 1947 p 485-7. The general features, adjustment and method of use, of a universal type of goniometer for measurement of the angles be- tween crystal surfaces is described. The instrument consists of a 6 in diameter horizontal and 5 in diameter

vertical scale, both divided in half degrees, together with

verniers and magnifiers enabling readings to one minute

a crystal-holder attached to the centre of the horizontal

telescope, with total light from the crystal surface. The

telescope has a combination objective so that it can also be used as a low power microscope. A photograph of the assembled instrument is given. Applications of the Hilger Angle Dekkor, B. P. HARROLD

Machy (London) v72 nl848, 1850 Mar 25 and Apr 8 1948 p

391-7, 458-60 27 figs. An instrument intended for measuring and comparing angles. The standard instrument

gives readings through an eyepiece to 1' and by estimation

to 6". The large instrument reads directly to 30" and by

estimation to 3". Comprises a telescope, base, and tele- scope arm. Numerous accessories and their applications are described. Alignment Testing, K. J. HUME, Eng. Inspection vl3 n4 Winter 1949 p 163-73. Methods in accurate establishment and checking of large dimensions and measurement of deviations from straight line or plane ; use of instruments and autocollimators ; applicability to testing of machine

tools, jigs and fixtures. Electro-optical Measurement of Angles by a Photometric Method, H. BENDER. Optik v8 n5 1951 p 206-23 in Ger- man. A detailed description of the apparatus necessary

for surveying operations using i.r. lignt for its greater penetrating properties. The light is detected by a photocell, and the visual alignment of a telescope is replaced by an adjustment similar to a photometric setting. An

accuracy of 4" of arc is claimed under favourable conditions. Grundlagn der Technischen Winkelmessungen (Fundamentals of angular measurement in industry), K. RAENTSCH, Carl Hanser Verlag, Munich. Germany, 1952. 110 p illus, diagrs, tables, graphs. Publication deals with most useful methods, procedures, and fields of application

describes and discusses German and foreign instruments

for both direct and indirect measurement and layout of angles in machine shop work. Eng Soc Library, N.Y. A New Mirror Multiplier, B. M. LEVIN. Zh Tekh Fiz v22

nl 1952 p 105-10 in Russian. A method is described per- mitting of raising and varying the sensitivity of auto- collimation readings and photo-recording arrangements

this is accomplished through the corresponding selection of angles with the known multiplier having two mirrors. On the Elimination of Some Errors of Angular Measurement, E. TERRANA. Atti dell' Accademia Nazionale dei Lincei Randiconti della Classe di Scienze Fisiche, Mate- matiche e Naturali. vl2 Mar 1952 p 290-3 in Italian. Messgeraete fuer 90° Stahlwinkel (Measuring instruments

for 90° tool angles), G. BERNDT, K. SCHMIDT. Dres- den—Tech Hochschule—Wiss Zeit v3 n3 1 953-54 p 397-406. Angle measuring apparatus with precision indicator; de- termination of angle error. Construction and Use of Angle Dekkor, B. P. HARROLD.

Machy ( London ) v82 n2104, 2105 Mar 13 1953 p 481-6, Mar

20 p 547-9. New type redesigned by Hilger & Watts

modified set of angle gages, consisting of gage blocks for

5, 15. and 30 min of arc. in addition to five original prisms,

is included ; checking of tools and production equipment

setting up precision optical instmment casting; use of Angle Dekkor in fitting shop; testing motions of optical projector workstage.

Reflection Goniometer for Microscope, B. RANKIN. Rev

Sci lustrum v24 n5 May 1054 p 496-8. Instrument which

measures angles accurately and rapidly under microscope ; use of mathematical model to display principles involved

it is shown that accuracy is achieved with "optical lever

p arm" which moves when eyepiece rotates, being comparable to 25-cm mechanical arm attached to outside of eye- 154
piece; rapid measurements are possible by reading relative positions of "optical arm" on illuminated scale. The Calibration of Circular Scales and Precision Polygons,

A. H. COOK. Brit J App Phys v5 Oct 1954 p 367-71. The

theory of two methods of calibration is discussed and ex- pressions are obtained for the values and standard deviations of the corrections to the nominal values of the

angles. Ways of setting out the computations are also

given. Instrument for Direct Measurement of Angles in Field of View of Naked Eye, A. H. BOERDIJK. Rev Sci Instrum

v26 n4 Apr 1955 p 382-3. Instrument which contains

illuminated scale of which virtual image is formed at

infinity by means of spherical mirror and glass plate; image of scale is superimposed on normal field of view

of naked eye, enabling direct measurement of angles in that field ; applicability to measurement of apparent

angles between remote objects such as stars and clouds, halo phenomena, or of apparent angular velocities. Use of Polarized Light for Measurement of Small Angular

Displacements, A. J. BARTLEY. J Sci Instrum v33 nl Jan

1956 p 20-2. Method of measuring displacements of order

of 1 min of arc ; features of test system built to determine

sensitivity of method; suitability of system for dynamic

measurements ; recommendations regarding possible future developments; applicability to measurements on shaft which is subject to torque. Mirror Micrometers, N. BARANY. Periodica polytech

Elec Eng v2 n3 1958 p 205-27. Some of the known micrometers for measuring small angles and short distances

are described above. An attempt was made to replace

the 200 years old Boscovich rotating pair of wedges by a mirror micrometer. In the new instrument a mirror micrometer is used as a penta mirror, thus associating

the penta mirror with the mode of drive on one hand,

the deformation of the mirror mounting owing to changes

of temperature on the other. As regards the mode of

drive, a gear mechanism can only be applied on a laboratory scale, as it does not give a satisfactory accuracy in the transmission of angles. Therefore, one has to apply

other modes of drive. Temperature influences can be felt by the mirror mounting, generally used for penta mirrors

too. It is therefore essential to provide for heat insulation, and to resort to the most careful methods of manufacture. Photoelectric Angular Error Sensors, R. A. NIDEY, D. S. STACEY. Rev Sci Instrum v27 n4 Apr 1958 p 216-8. A technique is described for the accurate measurement

of angular errors using photoelectric detectors. Utilizing two types of robust, compact cartridges, a wide range

of characteristic curves may be synthesized. Examples

of various systems are shown, including one for high- accuracy servo. The latter has coverage of 360 degrees,

a null accuracy of one minute and is in current use in Aerobee Rockets. The Phasolver System for High-Precision Rotational Measurement, E. BURGESS. Data Instrum Div of Tele- computing Corp Mar 1959 29 p 12 figs. A system for

digitizing azimuth and elevation shaft positions to a precision to 1 part in 2X105

. Use of Radial Gratings in a Small Inclinometer, A. LEWIS, I. R. YOUNG. J Sci Instrum v36 n4 Apr 1959

p 153-7. Some of the factors involved in the choice of

" gratings for use in the digital measurement of angles

are discussed. This problem is accentuated in the case

of the instrument described by its small size and the decision, therefore, to use two complete circles for the gratings, instead of the less critical method using one circle and adjustable grating cursors. The tolerances which

have to be achieved for satisfactory performance are considered and the instrument itself, a pendulous inclinometer intended to measure the pitch angle of wind tunnel

models, is described. Micrometer Adjustment of Mirrors and Prisms, N. BA- RANY. Periodica Polytech Elec Eng v4 nl 1960 pl-16. The paper gives the geometrical conditions to be satisfied by a rotating mirror or prism in an angle-measuring in- strument. In particular the optimum point of rotation

is determined. Such mirrors or prisms are commonly

rotated by a micrometer screw and cam. The shape of the cam for typical cases is derived and the effect of the shape

of the cam-follower considered. A typical mechanical

design is described in some detail. A Method to Detect the Direction of Normal of a Small

Flat Surface and Its Practical Application to Measurement

of the Profile of Vickers Diamond Pyramid, K. YAMAMOTO. Report of the Central Inspection Institute of Weights and Measures, Japan. v8 n4 rept 20 1960 in Japanese. The direction of a normal of small flat surface,

for example the surfaces of Vickers diamond pyramids, cannot be determined accurately by autocollimation, for

diffraction effect is produced by the apparent minuteness

of the diameter of the collimator lens. Therefore a new

apparatus is invented. The apparatus is composed of an

ordinary microscope to which a half reflecting mirror and cross hairs graticule are attached. When the graticule

is illuminated, its primary image is formed at a point of some distance apart from the object point of the microscope. And when a mirror is so placed that its normal is parallel to the optical axis of the microscope at the middle

point between the object point and the primary image

point of the cross hairs, the image of the cross hairs is visible through the microscope. The mirror is tilted by

a small angle, then the images of the cross hairs are dis- placed in the view field of the microscope, the displace- ment is proportional to the tilting angle of the mirror. The performance of the apparatus is studied by introduc- ing the parameters of m (magnification of the objective) and n (magnification between the cross hairs and their primary image). And the following results are obtained : 1 ) The sensitivity of the measurement A can be calculated by the following equation, f(m+l) (m—n)$

n(m-\-l) where f: focal distance of the objective (mm)

6 : tilting angle of the mirror (rad)

2) The lower limit of the diameter of a measurable flat surface can be calculated by the following equation, f(m+l) (m—n)

2r= m2 («+l) tan u (mm)

where sin n: numerical aperture of the objective

3) An apparatus for inspecting angular accuracy of Vickers diamond pyramid is designed and satisfactory results are obtained. Checking Squares of Over 500 mm by Simple Devices.

V. I. NIKOLAEV. Meas Techns 1959 n6 June 1960 p 412

2 figs. Translated from Izmer Tekh n6 June 1959 p 17. Describes surface plate set-up for checking squares of over 500 mm.

Remote Measurements of Large Displacement Angles,

A. D. BARINBERG. Meas Techns 1959 nl2 Sept 1960 p 938-9 1 fig 1 ref. Translated from Izmer Tekh nl2 Dec 1959 p 12. Proposes a new type of transducer in- tended for remote measurement of large angular displace- ments ; is based on the use of a transformer whose sec- ondary winding has a smoothly variable transformation

ratio. Measurement of Angle in Engineering, J. C. EVANS, C. O. TAYLERSON. Notes on App Sci n26. NPL. Her

155
Majesty's Stationery Office 1961. Contents : Systems of

units, reference and working standards for use in engi- neering, auxiliary instruments, calibration of angle

standards, engineers' angle measuring machines and in- struments, measurement of displacement through meas- urement of angle, references, appendixes.

Sensitive Method for Measuring Small Rotations of Distant Object, R. J. KING, S. P. MIDDLETON, I. M. G, THOMPSON. J Sci Instrum v38 n5 May 1961 p 207-8. Application of polarimetrie system to measurements of

relative orientation of 2 units separated by large distance

sensitivity of 0.1 min of arc is easily obtainable, with

separation of 2000 ft. Suggested Arrangement of Mirrors to Form Multiple Ref- erence Angles, J. B. SAUNDERS. J Opt Soc Am v51 n8 Aug 1961 p 859-62. Reference angle to be used as stand- ard for calibrating circular scales with autocollimator or interferometer ; angle forms, by successive or multiple

reflections, multiplicity of equal optical angles having common vertices. Analog-to-Digital System for Recording Angular Rotation,

S. SHENFELD, H. R. MANKE, E. F. SODERBERG. Automatic Control vl5 n4 Oct 1961 p 40^4. Direct-reading

data-reduction system, developed at US Navy Underwater Sound Laboratory, provides high order of accuracy in bearing readout at appreciable saving in data-reduction time over that of former systems using analog or pho- tographic recording; system, intended for use in limited types of data -recording applications, permits recording of angular rotation with accuracy of 0.01°. New Angle-Measuring Table with an Induction Transducer, E. M. GOLOUL'NIKOV, M. I. KOCHENOV, A. YA. PELIKA, V. S. CHAMAN. Meas Techns 1961 n4 Nov

1961 p 270-4 5 figs 1 ref. Translated from Izmer Tekh

n4 p 9-13 Apr 1961. Discusses induction methods and de- scribes design of an instrument. This article deals with

the qualitative analysis of the degree to which various

errors affect the accuracy of the induction angle-measuring device. The value of the accumulated errors in the

shaft rotation angles did not exceed 5.3". These values

characterize the systematic errors of an angle-measuring

table made without a cam compensator. Random errors

in a single measurement of an angle did not exceed 2". A dividing head with geared rings 180 mm in diameter has been developed and constructed. The measurement

errors of this head do not exceed 5". The rotation angles

of this head in the range of 1" are measured by means of a wedge and screw device graduated in 5" intervals. Untersuchung eines Winkelmessgerates (Investigation of an Angle Measuring Apparatus), R. NOCH. Werkstattstechnik v52 n5 1962 p 249-53. Instrument Measures Dynamic Accuracies of Gears to 0.05 Second of Arc. Machy (NY) July 1962 p 134. Electro

optical instrument used for checking the drift rates of gyros employed in inertial guidance systems. Raising the Efficiency of Testing Straightness by the Mieroleveling Method, L. L. MEDYANTSEVA, V. V. GOR- BACHEVA. Meas Techns 1962 n8 Feb 1963 p 646-8 2

figs. Translated from Izmer Tekh n8 Aug 1962 p 22. Recommends a method of measuring linearity by means

of a moving microlevel. Harmonic Drive, a Factor in the Gear Industry. Part I, Principles and Applications, D. L. MANSFIELD. Part II, Harmonic Drive Compared with Gearing, R. L. BEN- FORD. AGMA 109.12 Oct 1962 23 p 31 illus 7 refs. Harmonic drive is not a form of gearing but can be used

with supplementary gearing or as a substitute for gearing.

It could become a basic laboratory reference for angular

position accuracy, allowing rapid calibrations and measurements in place of current mechanical-optical instru- mentations.

Application of Precise Angular Measurement in Metrology,

A. W. YOUNG. ISA Proc Preprint 2.2.62 for meeting Oct 15-8 1962 6 p. Progress review of methods and in- struments for angular measurement. Voprosy teorii vozdushnykh induktivnykh datchikov ugla

s pechatnymi obmotkami (Air inductive angle pickups with printed windings), L. N. SAFONOV. Avtomatika

i Telemekhanika v23 nlO Oct 1962 p 1334-42; English

translation in Automation & Remote Control v23 nlO Oct

1962 p 1255-62. Theory of inductosyn is presented ; for- mulas for output voltage in terms of angle of rotation and basic parameters of pickup are derived; recommendations are given concerning choice of basic parameters

of pickups and power supply. Use of Solar Radio Emission for Measurement of Radar

Angle Errors, J. T. KENNEDY, J. W. ROSSON. Bell System Tech J v41 n6 Nov 1962 p 1799-1812. Method

of calibrating angle indicators of radar tracking antenna

to true direction of radio line of sight ; sun used as pri- mary direction reference ; technique accounts for displace- ment of "radio center" of sun. The Testing of Cylindrical Squares, J. C. MOODY. SCR612 Feb 1963 14 p 10 figs. Publ by Sandia Corp., Albuquerque, N. Mex. Describes the equipment required and

the procedure used to test the straightness and perpendicularity of the reference lines and the parallelism of the

straight lines formed by joining the end stations. Pre- sented at the 18th Annual Meeting of the Standards and

Metrology Division, American Ordnance Association. Dovetail" Type \ IP Measurement of Internal Angles

Prisms, V. YA. EIDINOV. Meas Techns 1962 n 11 June

1963 p 914 1 fig. Translated from Izmer Tekh nil p 18 Nov 1962. Describes method using accurate measuring

rolls. Optical Methods of Measuring Angle, A. W. YOUNG. Int Prod Eng Res Conf Proc Sept 9-12 1963 p 614-8. Published by ASME. State of art of optics in angular meas- urement is reviewed together with typical solutions and

their limitations. Measurement of Angle in Engineering, J. C. EVANS, C. O. TAYLERSON, Great Britain. Nat Phys LaboratoryNotes on Applied Science n 26 1964 32 p. Review is pre- sented of developments and current practice in angle measurement, including units of measurement, standards,

auxiliary instruments, and calibration of angle standards

angle measuring machines and instruments are reviewed, including rotary tables, dividing heads, precision levels, "Talyvel" electronic level, sine-bars, clinometers, Watts

circular division testers, Baty "Sinometer", and bevel

protractors. A Simulated OAO Fine Optic Error Sensor, M. I. BAKER.

Tech Paper n6 presented to Radio Stand Lab NBS Apr

7 1964 14 p 8 figs. The fine optic sensor is an angle trans- ducer designed to provide the time pointing error signal

to the Orbiting Astronomical Observatory control system. Calibration is limited to the readily available goniometric standards in the 0.1 to 0.01 arc second region. The author

suggests that a device similar to this might provide a secondary standard which, because of its simplicity of construction and operation, would actually be a "readily available" standard. 156
6.2. Alinement, Straightness, and Autocollimators

Optical Testing of Linearity, G. LIPPMANN. CR Acad

Sci vl34 Jan 6 1902 p 17-8. A movable carrier is guided by

the sliding base or scale whose rectilinearity is to be

tested. A lens is carried in this way to various points, and by it is viewed another coaxial lens fixed in position. The parallelism of the carrier in all positions indicates

the rectilinearity required. Straightness Test for Beds of Machines, Edges, etc., AT- WELL. Eng vlOO July 23 1915 p 92. A straight edge or bar is supported on the bed by two gage blocks differing in height 0.01 in, mounted at the same distance from either end of the bed. Other gages differing by small steps are

slipped into this space and their spacing is noted. Operation is repeated with bar turned over and thickness vari- ations in bar are also determined. Das Autokollimationsablesefernrohr (Autocollimation

Telescope), G. GELHOFF. Zeit fur tech Phys v3 n6 1922 p 225-8. Detailed description of the design of the in- strument. A New Autocollimator, F. E. WRIGHT. J Opt Soc Am

v9 Aug 1924 p 187-8 1 fig. Experience has shown that in autocollimation more accurate settings can be made if the two fields are not superimposed but, as in the range finder

of the coincident, self-contained type they are placed side by side in contact. In the autocollimator described this factor has been taken into account. The Determination of the Parallelism of the Measuring

Surfaces of Measuring Tools, G. BERNDT. Instrum vl June 1928 p 263-70 12 figs. Description of various types

of devices and instruments with two plane surfaces facing each other for measuring length such as vernier calipers, amplifying gages, dial gages, measuring machines, and

micrometers ; methods of determining parallelism of measuring surfaces ; advantages and disadvantages of different types for different purposes. Contains a detailed description of the application of the auto-collimating telescope

to determination of parallelism and the measurement of

angles. Ein Optischer Flucht- und Fuehrungspruefer (Optical ffjuipment for measurements of proper alignment of

guides). Maschinenbau vl3 n9-10 May 1934 p 265-6. Detailed description of equipment developed by Zeiss, Jena.

Visierorrichtung fuer das Ausrichten von Lagern (Sighting equipment for alignment of bearings), W. FRANKZEXBURG. Werkstattstechnik und Werksleiter v32 n20

Oct 15 1938 p 451-3. Details of equipment. Alignment projectors and the precision measurement of

angles, C. DEVE. L'Optique (Rev Opt Theor Instrum)

v20 1941 p 115-48. See 6.1 for abstract. A Multi-Purpose Collimator, R. J. BRACEY. Proe Phys

Soc London v55 May 1943 p 182-8. The collimator consists of an achromatic object glass with a graticule placed

I in its focal plane, the graticule having divisions 1 /10 and

1/100 of the equiv. focal length of the object glass. Additional features are (1) that about % along the tube from

the object glass a half-silvered prism is fitted, with an

additional eyepiece mounted at rt.a. The introduction of

this prism causes the focal plane of the object glass to be

displaced, and (2) in this new focal plane is placed a re- movable cell containing a stainless-steel mirror with a

circular pinhole at its centre. This provides an artificial

star, but its main function is to turn the collimator into a spherometer, when supplementary lenses are mounted

in front of the collimator, thus bringing the parallel beam

to a focus. Details are given of the method of using such

a collimator for measuring (1) radii of curvature of lens

surfaces, (2) the equivalent focal length of a positive lens,

(3) the back focal length of pos. or neg. lenses, (4) certain prism angles (w/i and ir/Q), for interferometric tests of plates for parallelism. Precision Measurement. Automobile Engr v34 n449 May

1944 p 208-10; Machy (London) v64 nl651 June 1 1944 p

608-12. Precision optical instrument developed by Adam

Hilger Ltd has primary function of checking angular rela- tionship of plane surfaces ; three models described. A Method for Precision Alignments, A. C. S. VAN HEEL.

J Opt Soc Am v36 Apr 1946 p 242-3. In aligning three

points, one point being midway between two end points separated by 30 to 50 m, an attempt was made to use the

diffraction max. and min. on the outside of the geometrical shadow of a straight edge. A precision of the order of 0.1 mm was thus obtained. A second attempt substituted a double slit for the straight edge and in this case a precision of the order of 0.01 mm was obtained. The suggestion is made that the method could be used for the determination

of the deviations of machine parts, lathe beds, etc. Precision of Telescope Pointing for Outdoor Targets, F. E. WASHER, H. B. WILLIAMS. J Res NBS v36 May 1946 p 479-88 4 figs 3 refs ; J Opt Soc Am v36 n7 July 1946 p 400-

11 22 refs. The probable error of a single pointing ( PES ) is measured for a single telescope with a variety of targets. This investigation shows that, although some change

in PES with distance does occur, the distribution of PES as a function of distance can usually be neglected and a value of 0.62 second assigned as a practical average. The

values of PE„ for an indoor target usually show a small

variation from one experienced observer to another, and

from right to left eye of the same observer. There is also a measurable systematic difference in pointing between

the right eye and the left eye of the same observer. In outdoor pointing, a long-period error or drift is usually superposed upon the short-period errors. Appareillages transportables pour Petude des tres petits Deplacements angulaires d'Ouvrages d'Art (Portable ap- paratus for study of very small angular displacements for structures, machinery framework, etc.), P. FLEURY, E. PERRIN. Tech Mod v39 nll-12 June 1-15 1947 p 185-8. Regulation and application of recording apparatus with concave mirrors and of indicating apparatus with plane mirror and autocollimatic lens ; measurements can be made with accuracy of some arc seconds.

Effect of Magnification on the Precision of Indoor Tele- scope Pointing, F. E. WASHER. J Res NBS v39 Aug 1947 p 163-71 4 figs 13 refs RP 1820. Derives formula for the

relation between the probable error of a single pointing and magnification under specified conditions. Collimators and Autocollimators for Workshop Control,

J. G. VOGL. Tekn Tidskr v77 Sept 6 1947 p 655-8 in Swedish. Describes various applications and special adaptations.

Influence of the Atmosphere upon the Precision of Tele- scope Pointing, F. E. WASHER, L. W. SCOTT. J Res NBS

v39 Oct 1947 p 297-302 3 figs 3 refs. The probable error

of a single pointing (PES ) was measured under conditions such that the effect of the air column intervening between

observer and target was introduced or eliminated at will. The substantial reduction in PES for the air-column-elimi- nated method as compared with the air-column-present method showed that precision in outdoor pointing is defi- nitely limited by the air column. Some approximate computations were made to show that the value of PES cannot

be appreciably reduced by increasing the magnification of the telescope above 20. Auto-Collimator and Its Applications. Machy (London)

v71 nl830 Nov 20 1947 p 568-70. Features of microptic 157
(B. R. Watts & Son) auto-collimator designed to measure

small angular deflections to fraction of second of arc

set up procedure ; applications in engineering and scientific work, particularly in measurement of parallelism, squareness, and alignment. The Auto-Collimating Telescope; Principle, Design, Application, C. B. KEANB. Inspection Gage Sub-Office, U.S. Army Ordnance 10 p. Optical Testing of Straight Slideways, J. TERRIEN, T. MOREAU. Microtecnic v2 nl Feb 1948 p 13-20. Comparison of several methods of measuring vertical deviations of straight slideways of precision comparator bed

use of autocollimator furnishing tilt angles of carriage

resting on slideways, Koesters double prism, duplicate image instrument, and optical straightness tester made

by Societe Jobin and Yvon. Measure-Scope System of Instrumentation for Precise Physical Measurement. American Instrument Co. Bui 216 Apr 1948 15 p 27 figs. Embodies an autocollimating tele- scope as sensing element. Basically an angle measuring

device to within 1 arc second. Discusses measurement of parallelism, comparison of angles, measurement of straightness of large flat surfaces, hole direction, true

level, etc. Detailed description of Tuckerman autocolli- mator. Reviewing Auto-Collimator Practice, H. ROCKWELL.

Mach April 17 and 24 1948. Principles are outlined with

descriptions of practical applications. Autokollimations-Spiegelablesung (Autocollimation Telescope), H. FREISE. Archiv fuer Techn Messen nl55! June

1948 p T75 2p. Sensitive autocollimating telescope for measuring small angles ; telescope is combined with mirror galvanometer for physical and chemical research ; illus- trations. Mirror Readings by Autocollimation, H. FREISE. Archiv

fuer tech Messen Issue 155 (Ref. J1112-1) T75 June 1948

in German. Description of an autocollimating telescope arranged to read angular displacements of mirrors. Optical Alignment. Aircraft Prod vlO nll7 July 1948 p

241-2. Details of two new instruments developed by

Hilger & Watts, Ltd. ; these are alignment telescope and

auto-collimator ; alignments or deviation from alignment

are measurable in angular terms with auto-collimator, and

in linear terms with alignment telescope. Some Practical Applications of Precision Alignment

Method, A. C. S. VAN HEEL. App Sci Res vBl n4 1949 p 306-24. Alignment method makes use of single slit, double slit, and cross wire with eyepiece ; by making

pointings on transition colors in interferences pattern, precision attained is of order of 0.1 sec. of arc or 0.01 mm

in transverse deviation for distances of from 3 to 60 m

use of method in construction of large steel bridge and in measuring deflection of reinforced concrete beam. An Optical Device Facilitating Accurate Alinement,

R. H. BROCKMANN. J Sci Instrum Phys Ind v26 July

1949 p 231-3. A device combining the angle-measuring

properties of an auto-collimating telescope with that of

lateral displacement indication is described. Both the measurements may be made at the same time ; the method

is essentially a development of the process for centering

lenses prior to "edging." Auto-Collimator for Precision Inspection. Tool & Die J

vlo n7 Oct 1949 p 80. Watts Microptic Autocollimator, designed to measure slight angular deflections to fraction

of second of arc ; two applications illustrated. Light Rays Can Be Tools, A. P. FULTZ. Tool & Die J vl5 n7 Oct 1949 p 64, 66, 68, 70-1. Description of autocollimator; inspection setup for checking parallelism of end faces of flanged tube and for measuring angular rela- tionship between two bearing surfaces and. ends of tubes

operation of combined autocollimator and aligning tele- scope used to align three bearings over four foot spread

described. High Precision Measurements with Simple Equipment,

A. C. S. VAN HEEL. J Opt Soc Am v40 nl2 Dec 1950 p 809-16. Method of obtaining precise alignment using

single slit, double slit, and cross wires placed respectively

at points to be aligned ; precision of at least 0.17 in. at- tained when use is made of pointings on transition colors

in interference pattern ; applications for measuring sag of loaded bar, flatness of surface, position of bridge members

during construction and alignment of ships' propeller

shafts. Interferometric Alignment Set, P. W. HARRISON.

Machy (London) v84 n2164 May 7 1954 p 976-9, 984 ; Engr

vl97 n5128 May 7 1954 p 670-1. Investigation by National Physical Laboratory in connection with new precision alignment method developed several years ago by

A. C. S. Van Heel : Principle of optical method employed ; tests conducted for examining variable factors likely to influence performance; design details of alignment set constructed by NPL; performance checkers, with regard

to accuracy of repetition and of alignment; possible

applications. Accurate Alignment Over Long Distance, P. W. HARRISON. Eng vl77 n4608 May 12 1954 p 654-5. Investi- gation carried out by National Physical Laboratory of precision method suitable for use by engineers, surveyors, and others, originally described by A. C. S. van Heel (see Engineering Index 1949 p. 694) ; interferometry ensures

0.0005 in. over 18 ft ; optical and mechanical design ; per- formance and applications. Communication from Nat

Physical Laboratory.

Principles and Applications of Alignment Telescopes, A. METZ. Instrum & Automat v27 nlO Oct 1954 p 1634-5. Special telescopic instruments useful for leveling benches and bedplates, for testing perpendicularity of machine

tool guides, or aligning bearings, etc. ; method of using alignment telescope in testing guideway of machine tool or

lathe bed. Alignment Testing, K. S. HUME. Engis Equipment Co. 1955 8 p. Line of Sight Replaces Squares, Levels, Straight Edges in Holding Tolerances on Large Work Pieces at Moore Dry

Dock, C. J. ALCIATI. Western Metals vl3 n2 Feb 1955 p 78-9. Details of measuring instruments employed in production of welded workholding fixture for milling machines ; how optical tools are used in measurements for checking alignment. Toepassingsmogelijkheden van een precisie-aligneermethode, J. G. DOEKES, W. DE BRUIN. Ingenieur v67 nlO Mar 11 1955 p 043-6. Precision alignment method devel- oped by A. C. S. van Heel permits three points to be put

in straight line with accuracy of order of 0.2 sec of arc "j| tn for distances up to 50 meters or more; explanation of

principle, description of applications of method, especially

of aligning of machine tools ; method is compared with water level and autocollimation methods.

Telescope Cuts Inspection Time, J. SEDORIC. Am Mach

v99 n6 Mar 14 1955 p 122-3. Large diesel and pump bores, machine tool ways, and big surface plate checked with

32 x magnification Leitz alignment telescope focusable with rack and pinion adjustment between 40 in. and 164

ft ; instrument has micrometer attachment reading to

0.001 in. for measurements in vertical and horizontal planes ; illustrated examples. 158
: Optical Tooling—New Equipment and Techniques Broaden

It Use, W. L. EGT. Tool Engr v34 n4 Apr 1955 p 86-91.

a Use of optical tooling for making precise measurements

- for automotive, machining and lofting work; alignment

id telescopes employed to form basic reference line, and jig transits or optical transit squares to set up planes per- pendicular to base line; accessory tools, such as microm-

•_ etera, for still greater accuracy, measurements made in

50 all three-dimensional planes by adding precision levels to

2 two-dimension system.

!; . Optical Tooling. Aircraft Prod vl7 n8 Aug 1955 p 301-10.

% One great advantage claimed for optical methods to check

r alignment of engineering assemblies is that greater accu-

-i racy can be achieved over larger distances, more easily

j. and quickly ; details of techniques now used and devel- opments in individual items.

y Auto-Collimator Quickly Measures Small Angular Differ- p

ences, J. C. MOODY. Am Mach v99 n20 Sept 26 1955

t p 124-5. Industrial use of autocollimator or autoeollimat- L ing telescope; rotational lag of synchro system was de- termined in 30 min by comparing displacement of polygj. onal surfaces ; observational error amounted to only plus

tt or minus 10 sec of arc.

j] Optical Trueing of Lathes Saves Time, E. B. BROWN.

;

" Tool Engr v35 n5 Nov 1955 p 75-8. Alignment telescope, being combined sighting telescope and autocollimator, de- termines alignment of ways of lathe to accuracy of plus

j>. or minus 2 sec of arc and measures lack of straightness to 0.001 in. or finer ; checking operations. £ How to Use Optical Tooling, Methods, E. B. BROWN.

2 J Tool Engr v36 n2 Feb 1956 p 93-8. Optical methods ap- B

plied in construction of large jig. for example, can obviate

_ need for angle plates, master squares, etc ; fundamental

u principle of optical tooling is that ray of light is accepted

definition of straight line: alignment telescopes, proce- dure for establishing jig fittings along basic reference line

1 by using tooling bar ; simplicity and accuracy of optical J tooling methods for locating and positioning over long

distances and large areas.

7, Aligning Large Machines with Optical Tooling, H. H. " POETT. Tool Engr v36 n3 Mar 1956 p 100-3. Use of alignment telescope for setting beds of spar mills, planers and skin mills : setting columns or points at exact right angles; setting given points exactly opposite point and

perpendicular to line ; other applications of optical equip- ment.

"J | Optical Tooling, A. R. PAOLI. Western Machy & Steel 2 , Wld v47 n4, 5, 6 Apr 1956 p 106-8, May p 84-6, June p 83-5. Apr: Definition of optical tooling and its application for J

; aligning generator bearings and shafts, checking surface

. .

'< plates and tooling bars for straightness, etc. May : Basic and accessory tools of optical tooling, and step-by-step procedure for installation of large planer. June: Versatile alignment telescope ; its functions and attachments

how it is used in installing turbine generator.

r* i Telescope-mirror Alignment Method, H. SCHULTZ.

; r { Power vlOO nl2 Dec 1956 p 117-9. Optical device for

f detecting bearing misalignment within thousandths of inch in hot machines that are running and under full Z

:, load; comparison of this "hot" alignment method with

cold alignment ; results obtained with hot alignment as applied to large turbine generator units ; use of Keuffel &

y

> Esser "tilting dumpy" level.

JjjJ Projection System Developed for Optical Instrument In- spection and Calibration, E. J. BARNET. Automotive

'..m Indus vll6 nil June 1 1957 p 64-8. Method evolved at

y Convair Div. of General Dynamics Corp. permits greatly enlarged image of focal plane of instrument being adjusted

to be projected upon screen ; projection system depends

upon powerful light source projected through very ac- curate and leveled collimator ; basic setup for alignment

procedure and instructions; tilt level, optical micrometer, and alignment telescope calibration. Optical Tooling: Short Cut of Accurate Alignment, W. CZYGAN. Iron Age vl80 nl8 Oct 31 1957 p 63-5. Nu- merous applications of optical tooling which is widely used

to align and level long machinery beds ; locating airframe

parts in large jigs and fixtures, alignment of bearings,

spindles, drive assemblies, etc., and closer control of angular and linear tolerances with optical tooling ; use of align- ment telescope, optical square, jig transit, optical level, and precision targets or scales described. Making Precision Measurements with Optical Tools, J. C. MOODY, J. M. BUNCH. Tool Engr v40 n2 Feb 1958 p

83-91. How autocollimation and geometry can be applied

in shop and laboratory ; principle of autocollimator ; opti- cal square tested by means of two mirrors and autocolli- mator ; checking 12-sided optical polygon ; setup for testing Dowell prism ; checking straightedge ; example of cali- brating 10° index stations of aerial plotting camera ; setup

for testing parallelism of pads. How to Recalibrate Optical Tooling Devices, R. LE

GRAND. Am Mach vl02 n3 Feb 10 1958 p 108-12. Compact test stand for recalibration of jig transits, alignment

telescopes, precision levels and optical squares developed by Keuffel & Esser Co., Hoboken, NJ ; method saves time and produces accurate results ; optical tooling devices are used to check alignment, levelness and squareness of components of aircraft jigs and machinery.

Optical Tooling and Its Uses in Industrial Plants, J. I. HANOLD, H. R. OSMICK. ASME—Paper n58-MPE-2

for meeting Apr 14—15 1958 11 p. Development and principles of instruments and accessories designed and built around optical lines of sight and industrial applications of

optical tooling ; benefits derived from application of opti- cal tools to alignment of production equipment are better alignment, reduced alignment costs, improved operation and reduced maintenance.

Optics Gain as Aircraft Tooling Aid, J. D. WOMACK.

Western Metalworking vl6 n9 Sept 1958 p 55-7. Description of sight level, transit, alignment telescope, and opti- cal square used in optical measurement, alignment and

positioning; optical tooling operations made possible by

these devices ; alignment of jigs in aircraft production

line ; other examples. The Adjustment of the Orientation of a Plane Surface by an Auto-Collimation Method, H. JURICIC. Rev Opt v38 n4 p 202-4 Apr 1959 in French. In setting up specimens

for the measurement of reflection coefficient with a monochromator as a light source, it may be difficult to determine

the normal by the standard auto-collimation technique. A modified method is described which does not require the

reflected beam to be found within the . monochromator. An auxiliary optical system is used, with a 45° semireflecting mirror to produce a second beam. Practical

details are given. The Measurement of Angles, K. W. BRITTAN. K. J. HABELL. NPL, Optics in Metrology, P. MOLLET.

Pergamon Press 1960 p 141-7 3 figs 3 refs. A brief survey

of existing methods. The high accuracy attainable with

interference comparators is discussed. Reports progress aimed at achieving comparable accuracy in absolute meas- urements with an automatic (continuously recording) goniometer.

Circular Diffraction Gratings as Alignment Devices, J. DYSON. Optics and Metrology, P. MOLLET. Pergamon

Press 1960 p 169-71 1 fig. Methods for measuring straight- ness using diffraction gratings of which the rulings are 159
concentric circles. Cross-hairs can be set on an inter- ference pattern with great accuracies over a considerable range of distances. Accuracy of setting approach 1 p

over distances up to 6 m. Alignment in Autocollimation, A. C. S. VAN HEEL. Optics in Metrology, P. MOLLET. Pergamon Press 1960 p

420-5 2 figs 7 refs. Apparatus for alinement of points

at distances up to 100 meters. Front lens of collimator

is provided with a ring system giving a diffraction pattern

consisting of rings and allowing very precise settings. Overall precision is about 0.4 sec. Optical Lineup Shortcut to Tooling Precision, L. E. BATCHELOR. Am Mach/Metalworking Mfg vl04 n4 Feb 22 1960 p 97-9. Optical tooling programs developed by aircraft industry are readily adaptable throughout metalworking industry ; examples of saving achieved by

Allison Div. of GM in checking gear boxes and aligning gun drill ; how four basic optical checking instruments

are employed. Modern Alignment Devices, A. C. S. VAN HEEL. Progr

in Optics vl 1961 p 289-329 26 refs. Review of work

mainly by the author and his co-workers on non-image- forming alignment systems, in which a straight line is produced as the axis of a diffraction pattern in space. A Two-Channel, Recording Autocollimator, L. R. BAKER.

Opt Instrum Conf London 1961 p 212-20. A visual path

enables this instrument to be used as a conventional auto- collimator for setting-up purposes, whilst an electronic system operated in parallel with it records simultaneously angular movements of the plane mirror about two axes

at right angles. For convenience of operation the instru- ment is provided with three ranges of full scale deflection which are, 0±2% minutes of arc, 0±20 seconds and 0±2

seconds of arc. The instrument employs a light source modulated at 400 c/s and a S.I.R.A. position-sensitive

photocell. An open loop system was required initially, and so there is provision for displacing the light beam by

a known amount for the calibration of gain and linearity of the complete instrument. The loop may be -closed if required by the addition of a simple a.c. servo system. An Alignment Telescope of Which the Direction of the Pointing Axis Is Defined by the Normal to a Fixed Surface, K. HILDEBRAND. Optik (Germany) vl8 nlO-11

p 547-8 1961 in German. The target is fixed at the real principal plane of the objective ; it, together with its image in a fixed plane mirror, defines the direction of the pointing axis as perpendicular to the mirror. The tele- scope is focussed by moving the objective and target

together. Testing the Straightness of Lines and the Flatness of

Surfaces, A. C. S. VAN HEEL, J. D. DE VEER. Opt

Instrum Conf London 1961 p 383^05. By making use

of conventional optical parts, alignment and the flatness of surface can be tested to within a few tenths of a second

of arc by making use of spherical aberration and diffraction. The range in some cases is several hundreds of

metres, and the brightness of the diffraction pattern is high enough for observation in daylight. Only flat and

spherical surfaces are needed. The most simple form to

test alignment is a sphere with a cap of the same material

of very good homogeneity. A concave spherical mirror and a fiat mirror were used in combination, in order to ob- viate the stringent requirement of homogeneity of the

glass. Though the sphere with cap -can be used also to test the flatness of surfaces, other means are more effi- cient. In the first place one spherical mirror with one minute light source (of white light) suffices to test the

flatness up to distances of, say, 20 meters with a precision below one second of arc. By combining a concave and a convex spherical mirror, precision can be lowered to a few

tenths of a second of arc, while the observation distance

is enlarged. The working of the mirrors is based on the forming of (colourless) "rainbow," a fact that is perhaps

not well known. The diffraction pattern associated with

these rainbows (Airy's fringes) makes it possible to at- tain the mentioned precision. Much time was given to testing the straightness of the line produced by the ap- paratus by independent means, a difficult process seldom

applied by other workers. Optische precisiemetingen op civiel en werktuigkundig

gebied in de praktijk, S. H. LI EM. Ingenieur v73 n8 Feb

24 1961 p 033^2. Optical precision measurements in civil and mechanical engineering ; precision alignment methods

developed by Van Heel, which permit three points to be put in straight line with accuracy better than 0.2 second

of arc, appear to be practical, accurate and simple ; optical instrument for measurements on experimental runways

at Schiphol airport described. High-Precision Pointing, A. MARECHAL. J Opt Soc Am

v51 n4 Apr 1961 p 396-8. Two methods permitting high- precision pointing (image location) have recently been

developed by members of the staff of the Institut d'Optique. The method of Simon for high precision in longitudinal

positioning is based on the use of two identical grids, longitudinally separated, one forward and one back of the object point. The position is determined by observing

the equality of contrast of the out-of-focus images of the

grids. The method of Arnulf and Duppuy for lateral pointing is based on the formation of a system of inter- ference fringes by light from a double slit illuminated by light from a single slit. By placing the entrance pupil of a telescope on a dark fringe, the image of the slits, though very dim, reveals and amplifies any irregularities

in the edges of the slits even though the irregularities are very small. If the two slits are separated only by a

fine line, the lateral position of this line can be located with high precision. Optical Alignment Devices Based on a Two Mirror Sys- tem, J. DYSON. Optica Acta (Int) v8 n3 July 1961 p 217-

31. The requirements to be satisfied by an optical align- ment system are indicated, and a two-mirror system is described. 'The elementary form of this is restricted in its field of application, but it can be converted into a very

sensitive interferometer for toolroom or laboratory use.

Its errors and coherence conditions are examined. Modifications of the simple system suitable for more practical conditions are described, and their errors are investigated.

It is shown that very high accuracies can be obtained with- out excessive demands on the optical workmanship. The

effects of atmospheric irregularities are indicated, and

test results are described briefly. Suggested Arrangement of Mirrors to Form Multiple Ref- erence Angles, J. B. SAUNDERS. J Opt Soc Am v51 n8 Aug 1961 p 859-62. A reference angle is described that forms, by successive or multiple reflections, a multiplicity

of equal optical angles having common vertices. This

angle may be used as a standard for calibrating circular

scales either with an autocollimator or an interferometer. The angle can be adjusted in an interferometer to a very

high accuracy. If the faces of the mirrors are 6 in. long, an error of 0.1 fringe corresponds to an error in the angle

of 0.02 sec of arc. Photelectric Angle Sensor. Electromechanical Components & Syst Design v5 nil Nov 1961 p 12-8. Principles of Refractosyn system, manufactured by H. H. Controls. Burlington, Mass., using two photocells to sense balance of energy refracted through glass prism, as angle of inci- dence of light beam to face of prism deviates from critical angle ; system can be used with various instruments and

measures angles down to 0.05 sec. of arc, drifts less than 1 sec. in 10 days. An Alignment Interferometer for Precision Straightness- Measurements and Control Even of Rapidly Moving Car-

' :,

160
riages, G. W. STROKE. J Opt Soc Am v51 nl2 Dec 1961 p

1340-1. A new, easily adjusted and very stable inter- ferometer, defining a seniistatic fringe field by reflection on two mirrors, has permitted a simple solution to the problem of rapid and accurate alignment of moving carriages, of fixed reference beams, and of carriage-ways in the interferometric domain. Precisions in the 0.1 sec-of- arc range are easily obtained in visual work in rotations up to minutes of arc, without the usual limitations of slow

fringe counting and of loss of fringe-contrast at large path

differences in particular. In fact, the fringe-constant is independent of the distance from the reference-support to the moving mirrors in this interferometer, and permits measurements and alignments over traverses and distances

of many feet if required. Precisions in the 0.01 sec-of- arc range and better can be obtained with the help of

electronic location of interference fringes. Experiments

with carriages moving at rates up to 1 ft/sec and over

distances of the order of 1% ft have demonstrated the

versatility of the alignment interferometer in various, applications, in particular in the alignment of ways on

a velocity-of-light apparatus and on ruling engines. Accurate Alignment. Aircraft Prod v24 n2 Feb 1962 p 38-

40. Optical instrument based upon circular diffraction grating made by Cooke. Troughton and Simms, Ltd.. comprises sighting head and target unit, which contains dif- fraction grating itself in adjustable mount; accuracy of

0.0001 in. (0.00025 mm) can be achieved in definition of

straight line over distance of 20 ft (6096 mm) ; characteristics of grating ; establishing alignment and vertical align- ment.

Optical Properties of Conic Surfaces. I. Reflecting Cone,

S. FUJIWABA. J Opt Soc Am v52 n3 p 287-92 Mar 1962. The optical properties of a reflecting cone, which have

acquired fresh importance in connection with alignment measurements, are treated on the basis of Huygen's principle. Approximate expressions for the intensity distributions in diffraction images of an axial point source and

an off-axis one are derived by the stationary phase method. The results of the calculation are found to be in good

agreement with the photographs of images made by an

actual reflecting cone.

„ ' New Optical Methods of Precision Alignment (Straight Lines and Flat Surfaces), A. C. S. VAN HEEL. Soc Instrum Technol Trans vl4 n4 Dec 1962 p 270. Growing

need for precision in civil and mechanical engineering and in shipbuilding, when putting 3 points on a straight

line ; review of methods useful in practice ; novel instru- ment described enables observer to determine deviations from perfect plane with precision; instrument is appli- cable for distances from 1 or 2 up to more than 100 m, ob- servations being made in daylight ; by slight modification,

:, distances from decimeter to about 10 m can be served.

- Applications of Setting Heavy Equipment, H. R. OSMICK.

-

. ASTME Creative Mfg Seminars Tech Paper SP63-108

1963 10 p. In 180° rotation method developed by du Pont

for setting and aligning heavy equipment, optical telescope

- and target is attached to shaft ; readings are taken at 0 and 180' and averaged to establish reference sight line

:

. j or plane; application of this method for installation of machine tools, multiple roll machines and 3 component

in-line drives (motor, magnetic coupling and gear box) is

r .. discussed. Use of Optical Tooling in Installation of Capital Equipment, W. M. SMITH. ASTME Creative Mfg Seminars

. Tech Paper SP63-122 Feb 1963 6 p. Methods of proce- dures employed by R. J. Reynolds Tobacco Co for per- forming alignment requirements; examples of optical alignment of printing presses, large drying drum and sole

plates. Optische Fluchtungspruefung. R. SCHULZE. Archiv fuer Tech Messen n.325, 327 Feb 1963 p 37-40, Apr p 89-92 20

refs. Optical alignment measurements; basic principles

of alignment measurements are reviewed and description given of some instruments used. Point Target Autocollimator, J. E. TAYLOR. Rev Sci Instrum (USA) v34 n2 Feb 1963 p 188. A simple, high

sensitivity autocollimation system uses the tip of an optical transmitting glass fibre as a self-illuminated target. Practical details are given of a system having 3 seconds

of arc resolution. Greater resolutions can be obtained with more elaborate reading methods. Alignment and Measurement Techniques Using Elec- tronic Levels, J. M. MILLER. ASTME Creative Mfg Seminars Tech Paper SP63-96 Feb 1963 9 p. Attempts made

by Grumman Aircraft Engineering Corp. to apply elec- tronic level to dynamic measurement situations, aiming

to decrease effort and cost in performing periodic checks on machine tools ; types of electronic level transducers employed for bearing race alignment and checking sur- face tables and other pieces of machine tool equipment

results of dynamic measurements described are significant, but inconclusive. Economics of Establishing Optical Tooling Group in Small

to Medium Sized Manufacturing Firm, A. W. YOUNG. ASTME Creative Mfg Seminars Tech Paper SP63-100 Feb 1963 6 p. Optical tooling requirements ; examples

of aligning drying rolls in paper company with micro- alignment telescope and target, and of using autocollimator on large boring mill in machine shop for solving bearing problems ; other applications and costs of instruments

discussed. Raising the Efficiency of Testing Straightness by the Mieroleveling Method, L. L. MEDYANTSEVA, V. V. GOR- BACHEVA. Meas Techns 1962 n8 Feb 1963 p 646-8 2

figs. Translated from Izmer Tekh n8 p 22-3 Aug 1962. Describes and recommends method of measuring linearity by means of a moving microlevel for use in factory testing. Optics in Manufacturing, P. KISSAM. ASTME Creative Mfg Seminars Tech Paper SP63-103 Feb 1963 26 p. Why

and how optical tooling is capable of developing high accuracy it attains; reasons for this high accuracy are analyzed ; how elements that create this accuracy are embodied in some of standard types of optical tooling equipment ; applications are not discussed ; in addition to materially reducing costs both in down-time on work and

in making measurements themselves, optical tooling often can be used to meet rigid tolerances that cannot be suc- cessfully handled by other means.

Testing Straightness of 40-ineh Ways to ±3 Microinches,

E. G. LOEWEN, B. L. BARLOW. ASTME Creative Mfg

Seminars Tech Paper SP63-92 Feb 1963 10 p. Design of new precision ruling engine at Bausch & Lomb called for pair of machine ways 4 ft. long, which had to be straight within 20 /itin. over 40-in. segment of length ; measuring

system capable of detecting surface displacements of 2

/xin. or less was required ; Davidson Optronics Model D665 Automatic Autocollimator was selected for inspection ; lapping of ways ; direct recorder of surface profile ; results given; advantages of surface inspection technique de- scribed over conventional methods. A Novel Prism for Total Reflection, A. N. DE JONG.

Optica Acta ( Int ) vlO n2 Apr 1963 p 115-9. For purposes

of autocollimation alignment a reflection prism was devel- oped with certain advantages over the triple mirror (cor- ner-cube). Not only is the parallelism of the incident and

emergent rays (travelling in opposite directions) inde- pendent of the orientation of the prism, but it is also possible to conserve the state of polarization much better. This makes the prism useful for the determination of the

optical thickness of thin layers in vacuo by Savart's

plates in autocollimation. Some advantages and disad- vantages are discussed. 161
A New Method for the Experimental Investigation of the

Position of the Line of Sight for an Optical Telescope System, K. KAROVIC, J. BOLF, L. KUBACEK. Optik (Germany) v20 n5 May 1963 p 259-74 in German. A

method for determining the sighting precision of a theodolite is given. Rapid Testing of Maximum Straightness Ways, E. G. LOEWEN. Stand and Metrology Div, AOA, May 16 1963. Evaluation of direct optical and indirect straightness measurement methods. Concerning Several Basic Relationships in Telescope Observation, H. KOEHLER. Reprint from Zeiss-Werkzeitschrift vl7. Discuss basic function, magnification, bright- ness of image, and telescope efficiency. Seven literature references. Angular Alignment Mechanism, J. P. GOLDSBOROUGH.

Rev Sci Instrum (USA) v34 n7 July 1963 p 806. A device

is described for making small variation in the angular

alignment of optical components to an accuracy of about

0.01". Its operation depends on elastic deformation, and

two orthogonal axes of rotation are provided. A sug- gested use is for adjusting the mirrors in a Fabry-Perot

type laser. Engineering Applications of Rodolite, R. J. TILLEN.

Prod Engr v42 n8 Aug 1963 p 462-78, 491. Tests of re- flection and mercury Rodolite, featuring equipment that

is based on optical properties of circular diffraction grat- ings which consist of series of equally spaced concentric

rings ; principles of instrument to define straight optical

line; use of reflection Rodolite to measure errors in ro- tation ; use of mercury Rodolite to measure crosswind

(roll) in vertical guideways ; yaw and pitch measure- ments using device as autocollimator. An Alignment Interferometer, J. B. SAUNDERS. J Res NBS v67C n4 Dec 1963 p307-9 7 figs. Describes a diverg- ing-beam type of alignment interferometer that permits

the use of large apertures, provides ruggedness, high sensitivity, and is relatively compact. Since this interfer- ometer is fully compensated, white light can be used. The

narrowness of the zero order fringe, relative to separation

of fringes, in such a well compensated system permits

settings to better than one twentieth of a fringe width. This corresponds to a lateral displacement of the light source of less than 1.5 mm at a distance of one mile for a one-inch aperture instrument and to less than 0.15 mm

for a 10-inch aperture instrument. Its performance, be- cause of its high sensitivity, is severely affected by the homogeneity of the atmosphere or medium through which

the light passes. However, this effect is also greatly re- duced by the proximity of any two interfering rays of

light.

Autocollimator with Photoelectric Display, G. A. LEN- KOVA, A. I. LOKHMATOV, V. I. SOSNOVSKII. Meas

Techns 1963 n8 Feb 1964 p 656-7 2 figs 4 refs. Translated from Izmer Tekh n8 p 20-1 Aug 1963. Measurements are recorded by a photoelectric method based on the properties

of a double rectifier photocell, which obviates use of a

vibrator. Electrical Read-Out from Optical Alignment Devices, J. DYSON, P. J. W. NOBLE. J Sci Instruments v41 n5 May

1964 p 311-6. Three methods are described of obtaining, from 2 types of alignment devices, electric output which

represents, in sense and magnitude, error of alignment; output can be used to operate recording or indicating meter for convenience, or if measuring head is in inaccessible position ; in some cases it can also be used as input

signal to servomechanism which corrects error; applications include alignment of large turbogenerator bearings, and installation and periodic checking of machine tools. Align Machinery by Optical Measurement, E. H. KOENIG.

Plant Eng vl8 n5 May 1964 p 140-3. Optical alignment method is described that makes direct precision measure- ments rapidly and consistently ; optical metrological and

alignment equipment sets up 3-dimensional pattern for making accurate measurements of point within its view

electronic autocollimator is featured that has sensing unit, power amplifier, and indicator ; sensing unit reads amount

of tilt of reflective surface mounted perpendicular to its axis. New Techniques for Very Accurate Measurement, E. H.' KOENIG. Civ Eng (N.Y.) v34, n8 Aug 1964 p 41-3. It

is shown how newly developed equipment and techniques with conventional instruments give new order of accuracy

to measurements and how optical metrology and align- ment aid in setting machines and equipment straight, flat, plumb, square and dimensionally correct; "square" may

be established by pair of jig transits, one of which has pre- cision-mounted mirror on its axle to reflect line of sight back on itself. Alignment Interferometer, R. R. BALDWIN, L. G. WHITTEN. ASME n64-WA/PROD-5 presented at Winter Annual Meeting Nov 29-Dec 4 1964 4p 10 figs. The devel- opment of an interferometer for the measurement of straightness is described. With this instrument, deviations from straightness can be measured directly without

resorting to trigonometric conversion techniques. Various modes of operation can be used to isolate errors due

to pitch, roll, or yaw. This characteristic greatly simplifies error analysis and correction. A deviation from a

straight line of less than 0.000010 in. can be detected at a

distance of two yards. Calibration is performed with

routine procedures and equipment. 6.3. Angle Gage Blocks and Polygons

A Machine Shop Square that is a Square, J. E. SWEET. Am Mach v31 June 18 1908 p 929-30. Illustrated description of a square in the form of a right 60-degree triangle having broad surfaces. Discusses advantages and uses, and methods of originating angles. Table for Spacing Holes in Circles, F. W. SEIDENSTICKER. Am Mach v31 Dec 17 1908 p 889-90. A useful table for dividing circles into parts up to 500. Table

gives the number of sides (3 to 250) of polygons, y2 of angle subtended by side, and sine of that angle. (See also Am Mach v31 May 14 1908 p 767). Johansson Angle Blocks and Other Precision Instruments. Am Mach v51 Oct 2 1919 p 669-70 5 figs. Details and

illustrations of some special precision instruments manufactured in Sweden to supplement blocks marketed by

C. E. Johnsson, Inc., New York City.

Die Genauigkeit von 90° Stahlwinkeln (The Accuracy of 90° Steel Angles), G. BERNDT. Zeit fur Feinmech und

Priizision v35 n23 Dec 1927 p 279-83, 295-9. Detailed

discussion of angle measurements, including: Testing

angles by the light-slit method ; indicating angle testers

measuring angles with the telescope and level ; measuring

angles with 2 auto-collimating telescopes ; interior angles ; effect of unevenness of the angle-leg on accuracy of meas- urement ; tolerances, measurement of 90° angles ; optical angle measurements ; measurement results on 24 steel angles. Apparatus for Measuring Solid Angles, A. AUBERTIN.

Rev d'Opt vl5 Aug 1936 p 263-71. The principle of the apparatus and a description of its construction, and its method of use are given. A. solid angle w is measured in terms of an arc rotating on a divided circle. The apparatus can also be used as a planimeter. 162
Gauge, N. TRBOJEVICH. U.S. Patent 2,134,062 Oct

25 1938. Describes invention in the formation and selec- tion of 15 blocks to form a set and the method of stacking

the blocks to obtain any desired angle from zero to 90

degrees in degrees, minutes, and seconds. A System of Combination Angle Gauges and a New Type

of Dividing Head, G. A. TOMLINSON. NPL S.S. 190 Feb

1940. Describes a set of 12 angle gauges which can be combined to form any angle required to the nearest 1.5 sec- onds. Certain uses of the gauges are given, in particular

their application to a new type of dividing head of high

precision and great simplicity. See also British Patent

n559748. New Gage System, G. W. BIRDSALL. Steel vll4 n2 Jan 10 1944 p 74-5. By using gage blocks, produced by Webber Gage Co., Cleveland, any angle from zero to 103° may be measured at 1-sec intervals with accuracy of %

Standards of Length and Angle for Precision Engineering.

H. BARRELL. Trans Instrum and Meas Conf, Stockholm, 1947. Includes description of combination angle

gages. Testing Circular Division with Precision Polygons, C. O. TAYLERSON. Machy (London) v71 nl821 Sept 18 1947

p 327-30, 333. Polygon method for determining accuracy

of readings of optical rotary dividing table incorporating graduated glass scale ; method utilizes micrometric autoicollimator for reading ; calibrating polygon using two autocollimators ; use of several polygons in combination

Tomlinson small angle tester used for calibration of miicroscope graticules. Testing Angular Divisions, C. O. TAYLERSON. Aircraft Prod v9 nl09 Nov 1947 p 430-2. Procedure described has

been evolved by Metrology Div of NPL, and makes use

of polygonal blocks of hardened steel, with polished faces,

las reference standards. Testing Circular Division with Precision Polygons, C. O. TAYLERSON. Eng vl66 n4304 July 23 1948 p 73-5. Polygon method described was devised in Metrology Div of XPL ; polygons themselves can be accurately calibrated by comparatively simple means and require only one optical micrometer reading at each point of comparison with table

ereadings; photographs and line drawings. How to Generate a Standard Square. Mach Oct 9 1948. A

rectangular block having faces square and parallel within

0.0001 in. in a length of 20 in. Production of Combination Angle Gauges, C. H. KNOYLE.

Engr \190n4936 Sept 1 1950 p 237-8; Machy (London) v77 nl975 Aug 31 1950 p 275-9. Methods successfully emjiployed in producing and in generating sizes of gages to

j'high order of accuracy from first principles ; machining

"and heat treatment of blanks ; preparing 27° and 9° gages ; [preliminary adjustment; production of gages in minutes and seconds ; diagrammatic drawings. Communicated by Nat Phys Laboratory. Assembled Polygon for Calibration of Angle Blocks, C. E. HAVEX, A. G. STRANG. J Res NBS v50 nl Jan 1953 (RP2387) p 45-50; abstract in Machy (London) v83 n2138 Nov 6 1953 p 915-6. Method described for constructing

and calibrating assembled, multiple sided, angular stand- ard of exceptional accuracy, although designed as master

for 30 or 45° angle blocks of series made in United States, polygon is equally suitable for test or calibration of circular dividing equipment.

Precise Angular Standard Made From Gage-Blocks. Machy ( N.Y. ) v59 nl2 Aug 1953 p 200-1. Exceptionally ac- curate polygon with 24 sides constructed by National Bureau of Standards to serve as basic standard of angular measurement ; polygon permits comparison of "unknown"

angle with consecutive angular intervals until total of such

intervals equals integral number of perfect angles ; design and operational details of instrument given. Calibration of Circular Scales and Precision Polygons, A. H. COOK. Brit J App Phys v5 nlO Oct 1954 p 367-71. Although there is extensive literature about linear scales, calibration of circular scales and polygons has had but

slight consideration ; yet, some of computations are very much simpler for circular than for linear scales; theory

of two methods of calibration ; expressions obtained for values and standard deviations of corrections to nominal

values of angles. La Mesure Precise a 1' Atelier des pieces ou Calibres a

Faces non Paralleles (Accurate machine shop measure- ment of pieces with nonparallel faces), H. GUILLAUME.

Pratique des Indus Mechaniques v42 nl Jan 1956 p 13-6. General method of measuring conic surfaces ; design and

operation of "Micyl" checking blocks. Angular Positioning Accuracy of ^oth Second. Tooling & Prod v24 n3 June 1958 p 51. New dividing head de- veloped by AA Gage Co. indexes to accuracy beyond

measuring capacity of best current scientific procedures

head incorporated two mating master plates, each with

360 precision ground serrations ; parallelism and flatness

of meshed plates is fast check on spacing accuracy.

Optical Polygons; Ultimate for Setting up, Checking

Angles. Tooling & Prod v25 n9 Dec 1959 p 58-60. Entirely new polygon concept offered by Webber Optical Polygons which are calibrated to extreme accuracy of 0.2 sec of arc; used with small telescopes (autocollimators) that beam line image to one of polygon's reflecting surfaces, they are economical, abrasion resistant, and built to last for years of hard shop use ; tools are especially helpful

for calibration of "space age" instruments and guidance

systems. Reproduction and Transmission of the Value of an Angle

in Reference Measurements, G. I. STRAKUN, L. I. SMIRNOVA, E. E. SHAROVA. Meas Techns 1960 nlO

July 1961 p 832-5 2 figs 5 refs. Translated from Izmer Tekh nlO p 13-5 Oct 1960. The reference angle measuring method, which is basic to the whole measuring system,

consists in determining the angles of polyhedral prisms by calibrating them with two independent autocollimators. These instruments are placed in such a manner that the

optical axes of their objectives are perpendicular to the

reflecting surfaces of the prism, and the angle between

the collimators is equal to the nominal value of the central angle between the perpendiculars to the sides of the prism. The above method is one of the simplest and most accurate ways of reproducing and transmitting discrete values of an angle.

163
6.4. Calibration of Graduated Circles, Dividing Heads, and Protractors

See also subsection 10.2.5 An Account of the Equatorial Instrument, G. SHUCK- BURGH. Phil Trans Roy Soc London 1793 p 93. Two

microscope method of calibration by making simple comparisons, plotting and noting deviations from the cosine

law. Untersuchungen der Theilungen der Kreises (Investigations of the Division of Circles) , F. W. BESSEL. Konigsberg Beobachtungen v7 1822 p IV. One of the early and

much-used methods.

Description of the Armaugh Mural Circle and Examination of Its Divisions. T. R. ROBINSON. Monthly Notices Roy Astron Soc v3 1835 p 111-3. Four microscope methods with one pair of diametrically opposite microscopes fixed, the other movable; no details given as to computational method.

tiber ein auf der Dorpater Sternwarte befindliches

Durchgangsinstrument—Repsold (Regarding the Repsold

Transit Instrument at the Dorpater Observatory), W. STRUVE. Astron Nachr vl5 n344 and 345 1838. Bessel's method of calibration (as used by Bessel on Cary's Circle)

Erste Leistungen eines auf der Konigsberger Sternwarte

befindlichen Repsoldschen Meridiankreises (First per- formances of a Repsold's meridian circle situated at the Konigsberger observatory )

, F. W. BESSEL. Astron Nachr

v21 n481 1844 p 482. Spherical Astronomy, F. BRUNNOW. Translated from 2d German Ed 1865 Section VII p 389. Theory of astronomical instruments, includes topic of errors of circles. Untersuchungen fiber die Theilungs-fehler beim Meridiankreise (Determination of circle errors by use of four fixed microscopes and two movable ones), F. KAISER. Ann

der Sternwarte in Leiden v2 1870 p 50. Eine neue Methode Kreisteilungen zu Untersuchen (A New Method of Investigating Circle Divisions), G. QUINCKE. Carl's Reportorium ffir Exper-Phys v9 1873 p 413. Mirror method for astronomical circles. Determination of the Errors of Graduation of the 12-Inch Troughton and Simm's Theodolite. R. WOODWARD. Report of Chief of Engineers, U.S. Army for 1876 part III p 64. Periodic error of circle observed with two microscopes ; application of method of Chauvenet. Untersuehung von Kreisteilungen mit zwei unci vier Mikroskopen (Investigation of Circle Divisions with Two

and Four Microscopes), O. SCHREIBER. Zeit fur InstrumKde v6 1886 p 1-5 47-55 and 93-104. Schreiber used the Wanschaff circle tester ; he developed one of the thorough tests. For description of the Wanschaff instru- ment, see Brun's article in Astronomische Nachrichten

130. 1892. On the Determinations of Errors of Graduation Without

Cumulative Error and the Application of the Method to the Scales of the Cape Heliometer, D. GILL. Monthly

Notices Roy Astron Soc v49 1888-9 p 105-18. It is stated that the general condition for freedom from cumulative

error for circles is that there shall be as many microscopes

(or the equivalent for as many microscopes) as the number of spaces into which the circle is to be subdivided. Untersuehung einer Wanschaffschen Teilung (Investigation of a Wanschaff Graduation), H. BRUNS. Astron Nachr vl30 n3098 1892. Contains description of Heyde

circle tester.

Untersuehung fiber die Bestimmung der Theilungsfehler am Nonius und an der Kreistheilung (Investigation Re- garding the Determination of the Division Error of a Vernier and a Circle Division), CAVILLE. Zeit fur Vermessungswesen v22 1893 p 385. A Simple Method of Determining the Eccentricity of a Graduated Circle with One Vernier, F. L. O. WADS- WORTH. Am J Sci v47 ser 3 n281 May 1894 p 373-6 3 figs. The method applies a telescope and mirror. Division Errors of the Repsold Meridian Circle, R. H. TUCKER. Publications of the Astron Soc of the Pacific v7 1 895 p 330-9. Two circle method used with 2 microscopes on each circle; simple calibration, duplicate re- sults considered only as checks ; 29,000 readings. Flexure and Division-Correction of the Circles of the Meridian Instrument at Albany, L. BOSS. Astron J n382,

383, 401. Total work on 4320 graduations with 350 hours

observing by two people and nearly as much more

computing. The Normal Equations That Arise in the Usual Schemes

of Observation for Division Errors and Their Solutions,

P. H. COWELL. Monthly Notices Roy Astron Soc v61

1901 p 527. Various schemes for calibrating circle, con- sidered as a scale, with different number of microscopes

mathematical. On the Determination of the Division Errors of a Graduated Circle. HOUGH, Monthly Notices Roy Astron Soc

v64 1904 p 461-88. Methode Nouvelle et Rapide pour la Determination des Erreurs de Division d'un Cercle Meridien (Division Errors

of Meridian Circle), LOEWY. CR Acad Sci vl43 Oct 15, 29, Nov 12 Dec 3 1906 p 529-35, 621-7, 719-26, 857-63

Ann de FObservatoire de Paris (Mem), v27 1910 p al. Announcement and preliminary description of a new

method of rigorously determining the errors of each divi- sion on instrumental circles of high precision. Details and formulas of reduction are given in later papers. Die Ausgleichungsrechnung nach der Methode der klein- sten Quadrate (The Compensation Calculation According

to the Method of Least Squares), F. R. HELMERT.

Publ. by Teubner, Leipzig (2d ed 1907 chapter 7 p 435-63)

Describes methods of calibrating circles. Sur la Methode de M. Loewy pour l'Etude des Cercles Divises (Loewy's Method of Determining Circle Errors), GONNESSIAT, G. FAYET. CR Acad Sci vl45 July 16 1907 p 157-65. The authors have applied Loewy's method

and find it practical, rapid, and accurate. Testing the Dividing Head of the Cincinnati Milling Machine. Machy (N.Y.) vl4 Jan 1908 p 315-7. Shows a sample inspection sheet and illustrates a variety of tests. Dividing Engine, G. T. McCAW. Monthly Notices Roy

Astron Soc v69 Jan 1909 p 226-8. Details of testing of a 55 cm circle ruled on a new dividing engine made by

E. R. Watts & Son, So. London. The range of errors is from +178 to -177. Sur la Determination des Erreurs des Traits d'un Cercle Divise (On the Determination of Errors of Lines of a Divided Circle), G. FAYET. Ann de l'Observatoire de

Paris (Mem) v27 1910 p A2 1. Method of Bruns. 164
Geodasie (Geodesy), H. HOHEXXER. Publ by Teubner.

Leipzig 1910. On p 42-5 is a discussion of the errors of graduated circles. Bemerkungen viber die Untersuehung von Kreisteilungen

L3 (Remarks Regarding the Investigation of Circle Diving.

: sions), H. BRUXS. Ber uber die Verh der Koniglich

• ,

' Sachsischen Ges der Wissensehafter zu Leipzig ( Mathe5j matisch-Physisehe Klasse) v64 1912 p 62-107. "Rosette" method using Heyde circle tester. Bestimmung des Regelmassigen und des Mittleren Zufallijj. gen Durchmesser-Teilungsfehlers bei Kreisen von Theo-

- doliten und Unirersalinstrumenten (Determination of the Regular and of the Mean Accidental Diameter-Division

Errors in Circles of Theodolites and Universal Instrur ments), H. J. HEUVELIXK. Zeit fur Yennessungswesen

-42 1913 p 441-52. Describes test of an assembled theodolite using collimators. Untersuehung eines automatisch geteilten Kreises (In- vestigation of an Automatically Divided Circle), J. SPAX- XUTH. Doctorate Dissertation, Univ. of Leipzig. Publ

g by Friedr. Vieweg & Sohn. Braunschweig, 1913. Test by

"Rosette" method using testing machine made by Heyde;

:his machine shown by photograph on p 6. Untersuehung zweier Teilkreise der Fa. Heyde und Hilde- brand auf dem Wanschaffschen Teilungspriifer (Investi- gation of two graduated circles on the Wanschaff graduation tester), G. FORSTER. Zeit fur InstrumKde v33 Jan and Feb 1913 p 10-9 and 39-51: Veroff des Geodatisehen Inst Berlin 1917. A considerable amount of theory

is involved in comparing two machines (a) by Heyde, (b) by Hildebrand, the error of a single measurement and

also the mean error, a number being worked out in each

case. Calibration tables and curves are given, the greatest error found anywhere on either machine being 1.5 seconds of arc.

a Calibration of Repsold Meridian Circle. P. HARZER. H. KOBOLD. O. TETEXS. Zeit fur InstrumKde v34 Jan

1914 p 20-3. Xotes of tests made on the calibration of the

divisions on the limb of a Repsold meridian circle. A

summary is given showing the variations at various positions. Movable Divided Circles. A. VERSCHOFFEL. CR Acad

Sci vl63 Oct 23 1916 p 421-7. Attention is drawn to the

possibility of considerably reducing the probable error of observations made with a divided circle by arranging for

it to be movable on its axis, so that readings on a given

f object may be made on different divisions. Description et Emploi des Appareils de Mesure et d'Observation (Description and Use of Apparatus of Measure- ment and Observation), H. BOUASSE. Publ by Libraire Delagrave. Paris. 1917. Method of graduating and cali- brating circles on p 184 and 203. On p 199 is given basic

. idea of a method employed in XBS testing.

Priifing von Kreisteilungen (Testing of Circle Divisions).

A. AREGGER. Schweizerischen Zeit fur Vermessungswesen und Kultxirtechnik, 1921. Method developed by

Aregger. geometer of the military-geographical institute

of Argentina. Test of assembled instrument using

collimators.

J' T i The Circular Dividing Engine of Edward Troughton. 1793. D. BAXAXDALL. Trans Opt Soc London v25 1923-4

p 135-9. Very interesting history of circular dividing

engines.

- Handbuch der Vermessungskunde (Handbook of Surveying), W. JORDAX. Publ by J. B. Metzlersche Verlags- buehhandlung Stuttgart v3 7th ed 1923 p 49-56. Section

entitled, "Kreisteilungsfehler", refers to various methods

of test. The Adjustment and Testing of Transit Theodolites, Levels and Surveying Cameras at the Laboratory of the Dominion Lands Surveys. Canada, Topographical Sur- veys Branch Bui 48 1923. Test of a complete instrument

using collimators ; errors given in tabular form ; eccentricity determined as described by Chauvenet, same as Hosmer. ( This method of determining eccentricity used at Xational Bureau of Standards.

)

Divided Circles, E. O. HEXRICI. G. W. WATTS. Article

in Glazebrook*s Dictionary of App Phys IV p 53 ( Pub by Macmillan London 1923). Winkelmessung ( Angle Measurement )

, F. GOPEL. Being

chapter III of Vol 1 of Handbuch der Physik. Edited by H. Geiger and K. Schell and published by Julius Springer, Berlin 1926. Method of graduation; types of graduation

error; calibration of circles by methods of Schreiber. Bruns, Heuvelink and Zeiss. Illustrations : Reichenbach arrangement (schematic drawing). Heyde 500 mm divid- ing engine. Zeiss circle tester. Priifung der Teilung eines Wildeschen Universaltheodolite (Testing the Graduation of a Wild Universal Theodolite).

F. ACKERL. Osterreiehischen Zeit fur Vermessungs- wesen v2o n6 1926. Tests made in Vienna of the circle as mounted in the theodolite, sighting telescopes on church

spires. Calibration of a Divided Scale, L. V. JUDSON. XBS Cir n329 1927. The method described here has been applied to

circle graduations at the Bureau of Standards. Untersuehung eines Breithauptschen Kreises nach der Methode von Heuvelink und Bermerkungen zu dieser Untersuchungsmethode ( Investigation of a Breithaupt Circle According to the Method of Heuvelink and Remarks on This Method). L. FRITZ. W. UHIXK. Zeit fur Instrum- Kde v48 n2 Feb 1928 p 53-68 4 figs 17 refs. The method of Heuvelink is applied to a triangulation theodolite having

a 235 mm diameter divided circle. The method here given

deviates in two minor respects from that of Heuvelink.

It corresponds to the Bruns method with four microscopes.

If there is the possibility of setting up more than two

collimators the Rosette method may also be used. However, this is not treated further.

Preisliste V : Teilmaschinen und Hilfsinstrumente ( Price

List V: Dividing Machines and Auxiliary Instruments).

G. HEYDE. 1929 ed p 33 and 34 illustrates and describes

circle tester of similar construction to that made for Dr. Bruns. Univ Observatory of Leipzig. On p 30 and 31 of 1911 ed are illustrated and described a variation of this. Prism Refractometry and Certain Goniometrical Require- ments for Precision, L. W. TILTOX. J Res XBS v2 n5 May 1929 p 909-30. Includes description of techniques

in using graduated circles to attain an accuracy of meas- urement to a fraction of a second. Geodesy, G. L. HOSMER. Publ. by Wiley, Xew York, 2d

ed 1930. Errors of circles, p 84-8. Apparatus for Testing Graduations on Circles, Soc Genevoise d'Instrum Phys. Pamphlet n425. Illlustrates and describes the apparatus at the Xational Bureau of Standards. Determining the Graduation Corrections of the Horizontal

Circles of Theodolites from the Filed Results of Primary

Triangulation, J. L. RAXXIE. Can Surveyor v3 n7 Jan

1930. Field measurements with assembled instruments

(16 positions of circle)

165
Bausch & Lornb Optical Bevel Protractor. Am Mach v72 Mar 20 1930 p 507. For precise work where the usual

protractor would not be sufficiently accurate, this optical bevel protractor can be used. The device has an accurately machined base on which the main body is hinged, and can be swiveled by turning the thiunb screw at the lower front. The level vial may be positioned accurately. The dial is graduated to one-sixth of a degree, and every

degree line is designated by a number. The graduations

are observed through the eyepiece, which so magnifies the spaces between the graduations that a vernier can be read with ease to within one minute of arc. The instrument has been found useful for checking dovetail surfaces of machine tool slides. Beurteilung von Kreisteilungen aus Exzentrizitatmessun- gen (Evaluation of Circle Divisions from Eccentricity Measurements) , W. UHINK. Zeit fur Vermessungswesen

v61 1932 p 177. Untersuchung eines Teilkreises nach zwei Methoden und

Aufklarung der dabei aufgetretenen Widerspriiche (In- vestigation of a Graduated Circle by two Methods and

Clarification of the Encountered Inconsistencies), F. Mt'HLIG. Zeit fur InstrumKde v53 Nov 1933 p 477-85

3 figs 5 tables. Der Einfluss einer besonderen Anordnung der Kreisstiinde auf die Bestimmung der Kreisteilungsfehler (The

Influence of a Special Arrangement of the Circle Positions on the Determination of Division Errors), F. HAUER.

Zeit fur InstrumKde v56 Aug 1936 p 309-21. Heuvelink's formulae for the general case for the determination of errors of fractions of a circle are first derived. These

can be simplified to find the amplitude and phase constant

of the errors of the partial circles if the necessary regular

subdivision of the circular distances of the half circumference of the circle is carried out. These considerations are investigated. Two practical examples are taken in which the instruments have the degrees divided into sixths and twelfths. The exact and approximate methods give almost identical results. The relations are generalized

in a table for fractions of 5', 10', 20' and 30'. Conclusions

are drawn regarding this method of operations. Notes on Testing of Workshop Dividing Head, F. H. ROLT, C. O. TAYLERSON. Machy (London) v51 nl311 Nov 25 1937 p 229-31. Objects of tests were to ascertain general degree of accuracy of angular spacing obtain- able with commercial dividing head, and to investigate

possible sources of error, by adopting modern methods of grinding gears and worm threads ; it should be possible

to considerably reduce errors. Calibration of Circular Scales From Eccentricity Measurements, W. KRUG. Zeit fiir InstrumKde v58 Oct 1938 p 412-6. Comparison of results obtained using Uhlnk's method of eccentricity measurements with those given by

Forster's method shows that the eccentricity method give's in practice curves which are sufficiently accurate to deter- mine considerable errors in circular division. Art of Original Circular Dividing (1650-1859), E. W. TAYLOR. Eng vl56 n4052, 4053, Sept 10 1943 p 204, Sept

17 p 235. Author traces developments made, pointing out urgent need that was felt, particularly through Eighteenth

Century, for improvement in accuracy of astronomical

instruments. From Empire Survey Rev July 1943. Equipment for Producing Divided Circles at the Zeiss

Plant. CIOS Rep. XXIX—59 (H.M. Stationery Office; U.S. Dept Comm.) 1946 5 p. Describes the dividing machines in use ; the main worm is driven by a gear shaped

like an hour-glass, so that contact is made with several

teeth at once, thus reducing the effect of irregularities in

pitch. Two lines are traced with each ruling, so that each

line on the finished product consists of a pair, very close

together, thus eliminating some systematic errors. Photographic methods were in the development stage. The

capacity is 300-400 circles per month, with an error

rarely exceeding 1.5 seconds of arc. Bevel Protractors (Mechanical & Optical). Brit Stand

Inst-BS nl685 1951 10 p. Standard relates to three types

of mechanical bevel protractors and to optical bevel pro- tractor with internal circular scale graduated in divisions

of 10 min of arc and read by means of optical magnifying

system. The Graduation of Precision Circles, B. L. PAGE, NBS.

Surveying and Mapping v!3 n2 Apr-June 1953 p 149-61

10 figs. Contents : The dividing engine ; the ruling points

the circle blanks ; setting of the engine ; mounting the

circle blank ; graduating the circle ; testing the circle. Effects of Alignment Errors in Dividing Heads, C. T. BUTLER. Machy (London) v83 n2144 Dee 18 1953 p

1211-4. Two causes for errors arising when checking angular spacing of work mounted on mandrel between

centers of dividing head ; analysis of errors resulting from

lack of alignment of axes of rotation of dividing head and work ; expressions are derived for these errors and ex- perimental confirmation of expressions is given. Reading Rotary Table to 1 Second of Arc. Machy (.N.Y.) v64 n5 Jan 1958 p 139-42. Ultra precision in jobs on jig borers and similar equipment requiring circular spacing

or angular positioning is obtained by using optical rotary

table; made by Pratt & Whitney, it embodies Gurley UNISEC optical coincidence system and can be read to

1 sec of arc ; diagram shows optical train in table. Theodolites. I-II, H. HOITZ. Arch tech Messen n285

(.11112-2) Oct p 213-6; n286 (J1112-3) Nov 1959 p 233-6

in German 14 refs. A descriptive survey covering design

of telescopes, circle bearings, glass divided circles, methods of circle reading which automatically eliminate cen- tering error, spirit levels and self-levelling devices. Photoelectric Method for Recording Circle Readings of Meridian Instruments, A. A. EFIMOV, YU M. OTRYASHENKOV. Astron Zh v37 nl 1960 p 146-50 in Russian. English translation in: Soviet Astron AJ (New York) v4 nl p 140-4 July-Aug 1960. A photoelectric technique for recording circle reading has been developed, and an ex- perimental working model has been built. Tests of the arrangement have shown that this method can be used

for automatic recording of limb readings to a precision of

0.1 ,u in linear units. Errors in the readings are largely independent of the quality of the calibration marks, which may be dark against a light background, or vice-versa. A New Dividing Head, E. I. FINKEL'SHTEIN. Meas

Techns 1959 n3 May 1960 p 164-6 2 figs. Translated from

Izmer Tekh n3 Mar 1959 p 8. How accuracy of optical dividing heads with single-sided reading can be increased by introducing more sensitive reading device, such as

optical micrometer and simultaneously raising accuracy of

circular dial scale and improving its centering with re- spect to axis of rotation features of modernized optical dividing head which has less error of old-type instruments,

yet preserves old construction changing only optical system. Attachments for the Optical Divider head, M. M. MERGOL'D. Meas Techns 1959 n5 June 1960 p306-7 2 figs. Translated from Izmer Tekh n5 May 1959 p 4. Describes development of very simple adaptors permitting wide

application of the divider head for this purpose, in con- junction with the ocular head, tube, objective, and stand

of a small microscope-type instrument which is widely used in machine construction. An Attachment for an Optical Dividing Head, F. P. VO- LOSEVICH. Meas Techns 1959 n7 June 1960 p 499-503

L66
7 figs 2 refs. Translated from Izmer Tekh n7 July 1959

' p 6. Attachments consist of : ( 1 ) lugs for truing articles having center holes; (2) blocks for raising head and tail- stock; (3) special adjustable angle pieces for determination of taper; (4) special mounting for centering two

instruments on a common axis; (5) special square fixed

in slot of base plate ; and ( 6 ) a dog having set screws. New Method of Testing Divided Circles, C. KUHNE. Rev

Sci Instrum v31 n8 Aug 1960 p 882-5. The residual uncertainties of angular measurements due to the circle graduation testing methods presently used are touched

, upon. A new method is described, and its mathematics

elucidated. Theoretically, the method permits one to obtain exactly equidistant angular intervals even if the master circles used have errors in their graduations. The

method suggested enables division errors of diameters to

be measured directly. Further, it is shown how the meas- urement procedure may be rendered automatic by suitable

technical means which would permit determination of the

totality of division errors for all graduated circles without

prohibitive cost. Messverfahren fur die Teilungsfehler eines Theodolit-Horizontalkreises in seiner Gebrauchslage (Measuring Methods for the Division Errors of a Theodolite-Horizontal

Circle in its Bearing), R. NOCH, PTB. Zeit fur Instrum- Kde v 69 1961 p 33-9 5 figs 19 refs. A measuring equip- ment for the angular pitch errors of gears and dividing

plates can also be used for direct high-precision measure- ment of the errors of the horizontal circular graduation in a theodolite. The errors of a theodolite WILD T3 were

measured for every 6 degrees; the equation of its regular

division errors is derived. jEin photoelektriscb.es Gerat zum Bestimmen von Kreistei- lungsfehlern (Photoelectric Apparatus for Determination

of Circle Graduation Errors), E. M. FEKLISTOV. Zeit

' Vermess-Techn v5 1961 p 159; VEB Verlag fur Bauwesen,

Berlin.

Investigating Errors in Optical Dividing Heads, L. YA. GUSTYR'. Meas Techns 1960 n9 Apr 1961 p 739-41 3 figs 3 refs. Translated from Izmer Tekh n 9 p 10-2 Sept 1960. The reading errors of a Leitz optical dividing head were

investigated by comparing the angles of a 18-sided prism

by means of autocollimator with the angles of rotation

of the head. The linearity of the working surface of the base was measured in two positions along the width of the base by a collimator method. New Small-Angle Generator for Calibrating Rotary Tables

to High Accuracy, L. W. NICKOLS. Machy (London)

vlOO n2589 June 27 1962 p 1456-8. Description of equip- ment developed at Nat Phys Laboratory, which is designed

to meet requirement for better method of calibrating ro- tary tables at intervals of less than one degree of are

effect of errors on accuracy of angular measurement ; per- formance tests on apparatus. High-Precision Circular Scales. Firm of Dr. Johannes

Heidenhain, Traunreut. Oct 1963 16 p 14 figs. Describes advantages of circular scales manufactured by the pat- ented Diadur process. Discusses assessing the accuracy

of circular scales including line errors, eccentricity error, and diameter error. High-Performance Indexing Fixtures, P. L. GARRETT. ASME n64-Meeh^2 presented at Mechanisms Conference,

Lafayette, Ind. Oct 19-21 1964 4p 4 figs. Indexing fix- tures of the type treated are inherently more accurate than optical polygons but lack the resolution required for

testing high-performance shaft position encoders such as those used on radio telescopes and tracking cameras. Double fixtures will increase the inherent error to one

half second but will permit a wide choice of test points, the choice being controlled by a Diophantine equation. The

properties of this equation show that the most frequently

desired division of the circle, namely 2

n exactly equal

parts, is impossible whereas certain other divisions are

entirely practical.

6.5. Angle Measurement by Interferometry

Mesure des tres petits Angles de Rotation (Measurement

of Very Small Angles), M. BRILLOUIN. CR Acad Sci vl37 Nov 16 1903 p 786-7. Two nicols are set for extinction. Between them insert (1) a thick slab of spar, cut

lat 45° to its axis, (2) a half-wave plate placed at 45° to the section of the spar; (3) a second slab of spar identical and parallel to the first. The half-wave plate reduces

these three to be equal optically to a slab of very small

^thickness. In parallel light a uniform color is obtained

| when the light has passed the analyser. A rotation of one

spar 54" on an axis perpendicular to a principal section corresponds to a wave length. Hence as 0.01 of the breadth of an interference band can be measured, we can

use the apparatus to show a movement of % sec. of arc. A New Contact Lever Using Achromatic Fringes, C. BARUS. Nat Acad Sci Proc v5 Feb 1919 p 39-43. The

method of measuring small angles by the rectangular inter- ferometer is here applied to delicate devices such as the

l contact lever or the spherometer. Measurement of Small Surface Angles, N. BARAKAT.

Letter in Nature (London) vl63 Apr 16 1949 p 603. In

using fringes of equal chromatic order to measure the

angle of a wedge, it is necessary to rotate the specimen in order to locate the maximum angle. It is shown that the wedge-angle can be obtained directly by the superposition

<>l fringes of equal chromatic order and Fizeau fringes. An angle of tan 9=0.001 was measured, with a suggested accuracy of 1% even in an unfavourable case. Recording Interferometer for Precision Wavelength Determinations, W. R. SITTNER. E. R. PECK. J Opt Soc

Am v39 July 1949 p 544-6. A recording interferometer

is described which permits the precise measurement of an

angle by means of interferometric measurement of chord

length. The present instrument, working in conjunction with a recording spectrometer, is applied to the problem

of precise wavelength determinations. Preliminary re- sults indicate that the average deviation of a single meas- urement is 0.044 A. The application of this interferometer to the measurement of linear or rotational motion

is discussed. Measurement of Angle by Interferometry, C. F. BRUCE,

W. A. F. CUNINGHAME. Austral J. App Sci vl Sept 1950 p 243-58. The method used has given a precision of the order of 0.1 sec of arc in angle measurement. The

variation in flatness of the existing angle standards and

the distortion of the surfaces that occurs in wringing have

been immediately observable and measurable to a high

precision. The method has shown that the angles of the gauges vary by 1 or 2 sec over their surfaces. The uncertainty in definition of angle is, therefore, of this order and will be still greater when gauges are wrung in combination. Work is proceeding on combinations of gauges

in order to calibrate complete sets and to investigate the

reliability of an angle made up of a combination of several gauges. An Angle Comparator for Laboratory Use, H. LLOYD,

A. T. F. SIMMONS, G. E. WINDER. Safety Mines Res

Establ Res Rept n37 June 1950 12 p. The instrument is primarily for use in experimental researches on explosives for improving the accuracy and ease of measuring

photographic film records of detonation speeds. The opti771-846 O—66 12
cal principles and construction are described, and an

analysis is given of its performance.

of the cam-follower considered. A typical mechanical

design is described in some detail. The Calibration of Standards of Angle by Interferometry,

C. F. BRUCE, W. A. F. CUNINGHAME. Austral J App

Sci v3 Sept 1952 p 210-8. The calibration by interferometry of complete sets of angle standards used in length metrology is described. A detailed account of the departures from flatness and the distortion that occurs in the use of these standards is given. The results confirm

earlier conclusions that standards from 3 seconds to 9° are reliable only to several seconds of angle and should be increased in thickness. The standards of larger angle have greater rigidity, but departures from flatness of the

surfaces can cause errors of several seconds if they are used in the normal way. An Improved Angle Interferometer, R. E. SUGG. NBS

Cir 581, Metrology of Gage Blocks Paper n6 Apr 1 1957. Discusses principle of angle interferometer, design and

construction details, results and conclusions. Use of Radial Gratings in a Small Inclinometer, A. LEWIS, I. R. YOUNG. J Sci Instrum v36 n4 Apr 1959 p

153-7. Some of the factors involved in the choice of grat- ings for use in the digital measurement of angles are dis- cussed. This problem is accentuated in the case of the instrument described by its small size and the decision, therefore, to use two complete circles for the gratings, instead of less critical method using one circle and ad- justable grating cursors. The tolerances which have to be achieved for satisfactory performance are considered and the instrument itself, a pendulous inclinometer in- tended to measure the pitch angle of wind tunnel models,

is described. Interferometric Method of Measuring Angles of Poly- hedrons, L. N. LOGACHEVA. Meas Techns 1958 nl Aug

1959 p 11-3 3 figs 2 refs. Translated from Izmer Tekh

nl Jan-Feb 1958 p 10. The interferometric method of measuring small angles (up to 2') described allowed

authors to measure the angles of polyhedrons with a

precision of the order of 0.2", using Koesters' inter- ferometer. When the angular standard is wrung by one

of its faces to the flat plate placed in the proper position on the table of the apparatus one can see in the field of vision two systems of interference fringes of different widths, one corresponding to the free working surface of the angular standard, and the other to the plate. Authors have calibrated two steel hexahedrons by this method, on

a vertical Koesters' interferometer by using the yellow

light of helium as light source. Interferometric Measurement of Small Angular Displace- ments, P. HARIHARAN, D. SEN. Brit J App Phys vlO nlO Oct 1959 p 455-52. A modified three-beam interferometer is described. The instrument is extremely sensitive

to angular displacements in a specified plane and is capable

of a high degree of accuracy. In addition it is easy to handle and quite stable, since it is relatively insensitive to angular displacements in any other plane and is also completely unaffected by a linear translation of the detecting element. Micrometer Adjustment of Mirrors and Prisms, N. BARANY. Periodica Polytech Elec Eng v4 nl 1960 pi-16. The paper gives the geometrical conditions to be satisfied by a rotating mirror or prism in an angle-measuring

instrument. In particular the optimum point of rotation

is determined. Such mirrors or prisms are commonly

rotated by a micrometer screw and cam. The shape of the cam for typical cases is derived and the effect of the shape

Fringecount Gonimet Interferometer, R. A. WOODSON

Paper WC11, J Opt Soc Am v50 nil Oct 12 1960 p 112a A two-beam interferometer system to measure angular

displacements. Fringes may be reversibly counted by a

pair of photomultipliers and a counting circuit. Interferometric Measurement of Small Angular Displace- ments. II. The Double-Passed Jamin Interferometer,

P. HARIHARAN, D. SEN. Brit. J App Phys vl2 nl Jan

1981 p 20-4. When the rays emerging from a Jamin inter- ferometer are reflected back through the instrument,

fringes similar in appearance and behaviour to three-beam

fringes are obtained. These fringes can be used to measure small angular displacements of one of the beam-dividing plates, with an accuracy of the order of 0.01 p. A

modified set-up is also described with which angular dis- placements of a comparatively light, auxiliary mirror can be measured with the same degree of accuracy. An Alignment Interferometer for Precision Straightness- Measurements and Control Even of Rapidly Moving Carriages, G. W. STROKE. J Opt Soc Am v51 nl2 Dec 1961 p 1340-1. A new, easily adjusted and very stable inter- ferometer, defining a semistatic fringe field by reflection on two mirrors, has permitted a simple solution to the problem of rapid and accurate alignment of moving carriages, of fixed reference beams, and of carriage-ways in the interferometric domain. Precisions in the 0.1 sec-of-arc range are easily obtained in visual work in rotations up

to minutes of arc without the usual limitations of slow

fringe counting and of loss of fringe-contrast at large path differences in particular. In fact, the fringe- constant is independent of the distance from the reference- support to the moving mirrors in this interferometer, and

permits measurements and alignments over traverses and

distances of many feet if required. Precisions in the 0.01 sec-of-arc range and better fringes. Experiments with

carriages moving at rates up to 1 ft/sec and over distances

of the order of 1% ft have demonstrated the versatility of the alignment interferometer in various applications

in particular in the alignment of ways on a velocity-oflight apparatus and on ruling engines. Extended-Range Gonimet Interferometer, R. A. WOODSON. Paper WD 17 J Opt Soc Am v52 nil Nov 1962 p 1315. An extended range interferometer has been de- signed to measure very large angles to an accuracy of ±0.025 sec. Neuentwicklungen bei Teilgeraeten (New developments

in indexing attachments), L. MEYDING. Werkstatt und

Betrieb v95 nl2 Dec 1962 p 805-8. Indexing errors in optical instruments ; description of attachments for more

accurate calculation of angular positions of uniform grad- uations and for reduction of setup times. Angular Measurements by Means of a Ronchi Ruling, J. R. MEYER-ARENDT, E. D. MINER. App Opt v2 nl Jan 1963 p 77 1 fig 4 refs. Describes goniometer which combines

a simple optical lever and a Ronchi ruling in which the

shift of one fringe equals 10 seconds of arc for a grid having 133 lines/in. An Interferometer for Precision Angle Measurements, J. ROHLIN. App Opt (USA) v2 n7 July 1963 p 762-3. In

a Michelson interferometer with cornerjcube reflectors, one

corner-cube rotates about an axis 300 mm from the optical axis ; the amount of rotation is deduced from the fringe displacement. 168
6.6. Sine Bars, Plates, and Fixtures

Use of the Sine Bar for Measuring Angles. Machy (N.Y.

)

vl8 Jan 1912 p 376 4 figs. Includes description of sine bar having one end formed to a 30 degree angle for insert- ing in narrow openings. The Sine Bar and How to Make it, A. H. SHIELD. Mech Wld Apr 16 1915. Diagrams and description. Improved Type of Sine Bar, W. G. GROOCOCK. Am

Mach v45 July 13, 1916 p 77, 342-3, 869-70. Slotted angle plate used for supporting sine bar. Discussion by

G. A. REMACLE and W. McARDELL. See also Am.

Mach. v44 May 11 1916 p 820. A Sine Protractor, L. C. BLOMSTROM. Am Mach v45 Aug 24 1916 p 340 1 fig. Combination of sine bar and

bevel protractor which is set by a micrometer caliper. Sine Bar Applications, D. BAKER. Machy (N.T.) v23

Oct 1916 p 120-4. Details of construction and methods

of obtaining accurate angular work, with tables of constants for 5-inch sine bar. A Sine Bar. Am Mach v45 Oct 12 1916 p 656. "Simplex" 5" sine bar. Adjustable Sine Bar, E. P. DAVIS. Machy (N.Y.) v23 May 1917 p 806. Buttons are adjustable in position to obviate precision boring of holes, but as buttons may be

displaced in use it is desirable to test their position before

using. Checking Angles with Swedish Blocks, H. B. LEWIS. Am

Mach v47 Aug 30 1917 p 353-5. Methods of checking

angles by means of precision gage blocks, principally in conjunction with the sine bar. Slocum Sine Bar and Indicating Square. Am Mach v47

Sept 27 1917 p 567. Sine bar fixture in which one button

is fixed and acts as fulcrum. Square has indicator reading from 80° to 100°. Universal Angle Plate for the Use of Toolmakers, R. BERNHARDSON. Am Mach v47 Oct 25 1917 p 736. Combined angle plate and sine bar. The angle plate consists of 11 parts, the body having all of its sides square,

tilting table, hinge plate, 2 locking screws, 2 adjusting

bars, hinge bar, sine bar, and 2 locating pins. Uses of the Sine Bar, E. J. BRYANT. Am Mach v47 Nov 1 1917 p 749-51 17 figs. Describes its use in one of

the large tool, gauge, and fixture shops. The sine bar

fixture shown in Fig. 1 is a self-contained tool and does

not have to be clamped to something else and measure- ment taken from still some other object. Sine Bars of Improved Design, W. C. BETZ. Machy

(N.Y.) v24 June 1918 p 933. Bar having notched ends for

location of pins. See also Am Mach v50 Mar 13 1919

p 515-6. Kar Sine Angle Plate. Am Mach v49 Nov 28 1918 p

1007-8. Consists of a movable plate swiveled on a sta- tionary base with adjusting screw and clamp. Micrometer measurements are taken over either of two buttons

at the side of the plate and the underside of an over- hanging reference plate located below the main pivot. Sine Bar and Attachment, PRESTO MACHINE WORKS. Am Mch v49 Dec 26 1918 p 1195. The sine bar is 4 in. long and the attachment is an accurately finished 4-in. cube. All faces of the cube are provided with a number

of tapped holes for attaching work, clamps, etc. Five

sides have accurate V-grooves for seating cylindrical work and one side has a T-slot quadrant for attaching the

sine bar. The sine bar can be set to either the sine or the cosine of the angle, whichever is most convenient, and

then by using the proper side of the fixture as a base the desired sine or cosine is placed in working position. "Loway" Sine Bar. Am Mach v50 Mar 13 1919 p 515-6. The sine bar has two right-angled notches cut in the side and two rolls are inserted therein and held in place by

small coil springs passing through the sides of the rolls and into the sine bar, the ends. being held by small pins. This construction is used to prevent distortion. A similar bar is described in Machy (N.Y.) v24 June 1918 p 933. Universal Sine Bar for the Toolmaker, J. B. GRAY.

Machy (N.Y.) v25 Aug 1919 p 1159-62 8 figs. Describes method of making a sine bar to meet the special require- ments of tool-room applications. Tables for Use With the Sine Bar. Western Machy Wld

vl2 Nov 1921 p 433-7 3 figs. Also explains use and gives

illustrations for application. The Use of the Sine Bar. Machy (London) vl9 Feb 2 1922 p 529-31 6 figs. Gives some examples of wide range

of angle work covered by it. Is more adaptable than the

protractor. Sine Bar Gage for Large Work, R. H. RAUSCH. Am

Mach v61 60 July 10 1924. Sine bar fixtures replace numerous special gages. Measurements of Cones in V-Blocks, N. P. SKINNER.

Machy (London) v68 nl743 Mar 7 1946 p 310-2. Principle of method described is similar to that applied to comparator method of inspecting taper pins, machine

tapers, etc. ; method claimed not suitable for small quantities, but economical for small to medium batches of several items recurring at intervals ; necessary equipment ; formulas proofs ; error possibilities. Calculation of Pin Measurement for Right and Oblique

Cones, C. D. WRIGHT. Tool Engr vl6 n2 Mar 1946 p 51. By use of formulas given, solution is reduced to simple

operation that can be done on calculating machine, with

but single reference to tables ; problem concerns determi- nation of measuring pin location, when measuring right and oblique cones in relation to each other, as in gages and tools. Sine Bars, Blocks, Plates, and Fixtures. Commercial

Standard CS 141-47. Superintendent of Documents, Gov- ernment Printing Office. Washington, D.C. Accurate Method of Measuring Dovetails, L. F. WIL- HARM. Machy (N.Y.) v56 n4 Dec 1949 p 178-9. Method

based on sine bar principle of measuring angles is de- scribed; details of tool used for measuring dovetail ex- plained and illustrated. Correction Charts for Sine Bars, C. T. BUTLER. Machy

(London) v83 n2125 Aug 7 1953 p 254-6. Errors occur- ring in sine bars, employed for establishing and measuring

angles to high degree of precision, can be readily analysed and simple corrections made for more important discrep- ancies; formulas and charts for corrections to be made. Compound-Angle Setups Made Easy by Unique Three-Ball

Sine Plate, J. R. HANSEN. Machy (NY) v63 n5 Jan

1957 p 160-1. Setup for machining or inspecting com- pound angles on jigs, fixtures, cutting tools, and work

pieces simplified by employing novel, three ball sine plate assembly ; example of using sine plate in inspection setup

to check compound angle. 169
High Precision Compound Angle Sine Tables, Coventry Gauge and Tool Co. Ltd., Coventry, GB (1958) 6 p 3 figs. The outstanding feature of these tables is the substitution

of a hemisphere riding in a hemispherical seating for the conventional hinged bearings at 90° to one another. Angles up to 45°, both simple and compound, can be set quickly and simply to an accuracy of 10 arc seconds. Sine Bars and Sine Tables. Brit Stand Inst—BS n3064

1959 14 p. First section of standard provides for three

types of sine bar made in inch sizes of 4 in., 5 in. and

10 in. and metric sizes of 100 mm, 200 mm and 250 mm

second section covers sine tables inclinable about single axis in sizes of 5 in. and 10 in. and metric sizes of 100 mm and 200 mm ; designating sizes represent center dis- tances between axes of rollers. Dividing Head with a Sine Rule, A. B. FRANKEL.

Meas Teehns 1959 n9 Aug 1960 p 685 1 fig. Translated from Izmer Tekh n9 Sept 1959 p 21. A combination of a dividing head for measuring 5° intervals and a sine bar

for measuring angles within the intervals. Measurement of Small Angles, V. I. NIKOLAEV. Meas

Techns 1959 nl2 Sept 1960 p 940 1 fig. Translated from

Izmer Tekh nl2 Dec 1959 p 14. Describes a structional modification of a sine bar in order to measure angles smaller than 10'. Kritische Untersuchung der Bestimmung der Verjiingung von Metrischen (und Morse) Kegeln mit dem Sinuslineal

(Critical Investigation of the Determination of Taper of Metric and Morse Tapers with the Sine Bar), E. H. G. BERNDT. Mierotecnic vl5 1961 p 45-53. Mathematical

investigation of errors in measurement using the sine bar. A New Small-Angle Generator for Calibrating Rotary

Tables to a High Accuracy, L. W. NICKOLS, Machy

( London ) vlOO June 27 1962 p 1456. Instrument operates on the sine arm. A mirror on the sine arm permits viewing by an autocollimator. Repeats to 0.1 Sec. Angles can

be set out to 0.5 Sec or better. New Sine-Table Method of Measuring Angle of Male Tapers, L. GOLDES. Machy (London) vl03 n2646 July

31 1963 p 242-52. Two standard methods, using plain and grooved type sine plates, are analyzed and their shortcomings shown ; theory of new method ; practical procedure illustrated by table for standard tapers and by graphs suitable for all tapers up to 45°, from which in- herent reliability and simplicity may be assessed; sensitivity of method is determined, and comparison with that

of plain sine table further establishes superiority over

latter; it is very simple in operation and only standard

equipment, of type in general use, is required. Universal Sine Mounting Block, A. P. EMEL'YANOV.

Meas Techns 1963 n3 Sept 1963 p 195-6 1 fig. Translated from Izmer Tekhn n3 p 12-3 Mar 1963. Describes a massive sine mounting block to avoid the cumbersome combined use of existing quadrilateral mounting blocks and

sine bars.

6.7. Spirit Levels

Irregularities of Spirit Levels, DR. RIETH. Zeit fur Vermessungen 1887 p 297. Abstracted in minutes Proc

Inst Civ Eng v90 1887 p 459-60. Irregularities in level

vials are shown to be due to excrescent formations insoluble in alcohol, formed on the side of the tube. Level of Variable Sensibility, L. MACH. Zeit fiir In- strumKde vl4 1894 p 175-6. The inner wall of the tube

of a level is usually made slightly barrel-shaped by grinding, great patience and skill being required. In the level described, there is employed a cylindrical glass tube which

can be curved to the extent desired, by means of pressure produced by a fine-pitch screw placed under the middle

part. A Level of Ye Olden Time, O. VON GELDERN. J Assn Eng Soc Dec 1897. Historical review of the earliest con- trivances for this use, and a memoir published with the papers of the Royal Acad, of Paris, for the year 1704, by M. de La Hire, describing a level on the principle of fast- ening an iron rule at its center of gravity to an upright support canting on its base. Discussion. Hydrostatic and Spirit Levels, R. P. KING. Am Mach

v26 June 25 1903 p 902-3. On methods of testing levels and

using them, determining the probable error, etc. Precision Levels and Accurate Leveling. Am Mach v31 Apr 30 1908 p 669-72 and 696. Articles on setting boringmill uprights with a novel form of level, and leveling planers properly for accurate work. Various contributors.

Spirit Levels, J. BONSDORFF. Zeit fiir InstrumKde v28 Nov 1908 p 344-6. Discusses the movement of the air bubble in spirit levels. Four levels tested, three very

sensitive. Motion of the bubble is similar to that of a

strongly damped pendulum. With the three very sensi- tive levels the motion was aperiodic, but with the fourth

the motion was periodic and the period increased as the

length of the bubble diminished. The equation for damped vibrations is discussed, and the various constants

are determined for the particular levels dealt with.

The Testing of Spirit Levels. Machy (N.Y.) vl8 Apr

1912 p 617-8 2 figs. Describes a device for testing spirit levels and its application.

Spirit Levels, E. O. HENRICI. Opt Soc Trans v20 Dec

1918 p 45-7. A description of the requirements which

should be fulfilled by levels used for the most accurate work. Bibliography.

Millionth Comparator, Tilting Level Type. NPL, 1919 p 87-8. Levels and Level Bubbles, S. G. STARLING. Trans Opt

Soc v24 n5 1922-23 p 261-88. Density, surface tension, and viscosity of water, benzol, xylol, chloroform, alcohol, and ether with varying temperature and pressure, length

of bubble and temperature ; damping and length of bubble, damping and diameter of tube ; calibration of levels ; pho- tographic method of calibration and investigation of the

irregularities of the tube; bubble having constant length. Grinding and Testing Level Vials, G. N. SAEGMULLER. Am Mach v56 Mar 16 1922 p 405 1 fig. Grinding tubes to curves of long radii. Formula for curves to produce deter- mined sensitiveness. Automatic machine for grinding

levels vials. New Types of Levelling Instruments Using Reversible

Bubbles, T. F. CONNOLLY. Trans Opt Soc v25 1923-

1924 p 21-37 ; v26 1924-1925, p 194-7. Describes the properties of reversible bubbles which can be used both graduated and ungraduated. Application of certain such properties to surveying levels. Pratt and Whitney 15-inch Precision Level. Am Mach v58 Jan 11 1923 p 94-5. Of trussed frame construction pro- viding lightness, rigidity, and comparative insensitiveness

to temperature changes.

Societe Genevoise 30 Deg. Precision Machine Level. Am

Mach v60 May 1 1924 p 671. A graduated level vial is 170
pivoted on a heavy cast-iron

of a worm and sector. and is tilted by

Bethel-Player Measuring Machine and Comparator. Am

Mach v61, Sept 25 1924 p 521. Embodies tilting-level indicating device. Capacity 12 in. length, 9 in. radius.

Self-Adjusting Precision Level. Eng vll9 June 12 1925

p 732-3 5 figs. Precision level made by E. R. Watts &

Son, London, which is so conveniently designed that it is common practice for its users to test daily the accuracy

of line of collimation : instrument is fitted with bubble, length of which remains invariable even under most

drastic conditions.

Spirit Levels, S. WESTON, V. TOWNS. Optical Convention 1926 pt 2 p 642-52. The development of the spirit

level is traced from the earliest to the present times. The

principal object of the paper is to show how modern

workshop methods and designs assisted by laboratory

research have brought it to its present high state. Paper

deals with regularity of the curve and mountings ; mobility or responsiveness of the air bubble; varying length

of the air bubble with change of temperature ; method of observation. New types are described. Examination of "Second" Levels ( Untersuehungen ) , B. WANACH. Zeit fur InstrumKde v46 May 1926 p 221-38

8 figs. Results of examination of some hundred levels for accuracy, geometric aspect ; technical testing for er- ror in curvature ; static testing tables of results ; shows

that in imperfect level, errors in readings are accentuated when length of bubble is small ; levels reading to one

second and to two seconds of arc, with from 30 to 80

divisions. Some Observations on Spirit Levels, K. LUDEMANN.

Ziet fur InstrumKde v48 Jan 1928 p. 31-9. The sensitivity

of various types of level has been investigated. It is con- cluded that the form now in common use on surveying

instruments, if used with care, is sufficiently accurate for

its purpose. This type consists of a closed glass vessel with a flat top. It is displacing the older type consisting

of a brass box with a glass lid. The great disadvantage

of this latter is that, in the course of years, the liquid gradually evaporates, finding its way out through the cemented joint between the glass and the metal.

Airtight Spirit Levels, A. DE GRAMONT, G. MABBOUX.

OR Acad Sci vl87 Nov 12 1928 p 885-6. In order to keep

the diameter of the air bubble constant the two glass discs are sealed by a bakelite cement to a metal barrel with a

similar coefficient of expansion.

Double-Reflection Level, D. S. PERFECT. Opt Soc Trans

v.30 n3 1928-1929 p 126-9 3 figs. Level designed to assist the initial leveling of a floating system and to enable ob- servations to be made on the constancy of level over ex- tended periods of time. Its error may be determined by

direct measurement and without reversal. The level in any direction is shown. Measurement of Angles, W. BLOCK. Instrum v3 June

1930 p 363-8 3 figs. Measurement of angles of reflection- goniometer and by levels is described. Extract from

i Instruction Book for Engineers.

Starrett No. 199 Master Precision Level. Am Mach v73

Oct 9 1930 p 607. A level for set-up men and manufacturers of machinery has been developed. The main ground

and graduated vial of 10 seconds accuracy has divisions equalling y2 thousandth of an in. per ft. An auxiliary

level is provided to show position laterally. A special

alloy iron is employed to obtain freedom from thermal

effects. The length of the device is 15 in., height, 3 in., width, 1% in. ; and the weight, 5% lb. Measurement of Very Small Angles of Rotation, G. SIADBEI, CR Acad Sci vl94 Apr 18 1932 p 1334-6; Zeit fur

InstrumKde v52 May 1932 p 234-5. A thin beam of light is reflected from the bubble of a liquid level attached to the

object whose rotation is to be measured. Angles of half a second may be measured accurately. Universal Level. Eng vl46 n3792 Sept 16 1938 p 348; Engr vl66 n4315 Sept 23 1938 p 343. Spirit level, which

appears to have numerous uses in building and contract- ing work, consists of bar of hardwood 2 ft long, with sensitive bubble tube in center which can be used for checking

level of horizontal surfaces ; pair of sights is fitted to top of bar or leveling staff, and inclined mirror mounted

over bubble tube enables bubble to be seen at same time. Precision Levels for Engineering Workshops. Brit Stand

Inst—BS 958: 1941 11 p. Recommended types; recom- mended scales and sensitivities ; finish and accuracy of working faces ; zero setting ; calibration of ; packing ; marking ; testing of precision levels. Electrical Head for NPL Level Comparator, D. V. BLAKE,

D. C. BARNES. Machy (London) v76 nl946 Feb 9 1950

p 205-7 ; Eng vl69 n4393 Apr 7 1950 p 395-6. Range of comparator designed at National Physical Laboratory in 1919 has been extended and its sensitivity increased by

replacing sensitive bubble tube of level comparator by

specially designed electromagnetic head which can be used with standard "Taylor-Hobson" electrical indicating unit. Level Vials—Their Manufacture, Use, and Peculiarities, D.

L. PARKHURST. J Franklin Inst v264 n2 Aug 1957 p

105-16. Level vials have many potential uses because of extremely small and accurate measurements that may be made with them and their freedom from mechanical wear

and error, but improvements must be made in methods of constructing and filling ; improvement could be assured by

vibrationless grinding ; better filling liquids and improved

filling processes ; applications. Remote indication of Angular Displacement, D.F.A. MAC- LACHLAN, A. M. SQUIRE, G. V. PLANER. Engr v214 n5559 Aug 10 1962 p 235. New instrument, Electrolevel, was developed by English Electric Aviation Ltd., and

G. V. Planer Ltd ; sensing head incorporates stable elec- trolytic cell in envelope of borosilicate glass with bubble which can be displaced in relation to 3 film electrode areas, forming active elements of a-c bridge ; indicator incorporates transistor oscillator to generate sine wave signal across bridge network ; applications in erection of struc- tures such as aircraft wing/fuselage structures and cer- tain types of machine tools. Level Tester with Optimeter, A. P. SHOKHTIN. Meas

Techns 1962 nl2 July 1963 p 992 1 fig. Translated from

Izmer Tekh nl2 p 8 Dec 1962. Describes a level tester of

rigid construction, providing stable readings of angles for

tested levels of considerable weights. Has a scale factor from 8 to 2". Die Verwendung von Sekundenlibellen zur genauen Mes- sung sehr Kleiner Neigungen (The Application of Seconds

Levels to the Exact Measurement of Small Inclinations), A. TARCZY-HORNOCH. Acta Imeko (Stockholm) v3 n21-HU-158 1964 p 105-13 3 figs 3 refs. The exact knowledge of the deviation from the axial horizontal is neces- sary in the case of high accuracy instruments to be able

to determine the corrections. There are other cases too when small deviations from the horizontal are to be de- termined. Second levels used for this purpose however

have not the sufficient accuracy on account of polishing

errors, etc. as experience has shown. On the basis of ex- aminations performed in the last 8 years by the author and by Mr. Gy. Alpar, these angles can be determined with

sufficient accuracy even with the use of lesser quality

levels. On this problem some results have already been

published by the author, among these an automatic level testing equipment. The paper contains a summary of these examinations together with further considerable

results. 171
6.8. Tapers

The Measurement of Taper Gages. Inspector v2 Dec 15 1919-Jan 15 1920 p 5-11 9 figs. Methods commonly applied by Gage Section, U.S. Bureau of Standards, for measuring

simple tapered plug, plug having double taper, plug having triple taper, taper ring gages and profile gages having tapered surfaces. See also NBS Letter Circular L. C. 22 Aug 1919. Die Messung von Aussenkegeln ( The Measurement of External Tapers), O. KIENZLE. Der Betrieb v4 n9 Feb 11 1922 p 299-302 19 figs. The previously used standard

gages for taper measurement left out the gradient completely. There are six indicated methods for the measure- ment of taper which may be developed into measuring

instruments. One method is described in detail in which

the top element of the taper lies horizontally. The tapered

piece is supported on a smoothly operating slide that is pushed under an indicator, which thus establishes the

deviation from horizontal. Measuring Tapers by Means of Discs and Rods, R. J. WORTHY. Mech Wld v73 Jan 26 1923 p 50-1 5 figs Particulars are given for providing simple and rapid formulas. La Mesure industrielle des dimensions et la verification des formes (Measurement of Dimensions and Checking of Forms) , H. STROH. Genie Civ v86 Mar 7 1925 p 230-4 12

figs. Application of length measure for precision measuring of cones, conic plugs, etc., screw threads ; checking by optical projection. The Manufacture and Measurement of Angular-Form

Gages, E. A. SWIFT. Machy (London) v29 Dec 2 1926 p 265-9 14 figs. Methods employed by author which have

proved satisfactory. Methods of manufacture and meas- urement of taper plugs, grinding of taper plugs, sine-bar method of determining angular forms, checking taper ring gage by direct measurement. Measurement of Tapered Fittings, H. S. KARTCHER.

Trans SAE E22-II 1927 p 209-11 7 figs. Discusses dimensioning of tapers for consistency with methods of measuring. Measuring Taper Gage. Machy (London) v33 Oct 18 1928 p 78-9 9 figs. Describes method of measuring a taper plug gage having beveled sides by means of balls. A System for Measuring Tapers. Am Mach v69 Dec 13 1928 p 907-11, 10 figs. Application of new system for accurate measurement of master taper plug gages for cartridge and gun chambers, worked out by Winchester

Repeating Arms Co., is described; system applicable to other taper gages; gagemaker should be furnished with

definite dimension measurements not eliminated in finish- ing of gage and further available for check after gage is in service. Methods of Measuring Tapered Bores, W. S. ROWELL.

Machy (N.Y.) v36 Mar 1930 p 589-90 3 figs. Analysis of methods of measuring diameters of tapered holes, both in duplicating and in originating tapered bore. Checking a Taper Gage. Machy (London) v36 n920 May

29 1930 p 263 2 figs. Description of method of checking

angle and diameter of tapered disks; master taper gage

with setting disks in place for checking working gages

of male bevel-side type. Methods of Measuring Tapered Bores. Machy (N.Y.) v36 Mar 1930 p 589-90 3 figs; Machy (London) v37 Dec 4

1930 p 294-5 3 figs. Analysis of methods of measuring

diameters of tapered holes, both in duplicating and in

originating tapered bore ; use of balls in measuring taper

bores and use of inside micrometer and guide. Cone Measurements with Steel Balls, E. ELKINS, H. MELLOR. Machy (London) v56 nl443 June 6 1940 p

298-300. Formulas and dimensions (in inches) for checking internal cones using balls and mandrels. Innenkegelmessung mit einem Bohrungsmessgeraet mit grossem direkten Messbereich (Internal Taper Measure- ment wth a Bore Measuring Instrument Having a Large Measuring Range), L. TSCHIRF. VDI Zeit v85 nl7 Apr

26 1941 p 403-7. Description of new instrument for meas- urement of inside taper with great accuracy and for large range of diameters ; optical system for transmitting feeler motion is based on Abbe principle; instrument suitable

especially for deep conical holes ; other types of gages and

instruments for measuring taper are reviewed. Taper Measuring Device. Engrs' Digest (Brit Ed) v5 nlO

Oct 1944 p 295-6; Engrs' Digest (Am Ed) vl nl2 Nov

1944 p 686-7. Illustrated description of device which makes it possible to rapidly ascertain dimensions of tapered bodies by direct high precision measurement, no

computations being required ; chief feature of instrument

is provision of self-adjusting rotatable feeler pads, their axes of rotation being tangential with piece to be measured. English abstract from Werkzeugmaschine v47 n6

Mar. 1943, p 136-8. Measurement of Tapered Plugs ; Alignment and Concentricity Plugs ; and Receiver Gages. Ordnance Inspection Handb on Gages, p 847- 67 899.21- 899.30. Taper Measuring Formulae and Methods, W. RICHARDS.

Machy (London) v69 nl784 Dec 19 1946 p 786-91 2 figs. Derives basic formulas for measurement of internal tapers with spheres ; spheres or discs flush with ends of taper ; measurement of taper plugs by means of rolls. Taper Production, Gauging, and Gauges, W. RICHARDS.

Machy (London) v70 nl788 Jan 16 1947 p 67-72 3 figs, i Describes the construction and application of a universal taper measuring gage ; also degree of accuracy attained. The sine bar method of testing and measuring a taper plug gage. Measuring and testing taper ring gages. Ac- curacy of the sphere method of measuring taper ring

gages. Large Cylinder and Taper Comparator for Gauge Measurement, R. H. FIELD. Can J Res v25 n3 (sec F) May

1947 p 238-41 3 supp plates. Illustrated description of comparator for accommodating cylinders or cones with : maximum diameters of 12 in. and lengths up to 48 in. designed and constructed during war at National Research

Laboratories, Ottawa.

Effect of Taper Tolerance on Taper Gauge Measurements, ( W. RICHARDS. Machy (London) v71 nl815 Aug 7 1947 i p 150-3 2 figs. Discusses general effects of taper tolerance upon measurements when using spheres or rolls ; relation between taper and angular tolerance ; testing taper plug gages with a sine bar. Checking Tapers by Sine Bar Method, J. W. LEE. Tool Engr v27 n4 Oct 1951 p 44, 52. Equation for calculating

j sine of included angle; examples show how to find 5-in. sine bar constant for Jarno tapers and for American

Standard Steep Machine tapers. Problems in Metrology, C. MINAIRE. Am Mach v99 n8 Apr 11 1955 p 105-9. Ingenious solutions to awkward . measuring problems; linear measurements on sine bar fix- i ture ; checking internal tapers ; flatness checking blocks

172
checking frustum of cone ; outside taper gage ; taper

checkers ; calipers for large diameters ; no go bore gage. Fehler bei der Kegelmessung mit Drahten und Endmassen

( Errors in measuring tapers with wires and gage blocks )

,

G. BERNDT. "Werkstatt und Betrieb v91 n2 Feb 1958

p 69-72. Examination of errors due to differences in rhickness of gage blocks, diameter of wires, and to fact

that taper is not mounted perpendicular to its base. Methods and Equipment for Checking External Tapers,

C. MINAIRE. Machy (London) v92 n2363 Feb 28 1958

p 483-9, v93 n2382 July 9 p 93-4. Feb 28: Inspection

operations for checking conical surface, verifying roundness of section, measuring angle of taper and checking

diameters at both ends of circular portion ; details of Micyl blocks and gages employed, July 9 : Pair of Micyl

blocks of latest design described. Measurement of Working Surface of Conoids by Comparison with Specimen, A. V. RUMIANTSBV, Meas Techns

1958 nl Aug 1959 p 7-10 1 fig. Translated from Izmer Tekh nl Jan-Feb 1958 p 7. Describes a new method of measuring on a special machine designed for measurement

by comparison with a specimen.

Direct Measurement of Taper, G. GERSHMAN. Tool Engr

v44 nl Jan 1960 p 85-7. New taper micrometer has made

it possible to measure taper directly and rapidly with

single piece of relatively inexpensive equipment and without necessity of removing work from machine ; micrometer, incorporating within itself sine-bar principle, gives

actual value of taper for small angles; parts inspected 10 times faster than with conventional methods. Measurement of Inside Cones by Universal Instruments,

A. S. OHICHEROVA. Meas Techns 1959 n5 June 1960 p 308-10 4 figs. Translated from Izmer Tekh n5 May

1959 p 7. Discusses various methods and sources of error. Eine neue methode der Winkelmessung an Werkzeug-und anderem Kegeln mit Hilfe des Sinus-Lineals (New method

for measuring angles on machine tapers and other tapers with aid of sine taper guide bar), L. GOLDES. Werkstattstechnik v54 n5 May 1964 p 223-9. Advantages of method described over two classical measuring methods, are greater measuring certainty, and simpler calculation; numerical table for usual tapers and graphical

illustrations for tapers with angle up to 45° are pre- sented which make it possible to evaluate sensitivity and

simplicity of method. New Sine-Table Method of Measuring Angle of Male

Tapers, L. GOLDES. Quality Engr v28 n6 Nov-Dec 1964 p 170-7. New method of self-deviation and compensation

for measuring angle of male tapers is described ; standard methods such as plain taper compensation and taper-plustilt compensation are discussed ; in new method, cone rests on sine table and against flat stop attached to side of instrument ; equations sufficient for solving problems of setting up nominal taper angle or determining actual taper

angle are given ; respective sequences of operation in application of method are shown ; graphical solutions simplifying work are described. Addendum to Section 6

6.5. Angle Measurement by Interferometry

On the Application of Interference Methods to Astronomical Measuremnts, A. A. MICHELSON. Phil Mag ser5 v30 nl82 July 1890 p 1-21 11 figs ; Nature v45 n455 Dec

17 1891 p 160-1 3 figs. When the cap of a telescope

objective is provided with two slits adjustable in width and distance apart the instrument is converted into a refractometer. If such a combination be focused on a

star there will be a series of colored interference bands

with white center, the bands being equidistant and parallel

to the two slits. The method is applicable to the measure- ment of the angular magnitudes of very small or very

distant sources of light, such as planetoids and satellites, or larger bodies, and the angular distances between very

close double stars. See also H. N. RUSSELL, p. 41. Addendum to Section 4 (continued from page 128) 4.3. Calibration of Tapes

(Invar.) Nouvelles Recherches sur la Dilatation des

Aciers au Nickel (New Research on the Dilatation of Nickel Steels), C. E. GUILLAUME. OR Acad Sci vl.36 Feb 2 1903 p 303-6. The production of alloys of small expansion depends upon the auxiliary substances, e.g., manganese, carbon, silicon. Has obtained an alloy of such

small thermal variation that its amount cannot be measured with certainty. A table of values for various alloys between 0° and 38°C is given. See also Mettalographist v6 Apr 1903 p 162-5. Changements Passagers et Permanents des Aciers au

Nickel (Transitory and Permanent Changes of Nickel

Steels), C. E. GUILLAUME, CR Acad Sci vl36 Feb 9, 1903 p356-8. The 64-36 iron-nickel called invar was dis- covered and has proved of considerable scientific and

practical interest because of its low coefficient of thermal

expansion at room temperature. Bars of the alloys were

kept for long periods at steady temperatures, and the

variations of length, due to the after-effect of a previous

heating, were observed. Alloys of different kinds were

considered, and their suitability as standards of length were commented upon. The distinction (previously

pointed out) between reversible and irreversible alloys was again remarked in these experiments.

Precise Measuring with Invar Wires and the Measurement

of Kootenay Base According to the Method of the Inter- national Bureau of Weights and Measures, P. A. CARSON. Roy Astron Soc Canada Jan-Feb 1911. The Dimensional Behavior of Invar, B. S. LEMENT, B.

L. AVERBACH, M. COHEN. Trans Am Soc Metals v43

1951 pl072-97 11 figs 15 refs. The dimensional changes which occur during the aging of invar have been studied

as functions of time, temperature, heat treatment and

chemical composition. Starting from a quench-anneal, it is found that a contraction takes place on aging because

of stress relief. However, there is also a superimposed

expansion due to a lattice change which occurs on pro- longed aging in the temperature range 20 to 95°C (70 to 205°F). The solubility of carbon in invar, as determined by X-ray diffraction, is 0.18 weight per cent at 830°C

(1525°F), and is vanishingly small at room temperature. Any excess carbon exists as graphite. The expansion coefficient has been studied over the range —40 to 4-40°

(—40 to 105° F) as a function of composition and heat

treatment, and a heat treatment which results in good

dimensional stability and a low expansion coefficient has

been devised. 173
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Section 7. Measurements of Deviations from Geometrical Regularity

CONTENTS Page

7.1. Planeness measurement 175

7.2. Parallelism measurement 180

7.3. Straightness and surface topography 181

7.4. Roundness and concentricity measurement 185 Addendum to Section 7 187

7.1. Planeness Measurement

Miscellaneous Papers on Mechanical Subjects. J. WHIT- WORTH. Longman, Brown, Green Longmans, and

Roberts, 1858 183 p. Contains a paper on plane metallic surfaces or true planes. Interference Bands and Their Applications, LORD

RAYLEIGH. Nature (London) v48 p212 June 29 1893. Includes a discussion of the use of a free surface of water

as a reference surface ; also the formation of interference

bands. Interference Fringes with Glass Wedges, S. R. MILNER.

Phil Mag vl6 Sept 1908 p 429-36. If two pieces of ordi- nary plate glass of approximately the same thickness are

placed one on the other, and the airfilm between them is observed by sodium light, the system of Newton's fringes, formed by the interference of the light reflected from the two surfaces of the air-film is seen. Occasionally, by very

close inspection, another system of fringes may be seen which is found by the interference of the rays which have

been farther reflected from the non-adjacent faces of the

plates so as to meet again at the interface. These fringes become clearly visible if we cut off all the light reflected from the film except that by which they themselves are formed. The method of doing this and its application to the testing of plate glass sheet are explained in detail. Testing Surfaces with a Glass Plate, L. P. ALFORD. Am

Mach v34 Apr 13 1911 p 682-3 8 figs. Describes a simple and valuable method of testing plane surfaces as the sur- faces of size blocks, by bringing them in contact with the accurate surface of a piece of glass and noting the bands,

or fringes, of color. The Testing of Plane Surfaces. P. E. SHAW. Roy Soc

Proc Ser A v86 Feb 28 1912 p 227-34. The usual plane

I surfaces, originated by the triplicate method, may have

minute undulations too small to be detected by the

"raddle" process. The author's apparatus is a very sensitive spherometer of special form with which the plate under test is surveyed. The zero reading of the spherometer is determined by comparing it with a similar spherometer with which the surface has been surveyed. Actual tests are described. The mean error of a carefully scraped surface plate is given as 2 X 10"B in. and of commercial plate glass from 3X10"3 in. to 3X10"" in. Note on a Sensitive Method for Examining some Optical

Qualities of Glass Plates. Earl of BERKELEY, D. E.

THOMAS. Phil Mag v29 Apr 1915 p 613-17 3 figs. Describes the use of a Rayleigh interferometer for testing a glass plate. Method 30% more sensitive than Michelson's can be applied in construction of echelon plates. Flatness Tests at Bureau of Standards, R. L. RANKIN, Am Mach v50 p 1218 June 26 1919. Gives account of

optical true planes made and used at the Bureau of Standards. The Optical Flat—A Practical Measuring Tool, H. L. VAN

KEUREN. Am Mach v53 July 15 1920 p 107-12 8 figs. Describes optical flat and its use for shop measurements in considerable detail. The explanation is summarized in a series of 17 rules covering the use of the optical flat for shop measurements. Van Keuren Optical Equipment for Comparison of Standards. Am Mach v53 July 22 1920 p 187. The equipment

comprises two working optical flats, one master flat and

one source of monochromatic light. Comparisons can be made in units of one-half wave length of light, which for daylight is approximately 0.00001 in. As it is easy to estimate with the eye one-tenth of the width of an inter- ference band, the difference of 0.000001 in. may be seen. Any one of the three optical flats may be used for flatness

tests, though only two are required for comparison of length. However, all the flats have one accurate surface and can be used to test each other by the method ordi- narily used in originating surface plates. It is claimed

that the accuracy of the working flats is within 0.000005

in. and that of the master flat is within 0.0000025 in. Testing Plane Surfaces by Interferometer, C. G. PETERS,

H. S. BOYD. J Opt Soc Am v4 Nov 1920 p 407-19 8 figs. In testing the planeness of an optical surface by inter- ference fringes in monochromatic light it is generally as- sumed that straight fringes equally spaced indicate planeness, and curvature in the fringes departure from a true

plane. These assumptions are correct for normal inci- dence, but when the surface is viewed obliquely they may

introduce considerable errors in the determination of planeness. Theoretical discussion of the magnitude of errors introduced in specific cases. For one percent accu- racy the obliquity should not exceed tan _1 l/7. A New Interference Apparatus for Testing Haemacytometers, C. G. PETERS, B. L. PAGE. Sci Papers NBS n507 June 3 1925 p 221-36. Describes interference apparatus

for measuring the planeness of cover plates and planeness 175
and parallelism of the surfaces of the supporting and central strips of the chambers within a few hundredths of a micron ; also for measuring the depth of chambers.

Optical Measuring Tools. Machy (N.Y.) v32 June and

July 1925 p 768-71 and 867-70 22 figs. Zeiss optical flats are described and their use to test the planeness of the

anvil and spindle faces of a micrometer caliper is shown

in Fig. 14. Untersuchungen ueber die Genauigkeit von gesehabten und geschliffenen Fliichen (Accuracy of Scraped and Ground Surfaces), O. MACKENSEX. Werkstattstechnik

v20 Sept 1 1926 p 526-8 3 figs. Examination of two

ledges, one scraped, other ground, by means of optical

ruler, showing great superiority of ground surface. Testing Flatness With Gage Blocks, J. R. GODFREY. Am Mach v65 Dec 30 1926 p 1059. Method consists in placing a straight-edge on four equal gage blocks on sur- face to be tested. Examination of Very Flat Surfaces for Interferometry, M. DUFFIEUX. Rev Opt vll Apr 1932 p 159-66. The

surfaces to be tested are resilvered with a layer which is semi-transparent and then examined in pairs with the

help of a specially constructed interferometer. The methodical displacement of the interferometer allows the

tracing of the fringes and thus the thickness of the air gap. Accidents of relief amounting to 3 m/i can be detected. The errors introduced by the silvering can be avoided or

disclosed. The individual topography of the two surfaces can be found by graphical methods. Determination of Defects in Flatness of Surfaces, A. BIOT. Ann Soc Sci de Bruxelles v52 June 8 1932 p 54-8. A comparison of two surfaces is made by selecting two

points along a line for each surface. With these surfaces

facing each other and using an interference method with

transmitted monochromatic light, the distance apart of successive fringes is found. This process can be contin- ued across the surface. A precision of X/200 can be readily

obtained. The process can be used to determine the three

principal radii of curvature of a body. Testing Planeness of Surface by Haidinger's Rings, O. SCHONROCK. Zeit fiir InstrumKde v 59 Jan 1939 p 31-

40. The author develops the theory of an interferometer method for determining the deviation from planeness of the surface of a glass plate without reference to a plane

liquid surface. Method for Measurement of Flatness of Polished Surfaces,

C. TUTTLE, R. CARTWRIGHT. J Opt Soc Am v30 n8 Aug 1940 p 348-50. Optical method providing for rapid

inspection of extended surfaces described ; two beams of

parallel light are reflected by sample through cylindrical

lens to form astigmatic image of source ; if this image is single line, surface is flat within accuracy of instrument

inspection device for testing glass to be used for photo- graphic purposes now in service. Optical Flats. Aircraft Prod v3 n27 Jan 1941 p 34-5. With optical flats it is possible to gage surface inaccuracies which are too small to be checked by micrometer ; use of optical flats is based on fact that if glass or quartz

plate is put into close contact with surface of another

plate, series of color fringes or bands will be visible and

these will indicate inaccuracies of surface being checked. Generating Flat Surfaces, E. V. WAIT. Eng vl52 n3957 Xov 14 1941 p 381-3. Particular interest centers around

Whitworth's three-plate method, because no machine made

tools or instruments are necessary, and because plates of highest degree of accuracy can be generated; speaking

generally, engineers are under mistaken impression that

this process is much simpler in operation than it actually

is ; this has been due to deficiency in published literature, I which it is purpose of this article to make good. An Interferometer for Controlling Large Mechanical Details, V. P. LINNIK, CR Acad Sci URSS v35 nl p 16-9

1942. Describes an interferometer for the examination j of long surfaces of linear nature (plane, cylindrical) for 1

" departures from recitilinearity. As compared with a pre- vious arrangement described by the author in the same

journal (32, 3, 1941), the present scheme is free from the drawbacks associated with aberrations due to superficial

irregularities. As an example, the interference pattern i . obtained from a plate of mirror-glass 400 mm. long is; ; reproduced. Checking Micrometers with Optical Flats. Machy (Lon- ]

: don) v60 nl541 Apr 23 1942 p 353. Method of checking ,

1 : anvils of screw micrometer for flatness and parallelism : - with assistance of optical flats ; sets of flats are made to j . nominal thicknesses of 1 in., 0.500, 0.5062, 0.5124 and 0.5186

in ; working surfaces are flat to within 0.00001 in., and : | they are parallel to within 0.00002 in. Auto-Collimator Test for Flatness, W. A. TUPLIN. j 1 Machy (London) v61 nl577 Dec 31 1942 p 729-34. Method r I of checking surface flatness, using optical instrument to ; ) j measure rise and fall of reflected ray from tilted mirror \ - on auto-collimator. Instrument is used for checking |

! - straightness of long narrow surface, such as lathe bed and ! '! determination of departures from flatness of surface, such 1 as large surface plate. On the Planenes of Interferometer Plates, E. K. RAS- 1 1 MUSSEN. Danske Vidensk Selsk Mat -Fys Medd v23 n3 -! 18 p 1945. Describes a method of applying interference

fringes to measure the planeness of Fabry-Perot plates !i! and discusses the accuracy of the method and the depend- j : ence of the resolving-power on the planeness. The use off I

a wedge between silvered plates is advocated for fine-struc- ( «

ture observations on intense lines, using Fizeau fringes. \ «

ij i The Measurement of Finely Finished Surfaces by Optical j ft Interference, C. J. TIMMS, Sci Instrum v22 p 245-6 Dec

1945.

11 Plane-Parallel Glass Indicators and Technical Interim-meters, J. G. VOGL. Tekn Tidskr v76 June 29 1946 p 657- i i< 64 in Swedish. The principle of measurement of surface s| s irregularities with interference by means of a plane-paral- ! 8

lei glass plate is explained in detail and the contour map- ( k ping of the surface is described. Usual interferometers, in- cluding the Twyman-Michelson instrument, are described I k and various applications are explained, with illustrations. |

ill 1 i Additional Interference Fringes Produced by Scattering and Reflexion. V. D. HOPPER. Nature London vl58 July i

ifl 20 1946 p 101. A double system of interference fringes, j « produced by a combination of multiple reflection and scat- t! tering similar to that suggested by Bauchwitz and Sehoenberg was observed with an arrangement of aluminized and i |i senii-aluminized optical fiats with scattering scratches i if which is described.

i | Interference Fringes Produced by Scattering and Reflection, V. D. HOPPER. Proc Roy Soc Vict v58 Pts I-II , t 1947 p 69-80. When a partly polished optical flat was

placed face downwards on a standard flat, and illuminated ,J by a small bright white-light source, the pattern cor1

, responding to the colours of thick plates was observed ,

' encompassing the image of the source. When the top sur- face of the standard flat was aluminized, the pattern was ji much more intense. A new phenomenon occurred when f the pair of plates was illuminated by light from a Hg "'t lamp which passed through a narrow slit, the single pat- j* tern giving place to two separate patterns, whose intersec- 1 * tions gave the locus of the pattern observed with white , light. When the scattering surface was made semi-reflect- j, *

ing, the double set of patterns became sharper, one set f ^ 176
being localized in the plane of the scattering surface, the other in planes corresponding to the position of the Newton

ring pattern formed by multiple reflections. Various ex- periments are described for studying these patterns. It

is concluded that all three systems of fringes are produced

by multiple reflections between the two reflecting surfaces, rhe assumption of Stokes that the colours of thick plates could only be produced by light passing and repassing the same particle being unnecessary. It is considered that the pattern corresponding to the colours of thick plates is pro- duced by the summation of the intensities of the light from

a pair of separate patterns of the simpler Newton ring

type, one set being produced by light scattered by the top

surface and then suffering multiple reflections between the surface before reaching the observer, the other set being produced by light from the source suffering multiple re- flections between the plates, and finally being scattered by

the scattering centres. Testing of Flatness by Beam Comparator Method, R. MARRINER, W. O. JENNINGS. Engr v 184 n4778 Aug

22 1947 p 164-5. Method described was devised at National Physical Laboratory and used for testing quickly and with reasonable accuracy large batches of surface

plates of same size ; it is particularly convenient for test- ing flatness of surfaces during manufacture ; principle is

. that of comparing by means of sensitive dial indicator

straightness of succession of generators in surface under

j test with that of known reference straightedge. A Liquid Surface Interferometer, H. BARRELL, R. MARRINER, NPL. Brit Sci News v2 1948 p 130 ; Nature n4118

. Oct 2 1948 p 52a. Describes a Fizeau type of liquid surface

: interferometer used at NPL.

Liquid Surface Interferometry, H. BARRELL, R. MARRINER, NPL. Letter in Nature vl62 Oct 2 1948 p 529-30. The surface of liquid paraffin has been used to provide a reference plane up to 25 cm dia. For this dia. the earth's curvature produces a difference in height of only 12 A, while liquid paraffin has less capillary curvature than

water, which has been used previously. Testing of Polished or Fine Ground Surfaces for Flatness,

A. J. ELLIOTT. Sci Instrum Phys Ind v26 Jan 1949 p 24. The testing of nearly flat surfaces by the astigmatism pro- duced in a light beam reflected from the surface is dis- cussed. The use of the test for ground surfaces is described, and attention is drawn to its use in the working of

soft materials such as rock salt.

a Test of an Optical Flat by the Fabry Perot Etalon, T. SAKURAI, K. SHISHIDO. Sci Rep Res Inst Tohuko

L'niv Ser A vl May 1949 p 83-6. An application of

j Fabry's fringe method for the examination of optical

flats. The flats are mounted as a Fabry-Perot, fringe or- der being changed by altering gas pressure between the

flats. The accuracy of l/50th of a light wave is claimed. Zur Messung der Ebenheit von reflektierenden Flaechen

mittels Interferenzen gleicher Dicke (Measurement of flat- ness of reflecting surfaces using interferences of equal

thickness), R. LANDWEHR. Optik v5 n6 Sept 1949 p

354-64. Consideration of deviation of uniform and non- uniform spherical surfaces from flatness; formulas and

] nomograms for determining curvatures. Improving the Quality and the Testing of Optical Flats, E. EINSPORN. Optik v7 n3 1950 p 147-68 in German. A discussion of the evaluation of slight curvature of opti- cal flats by means of Fizeau fringes. The method is shown

to be comparable to that using Haidinger fringes. A dis- cussion is included on the effect of combining slightly curved flats. Interferometer for Testing Measuring Gauges, Eng vl70

ti4417 Sept 22 1950 p 243-5. Instrument being manufactured by Coventry Gauge and Tool Co. under name of Matrix Interferometer ; by means of instrument, deviations from flatness of order of one millionth of inch on

highly finished surface may be seen by aid of interference

fringes which they produce. See also discussion, by H. BARREL and J. PUTTOCK, in n4426 Nov. 24, p. 412. Contour Mapping of Optical Surfaces with Light Waves,

Glass Indus v32 n8 Aug 1951 p 409-11. Vacuum light interferometer developed by J. B. Saunders of National Bureau of Standards makes contour maps by photographing interference patterns formed when light waves are

reflected from precise optical surfaces of specimen and

standard reference of known shape; adding additional

lines between half wavelength lines reduced spacing to 6

ten-millionths of inch. Precise Topography of Optical Surfaces, J. B. SAUNDERS, J Res NBS v47 n3 Sept 1951 (RP2239) p 148-55. Unit of length usually used in measuring optical surface

features, by interference of light, is one half wavelength

of monochromatic light that is used ; method is described

in which unit of length is much smaller fraction of wavelength ; topographic maps of optical surfaces are made in which contour interval is less than l/30th wave length. Determination of Planeness and Bending of Optical Flats, W. B. EMERSON, NBS. J Res NBS v49 Oct 1952 p 241-7. The true contours, undistorted by gravitational bending, were determined for four 10% in. diameter standard opti- cal flats of fused quartz. The bending deflections of these

flats were determined by a method based upon the differ- ential bending with thickness of the flats. Bending deflec- tion curves of a flat supported at three points equidistant from the center of the flat and equidistant from each other were obtained. The locus of the bending deflections at

the center of a flat, similarly supported but with supports

at different distances from the center, approximates a straight line. This paper describes the method used to ob- tain the true contours and the bending deflection curves

of the flats, and compares the bending values so determined

with theoretically derived values. Collimator and How To Use It, R. F. MITCHELL. Am

Mach v96 n23 Nov 10 1952 p 161^. Goniometer-Colli- mator for use in shop operations ; collet and lathe tool angles easily checked ; bedway flatness can be measured

to 0.00007 in. ; applications illustrated. The Science of Precision Measurement. The DoAll Co.

1953. Chapter 6 covers applications of optical flats. Why Don't We Standardize Surface Plate Specs? R. J. RAHN. Am Math v97 June 8 1953 p 169. Suggests a form of specification. A Micro-Reference Flat for Multiple Beam Interferometry,

S. TOLANSKY, M. OMAR. Note in J Sci Instrum v30

Sept 1953 p 337-8. For high definition multiple beam

interference fringes, the optical flat must approach very

closely to the object. A micro-flat is described enabling

close approach to selected regions of an object, such as a crystal, in which there are areas differing considerably

in surface level. This flat consists of the polished tip of a small truncated cone. The cone tip (i.e. the flat) has

a diameter of 1 mm or less. The mounting and method

of adjustment are described. The technique is illustrated by use with diamond and silicon carbide crystal surfaces. The Metrology of Surface Plates, J. C. MOODY. Sandia

Corp., Oct 1953. Discusses application of the autocolli- mator. See also : Tool Engr Feb 1958 and Dec 1958. Testing of Large Optical Surfaces With Small Test Plates,

J. B. SAUNDERS, NBS, J Res NBS v53 nl July 1954

( RP2514 ) p 29-34. With increased use of massive optical

parts, there is need for practical method of testing large 177
optical surface with small standards, available in average

optical shop ; simplified formulas are used to apply statis- tical method for obtaining increased precision; practical example illustrating procedure for testing surfaces as- sumed to have revolution symmetry. "New Look" in Surface Plates, A. P. DIEFFENBACH.

Machine & Tool Blue Book v49 n9 Sept 1954 p 196-8. New

forms of surface plates described and illustrated; long

surface plate made up of three individual plates is used

to check straightness on airplane wing struts ; advantages

of round type surface plate ; Surface Floor Tee-Rail.

It Takes Three-Point Specification to Insure Surface Plate

Flatness, R. J. RAHN. Tooling & Prod v20 n7 Oct 1954

p 123-5, 140. Details of specification for black granite surface plates produced by Rahn Granite Surface Plate

Co., Dayton, Ohio ; errors will be not over 100% of unit being used. Precision Measuring Tools. Catalog and Handb n36 Appendix G Optical Flat Specifications and Data. The Van

Keuren Co., Watertown 72, Mass. 1955. Discusses testing

of flatness. using an optical flat; testing of flat ring sur- faces ; and presents tentative optical flat specifications. Surface Plates Compared by Physical Tests, R. MERRIAM. Tool Engr v35 n2 Aug 1955 p 99-100. Strength

characteristics, compressibility and absorption, and ther- mal properties of granite and black granite plates ; comparison with cast iron plates. How to Calibrate Surface Plates in Plant, J. C. MOODY.

Tool Engr v35 n4 Oct 1955 p 85-91. Method used in metrology laboratory at Sandia Corp, Albuquerque, NM

is application and extension of procedures developed by

K. J. Hume and involves no new principles ; details of autocollimator employed ; directions for converting auto- collimator readings into linear displacement in hundredthousandths of inch are given, accompanied by work sheets

for calibrating 48 x 78 in. surface plate. Control and Interferometric Measurement of Plate Flatness. P. D. CARMAN. J Opt Soc Am v45 nl2 p 1009-10 Dec 1955. For two flatness requirements involved in the

testing of air survey cameras special techniques have been

devised. Photographic plates used for camera calibration should be flat to one or two microns. To achieve this the i/i-in. plate glass supporting the emulsion is bent flat and held flat during exposure. Flatness is determined

in an interferometer using infrared light. Camera register glass flatness is also checked interferometrically. Since counts of over 100 fringes are required, two monochromatic light sources are used, chosen to produce regular arrangements of black and coloured fringes which permit

counting by groups. Untersuchungen fiber die Eignung eines Flussigkeitsspiegels als Ebenheitsnormal (Investigation on the Use of a Liquid Surface Mirror for a Flat Plane of Reference).

R. BUNNAGEL. Zeit Angew Phys v8 n7 1956 p 342-50

in German. Experiments are reported using paraffin, silicone oil and castor oil on mercury. Distortions pro- duced on the liquid surface both by static charging and

by temperature variations are studied. With a disc of 24 cm diameter at 4 cm from the edge the radius of curvature is 2X10' km. The influence of earth curvature is not

established. The observed curvature is the same for the three liquids studied. Static charges can persist for sev- eral days and are formed even by the pouring of the oil on the mercury. To avoid this the oil used should have

a conductivity of at least 10"" ohm"1 cm"1

. With castor

oil, a temperature difference of 0.01 °C at the ends of a

11 cm disk does not produce a detectable effect. The Showing of the Degree of Planeness of a High

Polish by Means of Surface Topography, R. SEGELETZ.

Optik vl3 n2 1956 p 59-63 in German. A description of the best method for revealing clearly the topography of a

large "flat" as derived from interference fringe patterns. The method of computing the complexities of the topog- raphy in terms of contour lines 0.01,u apart is discussed. These contour lines are derived from ordinary fringe

patterns. Einfaches Verfahren zur topographischen Darstellung

einer Optischen Planflache ( Simple Method for the Topographic Representation of an Optically Plane Surface),

R. BUNNAGEL. Zeit Angew Phys v8 Feb 27 1956 p 447. Method is based on the evaluation of a unique photo- graph of Fizeau interference. (Partial translation avail- able). Intercomparison of Optical Flats, S. W. HUGO. Mech Wld vl36 n3444 Apr 1956 p 150-2. Comparison of three

flats, not supplied as set ; flats comprise circular one, 2%

in. diam by 7/16 in. thick and two rectangular ones, 2 in. by iy2 in. by y2 in. thick ; deduction from results leads to establishment of test routine ; several flats were intercom- pared but three described were selected as demonstration

set in view of their particular contour. Production of a Mercury Mirror which is Insensitive to Shocks and its Application as a Flatness Standard, R. BUNNAGEL. Optica Acta v3 n2 June 1956 p 81-4 in Ger- man. A mercury mirror which is insensitive to vibration

consists of a layer of mercury about 0.2 mm thick. The

formation of such a thin layer is achieved by using a vessel of a metal which readily forms an amalgam. By

silvering the inner surface of the metal vessel the mirror

is made durable, and the formation of a skin on the mercury surface is prevented. The flatness of the mercury

mirror has been tested by two different interferometric methods, and its suitability as a standard flat established. Multiple beam interferometry may be used to increase the accuracy of the testing for flatness. As every liquid mirror

flows when its position is slowly changed, a firm mounting

is necessary. A Simple Technique for the Topographical Evaluation of an Optical Flat, R. BUNNAGEL. Zeit Angew Phys v8 n9 Sept 1956 p 447-50 in German. A mercury surface is used as reference mirror. A geometrical method of deriv- ing the topography of a nearly plane surface from the Fizeau fringe pattern is described. The limits of error are discussed. Checking Flatness of Plane Surfaces with Straight-Edges,

C. MINAIRE. Machy (London) v91 n2335 Aug 16 1957 p 357-62. Wedge blocks for checking flatness, checking

flatness of surface plate ; topography of surface plate ; ob- taining true plane surface with minimum removal of material. Interferometric Testing of the Planeness of Long Beds. K. KUHNE. "Optics of all Wavelengths" Meeting, Jena, 1958 p 362-8 in German. The testing of beds of some

meters in length for precision machinery is described. An

interferometric set up is used which employs Fizeau

double slits and an autocollimation device. Constructional and operational details are given. As an example the

testing of a 4 m long test-bed is illustrated. Can You Prove Flatness of Your Flat Surface Plates? Here's How. E. W. PENNINGTON. Tooling & Prod v24 n2 May 1958 p 69-70. 72 74, 76. Planekator method devised by R. J. Rahn of Rahn Granite Surface Plate Co. for cali- brating out-of planeness of surface plate is simple, ac- curate, and fast working; master geometrical reference plane which is "suspended in air" above surface plate can

be established or located ; procedures described. Zur Steigerung der Genauigkeit mikrointerferometrischer Untersuchungen und zur einer Interferenz-Sphaerometrie

( Improvement of accuracy of micro-interferometric exami- 178
nations and problem of interferenee-spheronietry) , R.

i LAXDWEHR. Zeit InstrumKde v 66 n7 July 1958 p 134-

8. Corrections to be considered in precise micro-inter-

: ? ferometric work to determine form of objects, where double beam interference witb conventional micro-interfer-

-£ ometers is used ; possibility of more accurate interference- spherometry. 17 refs. ae Checking Flatness with Straightedges, C. MIXAIRE.

:> Machy (X.Y.) v64 nl2 Aug 1958 p 99-102. Set of three

special blocks used to check flatness instead of making

•5 ip various gage block combinations, which requires more

. - rime : checking flatness of surface plate ; obtaining true

r& plane surface with minimum removal of material. Applications of the Interference Strioscope to Metrology, M. PHILBERT. Rev Opt v37 nl2 Dec 1958 p 598-608

sa in French. A simple apparatus is described, using inter- ferenee between two beams formed by binefringence. Its

. ^ application in wind tunnel work is given in detail and some

results are shown. Other uses are the testing of the fig1- tire of optical surfaces and the detection of veins in opti-

. : cal materials. Interferometer for Large Surfaces, J. B. SAUNDERS,

F. L. GROSS. J Res XBS v62 n4 Apr 1959 (RP2943) p

1 137-9. Instrument described which permits testing of large areas, such as layout plates, obtains extension to

: large areas by causing collimated beam of light to reflect

7 - from specimen at large angle of incidence : resultant fringe

:>attern is contour map of surface relative to arbitrarily

Bj chosen plane and contour interval is function of wave-

- : length and angle of incidence.

$ Instruments for Measuring Surface Irregularities and

Alignments. Machy (London) v94 n2421 Apr 8 1959 p

tx. ! 775-6. Description of straight line interferometer capable

of measuring profiles of surfaces up to 15 in. long with

- • accuracy of 15 microin. ; instrument has been applied, for

•example, for checking straight edges and precision sur-

: faces of such parts as sealing rings for axial flow compressors.

-; Indicating Surface Flatness with Electronics,. P. E. CAR-

,

, BOXE. Tool Engr v43 nl July 1959 p 57-8. To fulfill need for fast checking method, electronic straightedge was

developed to measure flatness within 0.000025 in. over 120

in.

If A Method of Testing Optical Flatness of Pre-polished « Glass Surfaces. A. S. HAMEED. S. HARIHARAX. J Sci

"- Industr Res vl8A n7 July 1959 p 311-5. A method for

i -he quantitative estimation of the form of an optical sur-

. face, just before polishing, is described. The optical layer

I with suitable modifications is used for the purpose, so that departures from a standard form say an optical flat, can

be evaluated in terms of wavelengths of light. This data

I will be helpful in correcting surfaces even in the pre-polish- ing stages. The time spent in effecting the corrections at

this stage will be very much less than the time taken in the figuring stages, after polishing. The results obtained

. - were verified by interference methods. How to Calibrate Small Surface Plates, R. J. RAHX. Tool

I Engr v43 n3 Sept 1959 p 111-3. Dimensional variations

as small as five millionths of inch can be measured with

auto-collimator if instrument is used correctly : calibration

vith auto-collimator on plate and off plate : readings taken

gl are shown and curves obtained illustrated. Herstellung und Verwendung eines gegen Ershiitteriingen inempfindlichen Queeksilberspiegels als Ebenheits normal

' Production and Application of a Mercury Mirror Insensitive to Vibration as a Planeness Standard), R. BUXXAGEL, PTB. Optics in Metrology. P. MOLLET. Per- gamon Press 1960 p 172-8 2 figs 8 refs. Mirror consists

of a layer of mercury about 0.2 mm thick. Thin layer

- achieved by using a metal vessel which readily forms an

amalgam. The mirror is made durable by silvering the inner surface of the metal vessel, and the formation of a skin on the mercury surface is prevented. Flatness has been tested by two different interferometric methods, and suitability of the mirror as a standard flat established. As every liquid mirror flows when its position

is slowly changed, a firm mounting is necessary. Check Surface Plate Flatness by Applying Geometry of Sphere. R. J. RAHX. Tooling and Prod v26 n5 Aug 1960 p 41-4. Unusual approach to surface plate flatness based on premise that plane is actually sphere with infinite radius, and segment of sphere, having radius much less than infinity, would make very good surface plate ; mathematical calibration of spherical surface; inspection of surface plate with ordinary tool inspection. Fehlermoglichkeiten beim Messen Zylindrischer Teile mit Kugeligen Messflachen (Possibility of Errors in the Meas- urement of Cvlindrical Parts with Spherical Measuring

Surfaces), O. XIEBERDIXG, S. TROST. Zeit fair Praktische Metallbearbeitung v55 1961 p 163. Testing the Straightness of Lines and the Flatness of Surfaces. A. C. S. VAX HEEL and J. D. DE VEER.

Optical lustrum Conf London 1961 p 383-405. By making use of conventional optical parts, alignment and the

flatness of surfaces can be tested to within a few tenths

of a second of arc by making use of spherical aberration and diffraction. The range in some cases is several hundreds of meters, and the brightness of the diffraction pat- tern is high enough for observation in daylight. Only

flat and spherical surfaces are needed. The most simple form to test alignment is a sphere with a cap of the same

material of very good homogeneity. A concave spherical mirror and a flat mirror were used in combination, in order to obviate the stringent requirement of homogeneity

of the glass. Though the sphere with cap can be used

also to test the flatness of surfaces, other means are more

efficient. In the first place one spherical mirror with one minute light source (of white light) suffices to test the

flatness up to distances of 20 meters with a precision below

one second of arc. By combining a concave and a convex

spherical mirror, precision can be lowered to a few tenths

of a second of arc, while the observation distance is en- larged. The working of the mirrors is based on the forming of (colorless) "rainbows," a fact that is perhaps not well known. The diffraction pattern associated with these rainbows (Airy's fringes) makes it possible to attain the mentioned precision. Much time was given to testing the straightness of the line produced by the apparatus by in- dependent means, a difficult process seldom applied by

other workers. Analysis in Use of Optical Flats. S. W. HUGO. Mech Wld vl41 n3498 Jan 1961 p 6-10. Discussion of geometrical analysis of possible errors arising in lapping of gage

surfaces and their comparison with reference standard by methods of comparative interferometry ; methods are

equally applicable to checking of slip gages and notes on

checking of secondary gages are appended ; illustrated with diagrams and calculations. Investigation of Surface Deformation. L. GRUXBERG. D. SCOTT. K. H. R. WRIGHT. Brit J App Phys vl2 n4 Apr

1961 p 134-40. Methods used in Xational Engineering Laboratory for studying surface deformation ; enhanced

photoelectric emission is studied with open-ended Geiger Mueller counters or electron multipliers ; oxide films are

studied by electron microscopy and changes in chemical

reactivity by radioactive tracers ; surface topography, im- portant factor in lubrication and wear research, is studied with aid of interferometry, phase contrast and electron microscopy.

Optical Flats. Federal Specification GG-O-635 May 31

1960, Amendment 1 May 10 1961 6 p. Available from 179
General Services Administration Region 3, Federal Supply

Service, Printed Materials Supply Division, General Services Regional Office Bldg., Washington, D.C., 20407. 5f

Covers reference, master, and working flats. Material of fused quartz and borosilicate glass. Design, accuracy, and

testing. Multiple-Wavelength Multiple-Beam Interferometric Observation of Flat Surfaces, D. R. HERRIOTT. J Opt Soc Am v51 nlO Oct 1961 p 1142-5. Interferometric method

which reduces contour interval between multiple-beam

fringes to between 1/20 and 1/100 wavelength; application to critical examination of Fabry-Perot plates for use

in continuous helium-neon optical masers. Errors in Checking Linearity of Large Plates, K. I. ABADZHI. Meas Tech 1961 n2 Oct 1961 p 93-7 4 figs 7

refs. Translated from Izmer Tekh n2 p 3-6 Feb 1961. Discusses the relative merits of different methods of

testing. Flatness of Large Areas Verified Easily, J. H. WILSON.

Machy (N.Y.) v68 n2 Oct 1961 p 110-4; Machy (London)

v99 n2563 Dec 27 1961 p 1496-7. In lapping large ord- nance parts, problem of controlling flatness to 50 mil- lionths of inch on 7 ft table of Lapmaster machine had to be solved at General Electric's Pittsfield Ordnance Dept

solution was found in development of beam type checking

bar because it met joint demands of accuracy and speed

3 holes are tapped in bottom flange to accommodate 3 hardened spherical feet; this arrangement permits fast setting of indicators and good repeatability in results. Inspection of Flat Mechanical Parts, Determining Opti- mum Reference Co-ordinate Axes, M. FORESTIER.

Microtecnic vl6 nl Feb 1962 p 1-6. Two methods de- scribed ; first is based on principles of least squares and

utilizes exclusively means of computation ; second is based

on opinion and is graphical process.

7.2. Parallelism

Die Parallelitat der Messflachen verschiedener Messgerate, (The Parallelism of Measuring Surfaces of Different Measuring Devices) G. BERNDT. Zeit fur Feinmech und

Prazision v35 Oct 12, 26 1927 p 245-9, 256-9. Various methods of determining parallelism of contact faces on

micrometers, measuring machines, snap gages and end- standards are described. The Determination of the Parallelism of the Measuring

Surfaces of Measuring Tools, G. BERNDT. Instrum vl June 1928 p 263-70 12 figs. Description of various types

of devices and instruments with two plane surfaces fac- ing each other for measuring length such as vernier cali- pers, amplifying gages, dial gages, measuring machines and micrometers ; methods of determining parallelism of measuring surfaces ; advantages and disadvantages of dif- ferent types for different purposes. Contains a detailed

description of the application of the auto-eollimating tele- scope to determination of parallelism and the measurement

of angles. Testing of the Parallelism of the Planes of Plates, C. MUNSTER. Phys Zeit v33 July 1 1932 p 505-9. The

methods depend on interference principles and the apparatus can be used for interferometer measurements.

Optical Tools for Inspection and Testing I-II, C. F. SMITH. Machy (London) v41 Nov 24 1932 p 209-12, and Dec 15 p 309-12. Nov 24 : Operating principles and appli- cation of instruments made by A. Hilger for checking

angles and parallelism. Dec 15: Testing flat surfaces with Angle Dekkor and interferoscope ; accuracy of glass straight edges and set squares.

Multiple-Pinhole Multiple-Beam Interferometric Observation of Flat Surfaces, M. V. R. K. MURTY. App Optics (USA) vl n3 May 1962 p 364-5. It is pointed out that

in the testing of optical flats by multiple-beam interfer- ometry it should be possible to use a series of off-axis pinhole sources and thus obtain several sets of fringes dis- placed relative to each other. This will simplify the use

of the technique. Formulae are given for the relation between pinhole and uniform fringe spacing. A Simple Machine for Testing Flatness Using Air Gauging, B. GALE, L. WILSON. J Sci Instrum (GB) v39 nl2 Dec 1962 p 638-9. The machine consists of an ac- curately ground plate on which a carriage bearing a speci- men can be positioned using lead screws. The deviations

of the surface of the specimen are measured, with respect

to a fixed pneumatic gauge head, with an accuracy to ±1.5X10-" in. Fire Polished Glass as an Optical Interference Reference

Surface, S. TOLANSKY. Lab Prac (GB) vl2 n8 Aug

1963 p 722-4. A smooth reference is a recognized essential for the study of surface microtopography or the

structure and thickness of thin-deposited films. The

author, in the course of his experience, has found that fire polished glass can have an extremely smooth surface, and

in this paper explains its suitability for the purpose. Interferometer for Testing Extended Surfaces Such as Surface Plates and Precision Ways, J. B. SAUNDERS, V. MCDERMOTT. J Res NBS v68C n2 Apr-June 1964 p 83-

4 2 figs. A modification of the previously described "In- terferometer for Large Surfaces" is described that permits

the use of smaller prisms for a given sensitivity and a more practical arrangement of the optics. This arrange- ment allows for better structural connection of the ele- ments into a rigid and moveable unit. This is obtained by

a 90 degree rotation of the prism relative to the plane of incidence of the light. Measurement

Mirror Prism for Use with Angle Dekkor in Checking

Parallelism of Micrometer Anvil Faces. Machy (London)

v65 nl678 Dec 7 1944 p 636-8 ; Automobile Engr v34 n457 Dec 1944 p 535-6. Reflecting prism, used with Hilger Angle Dekkor, is so designed that it checks parallelism

in all planes simultaneously ; prism splits parallel beam of

light so that it is directed towards two micrometer faces from which light will be reflected back, two beams being

exactly parallel to each other and on same axis. Improved Interferometer for Determining Parallelism Errors in Long End-Gauges, L. G. TURNBULL. Can J Res

v25 n3 (sec F) May 1947 p 242-55 2 supp plates. Inter- ferometer designed for determination of parallelism of working faces and end gages up to 24 in. in length; it incorporates kinematic principles and features to permit

easy adjustment and operation; by addition of sensitive

level vial, difference in length of nominally equal end

gages can be determined to accuracy of 1 or 2x10"* in. Optical Method of Setting Two Opposed and Opaque Mirrors Parallel, D. S. PERFECT. J Sci Instrum v25 nl Jan

1948 p 15. Inclined partially reflecting plate introduced between mirrors divides collimated beam into two components both of which ultimately enter viewing telescope

one is simply transmitted by plate, other is reflected suc- cessively by two mirrors; condition for parallelism of mirrors is coincidence of two images of pinhole source. Interferometer for Checking Parallelism of Slip Gauges,

J. B. SAUNDERS, NBS. Machy (London) v92 n2361 Feb

14 1958 p 375-7 ; Engr v205 n5334 Apr 18 1958 p 595-6. New interferometer developed by U.S. National Bureau

of Standards enables parallelism of working faces of gages 180
_ j to be checked more conveniently and accurately than by

" j previous methods ; arrangement of principal components ^ ) of instrument ; double image Koesters prism comprises

r- j two 30-60-90° prisms cemented together. ? Interferometer Checks Gage-Block Accuracy. Tool Engr

.71 v41 n2 Aug 1958 p 70-2. Design and operation of inter

-~" ferometer development at National Bureau of Standards. which makes possible more rapid and convenient measure- ment of parallelism of opposite gage block faces ; instru- ment is adjusted by simple controls, and angle between

~X gage block surfaces is read directly on calibrated scale. Parallel Testing Interferometer. J. B. SAUXDERS. J Res XBS v61 n6 Dec 1958 (RP2917) p 491-8. Features of

. interferometer for measuring parallelism of gage blocks and other bodies of any reasonable length without necessity of wringing operation ; two forms of instrument used

are one for testing long blocks and other for short blocks. Determination of Parallelism of Work Pieces up to Several

: Meters in Length with the Help of Optical Interference,

; M. DUHMKE. Optik vl6 nlO-1 Oet-Xov 1959 p 646-9

in German. Industrial comparators can be used only up

to 20 cm. With a Roster's double prism a 4 meter length can be examined and adjusted for parallelism. A Michelson interferometer system is also described for the purpose. It is useful for matching the parallelism of the ends of an end standard of several meters in length. Ein interferenzoptisches Geraet zur Unparallelitaetsbe- stimmung an Endmassen bis 4 m Laenge (A Parallel Testing Interferometer for Slip Gauges up to Four Meters

Long.), M. DUEHMKE. Zeit fuer InstrumKde v67 nil Xov 1959 p 273-6. Parallel testing interferometer for

slip-gages up to lengths of 1000 mm, operating without

high monochromatic light-source ; accuracy of measuring

is plus or minus 0.02 urn.

Interferometer Method of Determining the Parallelism

of Large Block Gauges, V. P. KOROXKEVICH, V. P. GOLUBKOVA. Meas Techns 1961 n5 Dec 1961 p 346-7

2 figs 5 refs. Translated from Izmer Tekh no p 5-7 May

1961. Describes a method and interferometer which

proved to be particularly useful in checking gauges under

production conditions, since determining the difference

in the length of the gauge along one of its sides only re- quires a few minutes. The errors in determining the'parallelism of block gauges 100 to 1000 mm long does not exceed 0.05/*. The maximum measurable lack of parallelism amounts to 1.5/*. Improved Checking of Parallelism in Micrometer Operating Surfaces, G. I. SIMOXENKO, Meas Techns 1962 nl June 1962 p 16 1 fig. Translated from Izmer Tekh

nl p 14 Jan 1962. Describes the use of a glass parallel with the micrometer mounted vertically in a special fix- ture. Interference bands on anvil and spindle are ob- served simultaneously. Xew Method for Determining Parallelism of Block Gauges,

V. P. KOROXKEVICH, V. P. GOLUBKOVA. Meas

Techns 1962 n4 Sept 1962 p 276-7 4 figs 3 refs. Translated from Izmer Tekh n4 p 7-8 Apr 1962. Describes a modified Michelson interferometer which uses white light without

a reference gage. Device for Testing Parallelism of Measuring Surfaces in Flat Micrometers, S. I. IZOTOV. Meas Techns 1963 n2 Aug 1963 p 117 1 fig. Translated from Izmer Tekh n2

p 21-2 Feb 1963. It is possible to check the parallelism

of the operating surfaces of flat micrometers in the range from 75 to 1000 mm in any position of the microscrew

by means of the hole-gauge extension pieces. The parallelism of measuring surfaces in micrometers with a range

exceeding 1000 mm can be measured by means of two

micrometer hole gauges.

7.3. Straightness and Surface Topography

Straightness Test for Beds of Machines, Edges, etc. Mr. ATWELL. Eng vlOO July 23 1915 p 92. A straight edge

or bar is supported on the bed by two gage blocks differing

in height 0.01 in, mounted at the same distance from either end of the bed. Other gages differing by small steps are

slipped into this space and their spacing is noted. Operation is repeated with bar turned over and thickness variations in bar are also determined. Use of Monochromatic Interference Rings for the Meas- urement of Curvature, S. D. CHALMERS. Phys Soc Proc

v29 Aug 1917 p 362-5. Shallow convex surfaces can be compared directly with a plane surface, and if the plane

surface be placed uppermost, supported at the edge with

soft wax, there is only one curved surface to consider. Monochromatic light is used with a measuring microscope, and readings are taken of the diameters of the 3d and

20th rings. Details of method are given, and limits and

precautions briefly discussed. Micrometer Straight-Edge, H. HUMPHREYS. Am Mach

v62 Apr 30 1925 p. 705. Combination of a dial gage and

straight edge for checking the surfaces of planer rails, milling machine tables, and similar parts of other machines. Two feet are adjustable along the beam and are provided with clamp screws. A dial gage is mounted on a

slide. Prufung der Gradlinigkeit und Ebenheit (Testing of Straightness and Planeness). F. H. BOPP. Zeit fur Feinmechanik v34 June 3 1926 p 111 4 figs. Long trussed

straight-edge on which are adjustably mounted two steel cylinders. Between them an indicating mechanism is mounted. Work is tested by contact on the cylinders and

indicator.

The Contouring of Smooth Surfaces, J. P. AXDREWS. J

Sci Instrum v5 July 1928 p 209-13. By the employment

of a very narrow intense beam of light, the shapes of smooth surfaces may be investigated. Describes appropriate experiments, and gives the necessary calculations

for regular spherical and cylindrical surfaces ; a complete, nearly circular cylinder, and a metal surface of no pre- scribed figure. An accuracy comparable with an inter- ference method is attainable. Ein Optischer Flucht- und Fuehrungspruefer (Optical equipment for measurements of proper alignment of guides). Maschinenbau vl3 n9-10 May 1934 p 265-6. Detailed description of equipment developed by Zeiss, Jena.

Industrial Optical Testing and Gauging Instruments, H. ALQUIST. Eng Progr vl7 n5 May 1936 p 111-6. Description of German equipment for examination of surfaces, measurement of form and contour, comparative and

direct length measurement, and checking straight lines, angles, and directions. Visiervorrichtung fuer das Ausrichten von Lagern ( Sight- ing equipment for alignment of bearings), W. FRAXKZEXBURG. Werkstattstechnik und Werksleiter v32 n20

Oct 15 1938 p 451-3. Details of equipment. Asymmetrical Broadening with Multiple-Beam Interfer- ence Fringes, J. BROSSEL. Nature London vl57 p 623 May 11 1946. When using multiple-beam Fizeau fringes

of equal thickness for the study of surface topography it is necessary to know which parts of the fringe system

represent a projection or depression on the surface. By

using a slightly extended source in place of a pinhole, the 181
fringes spread asymmetrically towards the region of greater air-film thickness. The increase of intensity en- ables measurements to be made on the sharp side of the

fringe with precision nearly equal to the narrow fringes. A Wavefront-Shearing Interferometer, W. J. BATES.

Proc Phys Soc London v59 Nov 1947 p 940-50. A new type

of interferometer is described by means of which the

asphericity of an optical wavefront can be measured, by

testing it against itself with lateral displacement or shear. Continuous control of the amount of this shear, and the meridional or sagittal fringes is obtained in white light. La regie optique et ses applications (Optical rule and its applications), B. CUNY. Rev Universelle des Mines v4 n2 Feb 1948 p 193-5. Description of new precision device

for checking flatness and alignment, whose only support

is test piece itself and requiring neither regulation nor image adjustment; it is designed for accurate inspection

of surface plates and machine tool slide bars. Optical Testing of Straight Slideways, J. TERRIEN, T. MOREAU. Microtecnic v2 nl Feb 1948 p 13-20. Comparison of several methods of measuring vertical deviations of straight slideways of precision comparator bed;

use of autocollimator furnishing tilt angles of carriage

resting on slideways, Koesters double prism, duplicate image instrument, and optical straightness tester made

by Society Jobin and Yvon. An Instrument for Automatically Recording Waviness of Surfaces, C. W. MEDHURST. J Sci Instrum v28 July

1951 p 211-4. The instrument is of robust construction

suitable for everyday production tests on .surfaces and

yet is of such form that it will not harm the surfaces.

Its outstanding feature is that it charts the waviness of surfaces in only 5% of the time it takes when using a

.simple Ames dial instrument. Apparatus for the Control of Straightness, A. MIRAU.

Rev Opt (Theor Instrum) v30 Aug-Sept 1951 p 357-65 in French. A long tube contains seven pivoted, partially

reflecting mirrors and an autocollimator. The deflections of the mirrors can be read simultaneously in the eyepiece. The apparatus is adjusted on a flat surface and when

placed upon the test piece the deflections give a measure

of the profile. Constructional details are given and the accuracy (about 1 sec of arc) is compared with that of other methods of measuring straightness of flat tables, tubes, etc. The speed and ease of operation are features

of this method. Contour Mapping of Optical Surfaces with Light Waves.

Glass Indus v32 n8 Aug 1951 p 409-11. Vacuum light interferometer developed by J. B. Saunders of National Bureau of Standards makes contour maps by photographing interference patterns formed when light waves are

reflected from precise optical surfaces of specimen and

standard reference of known shape; adding additional

lines between half wavelength lines reduced spacing to 6 ten-millions of inch. Precise Topography of Optical Surfaces, J. B. SAUNDERS. J Res NBS v47 n3 Sept 1951 (RP2239) p 148-55. Unit of length usually used in measuring optical surface

features, by interference of light, is one half wavelength

of monochromatic light that is used ; method is described

in which unit of length is much smaller fraction of wavelength ; topographic maps of optical surfaces are made

in which contour interval is less than l/30th wave length. On the Examination of Nearly Straight Edges (Rulers) and of Nearly Plane Surfaces, R. E. H. RASMUSSEN.

Fysisk T v51 n5-6 1953 p 129-42 in Danish. Formulae

are derived for deducing the deviations from a straight

lime (plane) of an approximately straight edge (approx. plane surface) from measurements of gaps between three edges (surfaces) taken two at a time. Formulae for the

standard deviation in the final results arising from errors

in the individual gap measurements are given. Illustra- tion by means of an example in which interference fringes were used to measure the gaps. Two Methods of Measuring Degree of Straightness of Microscope Stage, R. M. TENNENT. J Sci Instrum v30 n3 Mar 1953 p 89-90. First of two techniques described makes use of Michelson interferometer and measures con- tribution to overall noise level made by stage; second depends on artificially produced straight line as standard and includes contribution due to observer errors as well as that due to stage. Testing Methods for Production of Accurate Machine

Slideways, G. N. LEVESQUE. ASME Paper No. 53-A-69

July 29 1953. The problem of making accurate machine

slideways is intimately tied to that of making accurate

straightedges and master planes. Paper deals only with

cast-iron machine ways and straightedges. Surface Curvature, A Tool for Engineers, E. WILD- HABER. Industrial Mathematics, Detroit, v5 1955 p 91-

116 22 figs. The usual mathematical treatment of surface curvatures employs plane sections laid in various direc- tions through the surface normal at a given mean point. The more direct treatment presented employs tangent

cylinders to define a curvature surface. Subject headings

are : surface elements ; a pair of component elements ; the surface normals ; principal directions ; line of contact with

a tangent cylinder ; curvature of tangent cylinder ; more

than two elements; addition of an element to a pair of contacting surfaces ; equidistant or parallel surfaces ; conical surfaces ; surfaces of revolution ; summary ; appli- cations. Condensation of article appears in Product Eng

v27 nl9 May 1956 p 184-91, 12 figs. An Interferometer for "Straightness" Measurement,

J. DYSON. Letter in Nature (London) vl75 Mar 26 1955 p 559-60. An interferometric system is described which

is of use in checking the straightness of a mechanical motion such as that of a lathe-cutting test. The system

is based on two identical concave mirrors separated by

their common radius of curvature. The reference straight

is defined by a line joining the two centers of curvature. Between the mirrors is a Wollaston prism. A fringe sys- tem is formed which moves if the Wollaston prism is dis- placed at right angles to the axis but not for displace- ment in any other direction, and this is the straight. A

sensitivity of 0.00008 in. per fringe has been obtained. A Non-Contact Interference Method of Checking Spherical Lens Surfaces. YU. V. KOLOMIITSOV, I. I. DU- KHOPEL. Optika i Spektrosk vl nl 1956 p 94-101 in Russian. Superposition of a test piece when checking

spherical surfaces of lenses is a method having certain shortcomings. The paper describes an equipment in which the lens is supported clear of a test surface. A

system of interference rings is observed from which it is possible to determine with high precision not only deviations of the radius of curvature of the surface from the nominal value but also local errors of the surface. Illus- trated with diagrams and photographs. Multiple-Beam Interference and Equidensities, W. KRUG.

Optik vl3 nl 1956 p 25-33 in German. A general survey

of the principles of multiple-beam interferometry as applied to the study of surface topography. This is followed by a description of the equidensity technique. In this interference fringes are photographed with two-beam sys- tems and then the photographic plate is examined by a

light-scattering technique which reveals the edges of the broad fringes as sharp lines. Comparison is made be- tween the two systems and the information content in the multiple-beam fringes and in the equidensity fringes

is discussed. 182
Einfaches Verfahren zur topographischen Darstellung

einer optischen Planflache ( Simple Process for the Topographical Representation of an Optically Plane Surface),

R. BUXXAGEL. Zeit fur Angew Phys v8 1956 p 447. Pomiary prostoliniowosci i plaskosci metodami hydro- statycznymi (Application of hydrostatic methods for measuring straightness and smoothness), B. D. NIKITTN.

Mechanik v30 nlO Oct 1957 p 413-6. Open hydrostatic sys- tems and systems with closed circuit and constant level. Adapted from Stanki i Instrument. Double Interferometer for Series Control of End Measure

Gauges, G. VOGL. Microtecnic vl2 nl Feb 1958 p 8-10. Instrument built for series control of planeness and plane

parallelism of slip gages; apparatus incorporates two

Fizeau type interferometers built into one another, and

two standard plates between which are put comparison

piece and piece to be measured ; 90° prism is used for observation of rear surfaces. Micro-Interference as an Aid to Testing the Shape of Aspherical Surfaces. R. LAXDWEHR. Ann Phys (Leipzig) Folge 7 v4 nl-5 1959 p 154-66 in German. The test- ing of the strongly curved aspherical surfaces of rotation now so widely used can be carried out with a microinterference method. Measurements made over small

regions permit an analysis of the whole. The theory of the method is developed in detail and the equations of the

interference curves are derived. Interference curves are

given for a paraboloid viewed in various zones and special cases are numerically evaluated. It is shown that the

interferometric results are in agreement with spherometer measurements.

Interferometric Measurement of Straightness of Plug

Gauges, F. R. TOLMOX. Machy (London) v94 n2412 Feb 4 1959 p 275-7 ; Engr v207 n5374 Jan 23 1959 p 136-7. Apparatus described consists of Flzeau-type interferometer and microscope with micrometer-controlled graticule

for viewing and measuring fringes : results of test on % in. diam by % in. long plug, and of independent test on

different generator of same % in. diam plug. Measurement of the Waviness of Bearing Rings, G. S. SIMKIX. 0. P. FOMIXA. Meas Techns 1958 n2 Aug

1959 p 131^3 4 figs. Translated from Izmer Tekh n2 Mar-Apr 1958 p 11. Describes device which makes it possible to measure the waviness on the working surfaces

of the main groove tracks of antifriction bearing rings. Discusses four main points which must be considered when

developing instruments for measuring the waviness of bearing rings. Interference Method for the Examination of the Surface Waviness of Balls, IU. V. KOLOMIITSOV. Meas Techns

1958 n3 Xov 1959 p 300-4 2 figs 4 refs. Translated from

Izmer Tekh n3 May-June 1958 p 43. The device and

method described enable to clear presentation of the profile of the ball surfaces being examined, and the measure- ment of the depth of local deviations of this surface from

a perfect sphere, with an error of 0.03-0.1/t to be made. An observation of rings is useful for a rapid qualitative assessment of the ball, while the measurement of the depth

of local irregularities on its surface is determined with

a higher accuracy from the distortions of the "straight" bands. The method can be recommended for the selective inspection of balls during their manufacture and also for use in the assembly of precision bearings. The use of this method can considerably increase the accuracy of the in- vestigation of deformations on the surfaces of balls during

the operation of the bearings. The Measurement of Geometrical. Dimensional, and Positional Errors of Technical Bodies by Means of the ESystem, H. VOX WEIXGRABER. Microtechnic vl4 Aug

1960 p 173-80. Discusses form error, dimensional error, and positional error.

An Optical Instrument for Measuring Generator Form

on Large Rolls, P. W. HARRIsOX. XPL. Optics in Metrology. P MOLLET. Pergamon Press, 1960, p 383. Instrument measures the camber on the surface of rolls such as those used in paper and steel mills, which may be

as much as 7 m (24 ft) long and up to 4 m (14 ft) in diameter, to an accuracy of ±10 microinches under opti- mum conditioning. Applies Young's interference fringes. An Instrument for Controlling Waviness and Deviations from the Correct Geometrical Shape, T. S. LOPOVOK.

Meas Techns 1960 n5 Jan 1961 p 381-2 3 figs. Translated from Izmer Tekh n5 p 9-10 May 1960. An instrument for checking the waviness and shape of cylindrical details 70 to 700 mm long and 10 to 70 mm in diameter. The

instrument provides measurements of longitudinal and

transverse waviness as well as deviations from the correct

cylindrical shape, such as a tendency to become oval, polyhedral, tapered, etc. It is also possible to determine by means of the instrument complex deviations along the

axis of the cylinder, such as the runout of one shoulder with respect to another, difference in diameters, etc. For

the evaluation of the tested dimensions, a micron indi- cator is included in the instrument. Determining the Waviness of Raceway Surfaces in Frictionless Bearing Races. B. E. BOLOTOV. Meas Techns

1960 n5 Jan 1961 p 383 2 figs 1 ref. Translated from

Izmer Tekh n5 p 10-1 May 1960. The IV-1 instrument

described provides, in practice, a measurement of the

height of waves in the range of 0.05 to l/i. Depending

on the initial gap between the plates of the transducer,

this range can be extended to 20/i. This device is based on the measurement of small displacements by means of a

capacitative transducer. Optische precisiemetingen op civiel en werktuigkundig

gebied in de praktijk (Optical precision measurements in

civil and mechanical engineering) . S. H. LIEM. Ingenieur v73 n8 Feb 24 1961 p 033-42. Precision alignment methods developed by Van Heel, which permit three points to be put in straight line with accuracy better than 0.2 sec- ond of arc. appear to be practical, accurate and simple ; optical instrument for measurements on experimental run- ways at Schiphol airport described. Recording Method for Surveying the Relief of Highly

Plane Surfaces. G. KOPPELMAXX, K. KREBS. Optik (Germany) vl8 n8 Aug 1961 p 349-57 in German. In

order to investigate the topography of accurately plane

surfaces, a photoelectric measuring device was developed,

the main part of which consists of a pressure scanning Fabry-Perot interferometer. In this instrument multiple beam interference is used under favourable conditions,

i.e. high accuracy of parallelism of the reflecting surfaces,

utilization of the steep slopes of the Airy intensity distri- bution and direct calibration of the scale of surface elevations. Thus very high accuracy of measurement

(±X/1000) and fairly high speed of recording can be

achieved. A corresponding photographic method is also described. Precise Measurement of Straightness of Cylindrical Surfaces, R. G. X. HALL. Engr v212 n5508 Aug 18 1961 p 273-5; Quality Engr v25 n5 Sept-Oct 1961 p 151-5. Interferometric method, using simply constructed equip- ment, by which straightness of generator of cylindrical surface up to 12 in. in length may be measured, without damage, to accuracy of plus or minus 5^in. even when

total error may be as much as 100/rin. ; pen recording en- ables magnitude and sign of errors to be deduced directly

helices ruled on cylinders are used in production of diffrac- tion gratings. Measurement of Wave Fronts Without a Reference Stand- ard: Part 1. The Wave-Front-Shearing Interferometer,

J. B. SAUXDERS. J Res XBS v65B n4 Oct-Dec 1961 183

771-846 O—66 13
p 239-44 4 figs 5 refs. The wave-front-shearing inter- ferometer may be used to test any converging wave front regardless of whether or not it is symmetrical. A mathematical operation is described that permits complete analysis of the data. This operation yields values of the devi- ations of wave fronts under test from a close fitting sphere. The reference surface may be chosen statistically so that

the results are the deviations from a best fitting sphere. Radial Shearing Interferometer, P. HARIHABAN, D. SEN. J Sci Instrum v38 Nov 1961 p 428-32 8 figs 8 refs. A new type of wave-front-shearing interferometer is de- scribed in which two images of the wave front under test which are of different sizes are made to interfere. When

the centers of the two images are made to coincide, this results effectively in shear along the radial direction. It

is shown that the interpretation of the resulting inter- ferogram is comparatively easy. The instrument is ex- tremely convenient to handle, since all the adjustments

can be made with a white light source. The Testing of Shape with Micro-Interference. A New

Surface Interferometer, R. LANDWEHR. Zeit Angew

Phys v4 nlO 1952 p 377-86 in German. The Linnik type

of micro-interferometer is modified to accept and examine

relatively large workpieces. By the introduction of a long

dividing prism interferometric tests can be carried out

over a surface length of 12 cm. An instrument is described employing the proposed modification. The workpiece can

be traversed over the full length and the system has in- dustrial and technological applications. A comprehensive

bibliography is included. Initerferometric accuracy is 0.03^. Measurements of Wave Fronts Without a Reference Standard : Part 2. The Wave Front-Reversing Interfer- ometer, J. B. SAUNDERS. J Res NBS v66B nl Jan-Mar

1962 p 29-40 13 figs 6 refs. Interferometers permitting the measurement of shape and altered distribution of fringes are usually used to compare either an unknown wave

front with a known one or an unknown surface with a standard reference surface. Any error in the reference

surface introduces a corresponding error in the results sought. This paper describes an absolute measuring in- terferometer and the associated mathematical operations necessary for analysis of the data. The reference surface

is purely mathematical in nature and is therefore free from error. Deviations of converging wave fronts from

perfect spheres, paraboloids or ellipsoids are readily meas- ured without the use of tangible reference surfaces. The

equation of the reference surface may contain one or more

parameters whose value is sought. Thus, the eccentricity

of the conicoid that best fits a mirror and deviations of the surface from the true mathematical curve are obtained

simultaneously. The sensitivity of the test can be varied

so that when testing large aspherical elements which

depart very far from spheres the number and width of the

fringes can be adjusted to any desired values. Mapping of High-Quality Optical Flats Without Beflec- tion Coating, F. L. BOESLEB. J Opt Soc Am v52 n4 Apr

1962 p 471. A pair of optical flats is enclosed in a pressure chamber. The pressure is adjusted so that /il=yi (n+ % ) X0 when the intensity of monochromatic reflected light varies most rapidly with I. A photomultiplier is used to measure the fluctuations in intensity when the plate is scanned by a beam from a movable slit. Distribution of Depression in Paper Surface: A Method

of Determination, B.S. HSU. Brit J App Phys vl3 n4 Apr 1962 p 155-8. When ink is applied to a paper surface from a smooth plate the area which becomes coated is well known to depend on the thickness of the ink film on the

plate. A simple, two parameter relation is found which

describes this dependence, and it is shown that this effect provides a convenient method of determining the top- ography of the surface of a paper. A treatment was de- veloped whereby the frequency distribution of the depth

of depression in a paper surface can be determined by measuring the areas covered with ink when films of dif- ferent thicknesses are applied. The area coated may be measured directly or found by observation of the diffuse reflectance of the printed paper: an equation is derived whereby the distribution of depression can be calculated

to a reasonable accuracy from measurements of the diffuse

reflectance. Typical distribution curves obtained by this method show maxima near the shallow end—at about

0.2/tm for coated papers and at about l/*m for newspapers.

Testing Straightness of 40-inch Ways to ±S Microinches,

E. G. LOEWEN, B. L. BARLOW. r ASTME Creative Mfg

Seminars—Tech Paper SP63-92 Feb 1963 10 p. Design of new precision ruling engine at Bausch & Lomb called for pair of machine ways 4 ft. long, which had to be straight within 20/iin. over 40-in. segment of length; measuring

system capable of detecting surface displacements of 2/dn. or less was required; Davidson Optronics Model D-665

Automatic Autocollimator was selected for inspection; lapping of ways ; direct recorder of surface profile ; results given; advantages of surface inspection technique de- scribed over conventional methods. Raising the Efficiency of Testing Straightness by the Microleveling Method, L. L. MEDYANTSEVA, V. V. GOB- BACHEVA. Meas Techns 1962 n8 Feb 1963 p 646-8 2 figs. Translated from Izmer Tekh n8 p 22-3 Aug 1962. Microleveling is the most common method of testing the straight- ness of large-sized bed-plate guides. The main defect consists of the large time required for testing, since the air bubble becomes agitated each time the level is displaced and a certain time is required to bring it to rest. The

time spent on checking linearity by the microleveling method and the effect of external conditions can be re- duced considerably if the mierolevel is displaced along the

tested surface uniformly by means of a special device in- stead of being displaced by hand. The improvement of the microleveling method provides higher accuracy in measurements and other advantages. Rapid Testing of Maximum Straightness Ways, E. G. LOEWEN. Standards and Metrology Div, AOA May 16, 1963. Evaluation of direct optical and indirect straight- ness measurement methods.

Multivariable Curve Interpolation, J. FEBGUSON. Assn Computing Machy-J vll n2 Apr 1964 p 221-8. Generalized method for solving problem of defining smooth surface through array of points in space is presented to include

cases where point arrangement is topologically equivalent

to planar rectangular grid, and resulting solution is smooth composite of parametric surface segments ; solu- tion is readily applicable to variety of problems, such as

closed surface body definitions, pressure envelope surface

definitions, numerical control milling, Newtonian impact, and boundary layer. Optical Systems for Observing Surface Topography by

Frustrated Total Internal Befleetion and by Interference,

C. W. McCUTCHEN. Bev Sci Instrum v35 nlO Oct 1964 p 1340-5. Distortion and tilting of image to which

Gaussian approximation applies, appear when optical sys- tem is arranged with its axis parallel to emerging light, and can be avoided by making axis of optical system nor- mal to object plane; system must then deal with light entering it at greater than critical angle ; this can be done

with special device for adapting conventional microscope

for study of topography ; method is illustrated by examples of application to dielectric and metallic surfaces. 184
7.4. Roundness and Concentricity Measurement

A New Form of Contour Caliper, W. F. DURAND. Sibley J Eng vl3 Jan 1899 p 129-35 6 figs. An instrument devised

to determine whether or not the contour or cross section

of a pin, axle, or spindle is circular, and if not, the finding where it departs from the true or circular outline. Comprises 3 micrometers spaced at 120° about a ring, fig. 5. Thus discriminates between a circle and other figures of constant breadth. A Three-Point Micrometer and Its Use. Machy (N.Y.) vl9 May 1913 p 688 3 figs. Describes a micrometer caliper for determining roundness of crank pins which may have a

tri-lobed shape. Zusammenhang zwischen Kraftfluss, Walzlager und Pas- sungen (Correlation Between Magnetic Flux, Antifriction Bearing and Fits), J. KIRNER. Betrieb v4 n20 July 8 1922 p 459-64 16 figs. In three parts. Part 3 : Indication on the necessity for differentiation between thickness and roundness. Description of regular and irregular sur- faces and bodies which are in no way round but instead are of equal thickness in every direction. Introduction of the designation "the equally thick". The hazard of unroundness. Testing of roundness. Figs. 6-16 show such

figures. Factors Governing "Out-of-Roundness" Measurements, A. H. FRAUNTHAL. SAE J vl3 Nov 1923 p 370-^ 7 figs. Types of out-of-roundness and those peculiar to certain machines ; three-point measuring system ; errors of V-block method ; use of V-block for elliptical objects ; other methods of checking elliptical forms and indicator-reading

correction ; three items for instrument improvement are

suggested. See also Trans. S.A.E. 1923, Part II, pp. 600-

613. Ammco Round-O-Meter Gage. Am Mach v73 Dec 11 1930

p 945-6. A direct reading indicator for checking roundness and size of objects from % to 6 in. in diameter has

been announced. Readings are accurate to 0.0005 in. By

using 'Ammco" gage setting rings, the "Round-O-Meter"

can also be used for direct measurement and comparative

checking. Gage setting rings are furnished on special order in any specified diameters, over-sizes or under-sizes, within the above range. Multipoint Gages, H. SHAW. Am Mach v75 n2, 4 and 5 July 9 1931 p 44-6, July 23 p 173-5 and July 30 p 208-11 42

figs. Possibilities of error in checking roundness with 3- point gages ; great variety of non-circular shapes will fit perfectly all positions of micrometer ; initial position of gage arms in relation to triangular path of center controls

limiting length of arm. Uber Gleichdicke (Regarding Equal Thicknesses), A. E. MAYER. VDI Zeit v76 Sept 10 1932 p 884-6. Analysis of

difference between circle and constant diameter figures with particular regard to formulation of maximum differ- ence. For supplementary note see VDI Zeit, v77, n6, 153, Feb. 11, 1933. Constant-Diameter Figures, F. W. SHAW, H. SHAW.

Machy (London) v40 Sept 22 1932 p 777-9 and 41 Oct 13 p 40-2, Nov 24 p 223-5 ; and Dec 22 p 349-51. Sept 22

Geometric characteristics of various types of constant-di- ameter figures from viewpoint of checking roundness

polygrams as evolutes of figures of constant diameter. Oct

13 : Figures with curvilinear evolutes ; stages in evolution of constant-diameter figures from curved centrode;

figures whose contours are wholly involutes of circles. Nov. 24: Application of constant-diameter figures in de- sign of cams, gears and levers. Dec. 22 : Effect of inac- curacies in balls and rollers; quasi-spheres of constant

diameter.

Messen und Pruefen des Unrunde (Measurement and

Testing of Out-of-Roundness), K. DRESS, VDI Zeit v84 n47 Nov 23 1940 p 909-12. Causes of imperfect roundness and methods of its determination ; instruments for checking roundness ; proposed roundness tolerances. Messung der Aussermittigkeit von Kreisen und der Nei- gung von Flaechen in bezug auf die Drehachse (Measure- ment of eccentricity of circles and inclination of planes about rotating axis), E. STUMPP. Archiv Tech Messen

nl23 Sept 1941 p T119 (2 p) (V8224-3). Theoretical study of method ; additional computation in case number

of points are insufficient for plotting diagram.

Cylinder Wear and Distortion as Measured With Cylinder Contour Gage, M. E. ESTEY. SAE J v56 n9 Sept 1948 p 30^; Diesel Power v26 n6 June 1948 p 54-8. Gage

consists of 0.0001 in. reading dial indicator on lower end

of 2y2 in. diam. tubular gage shaft ; shaft is so mounted

that it may be centered accurately in cylinder, then

raised, lowered or rotated to bring indicator into position ; optical system provides enlarged view of indicator dial

application procedure; examples of abnormal cylinder

contour. Precision Measurement of Circularity, Concentricity, and

Straightness of Plain and Tapered Rings and Plugs, M. J. PUTTOCK, NPL. Machine Shop Mag Oct 1948 6 p. Roundness Measurement. Aircraft Prod vl4 nl63 May

1952 p 151-3. Talyrond high precision instrument for checking departures from circular form of parts such

as balls, rollers, ball and roller races, pistons and cylin- ders, developed by Taylor, Taylor & Hobson, Ltd. How Round Is Round?, A. C. SANFORD. Am Mach v96

n23 Nov 10 1952 p 124-6. Definition of out of round;

double electronic gage head and differential classifier methods for out of round checking on automatic basis. Precision Measurement of Cylindrical Bores, J. C. CHERNA, B. GOODE. Tooling & Prod v21 nlO Jan

1956 p 73-5. Study made for resolving difficulties as- sociated with diametrical measurement of bores or holes ; determining major deviations from true circle; methods examined by which these deviations might be detected and measured ; Etalon Ingage developed as result of study makes possible detection of sources of geometrical error. What Makes Precision Spindles Precision Spindles?, E. W. PENNINGTON. Tooling & Production v23 nlO Jan

1958 p 84-6. Illustrated description of "zero spindle" used by N. A. Woodworth Co., Detroit, which permits checking of workpieces for true concentricity ; spindle is truly cylindrical and concentric with its own geometrical

axis; simplicity of design noted. Zur Steigerung der Genauigkeit mikrointerferometrischer Untersuchungen und zur einer Interferenz-Sphaero- metrie ( Improvement of accuracy of micro-interferometric examinations and problem of interference-spherometry )

,

R. LANDWEHR. Zeit fur InstrumKde v66 n7 July 1958 p

134-8. Corrections to be considered in precise microinterferometric work to determine form of objects, where

double beam interference with conventional micro- interferometers is used ; possibility of more accurate inter- ferences spherometry. 17 refs. "And Must Be Round Within." Am Mach vl02 n7 Dec 1 1958 p 109-20. Symposium on basic problems of measuring out-of-roundness; .XXXX" Full Indicator Reading, W. G. CANFIELD ; Critical Remarks, F. MEYER, JR. ; V- Block for Roundness Check in Toolroom, A. N. APPLEBY

V-Block Angle Depends on Number of Lohes, J. WOR- THEN; Adjustable V-Block for Machine Checkup, C. A. 185
WHITNEY; Electronic Gages Check Crankshaft Roundness, P. E. CARBONE ; Lobing of Cylindrical Features and Its Measurement, W. J. DARMODY ; Lobing Measure- ments in Metrology Laboratory, R. MAHLMEISTER;

Measurement of Roundness to Millionths, E. J. SCHNEI- DER ; Roundness Measurement by Radial Means, F. W. WITZKE.

Rundlaufabweichung und Unrundheit (Revolving Deviation and Out-of-Roundness), R. NOCH, PTB. Wiss Zeit der Tech Hochschule Dresden v9 n4 p 975-80 1959/60.

Lists several references. The Assessment of Roundness of Workpieces, R. E. REASON. Taylor, Taylor, and Hobson. Feb 13 1959 9 p 7 figs. The assessment of the roundness of workpieces, the stand- ardization of cut-off frequencies ; the true mean circle ; the assessment of spindle errors. Measurement of the Eccentricity of Articles Mounted at the Center, A. D. RUBINOV, Meas Techns 1958 nl Aug

1959 p 13-7 4 figs. Translated from Izmer Tekh nl Jan- Feb 1958 p 12. Discusses measurement of eccentricity of

cylindrical articles mounted on centers using a single indi- cator and taking into account deviation from circularity. Three cases are considered in some detail. Theory and Practice of Gaging Pseudoroundness, L. A. BOLDIN. Meas Techns 1958 n3 Nov 1959 p 307-12 5 figs 3

refs. Translated from Izmer Tekh n3 May-June 1958 p 48. Develops mathematical theory of lobed figures. An Interferometer for Testing Sphericity, J. W. GATES.

Optics and Metrology. P. MOLLET. Pergamon Press

1960 p 201^1 6 figs 3 refs. Instrument shows directly the departures from sphericity of convex surfaces up to 13 mm radius. A solid angle of nearly 2tt is covered at one

time. The problem of correcting the distortion caused by

projecting a spherical surface on a plane is briefly dis- cussed. Onrondheidsmetingen, A. VISSER. Ingenieur v72 nl6 Apr

15 1960 p 01-4. Out-of-roundness measurements ; by using gaging tip and that fiat anvil or gaging tip and Vee-block

true indication of out-of-roundness of cylinder cannot always be obtained ; Talyrond instrument designed by

British firm of Taylor, Taylor & Hobson, makes it possible

to obtain graphic representation of variation in radius of cylinders and borings. A Pneumatic Detector for the Control of Coaxiality of Two

Surfaces, A. V. VYSOTSKII. Meas Techns 1959 n5 June

1960 p 311-2 2 figs. Translated from Izmer Tekh n5 May

1959 p 9. Describes a device for measuring coaxiality by means of a special pneumatic detector, which is free from

imperfections of the "wobble" method of measuring the

coaxiality. The use of two carriers moving in a mutuallyperpendicular direction and contacts in the form of cylin- drical surfaces, permits the obtaining of correct measure- ment results by geometric addition, independently of the

direction of the maximum eccentricity of axes- Measurement of Surface Waviness of Rolling-Element Bearing Parts, O. GUSTAFSSON, U. RIMROTT. SAE

Paper nl95C for meeting June 5-10 1960 13 p. Principle

of waviness testing to evaluate irregularities of .surface of rotation ; current method of vibration testing ; cor- relation between waviness and vibration ; ball waviness

tester, applied at SKF Industries, Philadelphia, Pa., consists of true running spindle driven at constant .speed of 740 rpm, velocity sensitive pickup, and ball seat ; displace- ment and velocity reading instruments ; waviness tests in determining parts responsible for excessive vibrations

calibration method. Pneumatic Roundness Measuring Instrument, C. A. SCOLES. Machy (London) v96 n2485 June 29 1960 p

1648-53. Description of instrument developed from experimental vertical air bearing made at National Engineering J Laboratory ; experimental unit, consisting of simple shaft { supported pneumatically in vertical brass bearing, was I constructed to enable performance data of such bearings 1 to be determined ; details of air bearing unit ; pneumatic I measuring head; pneumatic circuit; performance of I instrument. Rotors in Polygons and Polyhedra, M. GOLDBERG. 1 Mathematics of Computation vl4 n71 p 229-39 July 1960. 1 Lists 36 references including a patent on a method of

' measuring out-of-roundness of machined parts. Selecting a Method of Reference in Measuring the Undula- f tion of Antifriction Bearing Races, V. V. MATVEEV, V. ,1

,

L. RYASKOV. Meas Techns 1959 nil Sept 1960 p 855-7 5 I figs 3 refs. Translated from Izmer Tekh nil Nov 1959 p 18. | Advantages of making recordings with reference to man- |

, drel surface, in order to determine size of undulations, de- I viations of ball race track from circular shape to oval one,

j and its eccentricity with respect to fitting surfaces. Errors in Determining Regular Undulations of Cylindrical [ I Surfaces, Z. P. GROZINSKAYA. Meas Techns 1960 n9 Apr 1961 p 730-3 6 figs. Translated from Izmer Tekh .j R n9 p 3-5 Sept 1960. Discusses various methods of measuring lobing. Investigating the Effect of the Microinterferometer I io Aperture on the Accuracy of Measuring the Height of

Irregularities in a Triangular Profile, I. I. DUKHOPEL.

Meas Techns 1961 n7 Dec 1961 p 517-20 3 figs. 6 refs. ; f; Translated from Izmer Tekh n7 p 3-6 July 1961. It has

been established experimentally that a reliable evalua- I tion of the value of an interference fringe irregularity can

be made only when the width of the fringe visible at the k side of the groove amounts to at least 0.3-0.4 mm. On

machined surfaces this condition is met with a microinter- i ferometer magnification of the order of 300—400.

I On the New Measure of Roundness, M. IDO, R. NAGATA, i> Rf T. HAZI. J Japan Soc Prec Eng v28 nlO 1962 in Japa- : nese. A new measure of roundness corresponding to the j \ amount of approach to true circle is given by introducing I ijt the conception of information theory, and is compared with 1

i that of roundness popularly used at present. The charac- j} si< teristics of the new defined roundness are as follows : 1. pi

Each datum obtained by measuring is regarded as sj ax sampling function from an ensemble. 2. The number of i & measuring points is decided by limiting bandwidth of ir- i § regular circle. 3. The factor of error is contained. 4. I By expressing quantitatively the amount of approach to a Ij I true circle, the comparison between two and more data E- becomes possible. 5. This new measure is extended to 2 Ei the definition of sphericity. High Precision Roundness Inspection—Production Applications, F. W. WITZKE, L. M. NELSON. SAE Paper is 509A for meeting Apr 3-6 1962 7 p. Accurate measure- 3. ment of roundness is obtained by use of precision spindle iir roundness gage with polar recording device, developed by

Cleveland Instrument Co. ; advantages of precision spindle - roundness gaging over other methods are shown by ex- ' I amples relating to grinding, ball and roller bearings, etc. ; f I in addition to roundness rotating table polar graph " P roundness gage can be used for concentricity, squareness,

flatness, and other geometric relationship measurements.

1 k Determining Roundness from Profilograms, M. A. PALEI. Meas Techns 1962 n3 Sept 1962 p 188-91 3 figs. 1 ref. Translated from Izmer Tekh n3 p 9-11 Mar 1962. Devel- ops rules for evaluation from the profilogram of the nature and value of deviations from roundness. How to Measure Roundness, F. W. WITZKE. Tooling &

Prod v28 n8 Nov 1962 p 65-8. Main characteristics of most common methods for determining roundness of parts, j

ir including diametrical comparison. Vee block measure- l! Hi 186
ments. bench center radial measurements, radial comparison to master round, and radial comparison to ultra-precision spindle; their limitations and advantages. The Measurement of Geometric Shape of Cylindrical Components. C. A. SCOLES, Nat Eng Lab. Paper nil p 357-

400 24 figs discussion of the accuracy of industrial meas- urement of length and diameter, NPL Conf nl4, Her Majesty's Stationery Office London, 1963. Contents: Intro- duction; errors in geometric shape; elementary methods

of form measurement ; ideal method of form measure- ment ; performance accuracy ; commercial instruments

interpretation of circular records ; the effect of roundness

errors on performance ; terminology and future trends in roundness measurement ; conclusions ; discussion. Roundness Deficiencies, Their Functional Effect and Methods of Measurement. F. FARAGO. ASTME Tech Paper

SP64-31, 1963-4 18 p 5 figs 2 tables. Suggests general

rules of procedure for the selection and application of the

best suited roundness measuring process. Microscope for Measuring Small Diameter Holes and

Their Concentricity. S. L. GONIK. Meas Techns 1962 n8 Feb 1963 p 648-9 2 figs. Translated from Izmer Tekh n8

p 23-4 Aug 1962. Describes the design of a microscope

for measuring small diameter holes and determining the

concentricity of two hole diameters in the body of a tractor jet atomizer. Measurement of Macrodeviations in External Surfaces of Cylindrical Components, T. S. LOPOYOK. Meas Techns

n8 Feb 1963 p 649-51 3 figs 1 ref. Translated from Izmer Tekh n8 p 24-6 Aug 1962. Discusses relations of macrodeviations of external surfaces and errors in the center

holes of the measured component. Measuring Roundness. Production Technology vl nl Apr

1963 p 29. Talyrond machine, developed by Rank Taylor Hobson Div of Rank Organization, is linked to special reference computer which, while profile graph is being

plotted, analyzes profile and computes reference circle based on principle of "least squares" ; having drawn profile graph, instrument proceeds to draw circle on chart during next revolution ; from reference circle it is easy to

spot highest peak and deepest valley and measure their sum as maximum peak-to-valley height of profile; refer- ence computer is also capable of separating ovality from

other irregularities, and then plotting '"least-squares"

ellipse as reference line ; other modes of operation. The Master Circle, L. G. WHITTEN. Y-KE-43 May 10

1963 11 p 9 figs, publ by Union Carbide Nuclear Co., Oak

Ridge. Term. Describes an accurate 12 in. round disc de- signed to check the accuracy of roundness measuring

equipment. It also provides an overall check of machine

accuracy. Combining slide inaccuracies, slide squareness, and spindle accuracy. Presented at the 18th Annual Meeting of the Standards and Metrology Division, American

Ordnance Association. Errors in_Measuring Waviness of Cylindrical Surfaces, Z. P. GROZINSKAYA. Meas Techns 1963 n2 Aug 1963 p

101-4 5 figs. Translated from Izmer Tekh n2 p 9-11 Feb

1962. Provides calculations which determine the errors produced in measuring the waviness of external cylindrical surfaces which are due to errors in the geometrical form of the components and inaccuracies in setting them

during checking. In each case when considering the effect of one type of error in the geometrical shape the effect of all other types of errors was excluded. Considers effect of eccentricity and effect of oval shape. Instrument for Measuring External Dimensions of Oval

Bodies. B. A. SHIPILEVSKII. Meas Techns 1963 n2 Aug 1963 p 118-20 1 fig. Translated from Izmer Tekh n2

p 22-3 Feb 1963. Measurements are made of the external perimeter of oval bodies with an error not exceeding

±15/i by comparing the tested dimensions with the dimensions of a reference cylinder, whose perimeter is inscribed on it for a corresponding mean section and external

diameter. The deviations of the tested body mean diameter are determined by dividing the perimeter deviations by jr. Measurement of the Roundness of Center Holes, G. S. BIRYUKOY. Meas Techns 1963 n8 Feb 1964 p 657-8

2 figs. Translated from Izmer Tekh n8 p 21-2 Aug 1963. The production methods of the component's center holes should ensure their coaxiality with minimum deviations, for which purpose it is necessary to machine the centers and after thermal treatment grind simultaneously both

center holes on special center-grinding machines with the

rotating component in the horizontal position. After

grinding, the holes should be lapped by means of cast- iron laps. Device for Measuring the Degree of Faceting in Wires,

Y. V. PEN'KOY. Meas Techns 1963 n9 Feb 1964 p 737 1

fig. Translated from Izmer Tekh n9 p 15 Sept 1963. A

handy device for measuring the lobing in wires in the range

0.118 to 7 mm without the use of special inserts and with- out resetting for wires of different diameters. Methods for Assessment of Departures from Roundness.

Brit Standards Instn—Brit Standard 3730 1964 37 p. Publication is concerned with assessment of roundness er- rors expressed in terms of variations in radius of part measured from common selected center, and with instru- ment requirements to be met in provision of these measure- ments; it embraces all instrumental and workshop

methods capable of providing required data. Telescopes for Measuring Linearity and Coaxiality of Medium-Size Articles by the Sighting Method, E. I. ROZENBERG, I. E. EFROS. Meas Techns 1963 nil Apr

1964 p 903-5 2 figs 4 refs. Translated from Izmer Tekhn

nil p 10-1 Nov 1963, Sighting characteristics of several

simplified sighting telescopes are tabulated. Two basic designs are described: (1) a double-image telescope for measuring the linearity and coaxiality of medium-sized

articles, and (2) three varieties for measurements at large

distances. Concentricity Gaging Problems Solved by Electronics, R. J. SPIKOWSKI. Machine & Tool Blue Book v59 nl2 Dec 1964 p 115-17. Measurement of concentricity de- pends on establishment of datum axis to which all readings may be compared ; this requirement can be met by

electronic radial roundness gage such as Indi-Ron, made

by Micrometrical Div of Bendix Corp ; this gage generates on polar chart imaginary centerline of part where engi- neer began his drawing ; in using it, workpiece is mounted

on gage spindle and adjusted so that axis of part and axis

of spindle are perfectly aligned ; this establishes datum

axis for part, imaginary centerline without which meas- urements can be inaccurate or misleading. Addendum to Section 7

7.1. Planeness Measurement

Ausmessung der Planheit von Flachen bisauf ein Milliontel Instrumkde v25 n5 May 1905 p 148. An interference Millimeter ( Measurement of the Planeness of Surfaces to method in which the reference optical flat is supported on

a Millionth of a Millimeter), O. SCHONROCK. Zeits three small steel balls. 187
Raster Method for Measuring Waviness and Deviations from Flatness in Machine Components, I. V. KRAGEL'-

SKII, A. A. PRIBYLEV, L. A. GOGAVA. Meas Techns

n" Feb 1965 p 586-9 7 figs 1 ref. Translated from Izmer Tekh n7 p 23-5 July 1964. Experience has shown that

the greater part of deformations in joints is not due to microirregularities, but is produced by the waviness of

the coupled surfaces. Therefore, the study of the surface 7.2. Parallelism

tiber eine neue Interferenzerscheinung an planparallen

Glasplatten und eine Methode, die Planparallelitat solcher Glaser zu priifen ( Regarding a new Interference Phenomenon with Plane-Parallel Glass Plates and a method for

testing the Plane-Parallelism of such Glasses), O. LUMMER, Ann Phys Chem v23 n9 Aug 1884 p 49-84 4 figs 7

refs. Describes an optical system in which circular inter- ference fringes are produced. Theory is developed. Interferometer Methods for Evaluating Deviations from

waviness of machine components is a very pressing problem. The raster method of determining waviness has the

facility for investigating a considerable section of a machine component and at the same time providing a graphic

picture of the surface under consideration. This method

is based on the use of an illuminated raster grid which

produces shadow patterns resembling Moire fringes. Measurement

Flatness and Parallelism of Large Block Gauges, V. P. GOLUBKOVA, V. P. KORONKEVICH. Meas Techns n9 Mar 1965 p 765-8 5 figs 11 refs. Translated from Izmer Tekh n9 p 9-12 Sept 1964. Reviews modern methods for an interferometric evaluation of the paralleleism of long gage blocks which have aimed at eliminating highly monochromatic sources of light. These methods are generally based on differential interferometers, in which the inter- ference pattern is formed by a part of the tested gage and not a reference plane.

188
Section 8. Measurement of Profiles

CONTENTS

Page

8.1. Measurement of radius or profile by mechanical methods 189

8.2. Contour measurement by optical projection 193

8.3. Measurement of involute contours 196 Addendum to Section 8 196

8.1. Measurement of Radius or Profile by Mechanical Methods

Lens-Curve Tester, G. HALLE. Zeit InstrumKde vl5 Aug 1 1902 p 142-3. A kind of spherometer with lever and

scale reading for measuring curvatures. On a Revolving Table Method of Determining the Curvature of Spherical Surfaces, G. F. C. SEARLE, A. C. W.

ALDIS, G. M. B. DOBSON. Phil Mag v21 Feb 1911 p 218-

24 2 figs. Method has the advantage that the radius is found directly from two readings on a straight, uniformly

divided scale, without corrections or calculations. Describes principles of method and details of equipment. Simple Method of Determining Radius of Curvature of Spherical Surfaces, W. C. BAKER. Nature v95 May 13

1915 p 288 1 fig. The small lens or object to be tested

rests on a ring on a little frame. A small three-legged

optical lever is then placed in two positions whose spacing,

s, is fixed by the arrangement of the frame and can be measured by a microscope. The angle 6 corresponding to these two positions is noted by the optical lever; hence

the radius desired is given by P=s/0.

Contour and Radius Measuring Instrument. Maehy v24 June 1918 p 898- 9. Designed by J. H. WILHELM for Frankford Arsenal. Universal type for measuring irreg- ular profiles, radius gages, and contours that cannot be

tested by ordinary devices. The Measurement of Gauges, E. A. FORWARD. Engr

vl27 Mar 21 and 28 1919 p 282-3 and 294-5 24 figs. Methods used for measuring three classes of gages: (1) plate or form gages the profiles of which are combinations of straight lines and curves; (2) conical plugs, rings and disks, combinations of cones with cylinders and

planes, and castellation gages; (3) position gages. Refinements in Spherometry, G. W. MOFFIT. Phys Rev

vl3 Apr 1919 p 261-71 8 figs. Precision in mechanical methods is asserted to decrease rapidly as radius becomes

larger; by auto-collimating method, up to limit of slide on turntable, precision is said to be high and independent

of radius ; methods are found to possess high degree

of precision of measurement for concave surfaces of any

radius and for measurement of convex surfaces to de- crease in precision with increase of radius. The Measurement of Radii on Profile Gages. NBS Letter

Cir LC 20, June 21 1919. Describes methods of measuring large and small radii. Use of Microscopes in the Gage Section, Bureau of Standards, R. L. RANKIN. Am Mach v51 Sept 18 1919 p 581-2. Discusses use of microscope in linear measure- ments on gages, etc.

A Spherometer of Precision, J. GUILD. Sci Am Supp v88

Sept 20 1919 p 184-5 3 figs. Designed with a view to obtain greater accuracy in determination of exact point

of contact of micrometer leg with surface of lens or flat under examination than is usually obtained with sphe- rometers of existing patterns. Paper read before Optical

Society. Profile-Curvature Gage, W. SOUDER, NBS. Am Mach

v53 nl6 Oct 14 1920 p 732 1 fig. Describes a convenient arragement of instruments for measuring the curvature

of an arc. Curvature Measurements, J. GUILD. Opt Soc Trans v22

1920-1921 p 127-38. Description of the arrangements of well-known optical methods of spherometry which the author has found most suitable for accurate determinations, and also of a new microscope method suitable for medium and large curvatures. Precise Inspection of Large and Irregular Curves, E. O. BROWER. Am Mach v54 Jan 13 1921 p 60-4. In this method only one of the sides which must be measured

directly is long, while the others are comparatively short and easily measured. Finding Dimensions of Profile Gages, W. G. HOLMES. Am Mach v54 Mar 31 1921 p 567, Apr 7 1921 p 614-5. Gives formulas for cases where side of an angle joins a

circular arc. A Modified Spherometer, H. S. ROWELL, Sci Instrum

vl Oct 1924 p 17-20. An inherent lever in the spherometer is utilized to magnify the readings obtainable by making one outer leg micrometric while the others are

fixed. Suggested that a unit of curvature is desirable. Inspecting Large Radius Gages. Machy (London) v27

1926 p 754; C. KUGLER, Machy (N.Y.) v32 Jan 1926 p

403-4 May 1926 p 736. Describes method of deriving

radii of large gages by applying rolls and precision gage

blocks to measure height of arc over a distance between

the rolls. The rolls are soldered to a base. Measuring Machine Simplifies Laying Out of Dies and

Gages. Am Mach v67 Dec 1 1927 p 843-4 4 figs. National Cash Register Co., Dayton, Ohio, has built measuring

instrument termed laying-out machine ; by its use average

laying-out time for work has been cut to approximately

one-third of that taken by former methods, with added

advantage of producing more accurate layout. (Ueber die genaue Messung grosser Durchmesser) (Precise Measurement of Large Diameters), H. SCHMIDT.

189
Maschinenbau v7 Aug 2 1928 p 720-1 2 figs. Mathematical

discussion comparing precision of direct micrometer meas- urement with indirect method by rise of arc ; finds latter

is less precise of two. The Inspection of Form Gauges. Machy (London) v32 Aug 9 1928 p 609-10 7 figs. Method of inspecting form

gages and calculations involved are described. Sur un Procede optique de Localisation des Surfaces

polies, et son Application a la Mesure des Rayons de Courbure. (Optical Procedure for Testing Polished Surfaces and its Application for Measurements of Radii of Curvature), A. ARNULF. CR Acad Sci vl87 Dec 3 1928 p 1044-

6. Microscope is used to view two sets of cross wires, one

of which is illuminated. The more distant one is viewed by a powerful Ramsden eyepiece. The virtual image of one set of cross wires serves as an object for the surface

tested, and a position is found such that its image in this surface coincides with the image of the other set of cross

wires. The application of the method for the measure- ment of radii is discussed, and its freedom from the usual

faults of auto-collimation. Annular Spherometers, A. BIOT. Ann Soc Sci de Bruxelles v49 Dec 1929 p 251-7. The author discusses fully the accuracy obtainable with the usual type of annular sphero- meter and the advantages and disadvantages attendant upon its use. In putting forward the superiority of the

special form using three non-tangential spheres it is claimed that the magnitude of the likely error can be re- duced from 1/5 to 1/10 of that of the ordinary instrument,

and, further, that the measurements can be more easily made. An Instrument for the Measurement of the Contour of Fibres and Filaments. S. G. BARKER, M. H. NORRIS.

J Sci Instrum v7 Jan 1930 p 22^4 3 figs. It is necessary

for purposes of wool examination, and to be able to ex- amine fiber at all points along its length, and at the same

time to examine filament completely at any point by rotat- ing it through 360 degrees and for this purpose fiber rota- tor has been designed ; it comprises improved form of existing apparatus (Polikeit) and is capahle of taking fibers up to 10 in. in length and of smaller lengths down to less than 1 cm. Markings on Bullets and Shells Fired from Small Arms,

C. O. GUNTHER. Eng Soc Boston J vl May 1930 p 7-25

16 figs. ; Mech Eng v52 Dec 1930 p 1065-9 14 figs. Study

of engravings made on cylindrical portions of bullets by

lands and groves of bore of automatic pistol and of breech- block and firing pin imprints on cartridge cases and

primers. Spherometers, A. BIOT. Ann Soc Sci de Bruxelles v51 Mar 12 1931 p 5-12. Description of a spherometer employing the compass principle. Classification of spherometers according to the geometrical formula on which they are based. Detection and Measurement of Longitudinal Curvature

of Small Surfaces of any Cross Section, H. E. GAUSS. J

Sci Instrum vll May 1934 p 157-62. Methods of illumi- nation of grooves for microscope work are reviewed and

a new method described for detecting and measuring

undulations that are too small to be resolved. Formulas

are obtained for determining the curvatures from the

observations. How to Lay Out Optical Systems, R. C. HITCHCOCK.

Prod Eng Dec 1934 p 450-1. For a given magnification, projection distance, image size, and type of lamp, aline- ment chart gives the optical efficiency, the diameter of the

lens or reflector, and its focal length. Radien-Messungen (Measurement of Radii), K. GIESS- BART, Archiv Techn Messen v44-5 n85 July 1938 p T89-

90 (4 p) . An account of the methods of determining radii of curvature, chiefly of lenses, by calculation and by direct and indirect measurement. Curved Rulers, F. EMDE, Zeit InstrumKde v58 Oct 1938 p 409-11. With curves of slowly varying curvature a useful method of representation is a series of circular arcs, since at any point a fairly long portion of the curve nearly

coincides with an arc of a circle of some definite radius. When the curvature varies rapidly, a knowledge is re- quired of the radii of curvature at a series of points along

the curve, together with the rate of change of the radius. Assuming as is usually the case, that only the convex edge

of the ruler is used and that the radius continually in- creases, a spiral of some sort is obtained. It appears very

desirable that this should conform to some simple equation. Typical forms are the logarithmic spiral and

Cornu's spiral. The properties of these are briefly dis- cussed and three illustrations are given of curved rulers based on what is called the "sici" spiral. A point on this curve is defined by the relation tD+iy=—LS°2 —-d<t>=Lci<t>+iLsi<p

<P where the functions CI and SI denote the integral cosine and integral sine respectively. The values of these functions can readily be obtained from Jahnke-Emde tables and hence curves of any required length and curvature

variation can quickly be drawn, using the relations 0=L/R, #=L CI <(> and y=\i SI <t>. Such curves have been

in use for a considerable time and have proved extremely

useful. Neuer Profilmesstand (New type of profile measuring

equipment), A. METZ. Werkstattstechnik und Werksleiter v33 nl6 Aug 15 1939 p 400-1. For measurement and

testing of thread cutting tools and similar equipment. Improved Spherometer, J. L. HOUGHTON. J Sci In- strum vl8 n8 Aug 1941 p 167-8. Spherometer is described which is fitted with device for indicating point of contact

plunger passes up center of screw and on contacting sur- face to be measured, rises relatively to screw; upper part

of plunger carries small glass disk which, when it rises, touches convex glass surface fixed to screw and so pro- duces Newton's rings ; spherometer can be used for measuring finely ground or opaque surfaces. Radius-of-Curvature Measurements, H. C. SCHEPLER, Am J Phys vl2 Apr 1944 p 107-8. Method uses a point source of light, a card having a hole in it, a collimating

lens, and a steel scale. Profile Gages (Measurement). Ordnance Inspection Handb ORD-M608-5 1 July 1945 p 899.0-899.18. Various methods of checking radii and profiles are described. Measurement of Radius of Curvature of Concave Spheres, D. H. RANK, J Opt Soc Am v36 Feb 1946 p 108-10. In the method of measuring the radius of curvature of a sphere with an autocollimating microscope it is claimed that the

substitution of an Abbe for a Gauss eyepiece leads to an improvement in ease of manipulation and accuracy. Abbe

eyepieces manufactured by Gaertner are described and

their method of use detailed. The sensitivity of the method is also discussed. The Measurement of the Radii of Curvature of Convex

Spherical Surfaces by Autocollimation, B. JUREK, F. KAUTSKY, Rev Opt (Theor Instrum) v27 June 1948 p

369-70. in French. The difficulties encountered in the pre- cision measurement of the radius of curvature, r, using

objectives of small size and small numerical aperture, due

to' the high values attained by a in the formula r=(D7- -a

2 )Vs and the slow change in quality of the returned image with displacement of the moving part of the instru- 190
ment used, are discussed, and the errors they introduce examined experimentally. It is concluded that a should

be made as small as possible, and the errors introduced by

its non-zero value controlled by a modification of the

microscope. Remarks on Precision of Optical Spherometer, B. JUREK.

Microtecnic v2 n5 Oct 1948 p 215-21. Description of in- strument ; experimental determination of error limits with consideration of diffraction, spherical aberration, eye accommodation and reading error. Measurement of Radii or Large Diameters, C. MIXAIRE.

Machy (London) v94 n2414 Feb 18 1949 p 380-2. Methods

of determining radii described for cases where difficulties may arise owing to lack of sensitivity, or expansions of micrometers or other instruments employed, and in instances where it is necessary to check radii of arcs on work

surfaces, which extend over less than 180°. The Determination of Radii of Curvature by Mechanical Methods of Measurement and a Comparison of Their Accuracies, H. JEXSEX. Optik v6 no 1950 p 261-72 in Ger- man. A brief illustrated review of the various mechanical instruments, including templates, test curves and

spherometers. Accuracy of Spherometer Measurements, H. SCHULTZ.

Optik v9 n4 1952 p 164-6 in German. For a ring type spherometer head, the radius of the ring cannot be taken

as constant when the highest accuracy is required. The

apparent radius has been found to vary in a linear fashion with the radius of the surface being measured. A correction chart for the spherometer head can be drawn. Accuracy of Spherometer Measurements, E. HEIXE- MAXN. Optik v9 nil 1952 p 525-6 in German. The re- sults of Schultz are confirmed and re-arranged to give a more convenient practical formula for the correction to the radius measured with a spherometer. The Effective Radius of Curvature of Knife Edges, G. F. HODSMAX, F. A. CHAPPELL. J Sci Instrum v29 Oct

1952 p 330-2. Knife edges used as bearings in fine chemical balances exhibit a finite radius of curvature. This

radius affects the precision of the instrument and its magnitude is of interest to the balance designer. A technique

is described for the measurement of this "effective" radius. Some results are given for brass and agate knife edges, values in the range 1-3 being obtained in the latter case. The Measurement of the Radius of Curvature of Test

Glasses with the Ring Spherometer, J. PICHT. Optik

vlO n9 1953 p 423-5 in German. When measuring the

radius of curvature of a pair of test glasses known to have

the same curvature, by interference, it is usual to substi- tute the arithmetic mean values of the sagitta and the

ring radius in the spherometer equation. It is shown

that a geometric mean value of the inner and outer ring radius should be used and that the value of the correction form is then very small. The Measurement of the Vertex Radius of Curvature of Parabolic Surfaces with a Moffltt Traversing Spherometer,

J. PICHT. Optik vlO nil 1953 p 557-63 in German. The

spherometer measures the position of a central probe held

in contact with the parabolic surface. The probe ends in a small sphere and the relationship between the probe

position and the zone radius is derived in terms of the parameters of the parabola and the probe radius. On a Method of Measuring the Radii of Curvature of Spherical Surfaces by Comparison, A. BIOT. Atti Fonderie Ronchi, v8 Mar -Apr 1953 p 114-17 in French. By

means of the Xewton rings appearing between two spherical surfaces in contact it is possible to find the difference AR between the two radii of curvature. With an ordinary

microscope, provided with a micrometric eyepiece, the radii

of any two rings can be measured, using nearly monochromatic radiation (wavelength \). If n'—n is the

difference between the orders of interference of the two

rings considered, then AR= \(n'—n)R2

The Production and Inspection of Aerofoil Models, R. S. MARRIXER, XPL. Machy (London) v83 Aug 14 1953 p 327-9. Describes process of machining delta wing type where the section progressively diminishes from root to

tip. Inspection was by means of SIP universal measuring machine type MU214B. The Accuracy of Spherometer Measurements, S. MOHOROVlClC. Optik vll nil 1954 p 493-5 in German. Pre- vious methods of using spherometer measurements have

required the approximate value of the radius of curvature

to be used in a small correcting term. A re-arrangement

of the equation is suggested which requires only measured

values and the spherometer constants to be inserted to obtain an accurate value of the radius of curvature. The Measurement of Radius of Curvature of Proof Glasses with the Spherometer, H. JEXSEX. Optik v 11 nil 1954 496-8 in German. The suggestion that the geometric mean

of the internal and external radii of the spherometer ring should be inserted in the spherometer equation is criti- cized. It is said that either the arithmetic mean radius

or the mean square radius gives smaller errors than the geometric mean radius. The Measurement of Radius of Curvature of Proof Glasses with the Ring Spherometer. II, J. PICHT. Optik vll nil 1954 p 499-504 in German. An extension of an examination of the criticism by Jensen. The residuals arising from various methods of using the spherometer ring radii are calculated. Measurement of Radii, K. W. B. SHARP. Machy (Lon- don ) v84 n2146 Jan 1 1954 p 15-20. Various methods for determining radius of circular arc on component ; apparatus for measuring radii of plate gages; measurement

with surface plate and rollers ; depth micrometer for ob- taining arc height ; methods using optical instruments

coordinate method; equations given and degree of ac- curacy attainable with each method indicated. A Precision Spherometer, J. W. GATES, K. J. HABELL,

S. P. MIDDLETOX. J Sci Instrum v31 Feb 1954 p 60-3. The instrument described has been developed from the de- sign of Guild ; it is suitable for the accurate measurement

of the curvature of transparent lenses and test plates, and

particular attention has been given to protecting the sur- faces measured from risk of damage. A brief comparison

with other spherometers is made, and, in conclusion, at- tention is drawn to the convenience of specifying optical surfaces by their curvatures, rather than by radius of curvature. A Xote on the Design of the Spherometer, H. S. C. CHEX. Am J Phys v22 Sept 1954 p 374-5. A discussion is made

of the errors involved in the use of a spherometer, and it is shown that the accuracy is limited by the accuracy with which the radius of the base circle is measured. A sug- gested change in design is given, which promises to mean

easier manufacture and higher accuracy. A Xote on the Accuracy of Measurement of Radius of Curvature of Proof Glasses with a Ring Spherometer,

V. BLUMOVA, J. HRDLlCKA. Optik vl3 n3 1956 p 122-7

in German. Previous papers have discussed the best approximation to the ring radius to be used in calculation

of results of spherometer measurements. An exact equation is derived and this is shown to give most accurate

results if the mean square value is used to obtain the first approximation to the radius of the proof glass. 191
The Accuracy of Optical Measurement of Radius of Curvature, K. ROSENHAUER. Optik vl3 nl 1956 p 5-6 in German. Mechanical measurements of radius of curvature of proof plates have am accuracy of about 1X10-4 of

the radius. An optical method is described which depends upon bringing two reflected images to coincidence, and is said to have an accuracy of ±1 /i or lxlO-6 of the radius

of 100 mm.

Correction Tables for the Measurement of the Radius of Curvature of Proof Glasses with the Ring Spherometer,

Z. CZERSKI. Optik vl3 n8 p 369-74 1956 in German.

Numerical tables to assist in the rapid calculation for the cases considered by Jensen and Schulz are presented. New Instrument for Measuring Camber on Large Rolls,

P. W. HARRISON. Machy (London) v89 n2287 Sept 14 1956 p 642-6 ; Engr v202 n5250 Sept 7 1956 p 327-9. In- strument designed at National Physical Laboratory to measure camber of top surface on very large rolls such

as those employed in paper making industry ; instrument makes use of Young's interference fringe patterns to pro- vide optical datum plane to which surface contour can be

referred ; design details ; method of use : performance of apparatus.

Precision Measurement of Small Radii of Curvature, R. N. WILSON. J Sci Instrum v33 nl2 Dec 1956 p 487-8. Conditions for accurate measurement of small radii of curvature by microscope methods ; relevant formulas

reference to work of J. Guild inasmuch as recent require- ments for precision measurement of radii of order of 5 mm have led to reassessment of techniques available ; applicability in optical industry. Praezisionsmessungen mit Ringsphaerometern, K. ROSENHAUER. Optik vl4 n7-8 July-Aug 1957 p 328-

34. Precision measurement with ring spherometers ; dis- cussion of differences between mechanical and optical calibration of ring radius of spherometer; it is possible

to make precise measurements of radius of curvature pro- vided that effective radius of ring is calibrated optically. Method for Measuring Plane Curves by Series of Straight

Lines, K. MIYAZAKI. Japan Soc Mech Engrs Trans v24 nl38 Feb 1958 p 93-8. Theory and experimental results

for testing plane curves given as profile curves of templets,

etc. based on principle of curves as series of straight

lines; relative errors of curves compared with standard

curves by use of simple instrument. ( In Japanese)

Bestimmung des Kruemmungshalbmessers von Kugel

(flaeche) n mittels Sphaerometers (Determination of curve diameter of spherical surface by means of spherometer ) , G. BERNDT. Dresden. Tech Hochschule Wiss Zeit v8 n4 1958-59 p 801-28, n5 p 1001-11, v9 nl 1959-60 p 77-

92. Critical study of method and instrument ; estimate of errors involved ; determination of curve diameter by

direct measurement ; method for determining curvature by means of difference measurement. Measuring to Millionths with Standard Equipment, L. KICKMAN. M. HOSKINS. Tool Engr v42 n3 Mar 1959 p 117-19. Conventional electronic gaging components and

fixtures can be used for measuring spherical and circular parts to six figure accuracy ; setup at Eli Whitney Memorial Laboratory, Sheffield Corp, Dayton, Ohio for measuring template having arc of approximately 100° with 4 in. radius is described ; instrumentation consists of two Accutron amplifiers and Electrojeet cartridge or pickup unit. An Optical Device for the Measurement of the Radius of Curvature, A. I. OMEL'CHENKO, A. V. MOKHOV,

Meas Techn 1958 nl Aug 1959 p 20-1 1 fig 2 refs. Translated from Izmer Tekh nl Jan-Feb 1958 p 18. The paper

describes the construction and principle of a new and

original optical instrument based on the optical section

principle and designed for the control of objects whose

surface radius of curvature is small. The Measurement of Geometrical, Dimensional, and Posi- tional Errors of Technical Bodies by Means of the E-sys- tem, H. VON WEINGRABER, PTB. Microtechnic vl9 n4 Aug 1960 p 173-180 12 figs. Starts by considering the geometrically perfect form of a technical body to provide

a unified spacial reference system for all errors of form and position. Defines form error, dimensional error, and

positional error. Investigation of Method for Measurement of Convex Surfaces, Z. REZNIK. Machy (London) v97 n2499 Oct 5 1960 p 786-8. In connection with need for measuring

radii of large circular segments, instrument was made

which comprised two balls carried by light rigid frame

with dial gage located centrally between them ; data

presented which enabled instrument to be correctly de- signd and dimensioned ; examples show procedure to be

followed ; method described could also be used to check

gages already in stock to determine their suitability for particular measuring applications. Kinetic Circuits of Devices for Continuous Testing of Components, N. M. KARELIN. Meas Techns 1962 n3

Sept 1962 p 181-4 5 figs 3 refs. Translated from Izmer

'Tekh n3 p 4-6 Mar 1962. The article deals with kine- matic schemes which can be used in designing testing devices for measuring component profiles described by

curves which are widely used in production. Such curves

include the ellipse, parabola, hyperbola, synoid and in particular cases limacon and eardioid. Profiles whose

components are described by the above curves include

elliptical wheels ; elliptical webs of crank-shafts ; parabolic templets in secondary instruments for linearizing quadratic relationships, for instance, between the flow and

pressure difference ; parabolic profiles, for instance, those

of control gauges used in the optical industry ; eardioid cams in automatic machines, etc. Investigation and measurement of the Cutting Edges of Razor Blades, E. V. LORENTS. Meas Techns 1962 n6 Dec 1962 p 464-5 1 fig. Translated from Izmer Tekh n6 p 15-6 June 1962. The author used a method based on the

utilization of diffracted rays by illuminating the cutting edge from one side. Primenenie metoda vytertykh lunok i ottiskov k izuch- eniyu iznashivaniya, V. P. MITROVICH, M. K. FOMIC1IEVA. Zavodskaya I.aboratoriya v29 n2 1963 p 217-

18 ; see also English translation in Indus Laboratory v29 n2 Feb 1963 p 202-4. Use of scuffed-pit and replica methods in investigation of wear; method used in in- vestigation of wear to lead-screws of precision metalcutting machine tools combine scuffed-pit and replica techniques and is suggested for measuring small wear, and profile of worn surfaces. Metrology for Ground Cams and Shapes, C. J. GREEN.

Machy (NY) v69 n6 Feb 1963 p 83-93, 129. Three typical

optical cam-contour reading devices which permit making

extremely accurate and consistent readings ; types of tap- pets and their relative accuracy ; checking cam contours

in toolroom ; quality check and control ; contour, angularity and timing checks; cam ramp design and how to measure base diameters ; new far superior cam contour composed of infinite series of instantaneous radii of curvatures. Measurement of Small Radii of Curvature, I. M. PASTU« KHOV. Meas Techns 1962 n8 Feb 1963 p 652-3 2 figs. Translated from Izmer Tekh n8 p 26-7 Aug 1962. Describes contact indicating gage for checking radii of curvature between 0.03 and 2 mm.

Computer Corrects Gaging Bias, J. R. GILSON. Tool & Mfg Engr v50 n3 Mar 1963 p 61-5. Studies made of 192
contour measuring systems at Livermore Laboratory. Sandia Corp, to determine what problems must be solved

to increase gaging accuracy, data bias resulting from mis- placing part in coordinate reference frame of gage ; mathematical repositioning; application of computer analysis

to gaging data permits increased inspection accuracy

while reducing dependence on operator skill ; it eliminates need for nonfunctional datums previously used to ease

fixturing problems : other advantages.

Effect of a Surface Shape Error on the Precision of Measuring a Circular Profile Radius. D. I. KOLPAKOV, V. V. MATVEEV. Meas Techns 1963 n3 Sept 1963 p 192-4 2 figs. Translated from Izmer Tekh n3 p 10-1 Mar 1963. A method for evaluating a radius by the chord and the height

of segment cannot be recommended for testing ball bear- ing races because the radius evaluation error may be more than 8 times greater than the geometrical shape

error which produced it. Kinematic Effects of Cam Profile Errors, M. D. ROGERS.

R. R. SCHAFFER. ASME—Paper 63-WA-269 for meeting Nov 17-22 1963 8 p. Numerical analysis of profile errors has been developed : computer program conducts

analysis of regularly spaced polar coordinate specifica- tions of cam profile; errors introduced in rounding off theoretical curves in incremental cutting are shown to correlate with accelerations determined from experi- mentally measured cam profile. Measuring the Critical Profile of Barrel Bearing Rollers with Microinch Sensitivity, F. FARAGO. Gen Motors

Eng J vll nl 1964 p 17-23 14 figs. 1 ref. Describes a pro- cess for measuring the form of accurate surface elements

of barrel bearing roller components by tracing a single surface element in rigorously controlled relation to other

significant dimensions of the part. Two methods for Determining Minimum Radius of Curvature of Disk Cams, N. E. REID. ASME—Paper 64- MECH-20 for meeting Oct 19-21 1964 7 p. Analytical method of determination of minimum curvature radius of cycloidal disk cam without use of computer is given for case of flat-faced follower ; numerical values of minimum

radius are obtained and tabulated for various values of parameters involved ; method is not suitable for cycloidal and harmonic disk cams when used with radial roller followers; instead, solutions are Obtained by using computer to solve equations and then tabulating minimum

values. Recent Developments in Cam Profile Measurement and

Evaluation, J. H. NOURSE. SAE—Paper 964A for meeting Jan 11-15 1965 47 p. New techniques are presented

for cam profile measurement and evaluation based upon

recently derived analytical methods and electronic computer programs ; new methods include mathematical re- finement of profile raw lift data and obtain following advantages, namely, accuracy, repeatability, evaluation and efficiency ; new acceptance criteria for cam profile quality control, and direction for further development of cam profile measurement and evaluation methods and

techniques are suggested.

8.2. Contour Measurement by Optical Projection

The Projecting Lantern, J. B. TAYLOR. Ilium Eng Soc Trans v 11 May 1 1916 p 414-35 12 figs. The early part

of the paper summarizes the fundamental principles of

optical projection, and also describes the means by which

solid objects may be projected. L. C. Porter discussed

the conditions in which electric glow lamps may be used

for projection. Deals mostly with projection of slides. Note on Setting Up and Using the Gauge Projection Lantern. NPL. Jan 20 1917. Projection Method of Testing Screw Threads, F. D. JONES. Machy (NY.) v24 Apr 1918 p 735-8 8 figs. Arrangement and use of projection apparatus as applied

to inspection of thread gages for munitions manufacture. Methods used in the New York Lab of the British Ministry

of Munitions.

Optical Projection Apparatus for Testing Gages. Engr. vl25 Apr 19 1918 p 346-7 3 figs : Sci Am Supp v85 June 15 1918 p 380-1 3 figs. Details of British Horizontal projection apparatus and the requirements and use. Extracted from "Notes on Screw Gages" by the staff of the National

Physical Laboratory, Nov 1917. Projection Lantern for Thread Measurement, H. L. VAN KEUREN, E. C. GRIESS. Am Mach v49 nl8 Oct 31 1918 p 805-11 11 figs. The measurement of screw threads

presents more kinds of difficulties than almost any other machine part. The apparatus here described has been

developed at the Bureau of Standards and is proving very

satisfactory, and in common with all developments of the bureau it is free to be used by anyone. The apparatus

is easily handled and is well worth careful consideration. Optical Projection for Screw-Thread Inspection, J. HARTNESS. Mech Eng v41 Feb 1919 p 127-35 10 figs; Iron Age vl03 Feb 6 1919 p 357-8 2 figs. Analysis of screw- thread elements essential to strength and dependability

description of method for their accurate inspection.

Optical Projection Applied to Inspection, H. S. BEAN.

Inspector vl Sept 15 1919 p 25-30 7 figs. Description of apparatus developed and used by Bureau of Standards. Some Optical Aids for the Engineer, A. C. BANFIELD.

Machy (London) vl4 Sept 18 1919 p 737-40 10 figs. Description of Wilson projection comparator. Operator

avoids distortion by special twin optical system of such a nature that respective optical centers are adjustable to diameter of screw under test. See also p 613 650 705. Optical Aids for the Engineer, R. J. WHIBLEY. Machy

( London ) vl5 Jan 8 1920 p 451-9 18 figs. Optical methods

that have been developed at National Physical Laboratory, Teddington, England, for aiding inspection work in metrology department.

Vertical Gauge Projecting Apparatus, National Physical Laboratory . Eng vl09 Feb 27 1920 p 273-6 14 figs. Stand- ard type designed in National Physical Laboratory, England, Nov 1917. Improved Type of Optical Projection Apparatus, L. A. FISCHER. Am Mach v53 Dee 16 1920 p 1158; Sci Am

vl24 p 94 1921. Description and illustration of horizontal

projection lantern developed by the Bureau of Standards.

Increasing the Scope of Projection Apparatus, L. E. KING. Machy (NY) v 27 Jan 1921 p 463-4 3 figs. Describes improvement of gage holder for measuring dis- tances on thin flat work ; also a chart for measuring center

distances. New Lantern for Screw Testing. Sci Am vl24 Jan 29 1921 p 94. Description of Bureau of Standards horizontal type

projection lantern, which incorporates the protractor for measuring the thread angle of screws as a component part

of the lantern. Mesure de l'Usure ou de la Deformation d'une Piece (Measurement of the Wear or Deformation of a Mechan- 193
ical Piece), P. BEURET. Rev Metallurgie vl8 Mar 1921 p 157-60 7 figs. Photographic projection of gears, screws,

etc.

and means for making measurements ; work is illuminated by single-filament 108-watt Mazda lamp, in conjunction with transformer on alternating current. Use of Optical Instruments in Machine Work. Am

Mach v56 May 11 1922 p 697-701 19 figs. Describes the use of the microscope and projector in checking the shapes of formed tools and their products. See also Contour Measuring Projector by the Bausch and Lomb

Optical Co. Inspecting by Optical Projecting. Machy (N.Y.) v28 Aug

1922 p 984-8 6 figs. Description of methods, with particular data on screw and gear inspection. Bausch and Lomb contour measuring projector which can be used

to measure thread gages, but is furnished with a universal screw holder and adjustable thread chart which per- mits its use as a projection comparator for inspecting screws in quantity. New Projector Measures Wide Range of Precision Parts. Automotive Indus v49 Aug 23 1923 p 364-7 9 figs. Describes contour measuring projector, an instrument de- veloped by Bausch and Lomb Optical Co., for visual in- spection of screw threads, forms of gear and cutter

teeth, and other parts; accuracy of 0.0001 in. can be

attained ; separate attachments make photographs. A New Projection Microscope. Eng vl37 June 27 1924 p 728. Description of Vicker's projection microscope

in which the image is projected upon one of two ground

glass screens, and on the other screen a microscopic trans- parency of a standard specimen is projected so that

it may be readily compared with the object under

examination.

Optical Method for Testing Wire Mesh, D. P. MUIR- HEAD. Am Mach v62 May 14 1925 p 785. Optical pro- jection apparatus for determining number of meshes per

inch. Measurement by Optical Projection, G. A. TOMLINSON.

Optical Convention Proc Part I 1926 (3d London), p

311-26. The paper commences with a brief history of the development of the method of projection at the N.P.L. leading on to a description of the two types of apparatus,

horizontal and vertical of N.P.L. design now widely used. A series of examples are then given, illustrating the wide

range of the utility of the apparatus. Other projection apparatus of British manufacture is described, including

the Wilson screw thread projector and the Beck projection microscope for fine wire measurement. In conclusion the theory of the formation of the image is con- sidered briefly. Some Applications of Optical Projection to Engineering

Practice, C. F. SMITH. Machy (London) v27 Jan 7 1926 p 473-5 6 figs. Describes instruments manufactured by

scientific instrument makers, Adam Hilger, Ltd. Zeiss Measuring Machine. Machy (London) v27 Mar 18 1926 p 815-6 5 figs. Details of design ; principle of optical system. A Screw Projector, C. F. SMITH. Machy (London) v29 Oct 28 1926 p 103 3 figs. Instrument designed by writer

to deal with screws of diameters varying from 2 to 10

inches in lengths between centers up to 16.5 inches of

parallel or taper form ; illuminating system is arranged

so that light may be directed along helix and lamphouse

is pivoted about center approximately coincident with

second nodal point of lens. Profile Measuring by Projection. Automobile Engr v20 Mar 1930 p 108-9 6 figs. Contour measuring projectors

consist of highly perfected optical system and suitable mechanical parts to protect and support system, to hold work in position, and to provide necessary adjustment

Projection Testing Apparatus, C. F. SMITH. Machy

(London) v37 n954 Jan 22 1931 p 547-8 6 figs. Projector made for Coventry Gauge and Tool Company, by A.

Hilger, Ltd. as applied to projection of contours of anvils used in Wickman screw gages. Vickers Contour-Projection Appartus. Eng vl39 Mar 15 1935 p 280-1. Apparatus made by Cooke, Troughton and Simms intended for accurate gaging of screw

threads, irregular templets and parts, cams, etc, and consists of optical system which projects magnified image

of part to be gaged on to horizontal translucent screen, on which measurements can be made by scale or in other ways. Die Projektion in der Messtechnik (Projection in measuring technique), P. NICHTERLAIN. Werkstattstechnik und Werksleiter v31 n23 Dec 1 1937 p 534-9. Optical and mechanical principles governing correct measure- ment ; influence of optical methods on accuracy and ef- ficiency ; ideal objects, such as templets, and sheet metal

parts. Optical Projection, H. F. KURTZ, Mech Eng v60 n6 June

1938 p 469-73. Possibilities and limitations of most modern optical projection apparatus in industry con- sidered ; optical systems for use in projection ; results of projection test; optical projection as means of comparasion ; contour projector used as measuring device, Before Am Soc Mech Engrs. Jewel Inspection Microscope, F. E. J. OCKENDEN. J

Sci Instrum n7 July 1939 p 228-30. Microscope incorporating objective with built-in illuminator anl illuminating system described ; use of this device greatly facilitates measurement of radii of polished spherical surfaces by

optical means, particularly when of order of 0.1 mm or

Die mikroskopische Abbildung von Zylindern und

Gewinden (The Microscopic Imaging of Cylinders and

Threads )

, N. GUENTHER. Zeit InstrumtKde v59 n8 Aug

1939 p 315-21. The object of this paper is to derive those

illumination apertures by which the geometrical data for cylinders and screw threads may be obtained within the

limits afforded by the microscope. The mathematical treat- ment deals with the physiological shading limits, the shade

limits of geometrical optics, the most favorable stops, and

the determination of flank diameters and angles of threads. From a large number of measurements with different apertures, interpolation and error formulas have been

derived. Measurement by Projection. Aircraft Prod v3 n33 June

1941 p 262-3. Description of Dekkor microprojector for measuring and checking machined parts. Dekkor Universal Measuring Projector, Eng vl51 n3934 June 6 1941 p 446-7. Principle embodied in instrument

is that of making all linear measurements with aid of

slip gages and micrometers, combined errors of which do

not exceed 0.0001 in ; angular measurements are made by

protractor having very high order of accuracy ; no drawing is required. Measurement by Projection. Automobile Engr v31 n412

July 1941 p219-20. Instrument and method suitable for

large contours illustrated and described. Optical Sections. Aircraft Prod v4 n48 Oct 1942 p 610-11. Principles and applications of Taylor-Hobson section projector by means of which it is possible to take optical 194
sections in any plane through all types of gears, splines, and similar objects. Ueber ein interferentielles Verfahren zur Bestiinmung

der Formfehler an Bohrungen und Innenkegeln (Interferential method for determination of form defects in

drilled holes and internal cones), K. HOLECEK. Werkstattstechnili und Werksleiter v36 n23/24 Dec 1942 p

481-86. Definition given of form tolerance and error; method described for determination of total form error for

cylindrical and tapered holes, by comparing specimen

with optically produced nominal form.

Hilger Large Toolmaker's Projector. Machy (London)

v62 nl591 Apr 8 1943 p 381-3. Illustrated description of projector which retains all mechanical advantages of toolmaker's microscope, and embodies stage of entirely new design capable of carrying work of considerable size and weight ; entire stage can be rotated over small angle

enabling lining up to be quickly and accurately carried

out. Optical Problems in Design of Comparator, F. J. ACTON.

Machine Design vl5 nlO Oct 1943 p 81^. Illustration, drawing and description of Postman optical comparator

capable of handling parts of size formerly considered

outside of range of optical inspection apparatus ; develop- ment of increased object-to-lens distance for greater opti- cal and mechanical capacity and increased illumination

flatness problem solved by use of thick mirrors. Inspecting Turbosupercharger Blades—By Optical Projection Comparator, E. C. POLIDOR. Iron Age vl59 n3 Jan 16 1947 p 40-4; Machy (XY) v53 no Jan 1947 p

185-8. Fast and accurate method of inspecting blade and bucket profiles, using newly developed Pant-OJector; operating principle is based on use of simple pantograph X and Y : Motion, tracing path of scribing end

of pantograph on projection instrument at known magnification; using beam of light to trace profile on special comparator chart indicates form of blade and also locates

it in relation to center of gravity. Xew Machine Speeds Turbine Blade Contour Measurement, W. A. LLOYD. Iron Age vl62 n6 Aug 5 1948 p

76-8. Features of measuring machine employing combination of optics, light beams and photography, to measure and dimensionally record contours and angular twists

of mixed flow and axial flow compressor and gas and

steam turbine blades ; machine will mechanically measure to ±0.00025 in. across width of blade in increments

of either 0.0125, 0.025 or 0.O50 in. at speed of approxi- mately 0.375 in. per min ; setup and operations detailed. Societe Genevoise Contour Projector for Turbine Blades. Machy (London) v74 nl907 May 12 1949 p 637-9; Aircraft Prod vll nl29 July 1949 p 234-6. Description of type AP-14 profile projector developed by Societe Genevoise d'Instruments de Physique, Geneva ; design incor- porates same optical system as firms AP-6 projector; on new projector entire blade contour at any selected section

is shown on screen at one time; photographs, sketches. Precision Measurement of Rockwell Hardness Diamond

Penetrators. F. R. TOLMOX. J. G. WOOD, XPL. Eng

vl72 n4460 July 20 1951 p 89-90. Photographs taken on

Linnik interference microscope gave clear general impression of shape and surface of tip of penetrator over re- stricted distance corresponding to axial depth 0.002 in. from apex of penetrator; photomicrographs.

Inspection by Optical Projection Methods, E. C. POLI- DOR. Tool Engr v27 n2,3 Aug 1951 p 43-6, Sept p 52^.

Recent developments in contour measuring projectors

arrangement of optical elements indicated ; requirements

of projector used for inspection ; laying out of chart by

drafting board technique and by scribing machine methods; new types of chart lines facilitate accuracy and

bring about other improvements ; advantages of this inspection method ; planning for typical part ; importance

of size and dimensions of parts; illustrations. Evaluation of Small Radii of Curvature Using the LightProfile Microscope, S. TOLANSKY, M. OMAR. Letter

in Xature (London) vl70 Nov 1 1952 p 758-9. The light- profile microscope is applied to the measurement of the

radius of curvature of a small metal sphere, calibration being performed by means of Newton's rings with a 0.6 mm sphere. Accuracy of 1% is attainable. The Optical Projection of the Profile of an Article at a Given Cross-Section, F. G. MORTON, V. E. GOUGH. J

Sci Instrum. v30 Aug 1953 p 277-80. Two types of projector are described which permit the continuous observation of the sectional shape of a rod-like or thread-like

Object, of substantially constant cross-sectional shape, as

the object is passed through the projector. The article may be of any length and may be flexible or rigid. The

projection of sectional shape may be accomplished by two

distinct methods. The first employs the projection of

light scattered from the surface of an illuminated peri- pheral band of the object. In the second method the

object is placed co-axial with a projection lens which

receives scattered light from all points on the surface of the object under examination. The lens selects a thin

section of the object and projects the peripheral shape

of this section on to a screen. The application of these projectors to the continuous gauging of the outside dimensions of rubber tubing is described. Two Precision Projectors. Engr vl96 n5091 Aug 21 1953 p 252. Measuring projectors made by Hilger and Watts

universal instrument performs normal comparison of projected image with template, and makes precise meas- urements in two mutually perpendicular directions over

distances greater than area projected on screen ; lathe projector can do most of work required from normal

projector; profile of work, magnified to suitable degree,

is clearly shown on screen together with cutting edge

of tool. Inspection of Prismatic Bodies by means of an Optical

Section and Application of this Method to Turbine Blades,

J. TURRETTINI. Eng Dimensional Metrology, Proc of Symposium at NPL Oct 1953. Her Majesty's Stationery

Office. Describes method of controlling optically inter- mediate sections of prismatic bodies. Variants of a New Spherometer Method, B. JUREK.

Letter in Czech J Phys v4 Feb 1954 p 97 in German. Two alternative layouts of a double prism attachement,

allowing the accurate measurement of radii of curvature

fry autocollimation, are described. Photometry of Microscope with Special Reference to Projection, G. E. J. OCKENDEN. J iSci Instrum v 31 n9

Sept 1954 p 309-13. Transmission losses in microscope

optical systems and their effect on brightness of both

visual field and projected images estimated ; it is shown

that production of large, well illuminated, projected images by means of microscope is subject to limitations

for which only solution is provision of illuminants having

higher intrinsic brilliance than any at present available. Blade-Profile Inspection. Aircraft Prod vl6 n9 Sept 1954 p 373-5. Comparator, based upon optical principles, and

built by Taylor and Hobson, Leicester, for inspection of turbine blade profiles; instrument is designed to project

profiles of either shrouded or unshrouded blades upon

ground glass screen, at magnification of X 10. Some Usual and Unusual Tool Room Measurements with Contour Projector, A. R. FULTZ. Tooling & Prod v20 7,

8, 9 Oct 1954 p 72-3, Nov p 61-3, Dec p 65-8 134. Measuring screw machine circular form tool on contour projec- tor ; solution for overcoming phenomenon known as "wall 195
effect" which is found wnen flat surface lies along line of

light projection; inspection by contour projection of single point turning tool for side rake angle ; method for examining punch and die indicated. An Optical Show-casting Miscroscope, S. TOLANSKY.

Lab Prac v3 nlO Oct 1954 p 405-9. The heights of small

objects can be measured from long shadows cast by illu- minating at a grazing incidence less than 5°. It is essential that the objects should rest on a specially prepared

surface which scatters light up into the microscope. The

technique is described in detail and is used with shadow

magnifications up to X2500. The technique is extended

to include features on crystal surfaces by producing the appropriate scattering surface in situ on the crystal. Ex- amples from diamond, quartz and zinc crystals are illus- trated. In addition to measuring surface structural features, local enhanced contrast of topographical features

results. Anisotropic Projector, R. B. LEIGHTON. Rev Sci In- strum v27 n2 Feb 1956 p 79-82, Optical projector having

different magnificatons, 5X and 50 X, in two rectangular

directions ; although designed principally for rapid meas- urement of cloud chamber track curvatures, it has been

applied to various situations in which plane-to-plane imaging at constant magnification is desired; simple plano-convex cylindrical lenses are used as image forming

elements. Measurement of a Profile in Coherent Light, J. C. VIENOT. Rev Opt v35 nlO Oct 1956 p 517-25 in French. The measurement of the diameter of a small object, such

as a thread, is difficult with incoherent light because of the out of focus images of the third dimension. The diameter can be measured more precisely from the diffraction fringes formed with coherent light. Conditions are ob- tained for best definition and most accurate measurement. Sample results are quoted. Precision Measurement of Small Radii of Curvature, R. N. WILSON. J Sci Instrum v33, nl2 Dec 1956 p 487-8. The

conditions for the accurate measurement of small radii of curvature by microscope methods are discussed and the

relevant formulae stated. On the Improvement of the Precision of Microinter- ferometry. Investigations Concerninng Interference Spherometry, R. LANDWEHR. Zeit InstrumKde v66 n7 Aug 1958 p 134-8 in German. A geometrical analytical examination concerning the calculation of corrections in exact two-beam interferometry. The displacements aris- ing both from the small angle of inclination between the

surfaces and also from the finite angles of the incident cone of light are computed. Tables of corrections are given for numerical apertures up to 0.65. The applicaton

of these computations to the possibility of accurate inter- ference spherometry is discussed. Microinterference as an Aid to Testing the Shape of Aspherical Surfaces, R. LANDWEHR. Ann Phys (Leipzig) Folge7 v4 nl-5 1959 p 154-66 in German. The testing

of the strongly curved aspherical surfaces of rotation now

so widely used can be carried out with a microinterference method. Measurements made over small regions permit an analysis of the whole. The theory of the method is

developed in detail and the equations of the interference curves are derived. Interference curves are given for a paraboloid viewed in various zones and special cases are numerically evaluated. It is shown that the interfero- metric results are in agreement with spherometer measurements.

Precision Measurement. Aircraft Prod v24 nl Jan 1962 p 18-20. Trioptic-machine built by Soc Genevoise Instrum Phys, Geneva, Switzerland, for measurement in 3 axes; direct readings can be made to 0.0005 in. (0.001 mm) and estimated to % of direct readings, accessories include feelermicroscope, goniometric microscope and illu- minating-table ; readings of carriage and inspection-head movement are displayed on projection screens ; for longi- tudinal and transverse movement there are 2 dial indica- tors reading to 0.05 in. (or to 1 mm) ; accuracies for i ordinate movements shown. New Comparator Gages-Photos on Glass, E. C. POL1- DOR. Am Mach/Metalworking Mfg vl06 nl5 July 23

1962 p 79. With special photographic process, glass chart gages are produced at Automation Gages that, inserted in optical comparators, give extreme accuracies needed to inspect jet engine blades; more permanent than plastic

charts, new chart gages are also cheaper and easier t> prepare than conventional etched glass gages. High-Magnification Optical Projector, W. G. RIDGE.

J. E. FURSE, P. W. HARRISON. Machy (London) vlO.1 n2593 July 25 1962 p 181-4. Reference made to prototype high magnification projector of horizontal type, described

in article by F. R. Tolmon, J. G. Wood; projector was now redesigned; with aid of accurately flat mirrors,

optical path has been folded so that projector appears in rigid compact form ; observer can take readings and adjust position of object while sitting in front of screen

optical system described ; 2 special attachments of fine wire were made for projector. Accuracy in Measuring the Dimensions of Components

by the Shadow Projection Method, V. P. KORONKEVICH, L. YA. GUS'TYR'. Meas Techn 1962 n5 Nov. 1962 p 362-5 7 figs. Translated from Izmer Tekh n5 p. 5-9 May 1962. Article shows that, providing the illuminator

is correctly adjusted, the accuracy of the shadow-projection method is higher than that of the blade method. Advanced Optics Solve Quality-Control Problems. Machy

(NY) v70 n7 Mar 1964 p 132-3. Timken Roller Bearing

Co, having one of finest tool and gage laboratories in country, uses universal measuring microscope called UMM,

manufactured by Zeiss in West Germany ; its basic function is measurement of irregular profiles, angles, radii and threads ; typical application is in measuring threaded components; one instrument can check all thread dimensions; it is also used in maintaining accuracy in master

gages ; various applications of UMM, pertaining to manufacture of precision bearings, are given. Ein Objective fur Profilprojektion (An Objective for Profile Projection), L. CANZEK. Optik (Germany) v21 nl2 Dec 1964 p 672-5 4 figs 1 ref in German. An objective for

profile projection (magnification X50 and object—image

distance about 1000mm) is described. .Methods of cor- rection are given and the state of correction is discussed. 8.3. Measurement of Involute Contours

All references under this heading are given in subsection 10.2.1. Addendum to Section 8

8.1. Measurement of Radius or Profile by Mechanical Methods

Measurement of Macrodeviations in External Surfaces

of Cylindrical Components. T. S. LOPOVOK. Meas

Techns 1962 n8 Feb 1963 p 649-51 3 figs 1 ref. Translated from Izmer Tekh n8, p 24-6, August 1962. Microprofilograms of external surfaces are distorted because of errors

in the center holes of measured components. The technol- ogy of producing better center holes was studied.

196
Section 9. Measurement of Screw Threads

CONTENTS

Page

9.1. General , 197

9.2. Lead measurements 202

9.3. Wire and ball measurements of screw threads and other helicoidal features 205

9.4. Tables for ball, pin, or wire measurements 212 Addendum to Section 9 212

9.1. General

A Microscope for Measuring Screw Threads. Am Mach

v27 ptl n3 Jan 21 1904 p 78 7 figs. Illustrations show the microscope, the arrangement of the cross wires, and vari- ous adjustments. Instrument made by the Cambridge

Scientific Inst. Co. for the Small Screw Gage Committee

of the British Association, by whom it was placed in the custody of the National Physical Laboratory. A Device for Measuring Screw Threads, M. E. ANDERSON. Am Mach v32 Oct 14 1909 p 665-8 11 figs. Il- lustrates and describes roller calipers which can be con- veniently adjusted to suit any angle of helix and to measure accurately threads of any lead. System evolved

to meet the needs of the S. S. White Dental Mfg. Co. 12

or 15 years ago. Instruction a L'Usage des Etablissements Constructeurs pour la Reception des Vis et Ecrous au Filetage (Instruction on the Usage of the Etablissements Constructeurs

for the Receipt of Threaded Screws and Nuts), S. I. Ministere de la Guerre, Artillerie, Dec 23 1913. Includes a description of a comparator for checking pitch diameter

of screw threads, which embodies V-shaped anvils for contact with thread. Also includes description of a lead

tester. New Measuring Instruments and Measuring Methods in Automobile Manufacture. Horseless Age Aug 12 1914. Deals with the measurement of. screws and gears. How to Measure Screw Threads. Greenfield Tap and Die

Corporation Bui nl Jan 1917 p 1-15. Gives methods of measuring screw threads. Gaging and Inspecting Threads, D. T. HAMILTON.

Machy v23 n6 Feb 1917 p 477-86 Front 15 figs (half-tones

sections etc.) tables ni-ix ; the same, ii. Machy v23 n7 Mar 1917 p 581-6, 7,000 words Figs 16-34 (half-tones,

sections, etc.). Table i. British standard Whitworth

threads.—Tolerances for bolts.—ii. British standard Whitworth screw threads, iii. Allowances to compensate for errors in pitch of British standard Whit- worth screw-threads, iv. Tolerances on included angle

of screw threads. (The Engineering Standards Committee), v. Tolerances on pitch diameters of U.S. Standard screws, taps and gages (loose fit tolerances),

vi. Tolerances of pitch diameters of U.S. Standard

screws (taps and gages close fit tolerances), vii. Propositions for Briggs standard reference pipe ring gages (Cadillac Motor Car Co.). viii. Propositions

for Briggs standard reference pipe plug gages (Cadillac Motor Co.). ix. Dimensions of ball points used in measuring screw threads. Part 2 consists of a general survey of devices for testing lead of taps and screws.

Subjects taken up : simple device for testing lead of screw

threads; Well's indicator for testing lead of screws and

taps ; indicating comparator for testing lead ; Wolfe dial indicator for testing lead of taps ; testing included angle

of thread; limit working and inspection thread gages;

limit, snap and plug gages for thread work; limit snap

gages for testing lead and pitch diameter ; indicating gage

for inspecting lead and pitch diameter; inspecting die chasers ; microscope for measuring screw thread gages

projection method for measuring screw threads. Screw Thread Measurement, A. BROOKER. Eng vl03 n

2666 Feb 2 1917 p 113-6 ; n2667 Feb 9 1917 p 139-41 ; 2668 Feb 16 p 165-6. Figs 1-28 (half-tones diagrs section etc.) formulas. Contents : Section I. Introduction.—Section

II. Definitions, p 113.—Section III. Methods of measurement. 1. Measurement of elements by microscope micrometer, p 114-6. 2. Diametrical measurements by

floating micrometer, p 139. 3. Optical projection apparatus. 4. Measurement of pitch by mechanical means, p

165. Section iv. Concluding remarks, p 165-6. This paper was read before the Liverpool Engineering Society. Deals with the Whitworth standard system, and with the methods of measurement. See also Cambridge Scientific Instrument Co., title no. 79. First installment. Gives Engineering Standards Committee definitions of configuration of screw and threads (effective diameter, core diameter, etc.) Author describes measurements of ele- ments by microscope micrometer method. In the second

installment are described measurements of core diameter and effective diameter by floating micrometers. This is a method which makes possible taking measurements on

the lathe during screw cutting operation, and also serves

to check optical methods. The optical projection apparatus method of testing form at root and crest of thread

described, with suggestions as to use of photography. Third installment, describes new method for micrometric measurement applicable to male and female screws with

addition of special optical device to indicate when thread

of rotating screw has reached exactly same phase as at preceding measurement. Discusses importance of close measurement. Includes comparative illustrations. Table showing constants of 10 screw thread systems. The Microscope for Inspecting Screws, F. R. WILLIAMS. Am Mach v46 nl7 Apr 26 1917 p 736 350 words

1 half-tone illus. The microscope and the fixtures used

in adapting it for testing threads. Author treats on accurate checking of hobs, taps, thread chasers, forming

cutters and a number of other tools with cutting edges. ... He also refers to the chapter on "The use of the compound microscope in the toolroom" in the work under

the title : Accurate tool work, by Goodrich and Stanley. 197
The Inspection of Screw Gages for Munitions of War,

H. J. BINGHAM-POWELL. Am Maeh v47 n25 Dec 20

1917 p 1065-73 incl figs 1-5 (half-tones). Contents : The

measurement of the pitch. Devices for measuring pitch.

Pitch from thread to thread.—Leveling operations. Ring

screw gages. Plug screw gages. The thread-micrometer

principle. One wire better. Tolerance allowed. Illus- trations: 1. National Physical Laboratory projection machine. 2. Bingham Powell pitch machine. 3. Apparatus for taking true casts or ring screw gages. 4. National

Physical Laboratory screw measuring machine. 5. At- tachment placed in Pratt & Whitney measuring machine. Aim of author is to assist screw-gage manufacturers in their work of making gages for munitions of war, which

have to be accurate within very low tolerances. Measurement of Internal Threads, W. S. ROWELL, Machy

v24 n5 Jan 1918 p 429 incl 2 figs formulas. Recommends

the use of an inside micrometer with ball points to assist

in making and gaging internal threads. Precision Screw Measuring Machine. Machy (London)

v24 Feb 1918 p 494-5 4 figs. Describes precision screw measuring machine made by the Cambridge Scientific

Inst. Co. Ltd. for the Small Screw-Gage Committee of the British Association. For measuring major diameter, pitch diameter, lead, and angle of commercially produced screw

threads and taps. The Measurement of Thread gages, H. L. VAN KEUREN,

Chief of Gage Section, NBiS. ASME J v40 nil Nov 1918 p 913-8 Trans ASME v40 1918 p 827^9. Contents : Meas- urement of plug thread gages, pitch, form and angle of thread, core diameter, full diameter, effective diameter. Choice of wires, standardization of wires, computation of

effective diameter, precautions in making three-wire measurements. Test of ring thread gages : Measurement

of pitch or lead, angle, thread farm, full diameter, core

diameter, and effective diameter. A Machine for Measuring Screws, P. E. SHAW. Eng vl07 Jan 24 1919 p 104-8 16 figs. Methods described depend upon a simple point contact in all cases. The machine

used deals with the diameters and the pitch and is of a simple type, easy to use. Mechanism consists of a beam

rotating about its center, one end bearing by a special pin on the thread surface, the other end bearing by another

pin on an optical lever. Beam has two motions, a rotation and a sliding action parallel with the axis of the screw

being measured. Especially adapted to measuring ring

gages. The Precision Measurement of Thread Gages. Can Machy

v21 Jan 30 1919 p 113-5 4 figs. Commercial equipment manufactured by Arthur Knapp Eng Corp after models

developed by Bur. of Standards. Automative Indus v39

p 1008-10. A New Screw-Measuring Machine, P. E. SHAW. Eng

vl08 Dec 19 1919 p 816-7 4 figs. Suggested simplification

of machine described in Eng Jan 24 1912 p 104. Principle employed is to measure profile of imaginary axial section of screw whether plug or ring. Messen und Priifen von Gewinden (Measuring and Verify- ing of Screw Threads), F. MEYER. Betrieb v2 Feb

1920 p 136-9 9 figs. Discusses measurement of pitch dia- meter, lead, and thread angle by means of a screw thread measuring microscope in which knife edges to contact

the thread surfaces are used. Screw Thread Measuring Instruments. Eng Prod vl June 1920 p 221-5 13 figs. Machines designed by Metrology Department of National Physical Laboratory, England. Measuring Templets and Screw Threads with a Microscopic Measuring Machine. Am Mach v53 July 22 1920

p 187 ; Eng Prod v2 Jan 13 1921 p 40-4 12 figs. ; Machy

(NY) v24 May 1918 p 791-3 5 figs. Construction and ad- justment of Alfred Herbert design of measuring machine

and application for testing accuracy of templets or contour gages and screw threads. Zwei Apparate zur Messung von Gewinden and Lehren (Two Apparatus for the Measurement of Threads and

Gages), F. GOPEL. Werkstattstechnik vl4 Nov 1 1920

p 559-63 14 figs. Description of a measuring machine

with spirit-level indicator for determination of pitch of thread ; and an anglemeter for chasing tools based on

principle of goniometer. The Bath Internal Thread Micrometer. Am Mach v54 n25 June 23 1921 p 1102; Machy (N.Y.) v27 July 1921 p

1070. An internal micrometer having sliding-wedge-op- erated threaded measuring jaws available with any number of threads per inch in sizes from 1 to 5 inches in diameter. Die Messung des Flankendurchmessers ( The Measurement

of the Pitch Diameter), G. BERNDT. Betrieb v4 n3 Nov 12 1921 p 70-81 26 figs ; nlO Feb 18 1922 p 333-8 7 figs German. Nov 12 : Critical considerations regarding

errors occurring in the measurement of flank diameter by

different methods (thread micrometers, special micrometers) wire methods and optical measurement. Application of the results to the allowable error in the measure- ment of pitch. Feb 18: in the comparison of thread gages with standard gages by means of thread micrometers, in measurement with a micrometer having ball contacts. Error of an inaccurate adjustment or positioning

of the thread axis in the vertical plane in the measure- ment of flank diameter or pitch. It is absolutely neces- sary to measure on 2 oppositely leaning flanks and to take

the mean. Gewinde-Messkomparator (Screw-Thread Measuring Comparator )

, C. BCTTNER. Betrieb v4 Feb 11 1922 p 289-93

11 figs. Describes construction and function of a new

Zeiss optical screw-thread measuring machine for maxi- mum accuracy, with which all thread dimensions can 'be determined.

Sine Bar Fixture for Accurately Checking Thread Angles, Machy (NY) v28 May 1922 p 722. A sine^bar fixture attachment for a bench lathe comprising a pivoted plate carrying at one end a contact point accurately ground to the basic thread angle and at the other end a plug or

button, which, with the plate pivot, comprises the sine

bar, screws for adjusting the angular position of the plate, and a fixed block opposite the plug on the plate which

serves as a reference point for taking micrometer meas- urements over the block and button. The fixture is first set to a master groove cut on a cylinder by aligning the

contact point with the conical sides of the groove, and a micrometer reading over the block and button is taken. The master is then replaced by the work to he checked, and from differences between measurements taken when

the sides of the contact point are aligned, first with one

side of the thread and then with the other, the error in thread angle is determined. Work at the National Physical Laboratory. Machy ( London) v20 Aug 3 1922 p 558-61 7 figs. Internal effective diameter measurement of screw threads. Thread Measuring Devices, B. M. W. HANSON. Machy

(N.Y.) v29 Aug 1923 p 946-8 4 figs. Describes different devices with special reference to lead-measuring machine.

Inspection of Taper Thread Gages. NBS Letter Cir nl3

Oct 20 1923 27 p 15 figs. Describes methods of measuring

taper screw thread gages, with seven tables of wire sizes, constants and other data.

tlber Fortschritte in der optischen Gewindemessung (Re- garding Progress in the Optical Measurements of Screw 198
Threads), O. EPPENSTEIN. Zeit Feinmeehanik v32 June 5 1924 p 115-7 6 figs. Communicated from Zeiss works in Jena. Discusses measurement of pitch diameter, using knife edges. Zeiss Thread-Measuring Instruments. Am Mach v62 May

28 1925 p 861-2 5 figs. Describes several thread-measuring

devices, including screw-thread micrometer caliper, thread-profile gage, optical thread caliper and toolmaker's

microscope. Herstellung der Gewindelehren (Manufacture of Screw

Thread Gages), E. KREIS. Technik und Betrieb v2 n8 Aug 1925 p 253-62 22 figs 7 refs ( In German ) . Describes measuring methods. For highest accuracy of measure- ment of thread elements of thread gages, author advocates

use of optical means such as the Zeiss universal measuring microscope with contacting knife edges. Discusses

inadequacies of wire measurements. The Measurement of Screw Threads. Mech Wld v81 Feb

11 Mar 4, 25 May 6 and June 24 1927 p 103-4, 159, 211, 320-321 and 446-^47 18 figs. Coarser and finer tests; causes of inaccuracy ; temperature changes. Mar. 4

Origination of screws : evolution of thread sections. Mar.

25 : Pitch errors ; effective diameter. May 6 : Adjustment

of external gages, snap type of thread gage ; snap limit gage. June 24 : Microscopic methods of determining

errors in screw threads. Devices for Thread Measurements—Methods and Equip- ment for Accurately Gauging Tap Threads, A. L. VALENTINE. Machy (London) v31 Dec 29 1927 and Jan 14 1928

p 417-21 and 476-8 14 figs. Dec. 29 : Accurate measuring

devices suitable in quantity production plant : Hanson de- vice measures to 0.000025 in. ; Wickman machine measures

all dimensions of tap and other external and internal dimensions on plain, threaded, and tapered work ; measuring pitch diameter with wires and micrometers ; measuring

root diameters with micrometers. Jan. 14 : Four gages

for resharpened taps; Wickman go and not-go gages;

device for measuring odd-fluted tools in process of manufacture ; standard micrometer head, specially designed

anvils and wires used ; formulas for taps with five flutes and Whitworth form of thread ; and international forms

of threads ; formulas for three-fluted taps ; errors in measuring pitch diameter with wires ; device for measuring

outside and pitch diameters of taper taps. The Measurement of Taper-Screw Thread Gauges, J. E. BATY. Machy (London) v32 Aug 16 1928 p 617-21 13 figs. Methods of inspecting outside, effective, and core dia- meters of taper screw plug gages, which are applicable

to British Standard pipe. Briggs, American Petroleum

Institute or any other standard thread and taper ; measuring fixture described and formulas for each computation

given. Ein neues Verfahren zum Messen von Innengewinden (New Method for Measuring Internal Threads), A. HAERTEL. Zeit InstrumKde v49 n6 June 1929 p 301^

4 figs. Principles of F. D. Jones, Machy v24 1918 p 35, have been improved by equipment described, which allows

positive casting of small inside threading to be taken out undistorted in two parts. Machine for Measuring Up to One Hundred Thousandths

of an Inch. West Mach Wld v20 n9 Sept 1929 p 329-30

4 figs. Description of Zeiss universal optical measuring machine for measuring dimensions of screw thread, in- cluding correct pitch diameter, and for checking, laying

out, or spotting of all kinds of jigs, templets, and forming

tools, measurements being made up to 0.00001 in.; comparison made with mechanical methods of measuring pitch diameter.

Die Priifung konischer Normalgewinde (Testin* of Conical Standard Threads), F. GOPEL. Werkstattstechnik v23 Oct 15 1929 p 586-90 7 figs. Communication from German Governmental Phys Inst; new equipment for measuring conical pipe-threading gages and results ob- tained with this : testing of threads was carried out on

basis of pipe specifications of American Petroleum Insti- tute and directions of U.S. Bureau of Standards. The Measurement of Internal Threads by Means of Casts, G. BERNDT. Mech Wld v86 n2234 Oct 25 1929 p 395. Method devised for measuring internal threads by means

of casting ; some form of material used by which diameter,

pitch, and angle of thread can be measured, and tools for making correspondingly correct external threads can be

designed. From Werkzeug, p 157-63. Gewinde-Priifmethoden ( Screw-Thread Testing Methods )

,

H. PAMPEL, A. SOMMER. Automobiltechnische Zeit v32 n30 Oct 31 1929 p 689-93 13 figs. In connection with

recently conducted investigations of thread tolerances, authors present detailed description of measuring and

testing methods and equipment. Methods of Measuring Odd-Fluted Taps. Am Mach v71 n23 Dec 5 1929 Supp No 17 p 945 8 figs. Five methods

of measuring type taps are described. Condensed from

Nat. Screw Thread Commission Bulletin No 143 Oct 22

1929. Verbessertes Gewindemessgeraet (Improved Screw- Thread Measuring Equipment), F. GOEPEL. Zeit In- strumKde v50 Jan 1930 p 33-42 10 figs partly on supp

plate. Measuring equipment described in Zeit Feinmechanik und Praezision 1924 has been improved ; equip- ment and its applications are described. Ein neues Verfahren zur Messung von Innengewinden (New Method for Measuring Internal Threads), G. BERNDT, E. BOCK. Zeit InstrumKde v50 n6, 7 June

1930 p 375-84, and July p 407-16 7 figs. Principles of measuring methods based on use of balls and prisms and

Universal measuring microscope, developed by University

of Dresden and Zeiss Co., mathematical analysis of accu- racy and errors; tables give instrument correction for Whitworth and metric thread. Flankenmessungen an Schnecken und Trapezegewinden (Measurement of Pitch Diameter of Worms and Trapezoidal Threads), A. RICKENMANN. Maschinenbau/Betrieb vlO nl9 Oct 1 1931 p 619-20 4 figs. Describes a special micrometer having three conical contacts for measuring worm and trapezoidal threads. Discusses measuring

errors. Die Pruefung Konischer Innengewinde, (The Testing of Internal Taper Threads), A. WERNER, G. BOCHMANN,

R. LEHMANN. Zeit InstrumKde vl Jan 1932 p 14-9. Methods and equipment for measuring internal dimensions

of ring gages for taper threads developed by Physikalische-Technische Reichsanstalt, according to specifications of American Petroleum Institute. Die Messung des Flankendurchmessers dreinutiger Gewindebohrer (The Measurement of Pitch Diameter of Three-Fluted Taps, G. BERNDT. Zeit InstrumKde v52

July 1932 p 307-19, and Aug p 353-64; Sept p 408-16. Mathematical analysis of accuracy of methods of measuring diameter of taps with three flutes, including use of wires, cones, cylinders, prisms, etc. ; experimental verification. Fortschritts und Forschungen auf dem Gebiete des technischen Messwesens (Progress and Research in Field

of Technical Measuring Methods) . G. BERNDT. Maschi- nenbau vl2 n5 Mar 2 1933 pll8-21. With particular regard to equipment for measuring screw threads and

gears. Bibliography. 199

r71-846 O—66
Das Messen von Saegegewinden (Measurements of Buttress Screw Threads), W. KNEDEL. Werkstattsteehnik und Werksleiter v29 n3 Feb 1 1935 p 50-2. Outline of measuring methods with data on calculation of face diameter and of gage wire. Optical Inspection of Screw and Worm Profiles, C. F. SMITH. Machy (London) v46 nll79 May 16 1935 p 185-

9. Limitations of optical thread inspection ; method of determining whether interference is present ; optical sys- tem providing compensation for varying helix angle

Matrix projector. Untersuchungen von Gewinde-Raehenlehren (Study of Screw-Thread Micrometer Calipers), H. SCHORSCH.

Wertstattstechnik und Werksleiter v29 n21 Nov 1 1935 p 419-21. New method recommended for adjustment of calipers in which natural weight is changed by additional

weight. Also published separately as a book. Gewindemessungen (Screw Thread Measurements), G. BERNDT. VDI Zeit v80 n48 Nov 28 1936 p 1455-60. Outline of various methods and equipment at present

available for measurement of screw threads. Bibliog- raphy. Measuring Plating on Screw Threads, E. C. ERICKSON.

Bell Lab Rec vl5 n6 Feb 1937 p 187-9 ; Wire & Wire Prod

vl2 n3 Mar 1937 p 144-5. In absence of any standard gaging apparatus which could be used to make determinations accurate for ascertaining thickness of coatings on

finished screw threads, optical contour projector was de- vised to determine such measurement ; apparatus and

methods used, with special reference to screws used in telephone apparatus. The Measurement of Pipe Threads, B. B. WESCOTT, Am.

Petroleum Inst June 3 1937. A critical discussion of the various instruments available for the purpose and sug- gestions regarding a proposed standard measuring

practice. Machine for Measuring Plug Screw Gauges in Quantities,

F. H. ROLT, A. TURNER. Machy (London) v52 nl352

Sept 8 1938 p 701-2. Illustrated description of machine

for measuring diameters of batches of gages of same no- minal size ; machine closely resembles floating micrometer

type of screw measuring machine ; only difference is in

fittings of upper measuring carriage ; in present machine

these units are replaced by adjustable anvil and measuring indicator. Begriffsbestimmungen in der Gewindemesskunde (Definitions in the Science of Thread Measurement), G. DIETTRICH, Maschinenbau vl8 nll/12 June 1939 p

289-93. Measurement of screw threads ; geometric re- lations explained and universal rules generally applicable

in measuring practice given. Genaue Innengewindemessung durch ausschraubbare

Gewindeabguesse, L. TSCHIRF. Werkstattsteehnik und

Werksleiter v33 nl9 Oct 1 1939 p 467-9 ; Pratique des In- dustries Mechaniques v23 n4 Jan 1941 p 89-91. Accurate measurement of internal screw threads by molds which

can be unscrewed ; descriptions and principles of system. X-Ray Measurement of Internal Screw Threads, R. C. WOODS, E. K. HIGHT. Aero Digest v38 n5 May 1941 p

199-200. Methods used at Bell Aircraft Laboratories

for measurement of internal screw threads ; radiographic procedure as routinely applied is illustrated. Optical Projector for Measuring Tapered and Square Threaded Screws, J. W. DRINKWATER. Machy (Lon- don ) v62 nl590 Apr 1 1943 p 353^. When measuring ef- fective diameter of tapered screw plug gage, it is essential to relate measurements to position of thread along

taper ; optical projector described is used in conjunction

with thread form layout, to find start of thread on tapered

screws. Measurement of Large Ring Screw Gauges, J. W. DRINK- WATER. Machy (London) v64 nl638, 1647 Mar

2 1944 p 238^10 and (discussion) May 4 p 49-56. Illus- trated description of omtimeter (E. H. Jones, Ltd.) fl' which is optical comparator arranged for measurement c in horizontal plane ; principle of measurement is to com

pare ring under examination with assembly of Matrix

slip gages and pair of adapters arranged to simulate

perfect ring gage. Measurement of Screw Thread Gages. Ordnance Inspection Handb on Gages, ORD-M608-5-See 800 Sept 1944 p

110-11. Inspection Gage Sub-Office, Office of Chief of Ordnance, U.S. Army. Describes measurement of thread | plug, ring, and snap j Simplified Inspection of Thread Gages F. W. BOECKEL.

Tool Engr vl4 nil June 1945 p 29. Illustrated description of simple fixture, in combination with three wire method, which provides easy checking of pitch diameters

of pipe thread gages ; method provides accurate means of analyzing many perplexing problems associated with pipe thread inspection. Two Screw Thread Measuring Devices. Eng vl81 n4703 Mar 1 1946 p 208. Brief illustrated description of simple means of measuring effective diameter of screw thread, introduced by Thos. Firth and John Brown; first is by means of ascertaining points on flanks of thread vee where

width is half of pitch ; second effective diameter measuring instrument is comparator arranged for use by

setting with standard thread. See also Machy (London)

v68 nl757, p 756-7, June 13, 1946. Internal-Thread Comparator. Eng vl62 n4201 July 19 1946 p 55. Illustrated description of instrument de- veloped by Machine Shop Equipment, Ltd, for rapid and

precise measurement of effective diameter of internal screw threads ; it consists of beam, on which slide pair of heads carrying brackets furnished with projecting ball

tips, and dial indicator. Measurement of Straight - Flanked Helicoids, J. W. DRINKWATER. Machy (London) v69 nl762, 1764, 1767, July 18 1946 p 77-82, Aug 1 p 139^3, Aug 22 p 235^0. Methods of mathematical treatment for determining re- lations existing between radius and rake of measuring

cylinder, thread form, effective diameter and helix angle

effect of helix angle from zero to 90°, including straight

splines ; thread angle in axial, normal and transverse sec- tions considered for screw threads, taps, hobs, spiral broaches and gears. On the Influence of Periodic Screw-Error on the Density

Distribution in Spectroheliograms, V. VON KEUSSLER,

Zeit Astrophys v24 n3^ p 233-9 1948 in German. Even

small periodic errors of the order of 0.002 mm prove very

disturbing. A new device for testing measuring-spindles

is described. Gauging of Precision Screw Threads, A. C. PRULIERE.

Microtechnic v2 n2, 3, 5, 6, Apr 1948 p. 71-8, June p

115-22, Oct p 222-8, Dec p 234-40. Description of dif- ferent methods such as Zeiss measuring prism method,

optical-mechanical and mechanical method ; illustrated description of measuring apparatus. Comparator-Chart Inspection of Tapered Pipe-Thread

Gages, K. A. CLARK. Machy (NY) v54 nl2 Aug 1948 p 165-7. Inspection practice at Lockheed Aircraft Corp., in use of comparator charts to check pitch diameter, gaging notch diameter, taper, angles, and forms of pipe thread production gages ; charts are designed to provide : Ifc all contours and check points necessary for inspection of

2(H)
each of National pipe thread standard pitches, as outlined

in Army-Navy Specification An-GGG-P-363.

lai Ein stufenloses Schaltgetriebe hoher Genauigkeit (A

- Stepless Switchgear of High Accuracy), A. BUDNICK.

Werkstattstechnik und Maschinenbau v39 n2 1949 p 45-8.

Mi High precision apparatus with stepless switchgear for * measuring cylindrical milling cutters and spiral shaped

ilia objects ; indicator motion in measuring slide by precision

spindle screw and frictional transmission ; indicator is set up at angle by set of permanent and varying gears with holes on rim; measurement errors do not exceed

- 4X10"5 in. ; photographs, table. Gauging and Measuring Screw Threads. NPL Notes

Appl Sci nl 1951 109 p 7 supp plates. General definitions and symbols; gaging of parallel screw threads; errors

of screw threads ; control of accuracy of pitch ; hardness

EEL J of screw gages; measurements of parallel screw plug and ring gages; inspection of parallel screw ring gages

: with check plugs ; testing of screw caliper gages ; optical a projection apparatus ; gaging of taper screw threads

- i < measurement of taper screw plug and ring gages. (See

.y. also 1958 edition.) Interferometric Calibration of Precision Screws and Con- v« trol of Ruling Engines, G. R. HARRISON, J. E.

::ti ARCHER. J Opt Soc Am v41 Aug 1951 p 495-503. A

: new device is described with which screws of any length

" can be calibrated rapidly for both periodic and cumula-

•:- rive errors in terms of interference fringes. It can also

_ - be used to plot correction cams to remove fixed errors of

-

" translation or rotation, and to monitor the operation of an engine while ruling diffraction grating or scales, cor- recting by automatic feedback differences between the

actual carriage position and its proper position as shown

.: by an optical interference field. The "Commensurator"

.- • i i.e. for over-coming the incommensurability of the wavelength of the light used for calibration and the lead of

"i!

1

! a screw) consists principally of a screw drive system,

:.:: i

' eight-figure dials, and a generator, geared together in

ratios that can be controlled to one part in 10 8

. Fringes produced by a Michelson interferometer are changed

photoelectric-ally to a wave train that measures translation to within 0.1/t in. A second wave train of almost

identical average frequency is produced by the Commen-

- surator generator to measure screw rotation, and the two

trains are continuously compared by means of a phasering sensitive amplifier and motor to within 1/100 cycle or

fringe. Corrections for changes in barometric pressure

i r in temperature can be introduced during operation. Transient as well as fixed errors of run and period can

4 be automatically compensated for. If the fringe system

is lost, it can be re-established from the Commensurator

record, so that controlled ruling of gratings wider than

- any available coherent fringe-field appears possible.

--. Die optische Messung von Aussengewinden (Optical

- Measurement of External Threads), G. BERNDT, K. H.

. KUEBLER, Dresden. Tech Hochschule Wiss Zeit v2 n2

1952-53 p 199-213, n3 p 467-78, n6 p989-1000. Part 1

Measurements of threads with symmetrical profile. Part

gjjjj 2 : Threads with asymmetrical profile. Part 3 : Measure-

.„. p jjonent of identical threads. Screw Gauge Measurement Gives Continuous Record, P. W. HARRISON. Mach Feb 14 1953 p 250. An electric measuring head replaces the indicator of the floating micrometer-diameter measuring machine designed by the National Physical Laboratory. It thus shows variations

in effective diameter to be continuously recorded. 0

Methods and Instruments for Thread Gauge Inspection,

• C. A. LE BOURHIS (Laboratoire Central de l'Armement,

( T ranee). Proc of Symposium on Eng Dimensional Metrology, H. M. Stationery Office, vl Paper 5 Oct 21-24 1953

I P 81. Describes some methods and instruments which

have proved efficient in daily practice.

Methods and Equipment of the Physikalisch-Technische Bundesanstalt for the Inspection of (A.P.I) Taper Thread Gauges, K. BURGER, M. GARY. Proc of Symposium on Eng Dimensional Metrology, H. M. Stationery

Office, vl Paper 6 Oct 21-24 1953 p 97. Discusses meas- urement of pitch cone diameter, lead, taper of ring gages, and thread angle, 14 refs. Effect of Differences Between U.S. and British Practices

in Measuring Screw Gauges for Unified Threads, L. W. NICKOLS. Machy (London) v90 n2315 Mar 29 1957 p

723-5. American and British methods of measuring ef- fective diameters of screw plug gages and setting plugs

effective diameter measurements made at single specified position on each of five screw plug gages having unified threads in order to determine experimentally effect of differences between two methods. The Effectiveness of Various Contacting Elements Used

for Gaging and Measuring Pitch Diameter, S. G. JOHNSON. Johnson Gage Co. Bui n400 May 15 1957. Contrasts cone and-vee method against three-wire method

of measuring pitch diameter. Thread Gage Measurement, G. H. STIMSON. Automatic Machining Mar 1958 p 31. Points out some of the conditions which contribute to inaccurate results, and the measures which must be taken to avoid them. Screw Thread Flank Tester, O. ENDO, N. HOSHINA, Y. YOKOYAMA, M. SAWABE, S. SUKIGARA. Rept Central Inspection Inst of Weights and Measures, Japan,

v9 n4 rept 24 1960, vlO n3 rept 27 1961 in Japanese. A

new screw thread flank tester is developed in order to determine the flank profile and the half-angle of the

thread. The tester consists of bed, sine-table, column,

carriage, electronic micrometer and pen-recorder. The

measuring method is as follows. A screw threaded gauge

to be examined is set on the sine-table which can be

inclined by the nominal half-angle of the thread by

using the angle gauge block. Then the generator of the upper flank of the thread which lies in the vertical plane

containing the line of the greatest slope of the sine-table

is to become parallel to the direction of the displacement

of the carriage carrying the detector. The stylus of the

detector is brought into contact with the upper flank and the carriage is driven horizontally by the feed motor. The deviation of the profile of the flank from that of

ideal one is detected by the differential transformer. The recorded profile of the flank has the vertical magnification of 3200 and the horizontal magnification of 50.0. The error of the half-angle of the thread may be deter- mined by the ratio of the deviation from the horizontal

line to the horizontal displacement of the stylus. The

measuring error of the half-angle of the thread due to the fact that the line of the direction of the stylus dis- placement does not literally intersect the center line of the gauge is estimated. The measuring accuracy of the

flank profile being able to be kept within ±0.3/*, the half- angle of the thread can be measured with an accuracy

within ±2.0' in the case of the ring of the diameter 50

to 600 mm or the plug 50 to 140 mm. Lastly there are given some illustrations on several flank profiles which

are recorded by the tester of some screw thread gauges. In the measurement of the half-angle of the thread

carried out by a screw thread flank tester developed at the NRLM, it is unavoidable that the line representing the direction of the stylus displacement can not literally be made to intersect with the axis of the screw thread

and, therefore, an unnegligible error produces, especially when the diameter of the screw thread is small. A proce- dure for correcting the above mentioned error is found

out by treating this measuring method mathematically, and yet this correction is able to be given by a convenient nomogram. 201
Microscope for Measuring Internal Threads, A. I. OMEL'CHENKO. Meas Techn 1959 n8 July 1960 p 584-6 4 figs. Translated from Izmer Tekh n8 Aug 1959 p 7. The described microscope for measuring internal threads

provides better measurements than other methods of the

three basic internal thread elements with a nominal

diameter of 18 mm and over. The instrument is based on the double microscope of Academician V. P. Linnik. Note on Measurement of Rake Angle and Relief Angle

of Taps and Dies, K. EDENSOR. Machy (London) v97 n2507 Nov 30 1960 p 1237-9. Measurement requires set- ting of graticule cross line so that it is tangential to

circle, method described provides means for positive loca- tion of tangent. Further Report on the Effect of Differences between U.S. and Britsh Practice in the Measurement of Screw Gauges

for Unified Threads, P. W. HARRISON. Machine Shop

v22 n4 Apr 1961 p 207. Measuring the Profile Angle of Internal Conical Threads,

A. A. KHAIROV. Meas Techns 1961 n7 Dec 1961 p 521-4. Translated from Izmer Tekh n7 July 1961 p 6-7. Describes an electrical contact instrument for measuring

half the profile angle of internal threads with a pitch of 6 and 6.35 mm. With an appropriate change in the dimension of the electrical contact head it is possible to measure

profiles of threads with a pitch of 5 mm.

Measurement of a Large-Size Internal Buttress Thread Mean Diameter, N. V. SERGEEV. Meas Techns 1963 n2 Aug 1963 p 100 1 fig. Translated from Izmer Tekh n2 Feb

1962 p 8. Describes a micrometer hole gage for measuring a buttress thread 600 mm in diameter.

Interference Method for Measuring Thread Elements, V.

P. KORONKEVICH, L. YA. GUSTYR', A. N. RAZUVAEV.

Meas Techns 1963 n2 Aug 1963 p 100-7 5 figs. 8 refs. Translated from Izmer Tekh n2 Feb 1963 p 8-14. If the

distance between the first fringe and the edge of the

shadow contour is evaluated, it becomes possible for this fringe to be used as a setting line instead of the graduation of a measuring knife-edge. The application of inter- ference fringes for measuring the mean thread diameter and the dimensions of components which have a curvature along the optical axis is beset with certain difficulties which, in the first place, consist of the effect of microscope

focusing on the distance to the first interference fringe and of the effect of the light-beam aperture on the inter- ference pattern. This article aims at elucidating the

effect of these factors. Technique for Calibraton of Large Thread Gages, H. E. BROUSSEAU. ASTME Tech Paper 590 1964 14 p 6 figs 1 ref. Annular shaped thread gages remain mounted on

the arbor as processed in manufacture. The arbor center

holes locate the axis of the gage, permitting measurement

of lead and helical variation. Gages over 8 in. in diameter

are inspected on a modified optical comparator. Special holding fixtures and underside projection are used. Combined Micrometer and Sensitive Indicator Unit, W. F. ATKINS. Quality Engr v28 n4 July-Aug 1964 p 118-9. Combined micrometer and fiducial indicator unit capable

of measuring to accuracy of about 0.25 ,_m is described

unit is intended for incorporation in measuring machine

of type used to measure screw plug gages of sizes above

about 12 in. diam ; it enables operator to watch movement

of indicator pointer and micrometer simultaneously ; unit described is equally suitable for measuring diameter of sizes down to about 4 in. Combined Micrometer and Sensitive Indicator Unit, W. F. ATKINS. Machy (Lond) vl05 n2697 July 22 1964 p

271-2. To overcome difficulty when measuring work pieces

of large diameter, design was produced at National Physical Laboratory in which micrometer and fiducial indicator are combined in single unit that can be mounted on machine ; external and sectional views of unit are described

unit was fitted to diameter measuring machine used at NPL for checking API screw plug gages.

9.2. Lead Measurements

Note on an Instrument for Measuring Screw Threads, H. J. C, Standards Dep, Board of Trade, Westminster,

Oct 1 1901. A design of a measuring instrument, the Vis- ometer, for measuring the angle and pitch of a screw

thread. Determining the Errors in Screws, R. A. BRUCE. Am

Mach v27 Apr 7 1904 p 454-5 5 figs. Miscroscope and

scale arrangement for determining lead errors of lead

screws, with a micrometer for measuring the magnitudes

of the errors, a contact point being inserted in the thread

space, and a cross hair of the miscroscope being set on

the scale divisions. Measuring the Pitch of Nuts. GB NPL Rep 1906 p 43. A carriage actuated by an accurate guide screw can slide along a bed A, and on the carriage is a second slide B

making an angle 62y2

° with the slide A. On slide B is a pivoted lever arrangement. The nut is set up with its axis parallel to slide A, and the arrangement is such

that when the lever point on slide B is brought into contact with the side of the thread any movement of the point

in the direction of the slide B causes no displacement of the lever, the angle being 55°. This acts as an indicator

of contact between the point and the side of the thread, and by means of the guide screw the pitch may be measured.

Testing the Lead of Taps and Screws, E. OBERG. Machy

(NY) vl4 Jan 1908 p 317-8, 4 figs. Describes testing the

lead by gages and comparators for the lead of taps and

screws.

Testing the Lead Screw of a Lathe, E. R. CONNERS. Am Mach v31 Nov 19 1908 p 751. Uses micrometer to measure motion of carriage. Testing Pitch of Micrometer Screws, H. L. WHITTEMORE. Am Mach v34 Mar 9 1911 p 437-8 3 figs. Optical

lever device for testing uniformity of pitch and diameter. Calibration of New Screw-Measuring Machine, A. J. LEE,

H. B. STEELE. Astron J v30 May 5 1917 p 128-9. Description of tests of a new measuring machine designed by F. Schlesinger and made by Gaertner of Chicago. The

screw is 18 mm. in diameter and has 249 threads of 1 mm.

pitch. The periodic error was found to have a max. value

of 0.00013 mm., which is negligible in all work with stellar images. The progressive errors were determined for every cm. of the screw, with a temperature range, during the measurement, of 1.3° C. They are small and negligible for the work in view. Screw Thread-Lead-Testing Machine, West & Dodge Co- Am Mach v48 May 30 1918 p 931-2. Machy (NY) June

1918 p 949-50. To test the lead of threads the contact point is placed in position in one of the threads and the micrometer spindle adjusted so that the dial indicator points to zero. The point is then moved along a number

of threads and micrometer readings taken. Drunken

threads are detected by turning the gage partway around and again measuring. The dial indicator is not used for obtaining the actual measurements, but only to show the

correct amount of pressure to apply on the micrometer

spindle. The large graduated wheel gives readings to 202
0.0001 in. if desired and a solid plug can be used in place of

the indicator spindle and Johansson blocks used between

contact points on the base.

Sheffield Thread-Lead Testing Machine for Screw Gages. Am Mach v49 n4 July 25 1918 p 180 incl 1 half-tone. Description of a testing machine for the lead of screw- thread gages. The machine has been placed on the market

by the Sheffield Machine and Tool Co., Springfield, O. Coats Lead Testing Machine. Machy (N.Y.) v24 Aug 1918 p 1150 2 figs. A lead measuring machine in which a fluid gage is used as indicator and measurements of lead are made by means of precision gage blocks. Thread-Lead Testing Device. Arrow Tool Co., Am Mach

v50 Mar 13 1919 p 517-8. To use the device the gage to be tested is placed on the centers and tightened. One

of the gaging points is then brought into contact with the

gage, observation being made against a piece of white

paper or other reflecting material laid on the base. After

this adjustment is made the slide is clamped, and the measuring spindle of the micrometer head, which has been

brought to some predetermined reading is brought into contact with the raised hub. and slide is then clamped. The micrometer spindle is then turned back, the first gaging point is withdrawn and the second one advanced

to contact with the thread. The gage under test must not

be allowed to rotate on the centers. If any error exists

it must be met moving the slide along the slideway until the second gaging point is in contact. When this is done

the variation from true lead is measured directly plus or minus with the micrometer. Checking the Accuracy of Lead Screws. Machy (N.Y.) v28 July 22 1922 p 903-4 3 figs. Lead screws are checked by determining the distance that the nut moves for a given

rotation of the screw. Measurements are made by means

of a micrometer and end standards, using P. & W. measuring machine. The Mechanical Measurement of Pitch, H. T. WRIGHT.

Machy (London) v23 Nov 22 1923 p 236-9 8 figs. Method

of recording and analysis of test results : describes pitch- measuring machines. John-Sons Screw Thread Lead Tester and Comparator. Am Mach v61 July 10 1924 p 79. Made in two sizes, No. 0

to %" and %" to The cradle of the screw is composed of annular gaging elements which are free to rotate on their holding stud and, with the exception of one fixed

roll, can also move laterally to adapt themselves to the

lead variations of the screws to be measured. A wedgeshaped plunger which runs in a groove in the "indicator

roll" is elevated against the spindle of the indicator, when

the screw is placed in the cradle, and provides the means

by which the lead errors are recorded on the indicator. The indicator is set to zero by masters.

Steigungspriifer fur Leitspindeln (Pitch Testers for Lead

Screws), H. WILDE. Zeit fur Feinmech und Prazision Dec 15 1926 p 265-8 6 figs. Describes Zeiss optical instru- ment and gives examples of measurements. Screw Thread Pitch Measuring Machine. Machy (N.Y.) v33 May 1927 p 710-1 2 figs. Am Mach v66 May 5 1927 p 752-3, 2 figs. Apparatus brought out by Soeiete Genevoise d'Instruments de Physique, Geneva, Switzerland, embodying a micrometer having a range of 4 in. and a

knife-edge multiplying lever system sensitive to 0.00001 in. as the indicator. Machine is adapted to the measurement

of both internal and external threads. It will hold plug

gages up to 6 in. in diameter and 8 in. in length, and has a

travel of its micrometer screw of 4 in. Michigan Spiral Gear Lead Checking Fixture. Am Mach

v75 Sept 3 1931 p 395. This spiral-lead checking fixture

will handle spiral gears up to 16 in. in diameter and with

any lead of 10 in. or over, either right or left-hand. The

gear is mounted on a stub arbor or between centers up to 12 in. in length. The fixture is of the sine bar type. Mounted on top and towards the sides of the gear carriage are two lapped surfaces which drive the work spindle by

contacting two friction rolls. These rolls cause the spindle

to rotate in timed relation with the movement of the

carriage on which the indicator is mounted.

National-Cleveland Helical-Gear Checking Device. Am

Mach v75 Nov 26 1931 p 830. This device is shown at- tached to the Model "B" gear checking machine, and may

also be attached to the Model "C" machine. In addition,

it is furnished as a bench type, or mounted upon a pedestal

stand. The helical gear is mounted upon a stub shaft

carried by a slide, which is moved so that the teeth of the gear engage the teeth of the rack. The reading of the angle thus established is taken direct from the large drum. The device will cheek right or left hand helical gears. When mounted on a pedestal the device may be placed

in the production line to permit 100 per cent inspection. "Detroit" Lead Testing Instrument. Am Mach v75 Dec 17 1931 p 939-40. Measurement is made by means of a spiral micrometer and microscope, supported on a carriage and

focussed on an optical scale. The carriage is fitted with

a spring-loaded plunger, carrying at its extremity a removable ball point, which engages two adjacent threads of the piece. This plunger mechanically locates the carriage. Maximum error does not exceed a total of 0.00018 in. for

the 8-in. length. Develops Machine for Testing Lead of Helical Gears. Iron Age vl33 nl3 Mar 29 1934 p 35; Machy (N.Y.) v41 n3 Nov 1934 p 150-1 ; Automobile Engr v24 n319 May 1934 p 187. Details of machine introduced by Lees-Bradner

Co., Cleveland, Ohio, which accurately measures helix angles or lead of helical gears, and also calibrates machine

settings. New Helical Lead Checking Machine. Machy (N.Y.) v41 Nov 1934 p 150 2 p 3 illus. Details of machine introduced by Illinois Tool Works, Chicago, 111. for determining the accuracy of helices. New Helical Lead Checking Machine. Machy (London)

v46 nll95 Sept 5 1935 p 690-1. Machine, marketed by

Illinois Tool Works, Chicago, for determining accuracy

of helixes, has capacity for gears up to 12 in. in diam and

will take work up to 15 in. between centers ; checks helix angles from 0 to 90°. Measurement of Drunkenness of Screw Threads, F. H. ROLT, A. TURNER. Machy (London) v52 nl345 July 21 1938 p 489-91. Method devised by authors, which can

be applied to testing of machine tool ; based on fact that

if screw has true helix, then threads or grooves on one

side of it are always exactly midway between those on

opposite side in same axial plane ; machine for testing screw threads for drunkenness illustrated and described. Messen des Zahnschraegewinkels an Stirnraedern mit Schraegverzahung (Measurement of Helix Angle and

Pitch of Teeth on Helical Gears). F. LAESSKER. VDI

Zeit v83 n5 Feb 4 1939 p 133-5. Outline of measuring method and detailed description of testing equipment and

its operation, characteristics, and results attainable. "Sine Line" Machine for Checking Spiral-Gear Leads. Machy (N.Y.) v48 March 1942 p 162 1 illus. Machine of the adjustable sinebar type, is designed to check right- and left-hand spiral gear leads with spiral angles from

0° to 90°. Method of Screw Pitch Measurement, J. W. DRINK- WATER, Machy (London) v60 nl541, 1542 Apr 23 1942 p 341-5 and Apr 30 p 372-3. Outline of necessary meas- urements to be checked in screw threads if accuracy is desired; description of screw pitching machine; details 203
of how machine can be used to determine certain defects

in screw threads and machine tools. New Electromagnetic Method of Measuring Screw Thread

Leads to Few Millionths of Inch, H. T. RIGHTS. Instrum

vl7 n3 Mar 1944 p 134-5. Method has been embodied in instrument of comparator type, which can be read di- rectly to within 0.00001 in. and readings can be estimated

to within 0.000001 in. ; method being electrical rather than

mechanical, gaging point functions with pressure of only

three ounces ; it has no time lag and is rapid in operation ; anyone experienced in checking thread lead can set up

instrument quickly and operate it successfully. Fellows Introduces New Lead Measuring Instrument, A. JANSSON. Tool Engr vl7 n3 Oct 1946 p 53. Features and operation of new instrument developed by Fellows Gear Shaper Co; instrument incorporates arrangement whereby lead of helix is checked by continuous motion of measuring pointer in conjunction with desired rotation

of work; principle embodies two tangent bars and pins, both of which operate slides, one effecting traverse move- ment of member carrying measuring pointer and other, rotation of work. Autographic Me'thod of Checking Accuracy of Micro- meter Screws, F. H. ROLT. Machy (London) v78 nl993 Jan 25 1951 p 165-7; Engr vl91 n4957 Jan 26 1951 p

117-9. Conventional method necessitates recording of numerous readings ; new method of obtaining autographic

records compares travel of micrometer spindle contin- uously with that of master screw, differences being re- corded as trace on moving strip of paper ; design and general arrangement of micrometer head testing apparatus ; illustrations. Measuring Gear Components, F. M. BUTRICK, JR. Tool Engr v26 n2 Feb 1951 p 44-5. Lengthy but simple method

for measuring helix angle of helical, herringbone, or screw gear when regular gear cheeking machine is not

available ; equipment required and steps to follow ; in- accuracies are small ; illustrations. Homemade Checker Bridges Gap, F. M. BUTRICK, JR.

Steel vl33 n26 Dec 28 1953 p91. Lead comparator for

helical gears fabricated in tool room is designed to serve

until commercially made comparator arrives ; drawing shows how this simple device compares gear with master. Automatic Measurement of Small Deviations in Periodic

Structures, H. T. CLOSSON, W. E. DANIELSON, R. J. NIELSEN. Rev. Sci Instrum v29 nlO Oct 1958 p 855-9. Description of accurate microdeviometer, originally de- veloped for measurement and recording of pitch uniformity

of helices in traveling wave tubes ; instrument combines

optical, mechanical, and electronic techniques ; electronic

circuitry automatically stores and processes position in- formation and feeds processed information, in form of deviations from corresponding ideal structure, to pen

recorder. At Last a "Drunkometer" for Threads, W. M. STOCKER,

JR. Am Mach vl02 n26 Dec 15 1958 p 87-9. "Drunken

helix" being deviation of helix from theoretical or true

helical path can now be measured by new electronic thread comparator developed by Greenfield Tap and Die

Division ; new instrument compares two points, separated by predetermined angle such as 90 or 180°, on single thread and measures deviation from true helix ; typical recorded patterns showing rejected, acceptable and master thread for 8-32 thread plug gages are presented. Contribution to Testing of Precision Lead Screws, J. SIMONET. Mierotecnic vl3 nl Feb 1959 p 15-11; In- spection Engr v23 n6 Nov-Dee 1959 p 134-9. Details of design, construction, and operation of special precision measuring instrument developed at Metrological Laboratory, University of Liege for checking pitch of lead screws. Presents a critical study of a new lead measuring instrument and a statistical examination of results of measure- ' ments. Neues vereinfachtes Messverfahren fuer die Bestimmung I. des Steigungsfehlers innerhalb eines Oder mehrerer Ge- ' I windegaenge (New simplified measuring method for deJ termination of errors in pitch within one or several screw I threads), H. GIESLER. Werkstattstechnik v49 n4 Apr I 1959 p 192-5. Review of existing methods ; new method j described is more accurate, permits simpler handling and | saves time. New Method of Measuring Pitch Errors of Screws to

j Very High Accuracy, L. W. NICKOLS. Machy (London) 11 v96 n2480 May 25 1960 p 1171-6. r Method developed at National Physical Laboratory employs autocollimator technique to compare pitch of screw with end-standards

of length ; apparatus was designed to measure pitch errors

of V-threaded precision lead-screws, within certain limita- tions of size, and is also suitable for measuring pitch errors of reference screw plug standards used to calibrate pitch measuring machines ; apparatus and measuring

procedure described ; effect of errors on accuracy of pitch measurement. New Method of Measuring Pitch Errors of Screws to Very High Accuracy, L. W. NICKOLS. Quality Engr v24 n4

July-Aug 1960 p 107-11. Method developed at National

j Physical Laboratory for measuring pitch errors of screws having vee-thread form to considerably higher accuracy than formerly ; method employs autocollimator technique j to compare pitch of screw with end-standards of length ;

results indicate that, provided no temperature variations

occur, pitch may be measured in terms of measured sizes i of end-standards to accuracy better than ±5 fi in. Controlling the Curvature of Thread Gauges, N. M. ZHURAVLEV. Meas Techns 1959 nl2 Sept 1960 p 940-3

6 figs. Translated from Izmer Tekh nl2 Dec 1959 p 14.

Proposes a new instrument combining high productivity with great precision for measuring helix variation of screw thread gages. Checking of gages showed that such

variation sometimes exceeded the pitch tolerance. Can

be used for automatic thread testing in conjunction with

electric induction or pneumatic recorders. Checking the Curvature of Thread Gauges, F. P. J FROLOV. Meas Techns 1960 n7 Feb 1961 p 583-4 2 figs 1

j ref. Translated from Izmer Tekh n7 p 24-5 July 1960.

j Describes instrument for checking helix variation atj

180°. Method for Determining Comparator Screw Errors with I Precision, J. M. BENNETT. J Opt. Soc Am v51 nlO Oct 1 1961 p 1133-8. Precise determination of relative cumu

lative error and periodic error of comparator screw;*, measured curves for Mann comparator and Gaertner 1, comparator ; method gives relative lengths of intervals

j j on scales used. Mitsui Leadscrew Measuring Machine with Automatic ! Recording Equipment, R. E. GREEN. Machy (London) !

vlOO n2564 Jan 3 1962 p 37-41. Machine built by Japanese I company will detect inaccuracies as small as plus or minus

(2 plus or minus 3L/1000)/x, where L is length to be. measured in millimeters ; for such measurements, temper-

ature difference between workpiece and master leadscrew

built into machine, must be less than 0.05 C ; new measur-,

ing principle employed is based on use of 2 electrical measuring contacts, average of two readings being provided

electronically ; errors due to distortion or eccentricity of screw are automatically canceled out. Teilungsmessungen an Verzahnungen in der Praxis (Pitch Measurements on Gear Teeth in Practice), H. A. KOOP.

Werkstattstechnik v52 nl2 Dec 1962 p 646-52. Installations and devices employed are described ; interpretation

of measuring results with regard to various types of erJ rors is explained. 204
Interferometric Device for the Calibration of the Micrometer Screw of a Microscope, J. MONTILLA. Anales de

:;

\ la Real Sociedad Espafiole de Fisica y Quimica v59A nl-2

* Jan-Feb 1963 p 19-20 in Spanish. The device is based

- on the relation between the displacement of interference

" fringes of Fizeau type and the displacement of the microi scope tube. An accuracy of X/200 or better is obtained. The Error in Measuring Periodic Faults in Guide Screw

Pitches. T. S. KIRILLOVA, E. A. SHILOVA. Meas

Techns 1962 n7 Feb 1963 p 543-4. Translated from Izmer Tekh n7 Julv 1962 p 8-10. Compares accuracy of measurements obtained by the use of recorders with those

1 obtained with universal microscopes. Podatnose statvczna ukladu "O-P-N" i jejwykorzystanie

r' do korekcji bledow skoku przy obrobce srub pociagowych

* '• ( Static Flexibility of Machine Tool-TVorkpiece-Tool Sys-

- 1 tern and Its Use* for Pitch Error Correction in Lead-

' Screw Machining. H. KALUZKA. Prezglad Mechan- ^ } iczny v22 n6 Mar 25 1963 p 163-6. Sources of pitch errors

in machining high-precision lead screws are analyzed and

error formula derived ; simple method is suggested for

3| - eliminating pitch error by applying to workpiece axial

*\- force determined from expression derived and acting

j from back center towards chuck plate. Error in Measuring Pitch of Screw Propellers by Means

of Goniometers, F. M. KATSMAX, S. V. YAKOXOVSKII.

r:

! Meas Techns 1962 nl2 July 1963 p 992-5 3 figs. Transf

\lated from Izmer Tekh nl2 Dec 1962 p 8-11. Analyzes 2 ' the precision with which it is possible to measure this element by means of goniometers, in view of the stringent tolerances specified in GOST (All-Union State Standard)

8054-59 for the local pitch of screw propellers which must

not exceed ±2% for propellers of the higher and ±3.5%

for those of the lower grade. Investigation and Trial Manufacture of Leadscrew Measuring Machine with Automatic Recording Equipment, A. YAMAMOTO, S. YAMATO, S. ISA, C. KAWAMURA, I. KUMAGAI. Bui Japan Soc Prec Eng vl nl Oct 1963 p 13-6 9 figs. Contents : Machine construction ; measuring principles ; specification ; examples of lead measure- ment ; conclusion. On a Screw Thread Lead Measuring Machine with Auto- matic Recording Equipment, A. YAMAMOTO, M. ICHIKAWA. Bui of the Tokyo Inst Technol n58 1964 p 37^7 11 figs 3 refs. A SIP model 4 type screw thread

cutting lathe which had been used in a machine shop for many years, was repaired and adapted to serve as a screw

thread lead measuring machine with automatic record- ing equipment. From this investigation the following

results were obtained. (1) An electric micro-comparator

with automatic recording equipment was made by utiliz- ing wire strain gauges, and it was ascertained that it had

the satisfactory accuracy and linearity for the lead measuring machine. (2) Periodic error of measurement which was caused by the eccentric rotation of the lead screw was fully eliminated by using a suspension type lead nut

instead of the original one. (3) The screw thread lead measuring machine could measure to an accuracy of ±lju within the measuring range of 100 mm, by giving a

correction curve to the plate cam and repairing several parts of the machine. (4) Lead error of an internal thread could be measured without taking into account the

influence of eccentric chucking.

9.3. Wire and Ball Measurements of Screw Threads and Other Helicoidal Features

Note : Measurements described in this section relate to evaluation of thread groove diameter (or pitch diameter) of screw threads. As related to gearing where the pitch diameter is an exact theoretical value, not subject to any deviation from the ideal, such measurements are commonly designated as the measurement of tooth thickness or checking

of backlash. See also subsection 10.2.4. ~t Measuring External Screw Thread Diameters, W. CANTELO. Am Mach v26 n26 June 25 1903 p 904-6 7 figs * ' vp. tables. Describes three wire method and wire method

f >r Acme threads. Furnishes formulas and tables of

- constants applicable to measurements of standard threads by means of a micrometer caliper. Measuring External Thread Diameters, J. M. STABEL.

Machy (N.Y. Eng Ed) v2 n5 Jan 1904 p 248-50 3 figs ^3 tables. Describes method of thread measurement by means of wires and micrometers. mf

1 ' -Measuring External Screw-Thread Diameters. Am Mach

!*|*30 Mar 7 1907 p 356-7. The application of micrometers

jand wires in the measurement of USS, V, and Whitworth

^threads. "'Measuring Screw Thread Diameters, W. CANTELO.

Machy (N.Y.) vl4 Sept 1907 p 33-4. Gives formulas for

the limiting sizes of wires for 60°, 55°, and 29° threads. Notes on Screw Threads, H. H. JEFFCOTT, XPL. Proc

Inst Mech Engrs Dec 1907 p 1067-1108 17 figs. ; Collected

'. Researches XPL v5 1909 p 215-50 17 figs. Contain an

-account of some theoretical aspects of screw threads,

partly from the stand-point of accuracy in the interpretation of results of measurement. Equations of the surface

of the screw thread were obtained in two different ways

One by a consideration of the method of generation and

the other by the use of Fourier series. Approximate

formulas for the measurement of effective diameter of a screw are derived on the basis that measurements are taken over cylinders, which being free, set themselves

nearly along the rake of the thread. A similar ease in which the cylinders are fixed perpendicular to the axial plane of measurement of the screw is also considered. The effect of small errors in the various elements of a screw on the interpretation of the results of measurement

of effective diameter is exhibited as a formula. Compiler's comment: JEFFCOTT's (approximate) Three- Wire Method has been internationally used for almost 60 years in the measurement of standard screw threads, particularly for single-start screws. Making Thread Gages, A. L. MONRAD. Machy (N.Y.) vl4 Feb 1908 p 387-90 10 figs. Illustrates thread grinding attachment for lathe, fixture for charging diamond lap, thread tool setting gage, lap for plug gages, simple dia- grams for determining wire sizes, lead tester, gage for

testing angle of thread, holder for micrometer stop. Gives

tables of ware diameters for measuring thread angle. Measuring Metric Screw Threads. Am Mach v33 pt2 Dec 1 1910 p 1028. Includes tables of constants for 205
measuring the pitch diameter of metric threads by the three-wire system. Wires for Measuring Threads, J. J. STEWART. Am

Mach v36 May 23 1912 p 842. Illustrated discussion of use of wires. Measuring Screw Threads by Means of Micrometers. Machy (N.Y.) vl9 n5 Jan 1913 p 384, 1 fig 1 table. In- cludes a table of sizes of two types of micrometer ball points applicable to various threads per inch. One Wire System for Measuring Threads, I. BANWELL.

Machy (N.Y.) v20 July 1914 p 978. Gives a formula for measuring pitch diameter with one wire. Notes on Screw Gages. NPL (Teddington) Feb 1916 28 p. Includes discussion of measurements of effective diameter and angle by cylinders of other than best diameters. Use

of a reference groove and cylinder for effective and core diameter measurements. Measuring B and S or Acme 29 deg. Threads, K. FEN- NELL. Am Mach v45 Nov 16 1916 p 846. Gives formulas

for any size of wire that will touch the sides and project above the top of the thread, not taking the lead angle into account. Master Whitworth Thread Gages, W. T. ILER, Jr. Machy (N.Y.) v24 Sept 1917 p 51-2. Formulas for measuring the pitch diameter and checking the flank angle by means of two wires. Measuring Screw Threads by the Three-Wire System. Machy ( London ) vll Nov 15 1917 p 181. Formulas proving

that the effect of lead angle readings is negligible with

standard threads. Errors in Measuring Thread Pitch Diameters With Wire,

J. H. BILLINGS. Am Mach v47 n25 Dec 20 1917 p 1007-8

1 fig; Mech Wld v63 May 3 1918 p 207. Discusses dis- crepancy in measurements of pitch diameter obtained by means of wires and by thread micrometers. Measurement of Internal Threads, W. S. ROWELL.

Machy (N.Y.) v24 Jan 1918 p 429. Uses inside micrometer with ball points. Gives formulas for computing

pitch diameter from measurements.

Error in Wire Method of Measuring Worm Threads, H. H. WRIGHT. Machy (N.Y.) v24 n5 Jan 1918 p 439-40 1 fig. Points out the necessity of taking the lead angle into account. Simple Method of Measuring Pitch Diameter of Screw

Threads. Machy (London) vl2 May 2 1918 p 128. Sketch and formulas are given, using three wires and measuring from crest of thread to over wires. The Measurement of Internal Threads, W. RICHARDS.

Machy (London) vl2 July 18 1918 p 425-7. Diagrams.

Internal ball point micrometer, with calculations for its use, and table of diameters for ball points. Fortney Measuring Wires. Machy (N.Y.) v25 Nov 1918

p 269. Four styles of wires are shown designed for use with special machines for measuring pitch diameter. Thread Measuring Formulas, H. M. FUNNELL. Am

Mach v49 nl9 Nov 7 1918 p 839 1 fig. States that when

using the three-wire system of measuring threads the usual formulas given in various popular handbooks are

correct only when the thread is standard. Gives formula

based on "angle root diameter" for threads which depart from standard form.

Use of Measuring Wires, H. L. VAN KEUREN. Auto- motive Industries v39 Dec 19 1918 p 1056. Choice and

standardization of wires, Computations. Determining Error in Thread Angle by Three Wire

Method. Machy (N.Y.) v25 Feb 1919 p 552. Measuring Acme Threads Without Special Wires, H. W. MILLER. Am Mach v50 May 15 1919 p 932. Gives formulas for wires or balls. Gewindemessen mit Drahten (Screw Thread Measure- ments with Wires), J. REINDL. Betrieb vl nl4 Aug 1919 p 361-5 11 figs. Discusses manufacture of wires, use for

pitch diameter and thread angle measurements, and gives

tables for Whitworth, International, and Lowenherz

threads. Gaging Acme Threads Without Special Wires, H. A. PEARSON. Am Mach v51 Nov 6 1919 p 830 1 fig ; Mech Wld v68 July 23 1920 p 60. Equations are given which, it

is said, can be applied to any wire which may be available. Three-Wire System for Measuring Standard Worm

Threads, H. A. PEARSON. Machy (N.Y.) v26 Aug 1920 p 1131. Gives formulas and tabular data, when using wires of any suitable diameter. Discussion by T. A.

Reilly, Machy (N.Y.) v27 Nov 1920 p 238. Screw Thread Measurement. Eng Prod vl Nov 1920 p

440-4 8 figs. Determination of effective diameters by

three wire system. Measuring Screw Threads by the Three-Wire Method, V. E. AYRE, NBiS. Machy (N.Y.) v27 Nov 1921 p 281. Gives

formulas. Die Optische Messung des Flankendurchmessers von Ge- winden (Optical Measurement of Flank Diameter of Threads), O. EPPENSTEIN. Prcizision n22 1922 4 p 8

figs 2 refs. Describes measurement of pitch diameter

using a projector and contacting the thread by means of knife edges. Measuring Thread Plug Gages, J. M. HENRY. Machy

(N.Y.) v28 Mar 1922 p 545-6. Shows various set-ups in the Pratt and Whitney measuring machine. Van Keuren Thread-Measuring Wires. Am Mach v56 June 1 1922 p 833. Machine lapped wires, accurate as to roundness, uniformity, and size, furnished packed in glass

bottles to protect against rust, loss, or breakage. Measurement of Worm Threads, A. FISHER. Machy

(London) v20 Aug 10 1922 p 591-2 3 figs. Reply to an

inquiry as to formulas for measuring the addendum and

thickness of multiple-threaded worms with gear tooth

calipers. Discussion by E. A. Limming, Machy (London)

v22 Sept 20 1923 p 794-5 1 fig as to the different chords

involved. The Normal Thickness of a Worm Thread, E. A. LIM- MING. Machy (London) v20 Sept 7 1922 p 707-8 1 fig. Develops a more nearly correct mathematical formula for the normal thickness of a worm thread at a particular radius R, defined as the thickness in the plane normal to the lead helix of that particular radius. The Normal Chordal Thickness of a Worm Thread, A. FISHER. Machy (London) v21 Oct 26 1922 p 118-9 4

figs. A further discussion of preceding articles by Lim- ming and Fisher in which it is concluded that very accurate measurements with gear tooth calipers are obtained with difficulty. The dimension usually taken is the min- imum thickness obtained when the calipers are allowed to choose their own angle. 206
Notes on Worm-Thread Formulas, P. A. FREDERICKS. Am Mach v55 Dec 1922 p 1043. Discusses three-wire measurements. The Exact Calculation of Worm-Thread Dimensions, H. E. MERRITT. Machy (London) v21 Dec 14 1922 p 330-1 2

figs. Discusses preceding articles by Fisher and Limming.

Proposes an exact calculaion of worm-thread dimensions. Normal Thickness of a Worm Thread, E. A. LIMMING.

Machy (N.Y.) v21 Dec 21 1922 p 360-2 4 figs ; Machy (London) v22 Apr 1923 p 114-5 1 fig. Derives equation for

the calipered chord of a screw thread which is identical with the contact chord of the best-size ball of its contact

nut. (They are identical with Vogel's [see below] cor- responding equations for the best-size ball measurement

>f internal threads.) Discussion by A. FISHER. Machy

i London) v21 Mar 15 1923 p 759. States basis of defini- tions in Fisher's preceding articles. The Gauging of Involute Threads, H. E. MERRITT.

Machy (London) Apr 5, 19 July 26, Aug 2 1923 p 11-3 79-

81 525 569 13 figs. Deals with : gaging straight-spur teeth by tooth caliper, rack-generated gears corrected for undercut, gaging straight-spur teeth by the plug or wire method,

applications of the plug method, zone and line contact between spiral gear and rack, application of the plug method to spiral gears, helical gears. Discussion : E. A. LIMMING Apr 26, Mav 10 p 114. 191 : C. PETTIT May 17 p 210; H. E. MERRITT May 24. 31 p 251. 275; E. A. LIMMING June 7 p 307 ; H. E. MERRITT June 21 p 376

A. FISHER July 5 p 442 ; E. A. LIMMING July 12 p 475 ; H. E. MERRITT July 26, Aug 2 p 525, 569. Measurement of Pitch Diameter of Screw Thread Gages. XBS Letter Cir n23 July 14 1923 60 p 16 figs. Discusses measurement of pitch diameter of straight and taper threads by means of wires, measurement of thread angle by wires, and gives derivations of various wire formulas

in the appendix. (Minders and Spheres for Gauging Worm or Screw

Threads, E. A. LIMMING Machy (London) v23 Jan 3 1924 p 466-7 2 figs. Derives formula for angle between

axis of wire and axis of screw. Also diameter of wire which will touch at a given radius of thread. The Gauging of Finish-Ground Worms by Cylinders, H.

E. MERRITT. Engr vl38 Aug 8 1924 p 162-3 3 figs. Shows that from certain fundamental worm dimensions

size and position of a cylinder to gage any point on thread

contour may be calculated, and in spite of apparent diffi- culty of problem, solution . is very simple and easy of

application. Correction for Elastic Compression in the Measurement

of Screws with Small Cylinders. G. A. TOMLINSON.

NPL. Machy (London) v28 Aug 26 1926 p 616-8 2 figs. Points out that in accurate measurements of small screw,

correction should be applied on account of compression

that "ordinarily occurs ; nomogram for computing compression correction in effective diameter measurement.

See also "Notes on Screw Threads". The National

Physical Laboratory, 1930 ; Proc Inst Engrs n4 p 1031-6.

1 Correction for Rake in Screw-Thread Measurement, G. A. TOMLINSON, NPL. Inst Mech Engrs Proc n4 1927 p

1031-6 4 figs. Simple method of computing necessary rake

correction based on exact geometrical considerations and

equations, which is now being used at National Physical Laboratory for threaded work of large lead angle, measured by means of wires. Die Abplattung von Stahlkugeln und Zylindern durch den Messdruck (The Oblateness of Steel Balls and Cylinders

clue to Measuring Force), H. BOCHMANN, Zeit fur Fein- mechanik and Priizision v.35 Apr 1927 p 95 14 figs. English

translation available. Contents: The Hertz theory; review of literature ; experimental arrangements ; experi- ments on steel balls between planes ; experiments on steel wires between planes; experiments on gages between

planes; general evaluation of the several cylinder tests; experiments on crossed cylinders; groove tests on steel wires ; summary.

L'emploi des "Piges" pour la Determination Rationelle des Elements d'un Filetage ( Use of Wires for Proper Determination of the Elements of a Screw Thread), L. FRAICHET. Genie Civ v92 Feb 11 1928 p 138-40 2 figs. Use of wires for measuring pitch diameter is described

errors of measurement; measuring thread angle. Measurement of the Thickness of Involute Gear Teeth,

A. H. CANDEE. Am Mach v68 n9, 11, and 14 Mar 1, 15 and Apr 5 1928 p 365-8, 463-7, and 573-6 12 figs. Mar

1 : Formulas for pin measurement developed ; measuring

distance across round pins or plugs placed between teeth on opposite sides of gear to determine tooth thickness

tables from which dimension across pins for standard

involute spur gears can be obtained very easily ; direct methods of calculation given for special cases of spur

gears and for helical gears. Mar 15: Calculations for pin measurement with standard pin sizes ; simplification

of calculations by means of standard tables for both ex- ternal and internal gears ; center of pin generally will not come on pitch circle ; for given pitch and number of teeth dimensions between centers of diametrically opposite pins

will vary with tooth thickness and pressure angle. Apr 5

Development of formulas for measuring thickness of

helical gear teeth by standard pin method and their application to typical case ; in case of odd number of teeth certain advantage is lost because two pins cannot be placed symmetrically opposite each other : importance of correct tooth form. Determination Rationelle des Elements d'un Filetage a

l'Aide de "Piges" (Rational Measurement of Elements of a Screw-Thread with Wires), L. FRAICHET. Genie Civ

v93 Sept 8 1928 p 238-40 3 figs; Bui Technique, Service Technique et Industriel de L'Aeronautique, n51 Oct 1928. Principles of thread pitch and diameter measurements of screw threads by means of wires and micrometers, and

formulas used are described. Measuring Acme Screw and Worm Threads by Means of Wires or Cylinders, W. RICHARDS. Machy (London)

v32 Sept 13 1928 p 787-90 5 figs and discussion v33 Dec 6 1928 p 302-4 4 figs. Fundamental factors involved in measurement of Acme and worm threads by means of wires or cylinders are given with formulas which take

into account variation due to inclination of thread with

axis of screw or lead angle. Further discussion by F. W. SHAW, Oct 18 1928 p 80 ; E. A. LIMMING Dee 27 p 405

W. RICHARDS Feb 14 1929 p 637. Measuring Worm Threads by Means of Cylinders, E. A. LIMMING. Machy (London) v33 n846 Dec 27 1928 p

405-10 9 figs. Discussion of formulas developed by W.

Richards in v32 p 787 of this magazine ; method said to be

theoretically incorrect because geometrical principles un- derlying conditions of contact between sides of threads and cylinders have not been completely taken into ac- count ; other formulas are developed. Measuring Acme Screw and Worm Threads by Means of Wires or Cylinders, W. RICHARDS, E. A. LIMMING.

Machy London) v33 n853 Feb 14 1929 p 637-10, 4 figs and

discussion v34 n862 Apr 18 1929 p 82-5 5 figs. Answer to comments made by E. A. LIMMING appearing in Dec 27

issue of magazine upon author's articles which were published in Dec 6 and Sept 13 issues ; criticism of data for design of worm tools and production of worm thread

refuted. La Mesure des Filetages des Vis a Filet Triangulaire (Measuring Triangular Screw Threads), P. A.
LAURENT. Genie Civ v94 nl4 Apr 6 1929 p 333-6 9 figs. Precision method of French Navy described ; it is combination of wire measurements of angles, diameters and

pitch and mathematical derivations therefrom ; precautions to be taken and errors resulting (±1 micron). Messfehler durch Abplattung beim Gewindemessen (Errors Through Flattening in Measuring Screw Threads), H. BOCHMANN. Zeit InstrumKde v49 n4 Apr 1929 p

188-203 4 figs. Errors in measuring screw threads by ball or wire method due to flattening of measuring wires or

balls. English translation available. The Measurement of Screw Elements. Machy (London)

v34 n884 Sept 19 1929 p 789-93 7 figs. Description of methods employed in measuring pitch diameter of screw

threads with wires and verifying thread angle by two

different diameter wires; charts are given for use in checking thread angle of U.S. Standard, Whitworth, S.I., and British Association threads by using set (of three) of each of two different diameter wires. Measuring Pitch Diameters of Taper Threads, C. KUGLER. Am Mach v74 May 7 1931 p 730. Gives a practical procedure for measuring pitch diameter at a defi- nite point with three-wire system. Includes formulas. Measuring Cycle Engineer's Institute Standard Screw Thread by the Three-Wire Method. Machy (London)

v38 May 14 1931 p 212-3. Derivation of formulas for measurement over wires and the best size of wire. Table

of wire sizes. Flankenmessungen an Schnecken und Trapezegewinden, (Measurement of Pitch Diameter of Worms and Trapezoidal Threads). A. RICKENMANN. Maschinenbau/

Betrieb v 10 Oct 1 1931 p 619 4 figs. A cone and vee micrometer is used. Discusses corrections to measure- ments and gives curve for lead angle corrections. Determination of Thread Diameters by the 3-Wire Method, G. BERNDT. Zeit InstrumKde Nov 1931 p 560-

74. Describes method, derives equations for pitch diameter. Corrections are also obtained for the flattening of the wires and for the case of oblique threads, and tabulated. Three-Wire Measurement of Screw Threads, J. R. CORNELIUS. Am Mach v74 May 21 1932 p 805 ; discus- sion by W. S. ROWELL v75 Sept 10 1932 p 416. Gives

tables. Helical Gear Tooth Measurement, S. TRIMBATH, Am

Mach v76 Aug 31 1932 p 966-7. Advantages of sizing heli- cal gear teeth by measuring across pins ; standard form. Die Bestimmung des Flankendurchmessers nach der Drei- drahtmethode (The determination of pitch diameter by

the three wire method). G. BERNDT, Zeit InstrumKde

v.ol Nov 1932 p 560-74; Maschinenbau/Betrieb vll Apr

1932 p 133. Advantages, methods of making measurement,

calculations, and discussion of errors. Korrektionen bei der Messung von Innengewinden (Corrections for the measurement of internal threads) , J. WIL- HELM. Feinmechanik und Prazision v41 Oct 1933 p

147^52. Derivation of factors for correcting the measure- ment of internal threads by means of balls, V-blocks, and

size blocks taking into consideration the deformation of the balls and the errors relating the helix. Analytisches Verfahren zur Ermittlung der Giinstigsten Messdrahte fiir die Sogenannte "Dreidrahtmethode"

(Analytical method for determining the most suitable measuring wires for the so-called "three-wire method"),

N. GUENTHER. Zeit InstrumKde v53 Sept 1934 p 373. Das Messen von Saegegewinden (The Measurement of Buttress Threads.), W. KNEDEL. Werkstattstechnik

v29 Feb 1935 p 50-2. The method of measuring Buttress threads by the three-wire method. Explanation of calculations involved. Bestimmung des Flankendurchmessers von Gewinden nach-; der Dreidrahtmethode bei unsymmetrischem Profil (De- termination of pitch diameter of screw threads of un- symmetrical profiles by the three-wire method), G.[ BERNDT. Werkstattstechnik v29 June 1935 p. 237-9. Die Messung Konischer Gewinde (The measurement of tapered threads), G. BERNDT. Bauer and Schaurte Neuss 1937 81 p. Various calculations. Size Measurement of Gears, W. L. CHESLEY, Tool Engr

v5 n9 Jan 1937 p 14-5. Easily understood method pre- sented of calculating sizes over pins or balls for spur or

helical gears. Neuartige kopfkreisfreie Zahndicken-Messungen fiir Schragzahnrader und Evolventen-Schnecken (Novel Method of measuring tooth thickness for involute helical gears and involute worms without use of addendum

circle), W. F. VOGEL. Werkzeugmaschine v41 nil June

15, 1937 p 253-61. Mathematical analysis of span meas- urements and its application to both spur- and helical in- volute-shaped tooth forms. A section "Tauchkorper- Messungen" (Dive-Body Measurements) deals first with

pin- and ball-measurements of involute spur teeth. Extension of the analysis to ball-measurements of helical in- volute gears and involute worms leads to the introduction

of the author's "Substitute- (thin) Disk Method", which

reduces the measurement simply to that of involute spur

gears. The same simplified method and equations have

later been applied to pin-measurements of all involute screws. ( VOGEL 1945 see subsections 10.1.2 and 10.1.3 and ZAHORSKI in Van Keuren Handbook 33 1945.) Bibliog- raphy. Errors in Wire Measurement, O. E. KOEHLER. Am Mach

v82 n9 May 1938 p 367. When lead is great, as with Acme

or multiple V threads, consideration of lead angle should

be included when measuring by wire method. Pin Method of Measuring Worms and Helical Gears, E. BUCKINGHAM. Machy (N.Y.) v45 nl Sept 1938 p 1-7

2 figs. Gives general formulas for pin diameter and meas- urement over pins; general formulas for screw threads and helical gears; application to screw threads and to a

helical gear; compensation for possible deflection of pins

or w:' res ; errors in tooth thickness resulting from pin de-

\ flection ; relation between a formula for screw threads and the simplified general formula. Compiler's comment :

j Formulas take lead angle into account but are not exact, as stated. They are approximations similar to those of! Jeffcott. (See reference above.) NBS formula (10). quoted on p 5 is likewise not exact as here stated. In the

original B523 reference it was stated to be a close approxi- mation for screw threats. ( See BUCKINGHAM below.

)

Gauging Screw Threads by Wire Method. Machy (Lon- don) v53 nl359 and 1360 Oct 20 1938 p 71-4 and Nov 3 p 133-8. Screw threads can be measured with precision by making use of calibrated wires ; direct reading charts and tables prepared by Societe Genevoise d'Instruments de

Physique, Geneva, for use in conjunction with standard

calibrated wires and measuring instruments, are given. Includes formula for computing values, correction factor

for obliquity, method of computing best diameter, corrections for elastic deformation of wires. Gaging Multi-Start Threads by the Wire Method. Machy

(London) v53 Nov 17 1938 p 200. Formulas for determi- nation of best wire diameter in measuring multi-start threads and threads with very large lead angles. Checking Screw Threads and Vehicle Gears by Measure- ment over Pins. E. BUCKINGHAM. Machy (N.Y.) v45 n4 Dec 1938 p 273. Compiler's comment : This article was

208
obviously in answer to reader objections to the author's preceding September article. Particularly, the author's

allegedly exact theory was incompatible with the exact

contact conditions of pins and balls used in the measure- ^- ment of involute screws, as analyzed and published by

: A. H. Candee 1928. In this article the author tries to

i explain these contradictions by his obviously honest belief and statement that the behavior and contact geometry of a pin in the thread groove of an involute screw are basically

: different from those in other types of screws. More re- cent developments disprove this concept as well as the

author's theory of bending deformations of the pins and

their needed compensations. See TOMLINSON 1927,

? VOGEL 1947, and MARRINER and WOOD 1958, this

- - subsection. Die Messung der Flankendurchmesser mehrgangiger Ge- winde mit drei Drahten (Measurement of Flank Diameter

of Multiple Threads with Three Wires), N. GUNTHER,

H. ZOLLNER. Feinmechanik und Priizision v47 n9 1939

p 129-31 2 figs. Contents: The three-wire method; the theory of screw surfaces ; contact conditions with derivation of exact transcendental equation ; the approximation

process ; summary, and buttress threads. Ball Measurement of Helical Gears, A. ZAHORSKI. Am

Mach v83 nl4 July 12 1939 p 520-2. Method developed

consisting of substituting real ball by imaginary roll, which will permit carrying out computation of measure- ment of tooth thickness of helical gears in same manner

as done for spur gears ; formulas and examples illustrated and described. Same as the Vogel "substitute disk method" 1937. Die Bestimmung des Flankendurchmessers von Gewinden

mit symmetrischem Profll nach der Dreidrahtmethode

i The Determination of Flank Diameter of Threads with Symmetrical Profile by the Three-Wire Method), G. BERNDT. Zeit InstrumKde v59 nil Nov 1939 p 439-48. Determination of flank diameter of screw threads with

symmetric profile according to three-wire method ; mathematical and geometrical considerations and applications. The algebraic and geometrical considerations of the meth- od and the influence of various sources of error are

considered. Die Bestimmung des Flankendurchmessers von Gewinden

mit Unsymmetrischem Profll nach der Dreidrahtmethode

i Determination of Pitch Diameter of Threads with Unsymmetrical Profile by Means of the Three-Wire Method),

G. BERNDT. Zeit InstrumKde v60 Jan 1940 p 14-22. Theoretical principles and application of method, influence

of errors, smallest and greatest possible wire diameters, numerical examples, detailed explanation of calculations

involved. Die Anlagekorrekturen bei der Bestimmung des Flankendurchmessers von symmetrischen und unsymmetrischen Aussen und Innengewinden (Corrections of Posi- tion in Determination of Flank Diameter of Symmetric >nd Asymmetric External and Internal Threads According to Three-Wire Method or By Means of Two Spheres),

G. BERNDT. Zeit InstrumKde v60 n5, 6, 7, 8 and 9 May

1940 p 141-54, June p 177-86, July p 209-20, Aug p 237-48

! and Sept p 272-8 ; Werkstattstechnik und Werksleiter v34

fcd7 Sept 1 1940 p 277-82. Detailed theoretical mathematical study ; approximate formulas for corrections of

position presented. Bibliography. Durehmesser der Draehte fuer das Dreidrahtverfahren

| Diameter of Wires for the Three-Wire Method), etc. G.

.. BERNDT. Werkstattstechnik und Werksleiter v36 n23, 24 Dec 1942 p 507-19. Diameter of wires for three-wire method of determination of flank diameter of single

uj. threads with symmetrical profile ; determination of flank

fj diameter without regard to non-perpendicular position of

TJJ -wires to thread axis ; influence of position of measuring

wires inclined toward thread axis.

Calculating Screw Thread P. D., W. T. TAYLOR. Tool Engr vl2 n8, 9, Aug 1943 p 87-9 ; Oct p 99, 101, 103, 105. Purpose is to simplify general formulas for overwire (3- wire) dimension, to present formulas in terms of basic

pitch diameter and basic major diameter, to show

best wire sizes which may be used for any particular number of threads per inch and to show permissible plus- minus limits on wire diameter for Whitworth 55° thread

so that American wire sizes can he used to practical ad- vantage; method of calculating and measuring even and

odd fluted taps. Involutometry and Trigonometry, W. F. VOGEL. Michigan Tool Co., Detroit 1945 325p 28 figs 33 refs. Contains

simple exact equations, with derivations, for pin and

ball measurements of involute-shaped spur gears and

splines, also of involute screws (e.g. helical gears, helical involute splines and involute worms). Forms with step by step calculations are provided for various purpose measurements of spur toothed products. All measure- ments are explained as applications of a complete geo- metrical system of involutometry (see abstract in Sub-Section 10.1.2) and are tailored to be used with the large Main Table and a great variety of other numerical tables

(see abstracts in Sub-Section 10.1.3). Larmar Three-wire Measuring Instrument for Screw

Threads. Machy (London) v66 nl684 Jan 18 1945 p 75-6. Illustrated description of apparatus manufactured by Larmar Eng Co ; to obviate difficulty in positioning three wires prior to measuring over them with micrometer, wires

are held to micrometer anvil and spindle faces by clamps. Checking Pitch Diameters of Precision Screw Threads, E. BUCKINGHAM. Machy (N.Y.) v52 nl Sept 1945 p 162-4. Consideration of three classes of screw thread profiles af- ecting measurement in checking pitch diameter of screw

thread by measuring over pins or wires ; involute-helical gear formula provides theoretically correct results when

applied to screw thread of involute helicoidal form and

very close approximations for threads having intermediate profiles ; applicable formulas given. Compiler's comment : This is a new idea for attacking the

intricate problem of measuring screw threads over pins

or wires. The author is to be commended for his proposal

to utilize the simpler expressions of the corresponding measurement of involute screws (e.g. helical involute gears and involute worms) for this purpose. Simple ex- act equations for pin- and ball-measurement of involute screws have been known before (e.g. Candee 1928, Vogel

1937 and 1945 etc., of this subsection). They offer the great advantage of free pin selection and also yield the exact contact points between pins (or balls) and the

helical tooth surfaces. Any attempt, however, to pre- scribe the size of the contact radius of the involute screw

not only kills the free selection of the wire size but also leads to strictly transcendent exact equations of the whole

measurement. The same is true for the exact measurement-equations with best-size wires of all screw types, since such wires are meant to contact the screw exactly

at the pitch cyclinder. ( See Vogel 1947 and 1955 in this subsection.

)

Buckingham's equations of the pin measurement of heli- cal involute gears in his Manual of Gear Design, vol. 3, 1937, p. 150 were given without derivation and explanation

except the statement that they were meant for contact

at a given cylinder of the gear. Referring to those (non- transcendent) expressions the author now admits in this

article that those two formulas for both the pin-size and

the over-pin dimension were only approximations. Si- multaneously claiming very small errors of those ap- proximations, he proposes to utilize the pin-size formula

as best-size wire formula for screw threads. This claim was not borne out in later comparative error investiga- 209
tions of various best-size pin formulas (see Vogel 1947,

in this subsection). In his new Thread Measuring Method, Buckingham es- tablished a best-size wire by an approximate formula, but abandons completely his previous approximate formula

for the over-wire dimension of an involute screw. Working with the thus established best-size wire, he uses it like a freely selected pin dropped into an involute screw and instead, applies an exact equation for establishing

its over-pin dimension. The method would be strictly exact, if the best-size wire had exactly the theoretically needed diameter, but as this was not the case, the whole method is only an approximation, whose accuracy ob- viously is influenced by the error of the used best-pin

size formula. The author himself was aware "of this. In

his first "numerical example" he utilized the approximate

best-pin size formula from his manual of Gear Design,

1937, as initially recommended. In his second numerical example he silently discarded his own recommendation

and specified (without calculation) a wire size, which

happens to correspond to that of a formula proposed in another of his previous publications, namely 1938. His

preferred latter approximation is also used exclusively in his representation of his new method in Machinery's Handbook, 17th ed. 1964 on p. 1217-20. According to Vogel (1947 of this subsection) the latter best-size pin is always undersize, while the best-size pin formula

used in the first example always leads to an oversize for the wire. The quoted references and Van Keuren Handbook 36 (1955) also contain newer developments of simple exact best-pin measurement equations, numerical

tables, and more precise approximations. The compiler hopes his cross-references will result in a more nearly

up-to-date presentation in the next edition of Machinery's Handbook.

Three-Wire Thread Gaging Simplified, J. J. MEADOWS.

Iron Age vl57 nl6 Apr 18 1946 p 51-7. Formula for checking thread size using three-wire method, based on major

thread diameter; charts and tables commonly involved and cover National Fine and National Coarse series, Whitworth standard, British Assn, British Standard Fine, and French standard thread forms.

Effect of Elastic Modulus on Measurement of Thread

Wires. D. E. WILLIAMSON. Prod Eng & Mgmt vl8 n2 Aug 1946 4 p 5 figs. Analyses the various factors relating

to the use of Carboloy wires. Wire Dimensions for Screw Threads, J. W. LEE. Tool Engr vl8 nl Feb 1947 p 36-8. Develops formulas for calculating wire measurements of pitch diameter, taking

the lead angle into account. These are based on the as- sumption that the contact points of the wire with the thread are located on the normal to the central pitch helix

of the thread (which assumption gives more accurate re- sults than assuming contact in an axial plane but still is not exactly true). Presents relations between screw

dimensions and measurement data. The Best Wire for Over Wire Measurement of General

Screws. W. F. VOGEL. The Van Keuren Co. Watertown,

Mass. Sept 9 1947 56 p. Develops universal theory of screw measurements over pins, including prerequisites for a general screw measurement, significance of the involute

screw, the exact equations for general screw measure- ment (i.e. for cylindrical screws of any symmetrical thread

profile) , number of pins and balls to be used, and formulas

for routine calculations. Monograph copies deposited at Library of Congress, National Bureau of Standards, Detroit Public Library, and Wayne State University. Thread Grinding and Measurement, A. C. PARKINSON,

W. H. DAWNEY. Sir Isaac Pitman & Sons, London, and Pitman Publ Corp, New York, 1949 227 p illus diagrs

charts tables. Thread terms and definitions are classified and explained; limit systems and their special applications to screw threads, worms, and hobs ; in regard

to thread measurement, considerable amount of space de- voted to wire methods. Eng Soc Lib, N.Y. Determination of the Thickness of the Teeth of Worms

and Spiral-Toothed Wheels with the Help of Rollers and

Balls, F. L. LITVIN. Acad Sci (Russia) vlO n39 July 6 1950 p 22-7 18 figs 4 refs. English translation available

at NBS and Van Keuren Co. A distinction is made be- tween convoluted, Archimedean, and evoluted helical surfaces. Develops exact relationship between position

of the roll in the thread space of the worm, the lateral surfaces of the teeth, and the thickness of the teeth. Develops relationships connecting variation in the position of the roll and variation in thickness of teeth. Position of Contacting Sphere Between Teeth of Helical Gear, N. J. C. PERES, Machy (London) v77 nl977 Sept 21 1950 p 324 1 fig. Derives equation for angle between

center of pin and point of contact of pin and tooth. (Obviously the author was unaware of the existence of much

simpler exact equations offered in the "Substitute Disk

Method", see Vogel 1937 and 1945.) On Precision Screw Threads, M. OGAWA. Rep Inst Indus Sci Univ of Tokyo v2 nl ser 10 Apr 1951. Translation of Chapter 1 on Theory on the Three-Wire Method

is available from Eng. Metrology Section, NBS. Chapter

has 11 figs 10 refs. Contents of chapter : General theory ; states of contact between measuring wires and a helicoidal surface ; conditions for the stable contact ; general solu- tions; the most accurate ordinary solution; the best wires ; errors in the three wire method.

Priifen und Messen von Gewinden (Testing and Measure- ment of Screw Threads) F. WOLF, Munich 1952. Analysis of Screw Thread Measurement, W. H. HARRISON. Mach v96 Apr 2 1952 p 602^ 2 figs. Gives

analysis intended to make clear the exact conditions of contact of measuring cylinders to thread flanks, with- out taking account of deformation of work or measuring

cylinders. Solve example by iteration. New Thread Measuring Formulas, W. F. VOGEL. Catalog and Handb n36 Appendix D The Van Keuren Co 1955. Exact equations of the trigonometric solution of the Best- Pin method are provided with numerical tables (by the Van Keuren Co) based on it. Die Berechnung der Gewinde-Anlagekorrekturen, M. GARY, PTB. Forschung auf dem Gebiete des Ingenieur- wesens v21 n4 1955 p 107-17 5 figs 7 refs. Calculation of rake corrections in screw thread measurements ; conditions governing contact of spheres and cylinders in helical grooves of thread ; resulting transcendental equations

solved by iteration for all threads with straight flanks

in axial sections ; formula established for best, pilot wire diameter for asymmetrical thread profiles. Geometrische Probleme bei der Vermessung von zylin- drischen Evolventen-Schnecken und Evolventen-Sehragstirnradern (Geometric Problems in the Measurement of Cvlindrical Involute Worms and Involute Helical Gears). M. GARY, PTB. Konstruktion v8 nlO 1956 p 412-8 2 figs 4 refs. Methods are outlined for measurements of the standard gage with balls or measuring wires of cylindrical involute worms and involute helical gears. For symmetrical involute worms a method is given for determination of the base cylinder radius and the tooth thickness. Contents : Equations for the position of a cylinder in an

involute worm (1) cylinder with predetermined inclina- tion to the worm axis; (2) cylinder at minimum dis- tance from the worm axis. Equations for the position

of a ball in an involute worm. Computation of the base

cylinder radius and tooth thickness from the results of two

diameter determinations over cylinders or balls. Three

numerical examples. 210
Screw Thread Standards for Federal Services. NBS

Handb H28 (1957) Parts I and III and 1963 Supplement.

Supt. of Docs, Government Printing Office, Washington 25. D.C. Appendix 4, Wire Methods of Measurement of Pitch Diameter of 60° Threads. Appendix 13, Three-Wire Method of Measurement of Pitch Diameter of 29° Acme,

29° Stub Acme, and Buttress Threads.

Effect of Differences between U.S. and British Practices

in Measuring Screw Gages for Unified Threads, L. W.

NICKOLS. Machy (London) v90 n2315 Mar 29 1957 p

723-5; Metalworking Prod Mar 29 1957 p 539--11 2 figs. American and British methods of measuring effective di- ameters of screw plug gages and setting plugs ; effective diameter measurements made at single specified position on each of five screw plug gages having Unified threads in order to determine experimentally effect of differences be- tween two methods.

Precise Formulas for Over-Pin Measurements of Helical Forms, E. C. VARNUM, S. J. JOHNSON. Tool Engr v38

n6 June 1957 p 116-20 ; Also Letter to the Editor of the Tool Engr v39 n2 Aug 1957 p 183 by W. F. VOGEL ; also AGMA Paper 239.03 June 1957. (The print is an authorized AGMA paper only if it carries a sticker giving credit

to preceding exact solutions by W. F. Vogel in Van Keuren

publications.) Gives a desk calculator routine for computing over pin measurements by iteration. Discussion des methodes de mesure du diametre sur

flanes des filetages coniques males (Discussion of methods

of measuring diameter of conical screw threads on their

flanks). J. SIMONET. Revue Universelle des Mines vl4

n3 Mar 1958 p 73-9. Five methods of measurement are examined ; in each case there is serious difficulty in cali- bration of measuring instrument; advantages and

disadvantages of each method, and domains of their

application. Over-Pin Measurements of Worms, L. D. MARTIN. Tool Engr v41 nl July 1958 p 50-4. Simple approximate for- mula for over-pin measurement of worms presented which

yields results within practical limits affected by workpiece

elasticity, measuring pressure, profile deviations and ob- servational error. Criticism by J. SILVAGI, Nov 1958

p 195-6. Rake Correction in the Measurement of Parallel External and Internal Screw Threads, R. S. MARRINER, MRS. J. G. WOOD. Inst Mech Engrs (London) July 1958 9 p 6

figs 2 refs. Formulas are derived for calculating the rake

correction for a ball seated in the helical groove of an in- ternal screw thread and a ball or cylinder in an external

thread. The equivalence of a ball and cylinder in an external thread is discussed. A simple approximation for- mula, and an exact equation are derived for determining

occurrence of double contact between the cylinder and

thread flank. Determination of Helical Gear Sizes by the Two-Roller

Method. I. P. NEZHURIN. Russian Eng J v39 n8 1961 p 11-3 3 figs. English translation by PERA. Describes

a method of calculation of the size over rolls which

ensures an easy criterion of their displacement in the

tooth groove of helical gears with an odd number of

teeth. Demonstrates the existence of the "oddness

effect", that is : In contrast to even-numbered helical

gears, the axis of the micrometer when measuring over two rolls is askew to the axis of the odd-numbered helical gear; it neither intersects the axis nor is its location in a plane of rotation of the gear. The correctly recognized geometry of the problem was evaluated in exact equations

for the measurement. For one of them an approximate

simplification is offered. (Unfortunately, one of the

exact equations was found to be erroneous. See correction by KHALEBSKII, 1963, and acknowledgment by NEZHURIN, 1963, in this subsection, p. 212.

New Equations Simplify Pin Measurement of Gears, J. H. GLOVER. Prod Eng v32 nil Mar 13 1961 p 80-1 4 figs 3

refs. Gives equations for calculating over-pin and be- tween-pin measurements of ideal involute tooth forms of external and internal spur gears. The equations also es- tablish measurements for desired variations in tooth

thickness and pin size. This will be very valuable if the

calculations are made with the assistance of numerical

tables giving over- or between-dimensions only for a specified thickness (usually: standard thickness) and for a

specified theoretical value of the pin size, which may not be available at the needed accuracy. The same equations can be used for external helical gears only if they have an

even number of teeth. Internal helical teeth cannot be measured by pins. If balls are used for their measure- ment then the mentioned equations can be applied to both even and odd numbered internal helical gears. (The

author claims that his way of formulating the known basic exact equations simplify the measurement, but the simple

basic geometry of the measurement can no more be recog- nized in this presentation). Further Report on the Effect of Differences between U.S. and British Practice in the Measurement of Screw Gauges

for Unified Threads, P. W. HARRISON, NPL, Machine

Shop Mag v22 n4 Apr 1961 p 207-9. The application of rake correction to measurements made by American methods improves their agreement with the British values in seven out of eight cases and reduces the mean difference

to one quarter of its previous value. Getting Bugs Out of 3-Wire Measurement, R. T. PARSONS. Am Mach/Metalworking Mfg vl05 nl4 July 10

1961 p 86-8. Three sources of error in 3-wire method of measuring thread gages and threaded parts are discussed

including lead angle effect, calibration and accuracy of measuring wires and computation of correct constants, and measuring instruments and pressures ; 60° single- start threads with lead angles of less than 5° are con- sidered only. Study on a Ball Screw (Part 3), Z. MURASE, J Japan

Soc Prec Eng v28 n6 1962 in Japanese. There are many

reports on the measuring method about the triangular

heliciodal surface, but rather few about generalized heli- coidal surface. In the Part 3, the mechanical measuring method of the radius from the screw axis to any point on the race-way surface (generalized helicoidal surface)

of the nut or the threaded shaft of the ball screw, using

the balls or the cylinders as the measuring feelers, is studied. And the exact equations, by which the correction value of the measuring results will be calculated, are deduced. These corrections are necessary, because the

elastic deformation at the contact point of the race-way with the measuring feelers and the diametral error of the

feelers are always existent more or less. New mathematical method of determining the race-way surfaces, the exact equation of the principal direction and principal curvature on the contact point of the ball-race with the

ball, and the theoretical calculation of the elastic ap- proach between the ball-race and the balls of the ball screw are the fundamentals of the studies on this part 3, and they are reported in the previous two parts of this

series. Sonderfragen zur Geometrie der Gewindeflanken (Special Problems in the Geometry of Screw Thread Flanks), H. HAAKE. Werkstattsteehnik v52 n4, 7 Apr 1962 p

180-6, July p 339-43. Special problems concerning geometry of flanks of threads ; it is shown how diagrams can

be drawn which make possible general view of entire thread series and facilitate calculation in measuring flank diameter with three wires. Apr. Thread with unsymmetrical profile considered. July. Taper threads dis- cussed. Measurements of Helical Gears with Pins or Balls, Analysis of Pitfalls and their Elimination, A. S. BEAM, C. E. 211
HALL. AGMA 129.15 June 1962 7 figs 1 ref. Clarifica- tion of the geometry of measurements from center of gear

over one pin. Useful mathematical formulations are pre- sented as a new tool in the art of gear inspection. It is shown that when pins are used on helical gears with even numbers of teeth, the prevalent belief that the distance between the axes of the two pins assumes an extreme

value which can be found as a low or high point of the measurement is an oversimplification. The discussion covers: (1) Measurement over one pin or ball ; (a) meas- urement from the center over one pin and (b) measure- ment from the outside surface over a pin or ball placed in an opposite tooth space. (2) Measurement over two pins

or balls when (a) gears have even numbers of teeth and

(b) gears have odd numbers of teeth. (3) Measurement

over three pins of spur and helical gears. Neues Verfahren zum Messen von engtolerierten Innen- gewinden (New Method for Measuring Close-Tolerance

Internal Threads), G. VOENEKY. Werkstratt u Betrieb v95 nil Nov 1962 p 755-8. Explanation of 2-ball method

used in measuring effective diameter of internal threads

is followed by comparison with method using contact arms and with that of caliper microscope: application of

internal thread measuring device in connection with shop

microscope and universal comparator is described.

Determining the Size of Helical Gears by Rollers, N. T. j KHALEBSKII. Russian Eng J v42 nlO 1963 p 10-1. i English translation by PERA. Alleges an error in one ' of Nezhurin's (1961) exact equations and presents ij simpler approximations. Measuring Helical Gears with an Odd Number of Teeth by Rollers, I. P. NEZHURIN. Russian Eng J. v42 nlO

1963 p 11-3 2 figs 2 refs. English translation by PERA. || Calculations as given in previous articles have been sim- l plified by means of a nomogram which yields highly accurate values fully consistent with those derived byjj KHALEBSKII.

Specification for Screw Thread Measuring Cylinders, 'i Brit Standards Instn—Brit Standard 3777 1964 17 p. : Standard relates to two grades of screw thread measur- ;! ing cylinders intended for use in checking external screw

threads by means of pitch diameter measuring machines :

| first part gives bases for diametral tolerances of Grade A

and Grade B screw thread measuring cylinders and rela- tive merits of these grades ; second part gives complete

specification for both grades of cylinders suitable for forms and pitches of screw threads shown.

9.4. Tables for Ball, Pin, or Wire Measurements

See also subsection 10.1.3 for similar tables for gears. Note. The following references are either completely

tables or contain tables along with other material. Gewindemessen mit Drahten (screw thread measurements

with wires ) , J. REINDL. Betrieb vl nl4 Aug 1919 p 361-

5 11 figs. Gives tables for Whitworth, International

Metric, and Lowenherz threads for pitch diameter and

angle measurements with wires. Correction for Elastic Compression in the Measurement of Screws with Small Cylinders, G. A. TOMLINSON, NPL. Machy (London) v28 Aug 26 1926 p 616-8 2 figs. Contains nomogram for computing compression in "effective diameter" measurement.

Checking Gear Size by Measurement Over Pins, K. E. BAUERLE. Machy (N.Y.) v44 n6 Feb 1938 p 353-7. Tables simplifying application of this precise and generally available method to external and internal spur and

helical gears. Tables for Precise Measurement of Screws, H. L. VAN

KEUREN. Catalog and Handb n34 1948 The Van Keuren

Co., Watertown, Mass. See also Handbs n35 1952 and n36

1955. The tables, meant for wire contact exactly at the

pitch cylinder of the screw, were computed with the Vogel

(1948) approximate formulas Nos. 662 and 710 and spot- checked and (where necessary) corrected by applying

the exact equations of Vogel's Best-Wire Method, 1947 and

1955, referred to in subsection 9.3, p 210. The tables cover

a wide range of standardized and non-standardized

screws, including single-start and multiple-start threads and worms. Gauging and Measuring Screws. National Physical Laboratory, Teddington, 1951. Section VII, Formulae and

Corrections for Use in the Measurement of the Effective Diameter of Parallel Screw Plug Gauges by Means of Small Cylinders, p 23-32 5 figs. Includes charts for lead angle correction and compression correction. Screw Thread Standards for Federal Services. NBS

Handb H28 (1957) Parts I and III and 1963 Supplement.

Supt. of Docs. Government Printing Office, Washington,

D.C. Appendixes 4 and 13 contain tables for wire meas- urements for 60°, 29° and Buttress threads. Machinery's Handbook 17th ed 1964 2104 p. The Industrial Press, N.Y. A section on measuring screw threads. -., p 1208-25, contains tables of wire sizes and constants fori1 wire measurements of Unified, Whitworth, and Acme

Screw threads.

9.3. Addendum to Section 9Wire and Ball Measurements of Screw Threads and Other

Helicoidal Features

Compiler's comment: TOMLINSON (see p 207) deserves

credit for apparently having derived the first exact solu- tion for the over-wire measurement of "Archimedean

Screws" by means of freely selected wires. The solution

is applicable to all screws, helical splines, and worms

having symmetrical straight flanked axial profiles. General Equations for the Conditions for Single Contact between a Measuring Pin and a Screw, R. A. MacDONALD. A thesis submitted to the College of Engineering

of Wayne State University, Detroit, Michigan in partial

fulfillment of the requirements for the degree MS in Engineering Mechanics. Approved Nov 1 1965 33p 9 figs 12

refs. The author first offers a general procedure, includ- ing new exact equations, for location of a freely selected

ball or measuring wire in a thread groove of a cylindrical "general screw" having any contour which is a continuous

function of y that has at least a first derivative. The

second part of his procedure established the necessary cri- teria for examining multiple contact in any plane of those screws and changing the wire size, if necessary, to obtain

single contact. 212

111

'I i
LtM I

rtfi

MS 5 aial I

Section 10. Measurement of Gears

CONTENTS

Page

10.1. Gear metrology, general 213

10.1.1. Standards and nomenclature 213

10.1.2. Textbooks and handbooks dealing partially with measuring methods 215

10.1.3. Numerical tables 217

10.1.3.1. For involute calculations and plotting 217

10.1.3.2. For uniform angular indexing 219

10.1.3.3. Orher tables for uniform subdivision of the circle 220

10.1.3.4. For pin and ball measurements of involute spur gears and spur

splines 220

10.1.3.5. For span measurements 221

10.1.3.6. Tables of base tooth dimensions 222

10.1.3.7. Miscellaneous gear tables 222

10.1.4. Technical papers on gear measurement, general 222

10.2. Spur and helical gears 228

10.2.1. Involute form measurement 228

10.2.2. Master gears ; composite deviation testing 230

10.2.3. Lead measurements 232

10.2.4. Pin and ball measurements of spur gears and splines 232

10.2.5. Tooth index position measurement 234

10.2.6. Tooth thickness, pitch, and span measurements 234

10.3. Bevel, hypoid, spiroid, and worm gears or drives 238 10.1. Gear Metrology, General

10.1.1. Standards and Nomenclature

Note : Most of the references in this subsection do not deal with measurement, but they provide

geometrical information which is essential to the measurement of gears. Standards are revised so frequently that readers should consult the latest edition of the reference listed. .'reposed Standard Practice for the Inspection of Gears, un Mach v70 nl7 Apr 25 1929 p 657-60 10 figs; Power

Transmission v34 n5 May 1929 p 37^0 10 figs. Proposed

uneriean recommended practice for inspection of gears, ncluding worms hobs, and other cutters, compiled by 5ub-committee No. 9 of Committee on Standardization

f Gears ; gear inspection of cylindrical and tapered holes

:eyways for Woodruff keys, shafts, shifter grooves, small

ize spur, helical, internal and bevel gears, backlash, in- •olute curves, angular velocity, thread inspection, external

hreads. internal threads and worm inspection ; hob in- spection, inspection of gear cutters (shaper and disc). Jachine cut gears, C. Worm gearing, BS 721 : 1937. Brit

( Stand Inst. Available from ASA.

lachine cut gears. A. Helical and straight spur. BS

t36 : 1040, with amendments. Brit Stand Inst. Available rom ASA.

7 ine Pitch Gears. Product Eng vl6 n9, 10, 11, Sept 1945

> 598-601, Oct p 710-13, Nov p 758-60. AGMA Standard

234.01 May 1945 for inspection and tolerances of gears of

to diametral pitch and finer. Sept: Scope of standard,

general specifications and classifications and spur and

nelical gears covered. Oct : Details pertaining to worms, vorm gears, bevel gears and backlash in gears. Nov

.nspection and tolerance.

Gear Tolerances and Inspection (AGMA 231.01, 232.01, and

233.01). ASA B6.6-1946, out of print. New High-Speed Helical and Herringbone Gear Standard. Machine Design vl9 nl2 Dec 1947 p 157-8. Standard

practice set forth by AGMA for use primarily in design

of self contained speed reducer units, but equally valuable

in design of other types of high speed helical gear drives

falling within this classification. British Standard Specifications for Gearing, W. A. TUPLIN. Engr vl85 n4819 June 4 1948 p 549. Discussion of

Specifications 436, 545 and 721. Bevel Gears (Machine Cut). BS 545: 1949 36 p. Brit Stand Inst. Available from ASA. Applies to machinecut, conical gears connecting intersecting shafts, the teeth being either straight or curved, pressure angle 20°. Three

classes of accuracy are covered and tolerances are given. Ein System fuer Verzahnpassungen (A System for Tooth

Fits), O KIENZLE. Werkstattstechnik und Maschinen- bau v39 n5 1949 p 129-39. DIN tolerance system for spur

gears with involute teeth ; report of work carried out at end of war under auspices of German Standards Committee ; general principles of fit system ; errors in gear

teeth tolerances ; system developed, known as "unit dis- tance between axes" ; tolerances given in 12 degrees of accuracy ; tables, diagrams. Bibliography. Fine-Pitch Straight Bevel Gears (AGMA 206.03 ) —American Standard B6.8-1950. Publ ASME, New York 1950

9 p out of print. Standard covering generated straight bevel gears of 20 diametral pitch and finer, for all shaft

angles, with numbers of teeth equal to or greater than

1%6. 15

/i7, u/20, n/so for 90° shaft angle ; standard is identical in technical content with AGMA standard on Fine

Pitch Straight Bevel Gears. 213
Gears for Traction. BS 235: 1951. Brit Stand Inst. Available from ASA. For drives of vehicles running on

rails. Gears For Instruments and Clockwork Mechanisms: BS

978 : Part 1 : 1952, Involute, spur, helical, and crossed

helical gears. BS 978 : Part 2 : 1952, Cycloidal type gears with Addendum 1, Double circular arc types. BS 978

Part 3: 1952, Bevel gears, Brit Stand Inst. Available from ASA.

Gears for Turbines and Similar Drives. BS 1807 : Part

1 : 1952 Accuracy. BS 1807 : Part 2 : 1958 Tooth form and pitches. Brit Stand Inst. Available from ASA.

Simplified Standards for Gears, W. A. TUPLIN. Engr

vl93 n5017 Mar 21 1952 p 394-7. Standard gear denned

as one that may be generated by standard cutter; it is desirable to use simple system of gear design that permits

full use to be made of versatility of standard involute generating tools ; any calculation procedure that demands

accuracy beyond that offered by 10-inch slide rule is (according to the author) not well conceived; diagrams. Worm Gear Design, H. WALKER. Engr vl94 n5035 July

25 1952 p 110-14. B S Specification 721 gives recom- mendations satisfactory for worm gears having involute

helicoid thread form, but there is range of multi-thread worms of high lead angle not adequately covered by

specification; experience has shown desirability of defining more clearly method of spacing gear designs so as

to reduce total number of new hohs and tools without

over-restricting choice of available designs ; proposals provide means for overcoming difficulties. Development of Gearing Standards, W. A. TUPLIN.

Machy (London) v81 n2090 Dec 5 1952 p 1173-7 ; see also Engr vl94 n5048 Oct 24 1952 p 538-42. Author's proposal

that blank diameter of gear should be one essential in manufacture is now being considered by British Stand- ards Instn for spur, helical and worm gears ; procedure

for designing pair of helical gears to work at specified center distance and to have specified velocity ratio; present standards for worm gears critically examined

features of proposed new standards. Before Brit Gear

Mfr's Assn. Straight-Sided Splines (for CylindricalShafts), Nominal

Dimensions in Millimeters. ISO Recommendation R14-

1953. Available from ASA, $0.60. Proposed Standard Design for General Industrial Coarse

Pitch Cylindrical Worm Gearing, F. G. EAST. ASME

Trans v76 n2 Feb 1954 p 163-72. Suggested method of standardizing general industrial coarse pitch cylindrical worm gear drives, particularly worm diameter and tooth

proportions, to eliminate present difficulties where no

recognized standard exists ; proposals do not insist on

single worm diameter for each pitch or center distance but

rather, limited group of worms that will cover range of good design. Letter Symhols for Gear Engineering. ASA B6.5-1954. Available from ASA, $1.50. Identical with AGMA 111.02. Gear Nomenclature, Terms, Definitions, and Illustrations ASA B6.10-1954. Available from ASA, $1.50. Identical with AGMA 112.03. System for Straight Bevel Gears (AGMA 208.01) ASA Am

Stand B6.13-1955. Publ ASME, New York, 1955 9p $1.50. Standard covering recommended tooth proportions and

dimensions of blanks for generated straight bevel gears

of tooth ratios in general industrial use; data given is development from system originated by Gleason Works

and adopted by AGMA in 1922, revised in 1940, and with

further changes in 1955 revision.

Stand der Verzahnungsnormung (Status of Gear Standardization), A. BUDNICK. VDI Zeit v97 nll-12 April 15 1955 339-43. Status of gear standardization and its further development ; standardization of spur gears ac- cording to DIN 3960 ; tolerances for spur gear based on DIN 867 ; DIN 3974 standard for worm gears ; status of international standardization. 20 Degree Involute Fine-Pitch System for Spur and Helical Gears. ASA Am Stand B6.7-1956. Publ ASME, 1950

16 p, (AGMA 207.04) out of print. 'Standard fine pitch

series includes gears of 20 diametral pitch and finer having 20° pressure angle; data concerning pinion enlarge- ments. Design for Fine-Pitch Worm Gearing. (AGMA 374.03) ASA AM Stand B6.9-1956. Publ ASME, 1950 18 p, $1.50. Standards covering worms and worm gears with axes at right angles, comprising cylindrical worms with helical threads, worm gear being hobbed for fully conjugate

tooth surfaces ; it does not include helical gears used as worm gears ; data for standard axial pitch range of 0.030, 0.040, 0.050, 0.065, 0.080, 0.100, 0.130 and 0.160. Inspection of Fine-Pitch Gears ASA B6.11-1956, out of

print. AGMA Stand 236.05 June 1956 41 p 27 figs. Available from AGMA, $2.50. Includes a section on pin meas- urements of fine-pitch involute spur gears. Inspection of Coarse-Pitch Spur and Helical Gears. AGMA Stand 231.02 July 1956 18 p. Available from AGMA, $1.50. Inspection of Coarse-Pitch Bevel and Hypoid Gears, AGMA Stand 232.02 Aug 1956 lip. Available from AGMA, $1.50. Inspection of Coarse-Pitch Cylindrical Worms and Wormgears. Tentative AGMA Stand 234.01 Aug 1956 12 p. Available from AGMA, $1.50. Whither British Standards for Gears? H. E. MERRITT.

Engr v202 n5256 Oct 19 1956 p 547-9. Attention directed

to difficulties encountered in attempting to revise certain standards for toothed gears, and to prompt wide based dis- cussion which may help to stimulate action in revision of standards. Normung, Tolerierung und Messen von Verzahnungen

( Standards, Tolerances, and Measurement of Gear Teeth)

,

R. NOCH. Konstruktion v8 nlO Oct 1956 p 406-12, Reference to German DIN standards ; tooth defects and

their measurement.

Basic Rack of Cylindrical Gears for General Engineering. ISO Recommendation R53-1957. Available from ASA, $0.60. See also ASA B6.1-1932, out of print. Modules and Diametral Pitches of Cylindrical Gears for General Engineering. ISO Recommendation R54-1957

Available from the ASA, $0.60. American Standard Drafting Manual—Gears, Splines, and Serrations (Section 7) ASA Y14. 7-1958. Available from ASA, $2.00. Gears for Turbines and Similar Drives. Brit Stand Inst BS nl807 pt 2 1958 7 p. Pt 2 : Tooth form and pitches

standard specifies basic tooth forms and standard pitches

of helical gears for high speeds, but should not be taken

to suggest that they are unsuitable for other speeds; diagrams.

Fine-Pitch On-Center Face Gears for 20-Degree Involute Spur Pinions. AGMA Stand n203.01 Feb 1958 20 p, Design

of face gear and its pinion ; recommended method of de- lineation of face gear on detail drawings ; two information 214
sheets show tooth proportions for pinions with less than

12 teeth, and one covering alternate method of calculating outside diameter of face gear. Tooth Proportions for Coarse-Pitch Involute Spur Gears. AGMA Stand System 201.02 Mar 1958 21 p. Available from AGMA. $1.50. Standard provides tooth proportion information required in designing spur gearing with 20° and 25° pressure angle full depth tooth forms ; two infor- mation sheets on tooth proportions for 14y2

° full depth and 20° stub involute, and 14%° composite coarse pitch spur gears, and formulas and limitations for coarse pitch spur gear tooth proportions. Zerol Bevel Gear System. AGMA Stand System 202.02 July 1958 19 p. Available from AGMA, $1.00. New Standards for Gears Span Wide Range of Qualitv,

L. D. MARTIN, Prod Eng v29 n52 Dec 22 1958 p 46-9.

All-inclusive standard presented that can be applied to spur and helical gear specifications without conflicting with present AGMA standards ; 15 classes established with logarithmic sequence resulting from detailed examination of thousands of gears. System for Spiral Bevel Gears. AGMA Stand 209.02 June

1959 11 p. Available from AGMA, $1.00. Involute Splines, Serrations and Inspection. ASA B5.15-

1960. Available from ASA, $5.00. New Formula Simplifies Worm-Gear Ratings, J. E. GTJTZWILLER. Iron Age vl86 nl3 Sept 29 1960 p 116-17. AGMA 440.03 is designation for new worm gear rating standard to replace separate standards AGMA 213.02 and AGMA 440.02 ; new standard includes formula for rating worm gearinng which is complete departure from previ- ously used ratios; standard also provides specifications

for design of worm driven speed reducers. Straight-Sided Splines and Gauges, Dimensions in Inches, ISO Recommendation R232-1961. Available from ASA,

$7.50. Design for Fine-Pitch Worm Gearings. (AGMA 374.03). ASA B6.9-1956 (R 1962). Available from ASA $1.50. Nomenclature of Gear Tooth Wear and Failure. (AGMA

110.03) Jan 1962 15 p 31 figs. Available from AGMA

$1.50. Specification for Master Gears. Brit Stand Instn—Brit Stand 3696 1963 8 p. Standard relates to 2 classes of spur master gears for use as reference and inspection

j standards with pitches in range 2 to 64 normal diametral

pitch inclusive ; class A master gears are intended to test precision class product gears and Class B to test gears

for general purposes; specification may also be applied

j to helical master gears so far as tolerances are concerned,

but tolerances given have been chiefly derived from infor- mation from spur master gears.

Specification for Worm Gearing. Brit Standards Instn—

Brit Stand 721 1963 34 p. Standard applies to worm

gearing and comprises cylindrical involute helicoid worms

and worm-wheels conjugate thereto, dimensions of which

are expressed in inches; 4 classes of gears are provided which are related to function and precision; range of modules is given in convenient steps from 0.052 to 1 ; it does not refer to pairs of cylindrical gears connecting

nonparallel axes known as crossed helical gears. 10. 1.2. Textbooks and Handbooks Dealing

Partially with Measuring Methods

Note : For further abstracts of most of these books see subsection 10.1.3, Numerical Tables.

Zahnrader (Gears). A. SCHIEBEL. Julius Springer

Verlag, Berlin, 1913, 1922, 1930. Authoritative German

presentation of theory and principles. See also 4th ed. by Lindner, 1954, abstracted in subsection 12.1. Spur Gears. E, BUCKINGHAM. McGraw-Hill Book Co.

Inc., 370 7th Ave., New York, N.Y., 1928. Chapter 9 on measuring gear teeth includes descriptions of gear-tooth

vernier, gear-tooth micrometer, roll measurement, tooth thickness and root diameter by vernier caliper, methods

of measuring tooth spacing and involute contour, the odontometer, projection methods, composite tests, rack

type tester. Schraubgetriebe, ihre mogliche und ihre zweckmassigste Ausbildung ( Screw Drives, Their Possibilities and Their Most Suitable Development). F. G. ALTMANN. VDIVerlag GMBH Berlin NW7 1932 30 p 73 figs 36 refs. Contents : Introduction ; fundamentals of toothing of screw

drives ; the screw surfaces of cylinder screws ; the inves- tigation of different cylindrical screws as to suitability for forming lubrication film ; the production of involute screws and the corresponding worm wheels ; operation

results of drives with involute screws ; summary.

Analytische Untersunchung des zylindrischen Sehneckentriebes mit gerader, die Achse schneidender Erzeugender

(Analytical Investigation of Cylindrical Worm Drive with

Straight, Axial Worm Profile), W. F. VOGEL. Omnitypie-Gesellschaft, Stuttgart, 1933. Doctoral Dissertation submitted to the Technische Hochschule Berlin on July 3, 1931 and endorsed Nov. 2, 1932, 62 p 52 figs bibliography.

( Exactly the same text published on the book market by

the author (in 1933) under the industrial title: "Eingriffsgesetze und analytische Berechnungsgrundlagen des

zylindrischen Schneckentriebes mit geradflankigem

Schnecken-Achsenschnitt" is now out of print.) Analytical computation methods are developed for cylindrical worm-wheel mechanisms with straight-lined axial worm

profile (Archimedean worms). All such mechanisms are reduced to dimensionless Unit-Worm-Drives having unit

pitch-radius "one" of the pitch cylinder. The equations

of the helicoidal surfaces of the worm are developed in rectangular as well as cylinder-coordinates. From them

equations of the imaginary "Surface of Contact" were

derived, yielding a complete analysis of the laws of contact between worm and wheel, including exact expressions

for the (utilized) "Field of Contact," undercut limitations, the contact ratio, the surfaces of the wheel-teeth, and frictional velocities. Several particularly simple

graphical constructions, especially for the paths of contact in longitudinal planes of the mechanism also are

revealed for the first time. The equations of the worm's

thread surfaces are also those of the customary cylindri- cal fastening and power screws and were later used by

the author for the establishment of exact equations and

the analysis of several tool profiles for all of these products. (See 6 abstracts: Vogel 1933, 1934, and 1935 in subsection 12.6.3, p 272.

)

Manual of Gear Design, E. BUCKINGHAM. 3 vols Machy (N.Y.) 1935. In vol 2, p. 26-9, are given equations

relating measurements over rolls and diameter of rolls to arc tooth thickness, and pressure angle at a given

radius for involute spur gears. Compiler's comment: In

vol 3, p 150, are given formulas, (which are not exact

equations), relating diameters of rolls and measurement

over the rolls to diameter, tooth thickness and pressure angle at the given diameter of a helical gear. (For

errors of these approximations, which are not negligible for small numbers of teeth, see abstract of Buckingham,

1945, in subsection 9.3, p 209.

)

Grundlagen fuer die Messung von Stirnraedern (Funda- 215

771-846 O—66
mentals of the Measurement of Spur Gears, G. BERNDT.

Berlin, Julius Springer, 1938 155 p diagrs charts tables. Measurement of involute toothed gears discussed ; fol- lowing determination of ideal gear wheels, methods for measuring contact angles and tooth flanks are given

determination of flank shape, tooth slope and circular

division of gear wheels covered, and effect of impulse blows of teeth on running of gear considered ; testing and

inspection methods included. Involutometry and Trigonometry, W. F. VOGEL. Michi- gan Tool Co. Detroit 1945 325 p 28 figs 33 refs. Main

Table provides columns of the natural trigonometric functions and involute functions conveniently arranged alongside each other. Complete sets of angular conversion

tables and involute and cycloid tracing tables followed by other numerical and algebraical tables presenting geo- metric relations of gear dimensions and gear tooth profiles. Exact step-by-step calculations for measurements

of external and internal spur and helical teeth over freely

selected balls and pins. Appendix gives a complete sys- tem of involutometry, classified as: (1) Geometry and

calculations of involutes of base circles and related curves; (2) involutoids, namely surfaces containing a multitude of such curves; and (3) solids bordered fully or partially by involutoids. Gears. Gear Production and Measurement, A. C. PARKINSON, W. H. DAWNEY, Pitman Publ Corp, New

York and Chicago 1948 260 p. Book intended for those

in trade who have gear problems, but who have little or no background of basic knowledge of gear forms, and

of range of manufacturing and measuring methods; special attention paid to inspection procedure. Eng Soc Lib, NY.

Analytical Mechanics of Gears, E. BUCKINGHAM.

McGraw-Hill Book Co. Inc. 1949 546 p. The first chapters give an analysis of conjugate gear-tooth action, nature of the contact, and resulting gear-tooth profiles of the

several types of gears. These include spur, internal, helical, spiral, worm, bevel, and hypoid gears. The last chapters give analyses of gear teeth in action including

frictional heat of operation and its dissipation, friction losses and efficiencies, dynamic loads in operation, beam

strength or resistance of the teeth to breakage and fatigue, surface-endurance limits of materials, and the limiting wear loads or the potential resistance to surface disinte- gration and excessive wear. Zahnradgetriebe (Gear Drives), R. RITTER. Verlag Leeman, Zurich, 1950 184 p 49 figs 34 tables 250 refs. Developed in three parts: (1) Assembly of the standard

drive with special consideration of the combined drive;

(2) tooth forms and tooth corrections,—the 20° standard

system, null, V0, and V (variable center) drives; (3) cal- culation of gear wheels as to strength and wear life. Devoted to the concepts of the interchangeable manufacture

of gear wheels, and tested specifications for the shop drawings and the manufacturing tolerances, in order to meet

the requirements of the technical bureaus and the workshops.

Practical Gear Design, D. W. DUDLEY. McGraw-Hill Book Co., Inc. New York 1954 335 p 158 figs. Contents

Gear design trends ; preliminary design considerations

design formulas ; gear materials ; gear-manufacturing methods : design of tools to make gear teeth ; the kinds and causes of gear failure ; special design formulas. Metrologie DAtelier (Workshop Metrology), L. COMPAIN. Editions Eyrolles, Paris 1952 261 p 91 figs bibli- ography. Chapter 6, Verification of Gears, p 144-92,

treats the following subjects : Verification of tooth profile, spacing, tooth thickness and tooth span, eccentricity, distortion ; geometrical tolerances of cylindrical gears.

The Barber-Colman Hob Handbook. Barber-Colman Co., Rockford, 111., 1954 388 p 25 refs. Contains general engi- neering data, trigonometric and involute relationships, plotting involute tooth profiles and engineering data for

fine-pitch gear hobs, spline and serration hobs and cutters, worm and worm gear hobs and cutters, and sprocket hobs and cutters. Gears, H. E. MERRITT. 3d Ed. 1955 527 p 29 tables 30 charts 32 refs. Sir Isaac Pitman and Sons, Ltd. London. Includes chapters on the geometry of involute spur,

helical, spiral, conical involute, bevel and worm gears. Derives formulas for roll diameters and measurements

over or between rolls for involute spur gears on p 114-6:

also for helical gears on p 149-50. The Involute Curve and Involute Gearing. The Fellows Gear Shaper Co. 1957. Covers the application of the

involute curve to gear teeth ; design, cutting and checking

of involute gears; definitions of gear-tooth elements, etc. A Treatise on Gear Wheels, G. B. GRANT. Philadelphia Gear Works, Inc., 20th ed 1958 (copyright 1899) 105 p

169 figs. Subject headings are (1) Theory of tooth

action. (2) The spur gear in general. (3) The involute system. (4) The eycloidal system. (5) The pin tooth system. (6) Twisted, spiral, and worm gears. (7) Irregular and elliptic gears. (8) The bevel gear. (9) The skew bevel gear. Presents condensation of geometry which is basic to measurement of gears. Basic Gear Geometry—Reference Information, ALLAN H. CANDEE, AGMA 115.01 July 1959 25 p 37 figs. Available from AGMA, $1.50. The information presented has been

collected and arranged to make the important geometrical

relationships as easy to see as possible to provide a sound

basis for a thoroughly logical and comprehensive system

of gear geometry. A clear and accurate understanding

of the elements involved is indispensable to all who deal with the design, dimensioning, cutting, and measurement

of gear teeth. Introduction to the Kinematic Geometry of Gear Teeth, ALLAN H. CANDEE. Chilton Company, Book Division. Philadelphia and New York. 1961 204 p figs refs. Contents : Introduction and general principles ; general ideas

of tooth design; cutting and generating spur gears; involute teeth and the involute curve ; fillet curves ; layout and construction of involute profiles, rectangular coordi- nates ; involute racks and involute tooth thickness

changes in center distance in involute gears; geometrical

strength factor for spur gear tooth; profile errors, modifications, variations ; involute approximations ; six tables of involute coordinates, rectilinear and circular with

derivations of equations. Gear Handbook, D. W. DUDLEY. 1962. McGraw-Hill Book Co., Inc. 24 chapters. Presents key information to solve the design of a gear, plan tooling for a gear job, analyze a gear failure, or select an appropriate manufacturing process. Chapter 23 deals with inspection or measurement of the various standard types of gears. Maag Gear Book. Maag Gear-Wheel Company Ltd. Zurich. Dec 1963 576 p charts figs tables 168 refs. Deals with gear geometry and load capacity, gear drives, gear

cutting, gear grinding, inspection of gears, gear materials and their heat treatment, gear dictionary, and

bibliography. Modern Methods of Gear Manufacture. National Broach and Machine Co., Detroit. 3rd ed 1950 revised 1964 164 p 170 figs. See abstract under 12.1. 216
10.1.3. Numerical Tables

Note : The references listed in this subsection are abstracted here only with respect to their numerical tables. For additional other abstracts of such

references see subsections 9.3, 9.4, 10.1.2, and

10.1.4. Index of Mathematical Tables, A FLETCHER. J. C. P. MILLER. L. ROSENHEAD, L. J. COMRIE. 2d ed, 1962. Addison-Wesley Publishing Co., Inc. Reading. Mass. The

most complete worldwide bibliography of important mathematical tableworks, systematically referenced, cross- referenced, and abstracted. Note : Its standard indication

for range and table progress of the entering column, for instance : 0° (0.01° ) 60°, was adopted in some descriptions

of our lists of numerical tables. 10.1.3.1. Tables for Involute Calculations and Plotting Note : Involute functions are needed for the cal- culation of the involute (of a base circle), which

is the principal part of transverse tooth profiles of most spur gears, helical gears, and other involute screws (including involute worms). Outside of these fields of application the involute functions are still almost unknown, although they had been

tabulated in large numerical table works for more

than three decades. This justifies a short intro- ductory description (see fig. 1).

FIG. 1.—INVOLUTE AND UNIT INVOLUTE

8 Polar Angle, <p Pressure Angle, e Roll Angle

Line sections, and curve sections of any involute are rb times their corresponding values of the unit involute. Authorized reproduction from W. F. VOGEL. "Involu- tometry and Trigonometry" 1945. Courtesy Michigan

Tool Co., Detroit, Mich. Any given single dimension of the unit involute

(of base radius "one") determines all of its shown

dimensions. For instance

»=inv 0=tan <p— <j> =7—arctan e ev e=sec 0=\/ 1+?2 Any one of these dimensions can be and has been used by different authors as the entering column

of numerical tables for the Unit-Involute. For any other involute (of base radius rb) Vogel's polar equation of the involute reads

simply: r=rb Xev e Spur Gears, E. BUCKINGHAM. McGraw-Hill Book Co., New York, 1928. An extensive presentation of theory,

problems, and solutions, particularly about involute gears. Contains probably first extensive table of the involute function : inv0, namely the polar angle in radians to 6 sig- nificant figures (without differences) plotted against the pressure angle 0°0' (1') 60°0'. Laying Out and Checking Involute Tooth Forms, F. W. SHAW. Machy (London) v 35 Jan 2 1930 p. 441-446 and

Jan 16 p 513-9 11 figs. For an abstract of the first article see subsection 10.2.6. The second article is also on in- volute spur gears and gives numerical tables as follows

Table 1 lists tooth thiekness-semiangles of gears (for standard thickness). For details see subsection 10.1.3.3. Table 2 gives 8-deeimal values of the involute's polar angle 0=inv <j> [in radians], tabulated against the pres- sure angle in degrees, namely 0=0° (0°.5) 45°. Other columns tabulated alongside list 8-decimal values for arc

<f>, cos <p, log cos 0, tan <p, and log tan <j>. No differences are given in the table. Table 3 contains functions for the lay-out of involute teeth using their axis of symmetry as one axis of the rectangular coordinate system, while the other axis passes through

the center of the base circle. The table refers to Unit- Involutes of base radius "one" and is immediately usable

only for standard-thickness gears (without backlash). The following functions; arc, sin, are-sin; vers=l—cos and log vers are tabulated at seven decimals (without

differences) against their variable profile-thickness semi- angle in the range 0°5' (5') 15°0'. Examples for the utilization of the 3 tables for lay-outs and even for calculation of span-measurements are given. The publication is chronologically remarkable for that

early date, but the calculations are too cumbersome in the

light of more recent and much more convenient numerical

tables. Manual of Gear Design, 3 vols, E. BUCKINGHAM. Publ., by Machy (N.T.) 1935 vl, Mathematical Tables, contains

the following tables : Gear ratios, factors of numbers to 6000 ; 8-place trigonometric functions : sin, cos, tan, cotan, with differences, plotted against <£=0°.00 (0°.01)90°.00

8-decimal radian table: arc <j> plotted against 0=O°.OO

(0°.01)45° ; 8-decimal values of inv <p, with differences, plotted against 0=O°.OO(O°.O1)37°.OO, and 7-decimal values

of inv 0, with differences plotted against </>=37°.00(0°.01)

60°.00. Neue Grandlagen der Evolventenberechnung fiir die Zahnradtechnik (New Foundations for the Calculation of

the Involute in Gear Metrology), W. F. VOGEL. Werkzeugrnasehine v40 1936 p 225-31 4 figs 5 refs. Mutual fer- tilization between theory and practice. Review of previous equations for computation. Additional new equations for establishment of direct relations between the polar coordinates. Introduction of the author's radius vector function, ev e, leads to his simple polar equation : r=rb ev 6, (see Fig. 1 at left). Simultaneous representation of the

involute functions and trigonometric functions on the unit

circle of trigonometry and involutometry. Introduction and significance of the "Compressed Involute." Rectangular coordinates of the involute and of the compressed

involute. Applications of the new equations: The base- tooth thickness semi-angle. The addendum of "pointed"

teeth. The law of profile thickness variation of involute

teeth. Pin-measurement laws for spur gears. Significance of the "involute screw", surprisingly simple equations for

its axial section. Summary of existing numerical tables. The article culminates in the demand for the creation of special numerical tables for involutometry and gear metrology. A sample of such a table was shown in the form

of a "frame table", and support by the German gear in- dustry for a pertinent project was solicited. (The support

materialized immediately and lead to the creation of the Peters Table, 1937, see abstract on next page.) 217
Neue Zahlentafelwerke zur Evolventenbereehnung (New

Numerical Tableworks for the Calculation of 'the Involute), W. F. VOGEL. Werkzeugmaschine v40 1936 p 436. Short supplement to the survey of existing and planned

numerical tables, listed in the preceding publication.

Sechsstellige Werte der Kreis- und Evolventen Funktionen

(6-place values of circular and involute functions), J. PETERS. Publ. Diimmlers Verlag Berlin and Bonn.

First edition 1937, second edition 1951. The Main-Table, planned together by Profs. Peters and Vogel, has the same

arrangement as described in Vogel's book (see next de- scription). All columns except those for the polar angle have one decimal less than the Vogel Table ; those for the

polar angle have even 2 decimals less. Some other tables

of PETERS' book are abstracted in subsections 10.1.3.3 and 10.1.3.6. Involutometry and Trigonometry, W. F. VOGEL. Michi- gan Tool Co., Detroit 1945 321 p 38 figs 33 refs. Main

table provides a conveniently arranged table for trigo- nometry as well as involutometry. Also presents tables and geometrical relations of gear tooth profiles and gears. Various other tables. Bibliography. The Main Table is a seven-place table, with differences of all .six trigonometric functions : sin, cos, tan, cotan, sec, and cosec tabulated

for 0=0° .00(0° .01)90°. The fact that the radians, arc 0, are also tabulated alongside, actually provides also the six reversed functions arcsin 0, arccos 0, arctan 0, etc. The

addition of (alongside tabulated) columns of the polar angle 6 of the involute in degrees and in radians (includ- ing difference columns) provides a complete table of the polar coordinates of the unit involute in the whole possible range. Since all of the mentioned functions (and their differences) are throughout tabulated on two opposite pages of the Main Table, one single opening of this table provides also the roll-angle and the radius of curvature

o-f the unit involute at the selected point and thus all data

essential for the calculation of involutes. Another set of tables, designated as Involute Tracing

Tables, provides seven-place polar coordinates and rectan- gular coordinates of the unit involute, this time tabulated

against the polar angle 6 as entering column, namely

<?=0°(0°.1)1° ; 1°(0°.25)3°; 3° (0°.5)20° ; 20°(1°)70°:

70° (5° )90°. All other essential values of the unit-involute are again tabulated alongside, while the radians and the

six trigonometric functions of the polar angle are listed (alongside) on the corresponding opposite pages. (For

abstracts of some additional tables of this book see subsections 10.1.3.3 and 10.1.3.6.) Gears, H. E. MERRITT. Pittman Publ. Corp., New York. Appendix of second edition, 1946, and third edition 1954

give 7 decimal table, without differences of the polar coordinates of the Unit Involute, tabulating its polar angle in radians against its radius vector : 1.0000 (0.0001)

2.0000. This corresponds to a range of pressure angle from 0° to 60°. The first edition, 1942, gave the same

table at only 6 decimals and for a smaller table progress, namely listing 1.000 ( 0.001) 2.000 in the entering column. The Construction of Large Accurate Involute Curves, C. ATTWOOD. Machy (London) v70 Apr 10 1947 p 374-8, May 29 p 561^1 8 figs. In a coordinate system, having its origin at the initial point of the involute (rather than at the center of its base circle), rectangular coordinates an and y of the Unit Involute are tabulated with differences

at seven decimals for x=0 (0.001) 0.500. The tabulated

values correspond to a range from 0° up to approx. 20° polar angle or approx. 71° roll angle of the involute. An

auxiliary table lists the roll angles in degrees and 2 deci- mals of the degree tabulated with differences against x, but only in the small range : x=0 (0.001) 0.075. Involute Rectangular Coordinates, Hogland Eng and Mfg

Co., Inc. Berkeley Heights, N.J. 1954. Seven decimal

rectangular coordinates of the Unit Involute tabulated, ,1 with differences, against the Roll Angle : 0° (0°.01) 90°. Taschenbueh der Langenmessteehnik (Manual of Length j Metrology), P. LEINWEBER. Springer-Verlag, Berlin, 1954 806 p 790 figs. P 733 gives a six decimal table

of the polar angle of the involute in radians, tabulated with first and second differences against the pressure angle 10°0' (5') 35°0'. Introduction to the Kinematic Geometry of Gear Teeth. ALLAN H. CANDEE. Chilton Company, Book Division, Philadelphia and New York, 1961. The appendix carries

five-decimal tables of involute coordinates, all for a table

' progress of 0.001 of the entering column. Tangent values i of certain angles, tabulated alongside, are however listed . only at 3 decimals. The tables are not only for different coordinate systems but also for different numerical units. ; Unforuntately the captions of two out of four explanatory

illustrations (p 170) refer to the wrong sets of tables.

' Tables 1 and 4 are for Unit Involutes (rb =l), with the 1

5 origins of their coordinates starting at the base circle and ; coinciding with the initial point of the involute. Table

1 is for rectangular coordinates ; its x and y axes are nor- f mal and tangential, respectively, to the base circle. Y- "1 5 values and the tangent of the roll angle are tabulated, : without differences, against x=0 ( 0.001) 0.470. With ) respect to arrangement and range the table is comparable

to that of Attwood (1947), which however does give dif- j . ferences and 2 more decimals. Table 4, headlined "cir- '. cular coordinates", lists values which are actually trun- cated polar coordinates of the Unit-Involute. The value ; : "x" Is the polar angle 6 (according to AGMA-Standards) : in radians, while the "y" value is the part of the radius- j vector which protrudes outside of the base circle (namely

ev 0—I=sec0—1). The polar angles "x" (in radians) ! and their differences are tabulated against y=0 (0.001) j

" 0.480 ; this corresponds to a range of the polar angle from

0° to approx. 15°. Tables 2 and 5 (for 0M =2O°) and ! 3 Tables 3 and 6 (for 0M=14y2 °) are for involute profiles of Pitch Radius One and the shown Main-Pressure Angles, ! respectively. Tables 2 and 3 list the rectangular coordi- i nates of those involutes in a system, whose x and y axes \ - are tangential and normal, respectively, to the tooth pro- i 1 file at the pitchpoint. The y-coordinates and the tangents j of corresponding roll-angle increments are tabulated f !i against x-coordinates : xi=0 down to the base circle (in- j ' side the pitch circle) and outer coordinates x0 =0 (0.001) P

1 0.450 [or 0.358] for 0M =2O° or =141/2

°, systems, respec- j I tively. Tables 5 and 6 list the circular coordinates of the fj 1 described Pitch Circle One—Involute Profiles for 0M =2O° :

' and 14%°, respectively. Their circular coordinates are 1 f actually increments of the polar angle "x" (measured in ! radians from the pitch point) and of the radius vector

"y", protruding inside [subscript "i"] or outside [sub-J ? script "o"] from the pitch circle, xi values are tabulated. » against yi values down to the base circle. Xi and x0 values s

jj are tabulated (with their differences) at 6 decimals | against their "y«" or "y„" values, the latter covering: 1 | y„=0 (0.001) 0.400. Gear Handbook, D. W. DUDLEY. 1962, McGraw-Hill 1 It Book Co., 24 chapters. More than 3 dozen specialists 1 M contributed various sections. Names of authors respon- B slble for the numerical tables are indicated below. \ ;

» I Table 7-7 p 7.10 and 7.11, Polar Angle of the involute, 1

jf M. F. SPOTTS. The polar angle 6— inv <f> is tabulated • in radians without differences, against the pressure angle : R 6 decimals for 0=0° (0°.l) 75°; 5 decimals for 0=76° j 1 (0°.1.82°; 4 decimals for 0=83° (0°.l) 87°; 3 decimals:) II for 87° (0°.l) 89° ; 2 decimals for 89° (0°.l) 89° .9. (For 1 * 0 greater than 29°, linear interpolation of the table leads I 1 to uncertainties larger than 0.5 unit of the last decimal , , and can lead to intolerable errors in some part of the j

' range.

)

218
Table 24-14, p 24.24 and 24.25, Polar Angle of the Involute, R. T. PARSONS. Seven-decimal table, with differ- ences. 0=inv 0 (in radians) is tabulated against the pressure angle 0=0° (0°.01) (40°). Most of the table is unusable for ordinary (linear) interpolation. (The error caused by such interpolation starts [with more than 0.5 unit of the last decimal] at <j> larger than 4.8° and grows

with increasing values of <f>. Table 8-2, p 8.9 and 8.10. Tangent and Normal Coordinates of Involute Curve, E. C. VARNUM. The heading

above is misleading, because only the axes of each selected coordinate system are tangential and normal, respectively,

to the involute of that system. The principle of the axes

selection is admittedly the same as that in Candee's, 1961, Tables Nos. 2 and 3 (see above). The x and y axes of

the coordinate system are tangential and normal, re- spectively, to the involute profile at its pitch point, which

is determined by its unit pitch radius (one) and by the

pressure angle of the selected system (3 systems namely

tf>=14°.5, 20° and 30° ) . The y-coordinates of each system

are tabulated, at 7 decimals, alongside each other against

selected values of x, namely: x=0.500 (-0.01) 0.100; x=10.00 (-0.100) 0.000; x=0 (-0.001) -0.014; and x=

0.000 (—0.01) —0.140. (Neither differences nor any of the involute angles belonging to these coordinates are

tabulated.

)

Table 8-3, p 8.10, Tangent and Normal Coordinates of

Circle of Curvature at Pitch Point. E. C. VARNUM. The

same type of coordinates as described in Table 8.2 above

for the involutes of the 3 systems is now tabulated for

their 3 special circles of curvature. Their y-values are

tabulated at 7 decimals, without differences, for x=0.200

f-0.01) 0.0120 and for x=0.010 (-0.001) 0.000. Comparison of Tables 8-3 and 8-2 gives a precise picture of the deviation in 3 systems of this special circle of curvature from the corresponding involute shape. Table 8-4, p 8.12 and 8.13, Tangent and Normal Coordinates of the Involute at Convenient Radii (20° Pressure

Angle) E. C. VARNUM. A rectangular coordinate system

with the x and y axes tangential and normal, respectively,

to the involute profile at the pitch point is also used in Table 8-4, but exclusively for an involute profile of the

20° Mainpressure Angle system. The addition of 2 other

columns, also makes this Table 8-4 different from Table

!s-2. The entering column is not x but the ratio R/r,

in which R is a freely selected radius and r, the radius

of the given pitch circle. The coordinate-ratios x/r and

y/r are tabulated at seven decimals against the radii

ratios, namely: R/r=1.200 (—0.01) 0.940 and R/r=1.020

1—0.001) 0.951. A fourth column lists the polar angle increments (in degrees) to seven decimals, counted from

.n axis connecting the pitch point of the profile with the

1 center of the base circle. Thus, this column together with

; the entering column may be considered as a table of truncated" polar coordinates of the involute. No

differences are listed. Table 8-5, p. 8.14, Involute Polar Coordinates m, D. W.

' DUDLEY. This table should also be named : "Truncated

L Polar Coordinates of the Involute". Here, however, the

L entering column is the polar angle increment, labelled

II and counted from the axis connecting the pitch point

of the selected involute profile with the center of its base

circle. The radii ratios R/r (as explained for Table 8-4)

|l is labelled here "m" and is listed for 3 different involuteprofile systems of 14°.5, 20°, and 30° pressure angles.

] Seven decimal m values, without differences, are tabu-

|, lated in adjacent columns for the 14°.5, 20°, and 30° sys- tems against the polar-angle increments, in radians, in

I the range: /i=+0.0015 (—0.0001) -0.0015.

' Table 23-1, p 23.3-23.5, Involute Roll Angles, A. S. BEAM. The roll angles, labelled "ez " of any involute

are tabulated against their diameter ratio D./Dh, in

which the subscripts "z" and "to" refer to any selected involute profile diameter and base circle diameter, re- spectively. Actually Dz /Db =sec 0 and e z (in radians) =

tan 0 mean the radius vector and the roll angle functions

of a unit-involute. The roll angles e z (in degrees to 2 decimals) are tabulated, with differences, against Dz /Db in the following range: D2 /Db =1.0001 (0.0001) 1.0100; 1.0100 ( 0.0005) 1.0500; 1.0500 (0.0010) 1.4500. (It ap- pears strange that the e z -column shows throughout one

or two less significant figures than the entering column,

but it is even stranger that the difference column, Af*. shows one more decimal than the e z column. This means

that the printed difference values are not the real differ- ences of the e z values and therefore worthless for inter- polation. Since the late author was known as a

perfectionist, his manuscript would not be expected to have contained such discrepancies. Someone else must

have cancelled the third decimal of the e z column and

neglected to adapt the difference column to this change.

)

Maag, Gear Book, Zurich 1963 by Maag Gear Wheel Company, Ltd. (English language edition of the German

issue: MAAG, TASCHENBUCH). Contains an elaborate and complete collection of information on gears, including

tables and a gear dictionary. On p 514-6 the polar angle

in radians, at 6 decimals is tabulated against the pressure

angle: 10°0' (3' )34°0'. For some additional tables see subsection 10.1.3.5. Machinery's Handbook (USA) 1964 p 270-4 carries a table of the polar angle of the involute [in radians] at 5

significant figures, without differences, namely inv 0 for

0=14°O'(1')58°O'.

10.1.3.2. Tables for Uniform Angular Indexing

( See also subsection 10.2.5

)

Cumulative errors in precision indexing and its inspection are avoided by starting all angular measurements from

one single selected space, (the zero space of reference). Consequently, angular spacing or indexing tables offer precalculated angular values of the form 360° Xn/N.

Herein "If" is the total number of uniform divisions of

the circle (i.e. the total number of teeth or the total number of spacings), while "w" (frequently designated as indexing number), is every integer number smaller than "N"

Angular Spacing Tables, W. F. VOGEL. Vinco Corp. Detroit, 1943 233 p. Contains table of the included angle between any point of beginning and any one or more uni- form divisions of a circle up to and including 200 divisions. Values of the Main Table are listed in degrees, minutes, and seconds up to the thousandth of the second. Appendix contains tables of fundamental dividing angles 90°/N, 180 °/N, and 360°/N, each tabulated in degrees, minutes, and seconds up to 0.0001 units of the second ; in degrees and decimals of the degree up to 7 decimals of the degree ; and in radians up to 10 decimals of the radian

conversion tables of minutes, seconds, and decimals of a second to 8 decimals of a degree. A collection of important constants gives w and 1/tt to 70 decimals; also, some

integer multiples of divisions of tr and l/ir to 35 decimals

also, 35-decimal radian-equivalents of some integer angular degree values and vice versa. Angular Spacing Tables, W. F. VOGEL. Vols 2 and 3, 1945. Vol. 2 : continuation of the Main Table for 201 to 300 divisions. Vol 3 : continuation of the Main Table for 301 to 360 divisions. Complete manuscripts of these un- printed volumes are in the hands of the Vinco Corporation,

Detroit. Teiltabellen (Division Tables), CARL ZEISS, Oberkochen. T60-410, 1957. Divisions of circles from 2 to 200 in degrees and minutes and 2 decimals of minutes. 219
Angular Indexing Tables ; numerical tables for dividing

circles and establishing rectangular coordinates, J. J. JAEGER, E. E. KIRKHAM, 1959. Publ. by Pratt &

Whitney Co., Inc. Provides for dividing a circle into any number of equal divisions from 2 to 210, inclusive. For

each division, the necessary angle is tabulated in degrees up to 4 decimals of the degree and alongside in degrees, minutes, and seconds. Also the sine and cosine of each

angle are given, which establish 8-decimal rectangular

coordinates of the corresponding points on the unit-circle of radius "one."

10.1.3.3. Other Tables for Uniform Subdivision of the

Circle

If N is any integral number, the angles 360°/N, 180°/N and 90°/N occur in regular polygons and, therefore, in gears and splines. They are sometimes designated as "Fundamental Dividing Angles". The values 360°/N and

180°/N are also denoted as "Angular Pitch" and "Angular

Semi-Pitch", respectively, while 90°/N denotes the tooth thickness semi-angle for such gears whose circular thick- ness of the teeth is equal to that of tooth grooves at the

pitch circle. Numerical tables of these angles and some

of their trigonometric functions are listed below

Angles 360 °/N : in degrees, minutes, and seconds : To 4 decimals of the second: Vogel 1943 p 212-3 for N=l to 200. To 1 decimal of the second : Vogel 1945 p 244-5 for N=l to 300. Without decimals of the second: Jaeger & Kirkham

1959 for N=2 to 210. Angles 360°/N : in degrees and decimals of the degree

To 7 decimals of the degree: Vogel 1943 p 214-5 for N=l to 200. To 5 decimals of the degree: Vogel 1945 p 244-5 for N=2 to 300. To 4 decimals of the degree : Jaeger & Kirkham 1959 for N=2 to 210. Angles 360°/N : in radians (i.e. 2tt/N) To 35 decimals: Vogel 1943 p 233 for N=l to 19. To 10 decimals: Vogel 1943 p 216-7 for N=l to 200. To 7 decimals: Vogel 1945 p 244-5 for N=2 to 300. Angles 180°/N : in degrees, minutes and seconds

To 4 decimals of the second: Vogel 1943 p 212-3 for N=l to 200. To 2 decimals of the second : General Electric Co. Standard Tables Div., Schenectady, Sect. G 902.4 1954

for N=3 to 500. Angles 180 °/N : in degrees and decimals of the degree : To 7 decimals of the degree: Vogel 1943 p 214-5 for N=l to 200. To 4 decimals of the degree : Peters 1937 and 1951 p 186-

90 for N=l to 500. To 5 decimals of the degree: Vogel 1945 p 217-9 for N=3 to 300. Angles 180°/N : in radians : To 35 decimals : Vogel 1943 p 233 for N=l to 19. To 10 decimals : Vogel 1943 p 216-7 for N=l to 200. To 7 decimals : Vogel 1945 p 217-9 for N=3 to 300. To 6 decimals : Peters 1937 & 1951 p 186-90 for N=l to

500. Angles 90°/X : in degrees, minutes and seconds : To 4 decimals of the second : Vogel 1943 p 212-3 for N=l to 200. Angles 90°/N : in degrees and decimals of the degree

To 7 decimals of the degree: Vogel 1943 p 214-5 for N=l to 200. To 5 decimals of the degree: Vogel 1945 p 250-2 for N=2 to 300.

To 4 decimals of the degree : Peters 1937 & 1951 p 186

for N=l to 250. Angles 90°/N : in radians

To 10 decimals : Vogel 1943 p 216-7 for N=l to 200. To 8 decimals: Shaw Machy (London) 1930 p 514 for N=l to 120. To 7 decimals : Vogel 1945 p 250-2 for N=2 to 300. To 6 decimals : Peters 1937 & 1951 p. 186-90 for N=l

to 250. Trigonometric Functions of 180 °/N : Sin, cos, 1-cos to 7 decimals: Vogel 1945 p 217-9 for N=3 to 300.

Sin, cos, tan & sec to 7 decimals : General Elec. Co. Sect

G. 902.4 1954 for N=3 to 500. Sin and cos to 6 decimals : Peters 1937 & 1951 p 186-90

for N=lto 500. Trigonometric Functions of 90°/N : Sin, cos, 1-cos to 7 decimals: Vogel 1945 p 250-2 for N=2 to 300. Sin and cos to 6 decimals : Peters 1937 & 1951 p 186-90

for N=l to 500. Function N sin 180°/N : Tabulates the "Chordal Pitch"

for gears of diam. pitch one

To 7 decimals : Vogel 1945 p 246 for N=2 to 300. Odd Numeral Factor: cos 90°/N for odd and integer val- ues of N

These factors and their reciprocals are needed in pin and ball measurements of gears having an odd number of teeth. Cos 90°/N to 8 decimals: Van Keuren Handbook, No.

36, 1955 p 130 for N=5(2)201; also for single values N=301 ; 401, and 501. Cos 90°/N and sec 90 °/N to 7 decimals : Vogel 1945 p

286 for N=3(2)299.

Cos 90°/N to 5 decimals: Buckingham 1928 p 332

for N=l(2)99, and Buckingham 1944 v2 for N=l(2)99.

10.1.3.4. Tables for Pin and Ball Measurements of In- volute Spur Gears and Spur Splines Pin Measurements of Spur Gears, R. TRAUTSCHOLD.

Machy (N.Y.) v24 Jan 1918 p 406-9 5 figs. Gives table of sizes of pins used in the measurement of 1 D.P. gears. Measurement of Gear Wheels with Ball Micrometer, W.

H. COWLIN. Machy (London) vl5 n389 Mar 11 1920

p 762-3 3 figs. Gives table intended to simplify calculations of distance between centers of balls. Measurement of Thickness of Involute Gear Teeth, ALLAN

H. CANDEE Am Mach v68 n9, 11, and 14 Mar 1, 15 and Apr 5 1928 p 365-8, 463-7, and 573-6 12 figs. Contains

tables from which dimension across pins for standard in- volute spur gears can be obtained easily. Checking Gear Size by Measurement Over Pins, K. E. BAUERLE. Machy (N.Y.) v44 n6 Feb 1938 p 353-7. Tables simplifying application of this precise and generally available method to external and internal spur and

helical gears. Gauging Involute Teeth or Splines Over Rolls, F. W.

HALIS. Machy (London) v78 n2012 June 7 1951 p 952-3. Contains graph and table for selection of roll diameter. Pin Measurement Tables for Involute Gears (based on

I. 728 series of pins), R. E. RAWLING. Am Mach v96 June 23 July 7. 21 Aug 4 1952 10 p. Available from Rawling Gear Works, Inc., Shrewsbury, Mass. For convenience in measuring without calcualtion of dimension over

pins, tables cover spur gears with pitches from 3 to 32 DP

and V± to 1 in. CP, 10 to 120 teeth, 14y2 and 20° PA. 220
Precision Measuring Tools. Catalog and Handbook No. 36. The Van Keuren Co., Watertown, Mass. 1955 258 p. Contains the following tables pertaining to gear measure- ments : Table 7, p92, gear wire sizes of 1.728, 1.68, and

1.44 diametral pitch for selected pitches from 1 to 200: Table 8, p 95 is a guide to wire selection ; Tables 9-18, p

9S-115 give measurements over wires and change factors

for 1 diametral pitch, standard pressure angles of 14.5,

17.5, 20, 25, and 30°, standard addendum external and in- ternal spur gears, and 2 or 3 wire diameters, 5 to 101 or more teeth. Table 20, p 117 gives wire sizes for circular pitch gears. Tables 23-24 p 125-6 give pin measurements

for 20° and 14.5° pressure angle long addendum involute spur gears. Table 26, p 134-5 gives change factors (K)

for 1.728 wires used on external helical gears. Table 28, p 143 gives basic pin measurements and change factors

for 30° involute splines from 6 to 50 teeth. Table 30, p

146 gives basic pin measurements for serrated shafts (ASA B5.26), 6 to 100 teeth. Inspection of Fine-Pitch Gears. American Standard ASA

B6.11-1956 41 p 27 figs. Publ by ASME, New York. Section 8, Pin measurements of fine-pitch involute spur gears

contains 4 tables for external and internal 20° involute spur gears. American Standard Involute Splines, Serrations and Inspection. ASA B5.15-1960 108 p. Contains extensive data and tabulations relative to measurements over or be- tween pins for space width and tooth thickness for involute

serrations and splines and straight-sided serrations. Vereinfachte Berechnung der Masse fuer die Messung

ueber Rollen bei Aussen- oder Innenverzahnungen mit

Eingriffswinkel 20° (Simplified calculation of dimensions

for measurements over rolls of external or internal gears with 20° angles of pressure) , H. BERGMANN. Werkstatt und Betrieb v94 n6 June 1961 p 341-9. Methods are

described and their application explained by diagrams, numerical tables, and examples. Gear Handbook : the Design, Manufacture, and Application of Gears, D. W. DUDLEY. McGraw-Hill Book Co.,

Inc., N.Y. 1962. Section 24 gives numerical data tables. Table 1 is a guide to wire selection. Table 2 gives gear

wire sizes for selected diametral pitches from 1 to 120. Table 3 for external gears 20° pressure angle, and 1 dia- metral pitch gives measurements over wires and change

factors with 1.728, 1.92, and 1.68 diameter wires, and numbers of teeth from 5 to 201 and 6 finer gears. Table 4

is the same for 14.5° pressure angle. Tables 5 and 6 are

similar tables for internal gears. Table 7 is for external

gears, 25° pressure angle. Tables 8-12 are auxiliary

tables. AGMA Standard Inspection Pin Measurement Tables for Involute Spur Gears. AGMA Standard 231.52 Dec 1962

18 p. Available from AGMA. Contains 8 tables of pin measurements of 20 and 14% deg external and internal involute spur gears and long-addendum pinions. The

tables and formulas given, as well as the standardization

of pin diameters, are for the purpose of simplifying and

facilitating the use of pins for measuring the tooth thick- ness of spur gear teeth. The scope is limited to spur

gears coarser than 20 DP.

Machinery's Handbook, 17th ed. 1964 2104 p. The In- dustrial Press, N.Y. Contains section on checking gear

size by measurement over wires or pins, p 845-64. Tables

1-4 give over-wire and between-wire dimensions, respectively, for 1 diametral pitch and 5 standard pressure

angles. Table 1 gives over-wire dimensions for 1.728/ diametral-pitch wire sizes covering external gears for even numbers of teeth from 6 to 170 and 6 finer gears. Table 2

is the same for odd numbers of teeth from 7 to 171 and

6 finer gears. Table 3 gives between-wire dimensions for 1.44/diametral-pitch wire sizes covering internal gears for even numbers of teeth from 10 to 170 and 6 finer gears. Table 4 is the same for odd numbers of teeth from 7 to 171 and 6 finer gears. Tables 7 and 8 are similar tables for external gears and over-wire dimensions using 1.68/ diametral-pitch wire sizes. 10.1.3.5. Tables for Span Measurements

Tables for Span Measurement of Spur Teeth

All tabulated values are for spur teeth of standard thick- ness at the pitch circle. All span-dimensions are in inches

for diametral pitch one or in mm, respectively, for metric module one. The "selector column" is for measurement

closest to the pitch circle. Peters and Vogel tables give additional tables for "more convenient measurement" pre- pared for "safer feeling" in the measurement of pinions, having small N-values.

Author Year

Gage system

(Pressure angle) N Total numberof teeth

Selector column

for number of teeth within

the caliper 2

Span di- mension 2 Span

decimals

(14°.5 X

18° X

Taylor Am Mach 1913, v36 p 1071-3 ^20° jlO to 50 1 1 X

22° _. X

130° X

Wildhaber Am Mach 1923, p 552 _ /14.5° 12 to 100 X

Buckingham Spur Gears 1928, p 333

120°. _ /14.5°

12 to ? 12 to 100 X

X

X

X

U7-

(20 12 to 96-

12 to 81

1935, v2 p 29 \22.5 12 to 72.... __ X

125 12 to 65 _ X

(14.5° 8 to 250 X X

Peters Sechsstellige.- 1937 and 1951, p 204-6 15° —

11 to 250 X X

(20° _ X X

Parkes Machy (London) 1939, p 326-7 ri4.5°_ 12 to 110 X X

Vogel Involutometry and Trigono 1945, p 265

(20°

ri4.5°

12 to 81_ _ 13 to 310 X

X X

Van Acker AGMA 239.01 1954

\20°__

114.5°

9 to 297

9 to 134 X

X

XXX

X

XXX

X

X

X

Maag Gear Book 1963, p 438-41

\20° /15°—

7 to 133

5 to 300

Machinery's Handbook i 1964, p 862-3 r

\20°

114.5° __

4 to 300 _. 12 to 110.. \30° 12 to 81 X

1 Note : This book also has such a set of tables for enlarged pinions on

2 X means that the table exists. 221
Tables for Span Measurement of Helical Teeth WILDHABER, Am Maeh 1923 v59 p 587 gives a selector table for the 14°.5 (normal press angle) involute system,

exclusively, covering N-values and helix angles of 10°

15° ; 20° ; 22.5° ; 25° ; 30° ; 45°. (The selector-values are based on the assumption of standard thickness at the

pitch cylinder.) VAN ACKER, AGMA 239.01, 1954 gives a selector nomo- gram for both the 14.5° and 20° (</> n ) involute systems, covering N-values and any helix angle between 0° and 45°. The selector values are based on the assumption of stand- ard thickness at the pitch cylinder. He also gives tables

of some auxiliary functions for facilitating the final cal- culation of the helical span-dimension. MAAG Gear Book 1963 p 442-3 gives 2 selector-nomo- grams, one for 15° and the other for 20° normal pressure angle system, respectively ; both covering N-values and

any helix angle between 0° and 45°. By contrast to the two preceding tables, this selector-graph also covers a range of varying modification coefficients featuring de- liberately and considerably modified tooth thicknesses. An elaborate system of numerical tables p 444-507 pro- vides auxiliary values facilitating the final calculation of the nelical span dimension. 10.1.3.6. Tables Of Base Tooth Dimensions

referring to the base cylinder of involute shaped teeth

Base Thickness Semi-Angles and Base Space Semi-Angles. Tables are valid only for gears having standard thick- ness at the pitch circle. For angles in radians their equations read, respectively

Tb= +inv <t> M and n= — — inv ^

where <p M is the Main Press Angle (in the plane of

rotation) at the pitch circle. Tables for angles in radians : To 6 decimals : PETERS 1937 & 1951 p 195-202 for <p M =

14.5° ; 15° ; 20° and N=l to 250. To 7 decimals: VOGEL 1945 p 273-85 </> M =14.5° and

20° ; and N=l to 300. Tables for angles in degrees ; To 5 decimals of the degree

VOGEL 1945 p 273 to 85 0M = for 0M =14.5° and 20°, and N=l to 300. Tables for Linear Base Tooth Dimensions : in inches for diametral pitch or in millimeters for module one. To 4 decimals : PETERS 1937 and 1951, p. 191-3, base

circle diameters for 0M =14.5°, 15°, and 20° and N=l

to 250. To 7 decimals : VOGEL 1945 p 273-85. Base radii, base

diameters, base tooth thickness and base space. (The

latter two dimensions are meant only for gears having

standard thickness at the pitch radius. ) All dimensions

for 0M =14.5° and 20° and N=l to 300. Table of Base Helix Angles, MAAG Gear Book 1963 p

444-507. The base helix angles of the 15° and 20° (</> M

involute systems) are tabulated in degrees, minutes, and

seconds against the pitch helix angles: 0°0' (l')45°0'. 10.1.3.7. Miscellaneous Gear Tables

Analysis of Stresses, New Departure Engineering Data, General Motors Corporation, 2 volumes, Bristol, Conn.,

1946. The second volume gives extensive curves for numerical evaluation of the pertinent Hertz equations. for the contact of two solid elastic bodies under compressive

force. See also KOZMA etc., 1962, on this page. The Sevolute, A New Function for Use in Involute Gear

Calculations, J. J. WILLIAMSON. The Fellows Gear

Shaper Co., Springfield, Vt. 1949. Also Supplements nl

and n2. Tabulates the function sev <£=sec 0—inv <p=

ev$ — e at 5 decimals to simplify the problem of calculating

'full-radius' fillets or tips. Geometrical significance is given to the function in the first supplement. The second supplement discusses the sevolute and the "extended

sevolute" in connection with pin measurements of gears and splines. Calculation of Testing Center Distance, J. L. WILLIAMSON. Pub Fellows Gear Shaper Co., Springfield, Vt., 1957. Six decimal values of polar-angle deviations A(inv0),

(differences Ainv0=inv0n om—inv^actuai) are tabulated

for varying ratios cos^actuai/cos^nominai ; also printed with

six decimals in small tables headlined each by a constant nominal pressure angle. From table to table the headlined (nominal) pressure angle changes: 0nominai=13° .0-

( 0.1 ) 24°.l. The tables are valuable for fixture-setup and/

or for numerical evaluations of gear testing by rolling fix- tures employing master gears. Tables for Calculating the Compressive Surface Stresses and Deflections in the Contact of Two Solid Elastic Bodies Whose Principal Planes of Curvature do not Coincide, A. KOZMA, H. CUNNINGHAM. Industrial Mathematics,

Detroit vl2 1962 p 31^0. The tables, based on the per- taining theory by Heinrich Hertz, are intended to facilitate the use of his equations. In that respect they may be particularly valuable for numerical computation

of the influence of surface deformations on the results of pin and ball measurements of precision-screws, gears, and worms. Simultaneous stress analysis could benefit from the establishing and/or standardization of load

limits for these measurements.

Table of Diametral Pitches and Modules with the Cor- responding Pitches and Base Pitches, Maag Gear Book

1963 p 39-41. The circular pitch and the circular base

pitch are tabulated each in inches and in mm against two

entering columns, giving in "bold face" standardized

values of the diametral pitch or the metric module, re- spectively. The values for the base pitches are printed

for the 15° as well as for the 20° involute spur gear sys- tem. All dimensions are given to 5 or 6 decimals. 10.1.4. Technical Papers on Gear Measurement, General A Spur-Gear Anglemeter, W. M. WILSON. Am Mach v28 Apr 13 1905 p 479-82 3 figs. An illustrated description of an instrument designed for determining the variation in the angular velocity ratio of gears, explaining its use. Gaging and Inspecting Gears, D. T. HAMILTON, Machy

(N.Y.) v23 Apr 1917 p 679-88 25 figs. Good discussion of

fixtures for testing pitch, pitch diameter, tooth shape, tooth thickness and concentricity with photographs and

illustrations. Subjects taken up in detail are : Inspecting gear blanks ; templets for gear blanks, bevel protractor

for testing bevel gear blanks, gear tooth templets and

calipers ; tolerances for bevel and spur gears ; testing center distances, pitch diameter and concentricity of spur

gears; fixtures for testing pitch diameter, concentricity, thickness of spur gears, transmission gears and pinion

shafts ; testing bevel drive gears and spur gears for noise under load; testing bevel drive ring gears; fixture for

testing involute curve of spur gear teeth ; testing ground

faces of bevel ring gears, testing fixtures for steering worm

sectors. Backlash in Gearing and Methods of Its Measurement. Automotive Indus v42 May 6 1920 p 1058-60. Shows that some backlash is necessary to provide free action between

teeth. Describes and illustrates methods of measurement.

Inspection of Involute Spur and Helical Gear Hobs, C. G. OLSON. Machy (N.Y. ) v20 Sept 1921 p 11-13, Oct 1921 p 138-40 ; Machy ( London ) vl9 p 90. Testing the accuracy
of hob and tooth parts, hobbing test, involute test, jump

test, roll test, and three tables of base circle disk

diameters. Inspection of Mill Reduction Units, R. H. RAUSCH. Iron Age May 25 1922 p 1440-2. Testing of tooth shape, checking helix angles, shaft alinement and other points. Testing Gear and Gear-Cutter Teeth, R. E. FLANDERS.

Maehy (N.Y.) v28 June 1922 p 817-9 6 figs. Description

of screw-thread comparator for quickly detecting imperfections. (Abstract). Paper read before AGMA convention. Adaption of Hartness comparator for inspection of gear cutters, testing uniformity of form cutter teeth, test- ing accuracy of a hob, method of projecting and testing gear shaper cutters, method of testing spur gears. Some Causes of Gear-Tooth Errors and Their Detection, K. L. HERRMANN. SAE J vll Nov 1922 p 391-7 14 figs. Discusses different gear noises, gives examples of defects

that cause noise, and describes device for checking tooth spacing; also instrument for analyzing tooth forms that produce noises. Quality Control in Gear Manufacture, S. O. BJORNBERG.

Machy (N.Y.) v29 Apr 1923 p 623-6 7 figs. Equipment

employed for inspecting hob, hobbing machine, and finished

gear. Fig 1, machine for testing the profile of hob teeth. Fig. 3, machine for testing the correctness of lead, by comparison with a master screw, and concentricity of cutting

edges. Fig. 6, fixture for checking the radial height and

the face of teeth on resharpened hobs. Zahnriiderprufung (Gear Testing), M. KURREIN. Werkstattstechnik vl7 Apr 15 1923 p 225-32 29 figs. Describes

various types of testing apparatus. The Gaging of Involute Threads, H. E. MERRITT. Machy

(London) v22 Apr 5 and 19 and July 26 1923 p 11-13, 79-81 and 525-8 13 figs. Apr 5 and 15: Gaging straight-spur

teeth by tooth caliper, and by plug or wire method. July

26 : Geometry of finished-ground worm thread ; funda- mental dimensions ; application of some of the properties

of thread surface to gaging problems. See also p 191, 210,

251, 275, 307, 376, 475, and 569. Gear-Measuring Machine. Eng vll6 July 27 1923 p 104-9

28 figs. Gear-measuring machine designed and constructed

at Nat. Physical Laboratory, for measuring individual specimens, such as spur and helical, plain and spiral bevel and worm wheels, and for recording errors in running

of combined gears. Gear-testing Machine at the National Physical Laboratory. Machy (London) v22 Aug 2 1923 p 579-83 8 figs. Elements

in gear teeth ; wheel clamps ; use of machine for straight spur gears ; helical and bevel gears. Zahnriiderprufung und Sonderherstellung (Gear Testing and Special Production), A. STEINLE. Werkstattstechnik vl8 Mar 15 1924 p 169-73 22 figs. Optical testing methods and instruments. Wiekman Gear Measuring Machine. Engr vl.38 Sept 5 1924

p 272-3 4 figs ; Automobile Engr vl5 Jan 1925 p 25-6 3 figs. Designed to differentiate between errors of spacing and

errors of concentricity and parallelism.

Soci6te Genevoise Gear Testing Machine. Am Mach v61

Oct 16 1924 p 635 2 figs. ; Machy (London) v24 1924 p 831

Eng Production v7 Nov 1924, p 317-8 4 figs. For testing

pitch, eccentricity, and tooth profiles of gear wheels. May

be used on bevel and helicoidal gears, and spur gears with

straight or helical teeth. Universal Gear Testing Machine, F. JOHNSTONETAYLOR. Machy (N.Y.) v31 Dec 1924 p 289-91 7 figs. Machine developed under the direction of G. A. Tomlinson

by NPL of Great Britain which may be used for any kind

of gear and for recording errors in running of meshed

gears.

Steel Tapes for Measuring Large Diameters, G. C. REILLEY. Am Mach v62 Jan 1 1925 p 26. Used for testing outside diameter of gears for turbine reduction-gear sets. Machine for measuring tapes also described. Measuring Gear Teeth, J. L. WILLIAMSON. Am Mach

v63 Oct 15 1925 p 609-12 7 figs. Points out that to check

eccentricity, points of contact should be as near as possible

to ends of teeth ; to check spacing, points of contact should be near pitch circle ; comparative readings cannot be ob- tained on different testing fixtures unless diameter of ball and pressure angle of rack tooth is same on both machines.

Testing Spur and Helical Gears or Cutters. Machy

(N.Y.) v32 Jan 1926 p 382-3 4 figs. Describes two machines used in tool room of Maxwell Motor Corp., Detroit, Mich., for determining accuracy of spur and helical gears and gear-shaped cutters ; how test is made ; using machine

as comparator; checking spacing and concentricity of teeth ; using optical micrometer. Measuring Inaccuracy in Gear Teeth, J. L. WILLIAMSON. Can Machy v36 July 29 1926 p 15-7 7 figs. Dis- cusses common errors in checking inaccuracies in gear

tooth form and spacing and describes simple methods of determining errors. Paper read before Am. Gear Mfrs. Assn. Machining and Measuring Gear Teeth, E. BUCKING- HAM. Am Mach v66-67 May 26 June 9, 23, July 7, 14, Aug 11, 18, 25, Sept 15, 29, Oct 20, 27 and Nov 10 1927 p 879-82 969-72, 1051-4, 7-10, 49-52, 233-7, 265-9, 313-6, 419-22, 497-8, 617-20, 657-9, and 733-6 83 figs. Accuracy in Gear Teeth. Automobile Engr vl8 Apr 1928 p 136-8 8 figs. Maag method of measuring along common

normal between successive tooth faces ; routine testing

of pitch and profile; instrument gives direct indication and record of departure of actual tooth profile from true

theoretical involute; checking backlash between pair of gears ; testing gears for concentricity.

Illinois Universal Hob and Worm Testing Machine. Am

Mach v68 June 28 1928 p 1068-9. Head arranged to test the lead, the pressure angle, and the contour of the teeth

in both straight and helically fluted hobs, and of corre- sponding parts of worm threads. Will also test the concentricity of the relief clearance of hob teeth, and the spacing

of threads or starts in multiple threaded hobs and worms.

Societe Genevoise Gear-Testing Machine. Maehy (N.Y.) v35 Oct 1928 p 147-8 3 figs. ; Automotive Indus v59 Dec 8 1928 p 842 1 fig. Am Mach v69 1928 p 558. Gear-testing machine designed for quick inspection of gears for errors

in pitch, concentricity, and tooth profiles, developed by

Soc Genevoise Instrum Phys Geneva, Switzerland, is described. A Gear Cutter Comparator, S. TRIMBATH. Am Mach

v75 p 296 Aug 20 1931 2 p 2 illus. An arrangement whereby the rack angle can be determined from a given

pitch circle and the involute. Discussion by F. W. SHAW. Am Mach v75 p 803 Nov 26 1931 1 p 1 illus. Cutter rolls in relation to steel tapes upon its base circle instead of upon its pitch circle; pressure angle is zero and angle

of testing rack tooth zero; device utilized also for testing accuracy of tooth spacing. Further discussion by S. TRIMBATH. Am Mach v76 p 229 Feb 18 1932 1 p 2

illus. Author further describes and defends his design. Zeiss Gear Testing Machine, Geo. Scherr Co. Inc. N.Y. Am Mach v76 Feb 11 1932 p 218. Measuring precision to 0.0001 in. combined with rapid operation are features of

this instrument. The gear tester will take spur, bevel, 223
helical and worm gears and test the following elements

circular pitch, eccentricity, uniformity of tooth spaces, and uniformity of tooth thickness. The gear is placed be- tween centers, where it can be revolved to bring successive

teeth into position. New Methods of Inspecting Gears for High-Speed Transmission. D. T. HAMILTON. Machy (N.Y.) v38 Aug 1932 p 932-8. Procedure followed in checking spur, helical, and

herringbone gears for shape, spacing, pitch diameter, and

eccentricity on machine designed by Fellows Gear Shaper

Co., Springfield, Vt. Fellows Gear Measuring Machine, Am Mach v76 Aug 3 1932 p 920. Various elements of a gear tooth that can be checked on this machine are: involute profile or shape,

circular pitch, pitch diameter and eccentricity ; also the

lead or corresponding helix angle on helical gears, guides, and the helically splined members. The column is posi- tioned by gage blocks. Work is held on a vertical arbor. The fixture, which carries the dial indicator and the various inspection units, can be moved about on the table. This machine has a capacity for measuring gears from 2

to 7 in. pitch diameter. Pruefen von Zahnraedern (Testing of Gears). Maschi- nenbau vl2 n13

/i4 July 1933 p 361-2 4 figs. Testing of gears; outline of test with regard to division, thickness

of tooth, true running, engagement axle distance, involute

curve. Gear Shaper As Inspection Tool, S. TRIMBATH. Am

Mach v77 nl7 Aug 16 1933 p 517-21. No. 6 Fellows gear shaper can be used in checking accuracy of spur and heli- cal gears and also spur and helical cutters ; machine had

been replaced by No. 7 high-speed gear shaper for cutting purposes and then converted into measuring machine at nominal cost. New Lees-Bradner Gear Tester. Iron Age vl33 p 33 Feb 1 1934 1 p 2 illus. Gear tester will check tooth contour, arc of action, length of line of action, tooth to tooth spacing, cumulative error and eccentricity of both spur and

helical gears. Methods for Checking Gears, D. T. HAMILTON, R. BEARDSLEY. Iron Age vl36 n3, 5 July 18 1935 p 14-7, 92 and 94 and Aug 1 p 20-2 and 94 ; Steel v97 n3 July

15 1935 p 32-5 and 67. Principal requirements to be con- sidered in production of accurate gears ; devices for checking individual gear-tool elements illustrated and de- scribed; automatic inspection of all errors in combination, by means of recording machine. Before Am Gear

Mfrs Assn. Messverfahren und Messgeraete der Zahnradfertigung (Measuring Methods and Equipment of Gear Finishing), H. GREGOR. Maschinenbau vl5 ny2 Jan 1936 p 17-21. Measuring methods and equipment in manufacture of gears ; reference to paper by A. SODEN indexed in Engi- neering Index 1933 p 532 from VDI Zeit Mar 4 1933 on

noise in gears ; measuring equipment used for this purpose

is described by present author. Zahnradpruefung (Gear Testing), G. ZIEHER. Werkstattsteehnik und Werksleiter v.31 n3 Feb 1937 p 49-53. Practical article on various methods of testing of gears with respect to isolated flaws, impact failures, thickness and width of teeth ; testing of pins ; overall tests. Fehlerpruefung bei Zahnraedern (Error Testing of Gears), R. BOCK. VDI Zeit v81 Feb 27 1937 p 267-72. Testing methods and equipment are described and

analyzed. Testing of Gears for Errors, R. BOCK. Eng Progr vl8 n9 Sept 1937 p 197-202. Notes on design and preliminary

operations, machine and tools, hardening, drawings, bores

and splineways, number of testing instruments required, checking for centricity, pitch and tooth thickness, tooth form ; axle spacing and engagement conditions of meshing

gears. Grundlagen der Pruefverfahren fuer gerade Zahnraeder

mit Evolventenverzahnung (Testing Method for In- volute Spur Gears), G. BERNDT. Werkstattstechnik und

Werksleiter v31 n23 Dec 1 1937 p 522-34. Extensive

treatise on principles of various measuring methods and

equipment and their application ; methods developed may

be applied to other forms of gears. Quiet Gears, S. O. BJORNBERG. Steel vl02 Feb 7 1938 p 46-50. Accuracy in gear teeth is real answer to quiet- ness, and correct inspection methods are means of ob- taining such accuracy; describes inspection methods of testing machines manufactured by Illinois Tool Works for involute profile, tooth spacing, composite errors, and lead

of spur or helical gears. Slide Rule for Variable-Center Distance System Gears and Measurement of Amount of Profile Shift, T. NAKATA.

Soc Mech Engrs Japan Trans v5 n21 Nov 1939 p IV^l-9.

Slide rule devised for computing center distance and other dimensions of pair of involute spur or helical gears;

giving number of teeth and amount of profile shift ; using such method, further generalization of variable center distance system is developed ; amount of profile shift in such gear, of which tooth proportion is unknown, can be estimated by roller method. (In Japanese.) Pruefen von Innenverzahnungen auf der Bearbeitungs- maschine (Testing of Involute Internal Gears on Production Machine During Manufacture ) , P. KLUWE. Maschi- nenbau vl9 nil Nov 1940 p 477-9. Illustrated description

of special measuring methods and gages employed for this purpose ; determination of nominal and actual dimensions. Adaptable Gear-Testing Machine. Machy (London) v57 Feb 27 1941 p 599 3 p 3 illus. Description of machine manufactured by Monarch Tool Co., Huddersfield, de- signed for testing spur, helical, bevel, spiral and worm

gearing ; suitable for either laboratory or shop use ; gears

tested by rolling together thereby eliminating many in- dividual measurements ; simple and easily mounted at- tachments enable whole range of gearing specified to be

tested. Instrumentation at Nuttall Gear Works. Instrum vl4 n5 ! May 1941 p 117-20. Pictorial presentation of instruments ranging from simple gages to control systems and uses from intermittent single measurements to continuous au- tographic tests and automatic control. Gear Inspection Methods, D. T. HAMILTON, Iron Age

vl48 nl6 17 Oct 16 1941 p 29-34 and Oct 23 p 38-44., Methods of measuring individual tooth elements, like tooth shape, tooth spacing, tooth thickness and eccentricity, are discussed; how gear errors may be checked in combination ; factors causing gear noise analyzed ; use of

helical gears is solution to noise problem and calls for

special checking apparatus ; importance of tooth bearing

is emphasized. Measurements of External and Internal Helical Involute

Gears, H. PELPHREY. Tool Engr vll n4 Apr 1942 p. 64. Simplified method for calculating proper dimensions where accuracy is vital. Compiler's comment : The method

is based on strict geometry and on exact equations for the

ball measurement of involute screws which are, however,

not simpler than Vogel's (1937) in subsection 9.3. It per- mits free ball selection and most of its equations could be

applied unchanged to more easily executed pin measure- ments of these products, [e.g., Candee (1928) and Vogel

( 1945 ) in subsection 9.3]

224
. Why Does a Gear Sing? How Can Singing be Avoided?

; A. MEHDAHL. Brown Boveri Rev v29 n9/10 Oct/Sept T 1942 p 284-9. Results of measurement on large helical

: gears ; pitch of note ; shadow lines ; table drive

-u - measurement.

I» J

i Measuring Errors in Involute Spur Gears, S. CORNELL.

2 Iron Age vl53 nl2 Mar 23 1944 p 68-73, 144. In order to

set up measuring standards for spur gears, author presents

i picture of ideal gear which has no errors and using this imaginary gear as reference point, presents general classification of spur gear errors and outlines method of re-

? : cording and evaluating deviations.

: (. . Improved Gear Tooth Vernier. Passenger Transport J

- v91 n2305 Sept 8 1944 p 129-30 : Transport Wld v96 n3073

vSept 14 1944 p 226. Illustrated description of simplified

riiitype developed by David Brown & Sons (Huddersfield) Ltd; instrument has advantage of only requiring setting

to linear dimension between fixed and moving anvils;

oj : measurements are over number of teeth and, as anvils are

7i . tangent to tooth flanks definite "feel" is obtained as in

;-i . using micrometer on cyclindrical object, no height meas-

:? J urement being involved. M ],How to Improve Accuracy and Efficiency in Measurement

ua

- and Testing of Gears, K. BUERGER. Engrs' Digest (Brit

. Ed) v5 n9 Sept 1944 p 275-9; Engrs' Digest (Am Ed)

: ,,vl nil Oct 1944 p 637-41. Illustrated description of methods and equipment for testing form of teeth ; testing surface of flanks ; testing circular pitch and chordal

-r. . pitch; thickness and width of teeth, and width of space;

,;: : parallelism of teeth; testing with regard to collective defects. English abstract from Masehinenbau (Betrieb)

: v22 n3 Mar 1943 p 101-7.

g ; Recent Developments in Gear Inspection Methods, D. MONCRIEFF. Instrum vl9 n 10 Oct 1946 p 586-8. Meth-

- ods of producing accurate gears that are quiet and smooth

, . running ; problem of heat treatment distortions, checking

I

- tooth- profile, hob contour checking ; tooth spacing tests ; - helical gear lead and spur gear tooth alignment check

: , -, , hob lead checking ; size and concentricity ; speeder test. Profile and Surface Analysis. Aircraft Prod v8 n97, 98

> - Nov 1946 p 509-12, Dec p 557-60. Nov : Napier technique

of checking gear teeth by combination of mechanical and

optical magnification described. Dec: Some variants of

..; method as applied to surfaces of certain other components,

, including valve sleeves, are dealt with.

" Measurement of Errors in Gears for Turbine Reduction

Drives, C. TIMMS, Instn Mech Engrs Proc vl57 (War

i Emergency Issue n35) 1947 p 418-32 (discussion) 432-51.

2 supp. plates. Review of work carried out at National

-

r; 'Physical Laboratory in development of methods for meas-

•-4 uring errors of large gears for turbine reduction drives by

jfjimeans of series of portable instruments; relationship ~t -between errors and inaccuracies of gear nobbing machines

,

i and gears cutting holes; methods of determining in-

, ! : accuracies.

, Practical Design of Gears and Gear Cutting Tools, H.

' PELPHREY. Michigan Tool Co., Detroit, Michigan 1947

31 p 50 figs. Gives analyses of gear design based on both

the involute system and straight-sided spline section. In-

\ eludes a set of exact equations for measuring involute

P * spur and helical gears using balls or pins. Contrdle des Engrenages a Denture en Developpante

'Gaging of Involute Gear Teeth), C. MACABREY. Pra-

: rique Indus Mecaniques v30 nl Jan 1947 p 3-11. Method

based on characteristics of development of circle and

l simple formulas ; derivation of formulas applicable to any

Inspection of Helical Involute Gear, W. H. WITTRICK.

Instn Engrs Austral J vl9 n2 Feb 1947 p 43-4. Inspection

of gear for aircraft supercharger drive ; data on inspection device used for determination of distance from axis where

ball should seat and of tolerance on dial gage reading for any given tolerance in tooth thickness. Some Gear Cutting Inaccuracies and Their Effect on Gear

Loads and Gear Noises, S. F. DOREY, G. H. FORSYTH.

North East Coast Instn Engrs & Shipblds Trans v63 pt6 Apr 194J p 267-330, (discussion) pt 8 July p D183-D208.

Study of causes underlying gear failures ; measurement

of magnitude of errors in gear hobbing machines ; gaging

of errors in finished gears ; measurement of undulations along tooth flanks ; equipment and apparatus used ; tooth form errors. Equations for the Normal Profile of Helical Gears, A.F. ZAMIS. Am Mach v91 Sept 25 1947 p 82^ 4 figs. Derives equations for the normal section of an involute heli- coid for application in checking the profiles of large heavy

gears and in verifying the operation of standard involute machines on smaller machines. From the equations rec- tangular coordinates of the normal section may be calculated. See also PERES (1959) and WATERS (1961), both on p. 227 in this subsection. Gear Tooth Inspection Method As Index of Performance,

L. D. MARTIN. Prod Eng vl9 n2 Feb 1948 p 87-9. Ele- ments that constitute good spur gear and fundamental

principles of involute curve outlined ; analysis and inter- pretation of inspection data obtained by pin measurement method and master gear or rack method of checking ac- curacy of gear tooth elements. Le Controle des Engrenages (Gear Measurements), M. WOLPER. Rev Universelle des Mines v91 n2 Feb 1948 p

196-205. Testing methods and apparatus described and

illustrated ; results tabulated. Comparator Chart Layout Checks Involute Gears, F. E. BROWNING. Am Mach v92 nil May 20 1948 p 89-92. Quick, accurate checking of involute gears is done on comparator with master chart laid out by calculating

points outlining tooth profile ; advantages of optical projection ; method is illustrated by calculation worked out

for gear having following specifications : 20° full depth spur gear, 30 teeth, 8 diametral pitch, 3.750 in, pitch diam and 4.000 in. basic outside diam. Measurement of Periodic Errors in Gear-Hobbing Machines, C. TIMMS, A. A. KING, L. E. JEANS. Eng

vl66 n4315 Oct 8 1948 p 337-40. Record of latest form

of G. A. Tomlinson's instrument and method for measuring errors of controlling movement of hobbing machines

while in motion ; equipment consists of notched disk which actuates microswitch and impulses from "make

and break" are recorded by piezoelectric record cutter on smoked plate carried slowly round on machine table. Helical Gear Nomograph, W. A. RING. Prod Eng v20 nil Nov 1949 p 159. Chart giving center distance and

normal pitch from helix angle and number of gear and

pinion teeth. Autographic Recording of Errors in Gear Hobbing Machine Tables, C. TIMMS. Machy (London) v76 nl947 Feb 16 1950 p 237-41; Engr vl89 n4909 Feb 24 1950 p

251-3 ; Eng vl69 n4390 Mar 17 1950 p 307-8. In investigation, table movement is linked to rotation of hob

spindle by means of friction drive, any variation in rela- tive movement being amplified electrically and recorded

autographieally on chart paper ; results of measurements

on commercial gear hobbing machines and on Pfauter

gear hobbing machine, type R.S.00, are plotted on charts. Communication from Nat Physical Laboratory. Hob Flank Angle Measuring Machine. Engr vl90 n4932 Aug 4 1950 p 131. Machine developed by Coventry Gauge 225
and Tool Co for checking by direct measurement form of involute helicoids and other helicoids straight sided in normal or axial planes; indicator is mounted on pillars on which it is adjusted vertically for setting stylus to correct plane by means of standard height block. Analysis of Gear-Tooth Undulation Records, P. M. GILET. Eng V172 n4469 Sept 21 1951 p 373-6. Method used in testing turbine reduction wheel ; appendix gives modifi- cation of undulation in recording; diagrams. Pin Measurement of Face Gears, J. SILVAGI, V. FRANCIS. Am Mach v96 May 12 1952 p 183-7 4 figs

Van Keuren Catalog and Handb n36 1955 p 248-50 2 figs. Describes method of measuring the tooth thickness of a face gear by measuring over a single cylindrical pin placed in a tooth space to some locating plane such as the back mounting face of the gear. A pin will rock in the same manner as a pin in the space of a helical gear. Analytical Gear Checking. Illinois Tool Works 1954. Discusses lead, involute, spacing, and composite checks. Geometry of Involute Helicoidal Hob and Gear Teeth,

N. J. C. PERES. Austral J App Sci v5 n4 1954 p 309-29

1 fig. 9 refs; vlO nl 1959 p 17-24 1 fig 4 refs. In the 1954 paper the geometry of the involute helicoid is treated quite generally in terms of familiar gear parameters. It is shown how the radius of curvature of the

axial section becomes very large when the pitch helix angle is large, and in the particular case of hob threads with helix angle approximately 87°, the axial section becomes practically straight sided. The coordinates of any point on the curve of intersection of a plane normal

to the pitch helix and the surface have been derived. These enable the theoretical normal section of an in- volute worm or helical tooth flank to be plotted for comparison with the normal profile as traced out on a smoked

glass plate by the pantographic technique of measurement. The equations for various other sections of the

surface, often given in texts without adequate proof, fol- low immediately from the general treatment. In the 1959 paper entitled "Involute Gear Geometry" the vector treat- ment has been extended from the particular to the general

case along similar lines to include every tooth and space

in any gear. The general geometry holds for internal as

well as external spur and helical gears, and particular properties follow from the general treatment. See also PERES (1959) in subsection 10.1.4, p 227. A Precise Technique for Accurate Checking of Gear

Dimensions, W. S. TANDLER, AGMA 239.02 Oct 1954. Describes Probograph method. The Universal Probo- graph consists of a base unit, an automatic rotary head,

tailstock, a probing head for longitudinal, transversal, and vertical measurements, and additional units includ- ing one for automatic stationing and a reciprocating

stylus unit especially for gear measurements. May be used for several types of gears for all gear dimensional

characteristics. Measurement of Gears, C. TIMMS. Eng vl78 n4G38 Dec

17 1954 p 789-92 (Editorial comment) p 779. Instn Prod

Engrs J v34 nl2 Dec 1955 p 792-801 (discussion) 801^.

Existing methods of gear measitrement and various measuring machines in use; recent developments and possible future trends; establishment of unified system of pitch tolerances based on results obtained from comprehensive

series of pitch measurements, proposed. From paper be- fore Brit Gear Mfrs Assn. Checking Accuracy of Gears. Eng vl79 n4643 Jan 21 1955 p 85. Machine made by David Brown Tool Co for cheeking concentricity, tooth contact center distance and tooth thickness of internal and external spur and helical gears ; machine will accommodate spur gears up to 24 in. in diam.

Examining Machined Surfaces by Interferometry, J. DYSON. Eng vl79 n4696 Mar 4 1955 p 274-6. Interferometer microscope applied to study of experimental double

helical pinion to investigate differences in surface finish produced by hobbing and by shaving; overall profile of tooth surface is much improved in smoothness by shaving, but fine surface structure is made considerably worse. Gear Gaging Goes Automatic, T. S. GATES. Tool Engr

v36 n5 May 1955 p 95-9. Application of automatic, in- process inspection to gears; requirements of automatic

gear gages and their function ; basic factors of gear gages and their application ; sound testing of gear ; future of automatic gear gages. Selecting Effective Gear Inspection Methods, F. BOHLE.

Tool Engr v34 n6 June 1955 p 111^. Determination of most economical checking procedure; functional gear checking; values for runout listed, with tolerances grouped according to pitch, pitch diameter and speed range ; advantage of analytical comparators ; other gear

inspection procedures. Der Einfluss von Werkstoff, Maschine und Werkzeug an

die Oberflachenguete der Zahnflanken (Influence of Material, Machines, and Tools on Surface Quality of Gear

Teeth), W. HAGEN. VDI Zeit v97 n25 Sept 1 1955 p

849-59, Sept. 21 p 956-62. Test method and surface roughness of tooth surfaces; photomicrographs. Messen der Verzahnungen an grossen Raedern, E. WAGNER, K. H. WEBER. VDI Zeit v98 n8 Mar 11 1956 p

304-8. Measurement of large gear teeth, survey of de- velopment of measuring methods and instruments in Ger- many and other countries. Production and Metrology of Gearing, R. L. COWEE. In- spection Engr v20 n5 Sept-Oct 1956 p 98-103. Elementary

design principles of involute gearing; production process on shapers and hobbers; preparation of gear blanks and

production of gears; errors in machines and tooling and

their results on gears produced ; hand measuring tools

instruments and machines available for gear metrology. Methods of Specifying Precision of Spur Gears, G. W. MICHALEC. Prod Eng v27 nl2 Nov 1956 p 135-42. Analytical and functional methods of specifying gear size and tolerance, including: over-pins measurements; ver- nier gear tooth measurements ; block gaging methods ; Am

Gear Mfrs Assn and modified methods; converting from

one system to another. Tooth Gearing and Research, S. A. COULING. Engr v202 n5266 Dec 28 1956 p 915-8. Attempt made to stimulate

interest in research, with view to remedying some of pres- ent defects ; fundamental and applied research ; tooth measurement, lubrication and other problems requiring

research. Vereinfachte Berechnung von Messweiten fuer aussenver- zahnte Gerad- und Schraegzahnraeder mit Evolentenzaeh- nen (Simplified Calculation of Measuring Width Stand- ards for Externally Toothed Straight and Helical Gears

with Involute Teeth) , H. HARTSCHEN. Werksstatt und

Betrieb v90 n3 Mar 1957 p 187-90: Methods for determining standard measuring width of O-type and V-type gears with or without flank and radial clearances, formulas and

tables. Surface Roughness of Large Gear Wheels for Ship's Turbines, W. DE BRUIN. Ingenieur v69 n3 Aug 16 1957 p

W115-8. Application of interference microscope with im- mersion cuvette for measuring surface roughness of tooth

flanks; study was made in connection with installation of new gear' hobbing machines in plant of N. V. Koninklijke Maatschappij "De Schelde" at Flushing; relatively small roughness found which compares very favorably with that shown in previous tests (in English).
Equipment for Testing Involute Gears. E. SCHULTHESS.

Microtecnic vl2 nl Feb 1958 p 1-7. High accuracy instru- ments for measuring distance between centers and for checking true running; single flank rotary type instru- ments; equipment for pitch measurements; instruments

for testing gear flanks; device for measuring angle of tooth ; micrometers for chordal measurements ; compound

and universal types of instruments ; testing equipment for bevel gears. Xew Hope for Angular Accuracy in Precision Gear Trains,

F. FREUDEXSTEIN. Prod Eng v29 n23 June 9 1958

p 70-1. Four equations are offered for measuring angular

errors in gearing, where suitable inspection methods are

lacking; besides predicting magnitude of error, equations

indicate corrective measures for eccentricity, wobble, profile errors and thickness and pitch errors. Measurement of Large Gears. C. TIMMS, Inst Mech Engrs

(Advance copy July 28 1958). Discusses surface finish of gear teeth ; adjacent, short span, and cumulative pitch errors ; tooth lead or helix angle : tooth profile ; and gear hobbing machine errors : 29 refs. Probleme der Grosszahnradmessung (Problems in Meas- urement of Large Gears). A. BUDNICK. YDI Ber v32

1959 p 57-67. Two most important questions are stated

to be those of stability and accuracy of test instruments

survey of English and German measuring methods and

devices, accompanied by illustrations. 23 refs. Die theoretische Grundlage fuer die Pruefung von Kegel- raedern (Theoretical Principles for Testing Bevel Gears).

G. ZIEHER, VDI Ber v32 1959 p 89-98. Straight bevel gear and its manufacture ; measurement of tooth profiles. On the Difference between the Normal Plane Helical Gear

Profile and the Virtual Spur Gear Approximation,

X. J. C. PERES. Australian J. App Sci vlO nl 1959

p 17-24 1 fig 4 refs. Helical involute gears are sometimes

milled with rotary cutters or ground with formed grinding

wheels, whose form corresponds to the tooth space profile of an imaginary "virtual" or "equivalent" involute spur

gear in the plane normal to the pitch cylinder helix. The

present paper gives equations for the difference between

the profile so produced and the correct normal plane profile and shows that in some cases the approximation is not

sufficiently accurate. See also PERES paper (1954)

p. 226; ZAMIS (1947) p. 225 and WATERS (1961) p. 227

in this subsection. Messen und Pruefen von Kleinstzahnraedern (Measuring and Testing Miniature Gears), L. MEYDIXG. VDI Ber

v32 1959 p 77-88. Gear errors in watch movements and

I other small mechanisms ; measuring instruments described. 23 refs. On the Difference between the Normal Plane Helical Gear

Profile and the Virtual Spur Gear Approximation, N.J. C. PERES. Australian J. App Sci vlO nl 1959 p 17-24 1

fig 4 refs. Helical involute gears are sometimes milled with rotary cutters or ground with formed grinding

wheels? whose form corresponds to the tooth space profile of an imaginary "virtual" or "equivalent" involute spur

, gear in the plane normal to the pitch cylinder helix. The

present paper gives equations for the difference between

the profile so produced and the correct normal plane profile and shows that in some cases the approximation is not

sufficiently accurate. See also PERES paper (1954)

p; 226; ZAMIS (1947) p. 225 and WATERS (1961) p. 227

in this subsection. Vereinfachte Berechnung der Zahnweiten und der Grundkreisdurchmesser, insbesondere bei korrigierten Schraeg- verzahnungen und Eingriffswinkeln, die von 20° abweichen

( Simplified Calculation of Width of Teeth and Base Circle Diameters, Particularly in Case of Corrected Helical Gears and Pressure Angles Which Deviate from 20°),

H. BERGMANN. Werkstatt und Betrieb v92 nl Jan 1959 p 10-14, Diagrams and/or numerical tobies for pressure

angles of 15°, 20°, 22°30', and 30° in standard and special gears presented. Der neue GOST-Standard ueber Messmittel fuer Stirnrae- der (New GOST (Russian) 5638-58 Standard of Measuring Instruments for Spur Gears), K. BOEHM. Standardisierung v5 n4 Apr 1959 p 1/152-6. Outline of Soviet standards and comparisons with East German standards

in this field. Measuring Gear Teeth Errors Under Load, B. WOOD.

Eng vl87 n4861 May 8 1959 p 614. Errors measured for pair of spur gears defined as deviation from uniform rota- tion of one gear when other gear is rotated uniformly

measuring apparatus consisted of two 2% in. diam steel disks and two 1%-in. diam steel rollers; practical diffi- culties. Measuring Kinematic Errors of Gears, M. BARASH, P. OXLEY. Machy (N.Y.) v66 n2 Oct 1959 p 139-40. Of

two instruments developed in Soviet Union, one measures

relative rotation between standard gear and gear being

tested while they are simultaneously run in mesh with

third gear, and second instrument is designed for checking fine pitch gears ; their design and operation. Die erweiterte Anwendungsmoeglichkeit des Taylorschen Grundsatzes (Possibility of Extended Application of Taylor's Fundamental Principle), H. WEINHOLD, Magdeburg Hoschschule Schwermaschinenbau Wiss Zeit v4 n2

1960 p 139-45. It is shown that this principle can also be applied to testing of gears, if complex notion of function is defined beforehand. Vybor toehnosti izmeritel'nykh sredstv dlya kontralya zub- chatykh koles, B. A. TAITS, N. N. MARKOV, Stanki i Instrument v31 nl Jan 1960 p 20-4. see also English translation in Machines & Tooling v31 nl 1960 p 22-6. Develop- ment by Intel-changeability Bureau of Committee on

Standards, Gauges and Measuring Instruments of guide

for selection of accuracy of measuring devices used for quality control of spur gears. Geometricheskii raschet tsilindricheskikh zubchatykh

koles s pomosch'yu spetsial'nykh tablits (Geometrical Cal- culation of Cylindrical Gears Using Special Tables), G. I. KOGAN. Stanki i Instrument. v31 n2 Feb 1960 p 24-32

see also English translation in Machines & Tooling v31 n2 1960 p 26-34. Calculation method proposed is uni- versal and simplifies direct calculations ; its use eliminates

calculations of intermediate values ; especially when deter- mining only individual features which characterize pinion

or gear ; examples of calculation of spur and helical gears

given. Brief Description of New Single-Face Gear Testing Device,

F. LOBE. Microtecnic vl4 n3 June 1960 p 101-12. Methods of measuring gear teeth accuracy are reviewed

manner in which control is performed on new single face

testing device for coping with all types of transmission elements is described ; design and construction of proto- type for testing worn gears by single face method is dis- cussed ; photographs and sketches. Exact Equations for any Normal Profile of an Involute

Helical Gear, W. C. WATERS. Apr 24 1961 63 p 7 figs 6 refs. An essay submitted to the Graduate Council of Wayne State University in partial fulfillment of the re- quirements for the MS degree in the Dept of Mech Eng.

Object is to investigate the errors inherent in the equivalent gear approximation. Subject headings include : Derivation of general equation set; test on equation accu- racy ; computer program formulation ; computer results

section normal to central tooth pitch helix ; section normal

to lateral pitch helix ; discussion of computer results

appendix. See also ZAMIS (1947) p. 225 in this subsection. 227
Ein Beitrag zur Pruefung der Zahnrichtung an Zahnraedern (Study of Tooth Direction in Gears). W. ROM- MERSKIRCH. Werkstattstechnik v51 nlO Oct 1961 p

529-33. Measuring methods and devices for testing straight toothed and helical gears, and internal toothing

described ; checking of measuring instrument. Achsabstand und Profilverschiebungen in Evolventen

Stirnradgetrieben (Backlash and Profile Displacement in Involute Spur Gears), R. NOCH. Tech Zeit fur prakt. Metallbearbeitung v56 n7 1962 p 365-71 5 figs 7 refs. Diagrams are given from which the corresponding values

for the axial clearance and the profile displacement can

be read out, in many cases, to a sufficient number of decimal places. Pribor dlya knotrolya kinematicheskoi toehnosti zubcha- tykh peredach (Instrument for Testing Kinematic Accuracy of Gears), YU. A. FEDUKIN. Stanki i Instrument

n5 May 1962 p 29-30 ; see also English translation in Machines & Tooling v23 n5 1962 p 32-3. Description of method developed in Saratov Heavy Gear Cutting Machine Works ; how continuous record of measurements was ob- tained by means of standard recorder ; method is based on

comparison of length of piano wires being wound (or unwound) on drums mounted on gears tested. Gear Measurement, Inspection Equipment and Practices. AGMA 129.15, June 1962. Seven papers presented at the 46th annual meeting of the AGMA. (See GREEVE and DEVOS references below in this subsection and BEAM in subsection 9.3.) Die Fertigung von Genauigkeits-Grosszahnraedern (Pro- duction of Large Marine Gears of High Precision), W. DREYHAUPT. Werkstatt und Betrieb v95 nil Nov 1962 p 733-43. Details of gear hobbing machine and operating

conditions, manufacturing procedure and measuring and

safety devices employed ; numerous measurement results presented indicate accuracy of gears. Pruefung der wichtigsten Verzahnungsgroessen an

Stirnraedern (Testing Most, Important Sizes of Spur Gear

Teeth), A. BANHART. Werkstatt und Betrieb v95 nil Nov 1962 p 745-54. Whole Meld of testing spur gears for individual and cumulative errors is discussed in detail, and testing methods and apparatus employed are described. Teilungsmessungen an Verzahnungen in der Praxis (Pitch Measurements on Gear Teeth in Practice), H. A. KOOP.

Werkstattstechnik v52 nl2 Dec 1962 p 646-52. Installa- tions and devices employed are described ; interpretation

of measuring results with regard to various types of errors

is explained. Measuring Method of Gear Accuracy, by Means of Two

Feelers, J. ISHIKAWA, H. OHMURA. Japan Soc Mech

Engrs Trans v28 nl96 Dec 1962 p 1655-69. New method

in which 2 feelers contact simultaneously on two adjacent

tooth surfaces and draw error curves in same way as with

usual tooth profile tester; center distance of 2 feelers is set equal to normal pitch of gear, so that two curves of

profile errors are recorded ; curves are superposed to give

entire error ; method is applicable for spur gears ; curves

for meshing and angle position errors were derived. InA Japanese with English abstract. New Instruments for Measuring Accuracy of Gears and Gear Trains, K. STEPANEK. Czechoslovak Heavy In- dustry nlO 1963 p 34--42. IMO-S equipment developed in Czechoslovakia makes it possible to determine exactly inaccuracies of gear hobbing machines, shapers, and

grinders ; apparatus is portable and measures gears

directly on machine ; results obtained are presented

graphically and analyzed ; accuracy of indexing gears can

be assessed with high precision by means of thorough

analysis of results or additional tests. Gear Checking Equipment, E. F. FABISH. ASTME | Creative Mfg Seminars—Tech Paper 586 1963-64 9 p., Gears should toe checked under conditions simulating ,

1 actual operation mounting conditions ; of two basic types

of test equipment, functional and analytical, first is avail- able in all ranges from manual to fully automatic ; effi- ciency of hand and semi- and fully-automatic gear rollers

analytical type equipment is exemplified by helical lead- measuring instrument and tooth-space comparators;

sources of gear errors are pointed out. Equipment for Measuring Driving Gears of Diesel and

Electric Locomotives, YU. V. IVANOV. Meas Techns

1962 n8 Feb 1963 p 643-4 2 refs. Translated from Izmer Tekh n8 p 19-20 Aug 1962. Discusses equipment needs

for measuring large railway gears. Determination of Cyclic Errors in Cylindrical Spirals Gears, B. YA. VERKHOTUROV, N. N. MARKOV. Meas

Techns 1962 nl2 July 1963 p 988-91 4 figs 5 refs. Translated from Izmer Tekh nl2 p 5-8 Dec 1962. Discusses the use of waviness meters for checking cyclic errors, which is the basic parameter for smooth operation of spiral gearing

in GOST 1643-56. Goulder Mikron No. 4 Analytical Gear Tester. Machy

(London) vl04 n2678 Mar 11 1964 p 594-5. Design and

operation of apparatus for checking gears for concentricity, involute profile, lead and pitch ; it incorporates Taylor-Hobson electronic recording equipment of paper

strip type, which gives 6 magnifications from lOOx to 5000x ; gears up to 48 in. diam by 10 in, wide, and weighing up to 3000 lb can toe tested ; separate attachment m : « available for carrying out dual-flank rolling tests. Improved Gear Measurement Techniques for the Correlation of Gear Error with Noise, C. H. McDOWELL, A. MARK, J. SPENCE. Res and Development Rep nl, Naval Boiler and Turbine Laboratory, Philadelphia,' Penna, Apr 1964 19 p plus 26 figs. Reports on project

to establish accurate methods and techniques to measure

undulation and pitch errors. The laboratory has devised - a measuring technique wherein undulations along a gear, tooth can be measured and recorded on a continuous strip chart and analyzed with a sensitivity capability of better than 5 /tin. Also, the measurement of pitch error by a differential technique may be made to an accuracy equal

to that of the divided table used for small diameter gears; | and superior accuracy with large diameter gears.

10.2. Spur and Helical Gears

10.2.1. Involute Form Measurement

Gear-Testing Machine, G. WIRRER. Machy (N.Y.) v26 Mar 1920 p 633-5 8 figs. ; Machy (London) vl5 Apr 1 1920 p 862-4 8 figs. Description of a machine designed to test spur gears for accuracy of tooth profile and concentricity by comparing the rolling action of the pair of intermeshing

gears with the rolling action of two accurate base circle

disks. The result of this comparison is graphically re- corded by the machine. "Kavle" Correct Involute Contour Indicator. Am Macr

v">2 Mar 25 1920 p 698, 2 figs. Used to test the accuracy

of the form of gear teeth. Operation employs the same

principle as used in laying out a true involute tooth form. As the straight edge is rolled about the base circle plug, the short arm follows the tooth form while the long arm
r -mains in contact with the indicator plunger. If the

tooth is of true form the pointer will not move. If the

tooth is not of true form the indicator will show any de-

;,

; viation from within 0.0002 of an inch.

: Gear-Testing Machine. Machy (London) vl5 Apr 1 1920

. _t-!P 862-4 8 figs. Machine designed to test spur gears for

.v accuracy of tooth profile and concentricity. Principle on

.o- which machine operates is comparison of rolling action of

* ipair of gears under test with rolling action of two circular

£ disks, result being recorded on chart. Inspection of Involute Gear Hobs. C. G. OLSON. Machy

(N.Y.) v28 Oct 1921 p 138-40 6 figs. Describes involute

~\2 2 contour tester for spur and helical gears used by the Dli-

. iTinois Tool Works. Gives three tables of base circle disk

j diameters.

I Lees Bradner Gear-Tooth Testing Machine. Am Mach

-i(;v58 Apr 26 1923 p 640-1 4 figs; Machy (N.Y.) v29 Apr

.^i 1923 p 649-50 4 figs. Measures the accuracy of that porU'zion of the tooth contour that conforms to an involute

• rve. and also measures the spacing of the teeth of the

> gear. A disk on the work arbor is of the same diamr er as the base circle of the gear to be inspected. A

£ tangent bar or straightedge is held against the base circle

. -''under spring tension by two ball bearings on the slide

^jjtfframe. As the slide frame is rotated upon the work arbor,

Zy. :he tangent bar rolls about the base circle and the point

Di the contact lever traces the involute of this base circle,

i The straightedge carries a bracket on which are mounted Jlne contact point, magnifying levers, and a dial indicator.

; J The contact point engages successive teeth of the gear, and

•Zj I if the tooth curve is a perfect involute the hand of the

Z ^indicator attached to the device will stand at zero while

he contact point travels from the base to the point or

. outside edge of the tooth. American Grinder Co. Gear Tester. Am Mach v59 Aug

•-30 1923 p 346-7. For checking and charting involute ."^curves and testing tooth spacing. The machine consists

r -iy -ot a base with a longitudinal slide upon which a transZZ^. verse slide is mounted and constrained by tapes to move

e a distance equal to the peripheral motion of the base circle

lisk. Both slides are moved by screws with hand wheels

ind micrometer heads. On the transverse slide are

I mounted the contact finger and an indicator. 'National-Cleveland" Tooth Form Tester. Am Mach v64

^Jjftlar 25 1926 p 495. For measuring tooth spacing and proj lie of an involute gear shaper cutter or a gear. The gear

T >r cutter is mounted on a spindle and held by a stop while

j j:he contact point on the lower end of a lever touches the

. "oth to be measured. The indicating lever is mounted

. >n a slide that is moved by steel tapes from a pulley on

„ he back end of the spindle that carries the gear being

ested. Moving this slide turns the gear and the contact

:< Hows the tooth form as the gear rolls in unison with the

. novement of the slide. Any inaccuracy in the tooth form

8 shown by the indicators at the upper end of the pointer.

. iear Measuring Equipment. Machy (London) v28 June 17

1926 p 30L4 9 figs. Gear-measuring instrument made

>? Maag Co., Zurich, Switzerland ; measurements ob- ained with this instrument are made with reference to :heoretically correct involute curves ; instrument for ex- amining involute tooth profiles and comparing these with

rorrect theoretical shape; also serves to examine sym- metry of two profiles of tooth. uvolute Gear Tester. Machy (London) v29 Mar 31 1927

j 838-9 4 figs. Zeiss tester is designed for accurate test- ng of involute profile curve of gear teeth ; instrument will commodate all spur gears with involute teeth up to

' .0-in. diameter; it is also possible to determine base dia- aeter of gear if this is not known, it being only necessary

x> find diameter which gives smallest deviation.

Co-ordinates of Involute Teeth. Machy (London) v34 n860 Apr 4 1929 p 6 2 figs. Method of determining co- ordinates of involute teeth is described with formulas ; in one particular type of gear grinding machine, application

of mathematics of tooth curve of setting of machine will greatly facilitate set-up. National-Cleveland & Gear Checking Machine. Am Mach

v72 Mar 6 1930 p 434. Improvements on the Model B

gear checking machine permit readings to 0.0001 in. with a one-to-one lever arm mounted on ball bearings. Ball bearings are also used on the work spindle and the base

circle disks. In addition to checking involute tooth forms, the machine has been found adaptable to checking

the concentricity of the involute curved tooth with the bore of the cutter, by checking through an arc of 180 degrees. The machine is also arranged to check the spacing

of .the teeth. It is made in 4-, 6-, and 8-inch sizes. Involute Gear Tooth Testing Instrument. Eng vl33 Jan 1 1932 p 22 ; Engr vl53 Jan 29 1932 p 138. Instrument produced by D. Brown and Sons, is simple, but accurate and reliable, mechanism for testing involute profile of teeth on spur and helical gears ; capable of accommodating

gears up to 12 in. in base circle diam., and records driectly on to dial with sensitiveness to one ten-thousandth of in. any deviations from correct involute form. Orcutt Involute Measuring Machine. Engr vl55 n4032 Apr

21 1933 p 408. Machine developed by Gear Grinding Co., Birmingham, England, to meet its own requirements

machine will measure any involute struck from any base

circle between 1 and 13 in. in diam. Die Bestimmung des Evolventenfehlers von Zahnraedern

(Determination of Involute Error of Gears), E. BOLBRINKER. Maschinenbau vl8 n% Feb 1939 p 73-5. Valuation of flank test; diagrams of involute testing apparatus. Charted Accuracy Minimizes Errors in Gear Profiles. Elec Mfg. v31 nl Jan 1943 p 90, 92, and 120. Gen Electric and Fellows Gear Shaper collaboration has lead to auto- matic electric chart recording of involute gear profiles in Fellows involute measuring machine which is illustrated and described. Involute Checking Machine for Large Helical Gears, D. W. DUDLEY. Machy (N.Y.) v54 n2 Oct 1947 p 142-5. Details of entirely new machine designed for checking

large industrial and marine gears ; gear profiles are checked in normal section by special checking head which

is moved across tooth profile and transmits deviation from straight line to recorder ; setup and typical application explained. Master Gaging for Involute Curve, C. H. BODNER. Tool Engr vl9 n5 Dec 1947 p 25-8 ; Am Mach v21 n26 Dec 18

1947 p 87-90. Proposed optical projection method and recommended practice for checking involute profile; method requires use of master spline chart gage pattern, separate chart for each spline size; proposal limited to side bearing involute with 30° pressure angle, but can

be applied to any involute profile whether straight or

helical. Selection of Measuring Rolls for 30-degree Involute

Splines, J. SILVAGI. Tool Engr v22 n2 Feb 1949 p 26-8. Method used to determine correct size of cylindrical measuring rolls for contour gaging involute spur gears and

involute spur splines; graphs simplify roll selection for standard SAE or SAS involute splines ; they are based on standard tooth space widths; they can also be used to determine location of contact; table gives general equation for determining roll diameter to contact at given diameter on nonhelical gear. 229
Epures Mobiles Universalis pour le Trace des Profils en Developpante ( Universal Movable Calculators for Outline

of Involute Tooth Profiles) J. BERGERE. Pratique des

Industries Mecaniques v32 nlO Oct 1949 p 311-7. Design and application of calculators and gages which permit

rapid and accurate tracing of tooth profile; illustrations. Simple Linkage Which Generates Close Approximation to Involute, E. R. WIGAN. Machy (London) v86 n2204 Feb 11 1955 p 321-5. Linkage described provides simple method of gaging profiles of involute spur gears ; geometry and parameters of linkage; tabulation of involute and mechanism parameters ; sources of error in mechanism

designed to conform to geometry of presented view. Involute and Helix Tester for Large Gears. Engr v202 n5256 Oct 19 1956 p 561. Tester, "Model PGZ," intro- duced by W. Perd. Klingelnberg Soehne, Remscheid, Germany, stated to make possible testing of profiles on

tooth flanks of gears too large for existing standard

equipment. Ermittlung des zu einer Evolventen-Sehragzahnflanke gehorenden Grundzylinderradius (Investigation of the Base Cylinder Radius Belonging to an Involute Helical Gear Flank), M. GARY. Konstruction v9 nlO 1957 p

397-9. Calculation, measuring process, and example. Measurements of the Form Error of Small Gears Under

Working State (Operating Conditions), K. YAMAMOTO.

Report of the Central Inspecton Institute of Weights and

Measures, Japan, v8 n3 Report 19 1959 in Japanese. There have been many measuring methods of gears, but few of them are applicable for small gears, because their minuteness necessitates an extraordinary accuracy in de- tecting form error of small gears. For example if the ac- curacy of measurement of gears with module three is to be required one micron, the equivalent measuring accuracy

of small gears with module 0.3 must be 0.1 micron, and

the detection of such a small dimensiion is very difficult. On the other hand the demand for such a high measuring

accuracy grows greater and greater as the fine instru- ments are developed. For the above reasons a method for measuring form errors of spur gears is developed. The

principle of the method is based on the fact that the driv- ing torque of a gear train is fluctuated by sliding friction and form errors of gear teeth contacting each other. A

gear and a pinion are meshed together and a loading torque is applied on the pinion and then gear is driven

so slowly that the angular motion of the gears can be as- sumed to be in an equilibrium state, and equilibrium can

be obtained, one pair of which are equations when the gear is driven clockwise and the other when the gear is driven anti-clockwise. From these equations the reaction

forces Q

+ and Q~ acting on the pinion from its bearings can be shown analytically, and Q

+ is the reaction force when the gear is driven clockwise and Q" is the reaction

force when the gear is driven anti-clockwise. The fluc- tuations of (Q+ +Q-) are brought about mainly by the form error of the gears but little by the sliding friction, while with the fluctuations (Q+ —Q~) the reverse happens. And hence the friction and form error can be ob- tained if Q

+ and Q" can be obtained. The apparatus

to obtain the forces Q

+ and Q

- is shown, and some ex- amples of records of Q

+ and Q~ are also shown. It is proved that the form error, the friction and the actual

contact of the gear and the pinion can be analyzed successfully. Die Ueberpruefung von Evolventenpruefgeraeten und das

pruefen von Stirnraedern mit sehr kleinen Ziihnezahlen (Examination of Involute Checking Devices and Testing

of Spur Gears with very small Numbers of Teeth), W. ROMMERSKIRCH. Werkstattstechnik v49 nil Nov

1959 p 674-6. Methods for checking accuracy of recording

device : nomogram as aid in testing of spur gears.

Pribor dlya kompleksnogo odnoprofiTnogo kontrolya zub- chatykh koles, A. T. DRAUDIN. Stanki i Instrument v31 nl Jan 1960 p 24-6 ; see also English translation in Machines & Tooling v31 nl 1960 p 27-8. Design of single

profile testing machine BV-963 with universal setting for center distance from 2.756 in. to 9.843 in. and transmission

ratios from 0.33 to 3.0 developed by Bureau of Inter- changeability. Investigating the accuracy of evolventometers, G. S. SIMKIN, G. Y. GAFANOVICH. Meas Techns 1961 n6 Dec 1961 p 435-8 1 fig 4 tables 3 refs. Translated from

Izmer Tekh n6 p 8-10 June 1961. Investigaton of several foreign make involute testers. Conclusion is that it is necessary to produce new instruments for measuring

gears of high accuracy by GOST standards. It is also necessary to develop a more reliable method of setting the measuring tip for a given base circle diameter. Gear Checking Method Eliminates Errors in Setup, J. W. GREEVE. Tool & Mfg Engr v48 n5 May 1962 p 121-4.

( See next reference by DeVos.

)

Ford Pin Type Master for Involute Gears, L. DeVOS. AGMA 129.15 June 1962 5 p 4 figs. New geometrically constructed masters use highly accurately ground and posi- tioned pins of circular cross section instead of involute- toothed master to qualify checking instruments at the Ford Motor Co., with the aid of calculated deviations. Thus the involute-master is removed as a source of error

in accurate measurement. This important basic principle was suggested by Albert S. Beam (then chairman of the Gear Panel of the Industrial Mathematics Society, Detroit). Die neue Evolventen- und Steigungspriifmaschine Modell PFS-U (The New Involute and Lead Testing Machine

Model PFS-U) , K. H. WEBER. Klingelnberg-Nachr vl3 n32 Dec 1964 4 p 5 figs. Describes function in detail and how this model evolved from PFS 500 and PFS 600. 10.2.2. Master Gears; Composite Deviation Testing

Device for Testing Truth of Cut Gears. Machy (N.Y.) vl5 Jan 1909 p 374-5. Device for rotating gear with master

gear and indicating changes in center distance. Testing Gear for Automobiles, M. E. HIDIEGAN. Am

Mach v32-2 Aug 26 1909 p 389-90 3 figs. Illustrated de- scription of a device for the final testing of all spur-cut

gears, either soft or hardened for out-of-roundness, etc., by rotating in mesh with a master gear. Device for Testing and Measuring Gears, C. BOELLA.

Machy (N.Y.) vl8 Apr 1912 p 635 2 figs. An indicating device for operating spur gears in mesh and determining

eccentricity. Testing Spur and Bevel Gearing. Internal Combustion Eng Oct 16 1912 p 341 4 figs. British machine by Parkinson and Sons in which bevel gear and pinion are run

together and errors are recorded on a chart. Inspection of Spur Gears, D. V. WATERS. Machy (N.Y.) v28 Feb 1922 p 465-6 4 figs. Describes rolling fixture of Gould & Eberhardt, Newark, N.J., in inspecting spur gears, with particular reference to uniformity of tooth spacing It | and concentricity of pitch circle relative to axis of gear, f | Testing Involute Spur Gears, M. ESTABROOK. Mech [ ,j Eng v45 Jan 1923 p 32-4 and 81 14 figs. Describes Saurer

gear-testing machine, a Swiss development by means of which accuracy of tooth curves, spacing, and eccentricities can be determined with high degree of precision ; and

odontometer, American instrument for quickly and accu- 230
rately testing gears for tooth curves and spacing, and with which it is possible to locate troubles in machines or tools. Gleason Spur Gear Testing Machine. Am Mach v73 Oct 16 1930 p 645. Running qualities of spur gears up to 14% in. pitch diameter can be tested on this machine. The machine

can be used for testing cluster gears as well as gears with

integral shafts ; also helical, herringbone, and internal spur gears. Heads are adjustable horizontally by means

of a lead-screw graduated to 0.001 in. A 5-hp. motor drives

the spindle. Specifications : distance between noses of spindles on brake and drive heads, min., 3 in., max., 18 in.

distance from center of brake-head spindle to center of drive-head spindle, min., 3 in., max., 10 in. ; distance be- tween adjustable tail center and nose of brake-head

spindle, min., 0 in., max., 14% in. floor space, 61% by 77

in., and net weight, 4,000 lbs. Gear testers designed to show combined errors. Iron Age

vl33 p 27 Apr 26 1934 1 p 1 illus. Parkson gear tester is designed to show composite errors of spur, helical, and

bevel gears as well as of worm gears and worms.

Meister-Zahnraeder als Normale fuer die Abrollpruefung

(Master Gears as Standards for Rolling-Off Test), K. BUERGER, Werkstattstechnik und Werksleiter v34 n24 Dec 15 1940 p 427-33. Principles governing method and

standards for acceptance testing of large numbers of gears ; measurement of master gears of different makes

recommended tolerance for tooth dimensions of master

gears. Bibliography. \daptable Gear-Testing Machine. Machy (London) v57

11481 Feb 27 1941 p 599-601. Description of machine

nanufactured by Monarch Tool Co, Huddersfield, designed

"or testing spur, helical, bevel, spiral, and worm gearing

t is suitable for either laboratory or workshop use ; gears

ire tested by rolling together, thereby eliminating many

ndividual measurements ; simple and easily mounted at- achments enable whole range of gearing specified to be

Master Gears, H. WALKER. Machy (London) v58 nl486

^pr 3 1941 p 9-11. Description of standard set of master

;ears and their uses in testing spur and helical gears

luring manufacture.

Bin neues Einflanken-Abrollpriifgernt fur Zahnrader (A

sew Single Flank Rolling Apparatus for Gear Wheel),

K. BURGER PTB, Werkstattstechnik und Werksleiter

' 'HQ n% Jan 1942 p 54-61; VDI Zeit v87 nl7/18 May 1

L943. Illustrated description of new and improved type

developed at Physikalisch Technische Reichsanstalt ; ad-

•antages over double-flank system pointed out Tom Werkstattstechnik v 36 1942 p 54-61.

1 Jome Facts About Master Gears, G. H. SANBORN. Am

dach v89 nl4 July 5 1945 p 116-7. Study of master gears nd their application in inspection of work gears during

-nd after production ; details of instrument used in measi irement of tolerances ; concentricity of teeth and back- ash; factors concerning selection and design of master

.Tears. Jear "Rolling," G. W. BIRDSALL. Steel vll7 n8 Aug

0 1945 p 126-7, 164, 166. Description of essential ele- ments of gear rolling fixture for checking spur, helical, piral and worm gears ; gear under test is fully meshed

vith master gear and change in center to center distances ead on dial gage as gears are rolled against each other

xplanation of operational details ; illustrations of modi-

'ied designs for checking various types of gears included. pew Concept of Gear Inspection, L. D. MARTIN. Tool

: Die J v 15 n4 July 1949 p 42-5, 67-8. Description of nodel 1-S Conju-Gage intended primarily for checking

•'11 types of spur gears commonly used in meter, instrument and watch industries, and of 4-U model incorporat- ing features which increase ease and rapidity of inspecting larger gears up to 4% in. pitch diam ; advantages of master worm section used in connection with Conju-Gage over circular master gears ; electronic charting device charts radial displacements occurring between

master and work.

Functional Checking of Gear Teeth, L. D. MARTIN.

Machy (N.Y.) v56 n8 Apr 1950 p 208-13. Procedures and fixtures for checking various types of gears ; variable center distance fixtures, Gleason fixture, Fellows Red

Liner, etc. described and illustrated; features of new Kodak "Conju-Gage" for cheeking spur or helical gears pointed out ; factors to be considered when measuring

backlash of gears. Functional Checking of Backlash in Gear Trains, L. D. MARTIN. Machy (N.Y.) v56 nil July 1950 p 161-5. Charts of reliable backlash checks made by rotating gear

being checked in contact with master of known accuracy and measuring their radial displacements, are presented

data sheets shown developed for finding change in center distance required to correct backlash in mating gears. Functional Gear Checking. Illinois Tool Works 1952. Describes various types of rolling fixtures and their uses. Functional Gear Checking, F. BOHLE. Machy (N.Y.) v58 n8 Apr 1952 p 170-5. Evaluation of gear inspection and its practice; gear rolling fixture designed for functional inspection of internal spur and helical gears; ar- rangement for making angular velocity test under load

recording of errors on charts; advantages of combining

graphic inspection with functional gear checking;

photographs. Die Einzelfehler von Evolventen Stirn- und Kegelradern im Fehlerschaubild der Ein- und Zweiflankenwalzpriifung (The Single Errors of Involute Spur and Bevel Bears

in the Error Presentation of the One and Two Flank

Roll Testing), G. ZIEHER. Werkstattstechnik und Maschinenbau, v42 n6 June 1952 p 242-8 6 refs. What Errors Can a Gear Have? Eastman Kodak Co. Presents Conju-Gage as more accurate than a master gear

for the same test. Standard Master Gears. AGMA Publ. 236, 04, June 1956. Tables Simplify Calculation of Gear-Testing Center Distances, J. L. WILLIAMSON. Machy (N.Y.) v64 nl Sept

1957 p 170-1; Machy (London) v91 n2353 Dec 20 1957 p

1445-6. Simple method for computing testing center dis- tance developed by Fellows Gear Shaper Co., Springfield. Vt; difference between involute functions of nominal

pressure angle and active pressure angle is first calculated from formulas ; numerical value for ratio of cosine of nominal pressure angle to cosine of pressure angle at meshing position is then found by referring to table; example. Toward More Economical Gear Inspection, F. BOHLE. AGMA 239.05, Oct 1957. Discusses principally various

types of rolling checks. Measurement Errors in Gear Roll Testing. Machy (N.Y.) v66 n9 May 1960 p 145-50. Nature of errors in roll test measurements described ; methods of obtaining most accurate results from roll testing equipment. Complex Checking of Spur Gears in Single-Profile Meshing with a Measuring Screw, M. N. BOKIN. Meas Techiis 1960 n3 Dec 1960 p 179-80 1 fig 4 refs. Translated from

Izmer Tekh n3 p 1-2 Mar 1960. Method of checking the kinematic error of spur gears in single-profile meshing

with a floating measuring screw has the following advantages as compared with the existing methods : the greater 231

771-846 O—66
precision of measuring screws as compared with reference gears makes it possible to measure gears of any degree

of accuracy ; the possibility of using the measuring screw

for checking gears of any diameter providing they are of the same module. Master Gears and Their Importance in Gear Manufacturing, R. NOCH. Microtecnic vl5 nl Feb 1961 p 20-3. Report on present state of development of using standards

in form of master gears for determining cumulative errors

of gear wheel by employing suitable gear testers ; newest

trends of development indicated. Handbook for the Calculation and Design of Master Gears. Quality Assurance Pamphlet ORDP 608-MC-14, Army

Tank Automotive Center, Detroit, Mich., Nov 5 1962 72 p. Deals with fundamental inspection concepts, master gear

design preparations and instructions, the master gear drawing, wire sizes, root clearance, and calculation sheets. Specification for Master Gears. Brit Standards Instn

Brit Stand 3696 1963 8 p. Standard relates to 2 classes

of spur master gears for use as reference and inspection standards with pitches in range 2 to 64 normal diametral

pitch inclusive ; class A master gears are intended to test precision class product gears and Class B to test gears

for general purposes; specification may also be applied

to helical master gears so far as tolerances are concerned, but tolerances given have been chiefly derived from in- formation from spur master gears. Checking Backlash in Gears, M. S. BRUNO. Am Mach/

Metalworking Mfg vl07 nil May 27 1963 p 77-81. How to obtain precise data on overall gear quality; roll testing spur gear; standard procedure for inspecting backlash,

total cumulative error, and tooth-to-tooth error simultane- ously ; converting to circular tooth thickness, with example; how to calculate center distance limits; setting center distance limits : master gears inscribed with "test- ing diameter" value ; finding correlated testing diameter. Das Lehrzahnrad als Mess- und Pruefmittel fuer Stirn- raeder, G. LICHTENAUER. Werkstatt u Betrieb v96 nil Nov 1963 p 807-11. Master gear as measuring and testing device for spur gears; importance of double flank total composite error test devices, and of measuring noise and

testing contact pattern with master gears is pointed out

design and construction of master gears. Goulder Mikron No. 4 Analytical Gear Tester. Machy

(Lond) vl04 n2678 Mar 11 1964 p 594-5. Design and

operation of apparatus for checking gears for concentricity, involute profile, lead and pitch ; it incorporates Taylor-Hobson electronic recording equipment of paper

strip type, which gives 6 magnifications from lOOx to 5000x ; gears up to 48 in. diam by 10 in. wide, and weighing up to 3000 lb can be tested ; separate attachment is available for carrying out dual-flank rolling tests. Sammelfehlermessung von Stirnradern (Cumulative Errors of Spur Gears), R. NOCH. Archiv fiir Tech Messen

V834-2 May 1964 p 105-8 9 figs 35 refs. Deals with form and position errors of gear teeth as detected by rolling. Considers both single and dual-flank contacts. Master Gears. Proposed Tentative AGMA Information

Sheet. AGMA 235.03 June 1964 18 p. Covers masters for checking spur and helical gears operating on parallel axes. Rights and Wrongs of Gear Checking Pressure, L. D. MARTIN. Indus Quality Control v21 n4 Oct 1964 p 197-

202. Physical procedures are described which are helpful

in determining optimum checking pressure for small pin- ions and gears with small bores where bending in either pinion journals or checking pin may be expected.

Lehrzahnrader und ihre Bedeutung fiir die Zahnradfertigung (Master Gears and their Significance for Finish- ing of Gear Wheels), R. NOCH, VDI Braunschweig.

Preprint available from author 4 p 6 figs 10 refs. Describes master gears and various types of rolling testers. 10.2.3. Lead Measurements

All references under this heading are included in sub- section 9.2. 10.2.4. Pin and Ball Measurements of Spur

Gears and Splines

References to helical gears are given in subsection 9.3,

p. 205. References to tables of numerical measurement

values are given in subsections 9.4, p. 212 and 10.1.3.4,

p. 220. Ring and Wire Gage for Measuring Fine-Pitch Gears, A. W. CHAPPELL. Am Mach v41 Oct 15 1914 p 689. Wire

method of measuring gear pitch diam. Correction, A. W. CHAPPELL, Am Mach v41 Nov 5 1914 p 825. Correction,

S. T. DORT, Am Mach v42 Jan 28 1915 p 167. Pin Measurement of Spur Gears, R. TRAUTSCHOLD.

Machy ( N.Y. ) v24 Jan 1918 p 406-9 5 figs. Principles gov- erning pin measurement and derivation of formulas used

finding size of pin ; discussion of formulas ; allowance for backlash. Table of sizes of pins used in measurement of

1 D. P. gears. Methods for even and odd numbers of

teeth. Measuring Gears by the Use of Wires, W. S. HUDSON. Am Mach v49 Aug 15 1918 p 291-2 6 figs. Simplified for- mulas and tables presented. Method involves use of wires

or pins, the diameter of which is constant for all gears of the same pitch, irrespective of the number of teeth. A

single gage for testing large numbers of gears of the same

size is also described, comprising a suitably shaped holder having two holes suitably spaced, into which pins are

pressed. Criticism by J. W. LEE, Am Mach v50 Jan 16 1919 p 123-4. Formula for Measuring Spur Gears by the Pin Method, M. D. WILSON. Machy (London) vl8 Apr 21 1921 p

92-4 4 figs. The Gauging of Involute Threads, H. E. MERRITT.

Machy (London) Apr 5, 19 July 26, Aug 2 1923 p 11-3 79-81 525 569 13 figs. See abstract under subsection 9.3. Standardized Roller for Checking Spur Gears, W. H. FOLDS. Machy (London) v23 Mar 13 1924 p 765-7 3 figs. Writer proposed to standardize to some extent, roller- check method by use of tables of factors, which makes it possible to use any size roller that will form contact on

tooth faces or flanks, and from given diameter of roller overall measurement over roller as it is located in teeth

of gear can be calculated. The Design and Inspection of Gear Teeth for Wear, P. M. GALLO. Blast Furnace & Steel Plant vl3 Sept and Oct 1925 p 368-9 and 392^ 2 figs. Presents roller formulas and explains their application to determining the defor- mations of gears under load. Checking Gears by the Wire Method, H. G. THUESEN. Am Mach v63 Nov 19 1925 p 824-5. Gives method and

formulas. Normal Pitch the Index of Gear Performance, G. M. EATON. Mech Eng v48 Jan 1926 p 27-32 13 figs. Brings

out certain departures from previously accepted practice which are useful in manufacture of heavy involute gear-
ing. as they ease performance during breaking-in stage of operation ; shows that material improvement in performance may be secured by adopting proper relation between normal pitches of driving and driven gears, measured at point of tooth engagement; outlines development of nor- mal-pitch indicators.

' Measurement of the Thickness of Involute Gear Teeth, ALLAN H. CANDEE. Am Mach v68 n9, 11, 14 Mar 1, 15 and Apr 5 1928 p 365-8 463-7 573-6 12 figs. See abstract under Subsection 9.3. Constant Chord Gaging, S. TRIMBATH. Am Mach v73

n20 Nov 13 1930 p 769-793. Methods of sizing gear teeth by means of one pair of rolls or pins per pitch, and micrometers ; chart giving size for 1 diametral pitch gears with

seven different pressure angles. Pin Inspection of Tooth Profiles, S. TRIMBATH. Am

Mach v76 May 26 1932 p 673-4. Method of checking tooth form by measurement across pins placed between teeth

as two teeth contact with four involutes at same time, errors in tooth form caused by difference in pressure angle

will be amplified approximately four times by measuring

pins. Helical Gear Tooth Measurement. S. TRIMBATH. Am

Mach v76 Aug 31 1932 p 966-7. See abstract under subsection 9.3. Checks on Gear Tooth Accuracy, I. J. GRUENBERG. Am Mach v78 n3 Jan 31 1934 p 123-^1. Pin measurement

at constant chord is recommended for final inspection of spur and helical gears. Size Measurement of Gears, W. L. CHESLEY. Tool Engr v5 n9 Jan 1937 p 14-5. See abstract under subsection 9.3. Xeuartige Kopfkreisfreie Zahndicken-Messungen fur Schragzahnrader und Evolventen-Schnecken (Novel Method of Measuring Tooth Thickness for Involute Helical Gears and Involute Worms without Use of Addendum

Circle), W. F. VOGEL. Werkzeugmaschine v41 nil June

15 1937 p 253-61. See abstract under subsection 9.3. Ball Measurement of Helical Gears, A. ZAHORSKI. Am

Mach v83 nl4 July 12 1939 p 520-2. See abstract under

subsection 9.3. Pruefung von Kerbverzahnungen mittels Draehten (Testing of Stop Gears with Wires), H. ZOELLNER. Werkstattstechnik und Werksleiter v33 Nov 1 1939 p 503-5. Development of equation by which gears may be tested by

3-wire method.

Controle des Cannelures au Moyen de Goupilles Cylindri- ques (Checking Gear Size by Measurement Over Pins). Pratique des Industries Mecaniques v22 n4 Jan 1941 p

84-6. As applied to straight and involute flanks; deter- mination of tolerances. Measurement of Spur Gear Teeth, W. T. TAYLOR. Aero

Digest v49 n3 May 1 1945 p 90-3 150, charts on p 94-96. Over- or between-pin measurement of involute spur and

helical gears is employed to determine circular thickness

of gear teeth ; simplified involute function spur gear for- mulas for determining dimensions to center of measuring

pins and dimensions over or between pins, presented. Engineering of Involute Splines, G. L. McCAIN. Chrysler SAE Trans v54 1946 p 245 310. Wire measurements.

Selection of Measuring Rolls for 30-degree Involute

Splines, J. SILVAGI. Tool Engr v22 n2 Feb 1949 p 26-8. See abstract under 10.2.1. Position of Contacting Sphere Between Teeth of Helical Gear, N.J.C. PERES. Machy (London) v77 nl977 Sept 21 1950 p 324 1 fig. See abstract under subsection 9.3. Gauging Involute Teeth or Splines over Rolls, F. W.

HALIS. Machy (London) v78 n2012 June 7 1951 p 952-3. Formulas developed for checking external involute gears and involute splines by roll or wire method ; graph and

table for selection of roll diameter presented. On the Influence of Surface Deformations in Over-Pin and Over-Ball Measurements of Spur Teeth, B. W. CART- WRIGHT. Nov 25 1952 50 p 12 figs 5 refs. An essay submitted to the Graduate Council of Wayne State University in partial fulfillment of the requirements for the MS degree in the Dept of Mech. Eng. Subject headings

include : Methods of spur tooth measurements ; location and character of contact ; compressive stress and strain

in the contact of solids ; special equations adapted to tooth specifications and special relations for standard

thickness ; establishment of maximum micrometer force

permissible micrometer loads based on stress limitations

permissible micrometer loads based on deflection limita- tions ; conclusions ; appendix. Gears and Splines . . . Checking Pin Measurement Data,

J. SILVAGI. Tool Engr v35 nl July 1955 p 93-8. Five

double-check methods and associated formulas presented

checking methods are simple and accurate, and avoid

repitition of same type of error. Geometrische Probleme bei der Vermessung von zylindri- schen Evolventen-Schnecken und Evolventen Sehragstirnriidern ( Geometric Problems in the Measurement of cylin- drical involute worms and involute helical gears), M. GARY, PTB. Konstruktion v8 nlO 1956 p 412-8 2 figs 4 refs. See abstract under 9.3. Inspection of Fine-Pitch Gears. American Standard ASA

B6.11-1956 41 p 27 figs. Publ by ASME, New York. Section 8, Pin measurements of fine-pitch involute spur gears

contains 4 tables for external and internal 20° involute spur gears. American Standard Involute Splines, Serrations and In- spection. ASA B5.15-1960 108 p. Contains extensive data and tabulations relative to measurements over or between pins for space width and tooth thickness for in- volute serrations and splines and straight-sided serrations. Determination of Helical Gear Sizes by the Two-Roller Method, I. P. NEZHURIN. Russian Eng J v41 n8 1961 p

11-3 19 3 figs 2 refs. Translation pub by Product Eng

1957. See abstract under subsection 9.3. Computing the Displacement of the Initial Contour of Gears When They Are Checked" by Means of Balls, P. M. DANILYUK. Meas Techns 1960 n7 Feb 1961 p 585-6

2 figs. Translated from Izmer Tekh 1960 n7 p 25-6 July

1960. Measurement of spur gears by means of balls. Obtains an expression for the radius vector in checking gears

in both an even and odd number of teeth. Involute function tables are not required. New Equations Simplify Pin Measurement of Gears, J. H. GLOVER. Prod Eng v32 nil Mar 13 1961 p 80-1 4 figs 3 refs. See abstract under subsection 9.3. Vereinfachte Berechnung der Masse fuer die Messung

ueber Rollen bei Aussen- oder Innenverzahnungen mit Eingriffswinkel 20° (Simplified calculation of dimensions for measurements over rollers of external or internal gears with 20° angles of pressure) , H. BERGMANN. Werkstatt und Betrieb v94 n6 June 1961 p 341-9. Methods are de- 233
scribed and their application explained by diagrams, nu- merical tables, and examples. Measurements of Helical Gears with Pins or Balls, Analysis of Pitfalls and their Elimination, A. S. BEAM, C. E. HALL. AGMA 129.15 June 1962 7 figs 1 ref. See abstract under subsection 9.3, p. 212. Computation of Ball Diameters for Testing Gearing, P. M. DAN1LYUK. Meas Techns 1962 n5 Nov 1962 p 371-3

2 figs 8 refs. Translated from Izmer Tekh no May 1962 p 12-3. Describes methods of computing diameters of

balls and checking dimensions for all the cases encountered in testing involute spur gears. A table of involute functions is not required.

10.2.5. Tooth Index Position Measurement

See also subsections 6.1 and 6.4. For angular spacing

tables see subsection 10.1.3. A Scheme for Making the Universal Dividing Head Universal, W. A. WARMAN. Am Mach v25 May 15 1902 p

698-9. Sketches and description of a device that gives accuracy. A Hobbing Machine and Dividing-Head Tests, Am Mach

v31 Jan 2 1908 p 10-15. Illustrated description of how ac- curate worm wheels for dividing heads are hobbed in a

special machine and the heads afterward tested. Various

tests are illustrated. Die Prufung von Zahnradern auf Exzentrizitat und

Teilungsfehler (Examination of Gears as to Eccentricity and Error of Pitch), G. BERNDT. Maschinenbau v4 Dec

17 1925 p 1232-6 7 figs. Shows that usual methods of

testing by means of radially and tangentially displaceable cones or cylinders are of no advantage; radial displace- ment gives greater accuracy.

"Zeiss" Optical Dividing Head. Am Mach v65 July 1 1926 p 36. Obtains the division of the circle from a glass

dial mounted directly on the spindle carrying the work. Indexing Head for Highly Accurate Spacing, F. C. DUSTON". Machy (N.Y.) v36 nl Sept 1929 p 14-6 3 figs. Design of precision indexing head employed in making

accurate gears and perforated disks required for tele- vision equipment.

Precision Angular Work. Machy (London) v39 Jan 14 1932 p 493-500. Accurate master dividing plate made for 23 divisions, obtained by 23 individual ring sectors ; design and use of precision taper gage machining and assembling

operations. Notes on Testing of Workshop Dividing Head, F. H. ROLT, C. O. TAYLERSON. Machy (London) v51 nl311 Nov 25 1937 p 229-31. See abstract under 6.4. Compudex. Compudex Engineering Co., Chicago, 111. 1946 8 p. A computer to be used with indexing heads and

rotary tables. Indexes every number from 1 to 1100 and

every even number from 1100 to 2198. Effects of Alignment Errors in Dividing Heads, C. T. BUTLER. Machy (London) v83 n2144 Dec 18 1953 p

1211-4. See abstract under 6.4. Automatic Indexing Machine for Measuring Gear Tooth

Pitch Errors, C. TIMMS, C. A. SCOLES. Engr vl99 n5169 Feb 18 1955 p 229-31 ; Eng vl79 n4649 Mar 4 1955 p 271-4; Machy (London) v86 n2209 Mar 18 1955 p 597-

602. Tomlinson hob and gear measuring machine from

which automatic pitch testing machine has been de- veloped at Mechanical Engineering Research Laboratory, East Kilbride; it is largely pneumatically operated and functions entirely without presence of observer;

repetitive accuracy per cycle found to be of order of 0.000005 in. Before Brit Gear Mfrs Assn. How Auto-Collimators Measure Gear Errors, T. R. KNOWLES. Machy (N.Y.) v63 n4 Dec 1956 p 137^3; Machy (London) v90 n2312 Mar 8 1957 p 519-24 8 figs. Two Watts auto-collimators used in one of special weapons

laboratories of Northrop Aircraft measure directly errors

in gears and gear trains in seconds of arc ; errors caused by pitch circle eccentricity (runout) ; determining random

errors ; errors in gear trains. Line-of-Action Dontometer Inspects Spur Gears to plus or minus 1 sec of Arc, R. J. ROSS, J. P. WRIGHT. Am

Mach vl02 nl Jan 13 1958 p 113-7. Use of gear analyzer

at Sperry Gyroscope Co., Great Neck, NY for checking

ultra-precision spur gears to maximum permissible non- adjacent tooth spacing error, for entire active profile, to within 1 sec of arc ; design, construction and operation

of instrument. New Dividing Head, E. I. FINKEL'SHTEIN. Meas

Techns n3 Mar 1959 p 164-6 ( English translation of Izmer Tekh) see abstract under 6.4. World's Most Accurate Dividing Head. Vinco Corp., Detroit, Mich., Bui 56 1960 8 p figs. Vinco optical master

inspection dividing head was created in 1937. States

total index error at spindle or face plate as 2 seconds. States tolerances on spindle runout, spindle end face, and

surface plates ; available in several models. New Method of Testing Divided Circles, C. KUHNE. Rev.

Sci Instrum v31 n8 p 882-5 Aug 1960. See abstract under

6.4. Zur Messung der Kreisteilungsfehler an Zahnraedem und

Teilscheiben (Measurement of Errors in Circular Pitch Distribution of Gears), R. NOCH. Werkstattsitechnik v51

n3, 4 Mar 1961 p 142-7, Apr p 188-93. Problems of geometry, sources of errors and accuracy of measurements

description of measuring installations ; temperature

changes which occur and their influence on accuracy. 25

refs. Widening Applications of Radial Diffraction Gratings, W. H. P. LESLIE. Machy (London) v99 n2559 Nov 29

1961 p 1269-70. Reference made to application at National Engineering Laboratory, of gratings to measure- ment and subsequent reduction of errors in gear hobbing machine ; method is now used to apply overall correction betwen hob spindle and table; further application of radial gratings, now under active development at NEL

is for singleflank checking of gears. Abstract of paper

before 2d Internat Machine Tool Design and Res Conf, Manchester College of Science and Technology. New Road to Index Error Evaluation, H. R. RONAN, Jr. ASME-Paper 62-WA-39 for meeting Nov 25-30 1962 10 p. Index error measurement by theodolite system, graduated plate measurements, and pitch variation measure- ments; in making latter measurements, most important

observation is that quantity measured is actually differ- ence between two points on index error curve; use of Laplace transform is explained and illustrated by ex- amples ; in addition to providing means to index error

plots, analysis technique is suitable to major purpose of span and pitch variation checks, cyclic error analysis; comparison is made of pitch variation system and two

approaches in use. 10.2.6. Tooth Thickness, Pitch, and Span

Measurements

See Subsection 9.3 for tooth thickness measurement of

helical gears. See also subsection 10.2.4 for tooth thick- ness measurement. 234
A Micrometer Gear Tooth Gage. Am Mach v23 Aug 30

1900 p 842. Two micrometers at right angles to measure

tooth thickness at the pitch line. A Worm and Spiral Gear Tooth Gage, E. J. LEES. Am

Mach v26 June 18 1903 p 875-6. Illustrates and describes a gear tooth caliper provided with scales for measuring

circular pitch and normal pitch, and a protractor for reading the angle of the spiral. The Measurement of the Teeth of Gears, G. W. BURLEY.

Prac Engr Jan 16 1913. Describes the measurement by means of the gear-tooth caliper, giving formulas and

curves. Gaging Teeth of Involute Gears, H. E. TAYLOR. Am Mach v38 June 26 1913 p 1071-3. Makes use of vernier

calipers. Gives derivation of pertinent equations. ( Probably the earliest publication on span measurements of

involute gears. ) See table under subsection 10.1.3.5. Teilungsuntersuchung fur Zahnrader (Testing the In- dexing of Gears), F. GOPEL. Werkstattstechnik v7

1913 p 643 and 675; Zeit InstrumKde v34 Mar 1914 p

84-91 5 figs. A simple apparatus is described for the de- termination of the correctness of toothed wheels employed

in instruments of precision. The errors are plotted as diagrams showing the correction necessary at any point. Measurement of Gear Wheels with Ball Micrometer, W.

H. COWLIN. Machy via (London) Mar 11 1920. The Wickman Pitch Measuring Machine. Automobile Engr vlO Dec 1920 p 481 4 figs ; Am Mach v53 Dec 2 1920

p 1068a. Machine is designed to measure tooth spacing

at pitch line as well as concentricity of pitch circle with

bore. Recent Developments in Gauging Apparatus. Eng Prod

v2 Jan 13 1921 p 40-44 12 figs. Machines recently in- troduced by Alfred Herbert, Coventry, England, notably

gear pitch and concentricity measuring machine and uni- versal gage measuring machine. The Odontometer for Testing Gear Teeth. E. BUCKINGHAM. Machy (N.T.) v27 Julv 1921 p 1029-31

6 figs; Machy (London) vl8 July 7 1921 p 412-3 6 figs. Apparatus consists of section of straight-sided rack with two parallel effective faces, one being fixed and other movable. Third face, set at angle to two working faces,

is used to hold fixed working face in contact with flank

of gear tooth. Developed by Pratt and Whitney

Company. The Sykes Gear-Tooth Comparator. Eng vll2 July 15

1921 p 103 3 figs; Machy (London) vl8 July 14 1921 p

454-5 3 figs. Instrument consists of short bar fitted with

one fixed and one sliding jaw. arranged with needle of a

dial indicator between the two, and is used for comparison of thickness of gear teeth and uniformity of pitch. Pratt and Whitney Odontometers. Machy (N.Y.) v28 Aug 1922 p 1010-11 2 figs ; Iron Age vllO July 27 1922 p

204. Instrument for testing gear teeth for uniformity

of profiles and spacings. Odontometer for gears from % to 4 diametral pitch is shown in fig. 1. and from 10 to 24 diametral pitch in fig. 2. The Normal Chordal Thickness of a Worm Thread, A. FISHER. Machy (London) v20 Aug 10 1922 p 591-2 3

figs; Machy (London) v21 Oct 26 1922 p 118-9 4 figs. See abstracts under 9.3. Machine for Measuring Gear Teeth. Eng vll4 Sept 29

1922 p 410-1 9 figs. Describe machine by Vickers, for measuring errors in axial pitch and circumferential pitch

of helical pinions. The pinion to be tested rests on rollers, and alongside and parallel to it is arranged a

straight cylindrical shaft resting freely in vees and bear- ing an indicator. The Van West Portable Gear Tooth Testing Appliance. Eng vll5 Jan 19 1923 p 74. Simple and handy device for

testing the accuracy of the axial pitch of helical gear

teeth, and also the truth of the alinement of the pinions and wheels when in place. Normal Pitch as a Basic Factor in Computing Involute

Gears, E. SHELDON. Am Mach v58 Feb 22 1923 p 285-7. A factor based upon parallelism of involutes; does away

with many complications and takes account of profile er- rors as well as errors of spacing ; normal pitch easy to measure. Measuring Tooth Thickness of Involute Gear, E. VVILD- HABER. Am Mach v59 Oct 11, 1923 p 551-2 1 fig. New

method for involute spur gears which is not affected by

errors in outside diameter ; ordinary vernier caliper used

formula for standard measurement. Measuring Tooth Thickness of Helical Involute Gears.

E. WILDHABER. Am Mach v59 nl6 Oct 18 1923 p 587-8 2 figs. There are straight lines along involute surfaces having an inclination equal to the helix angle in the base

circle. For actual involute surfaces all of the straight contour lines of the teeth in any one gear are parallel and

equidistant. The tooth thickness of helical involute gears may be determined easily and accurately by measuring the distance between the straight contours of outside tooth

surfaces, using an ordinary vernier caliper. Zeiss Optical Gear Tooth Micrometer. Am Mach v59 Dec 27 1923 p 964. For direct reading of the chordal

thickness of the tooth at the pitch line, and the addendum.

In setting the jaws the tool is held close to the eye and

two clear scales, engraved on glass, are seen by looking through the small aperture at the center. The range is from 18 to 1V2 diametral pitch and graduations read to 0.001 in., estimating to 0.0001 in. Measuring Variations in the Pitch of Gear Teeth, G. A. LUERS. Machy (N.Y.) v30 June 1924 p 799-800. Indi- cating gage for testing the spacing of groups of gear teeth. Normal Pitch—the Index of Gear Performance, G. M. EATON. ASME Trans v47 paper 1973 1925 p 587-617 20 figs. Brings out certain departures from previously accepted practice which are useful in manufacture of heavy involute gearing, as they ease performance during

breaking-in stage of operation ; shows that material im- provement in performance may be secured by adopting proper relation between normal pitches of driving and

driven gears, measured at point of tooth engagement

outlines development of normal pitch indicators. Normal

pitch and chordal pitch indicators are illustrated. A Quick Method for Obtaining Gear Tooth Caliper Settings, H. WALKER. Machy (London) v29 Oct 7 1926 p 17 1 fig. Usual method of measuring size of gear tooth

is by means of calipers placed across tooth ; points of cali- pers touch tooth profiles where latter are intersected by

pitch line ; gives close approximate method for obtaining

correction for height of arc which renders reference to such tables unnecessary. Formulas for constant chord

gaging. Gleason Tooth-Spacing Tester. Machy (N.Y.) v33 Nov

1926 p 230 2 figs. Gears of any type can be conveniently checked for accuracy of tooth spacing by means of tester now being placed on market by Gleason Works, Rochester,

N.Y., which is equipped with optimeter, an optical device having scale graduated to 0.00005 in. Now Possible to Measure "Normal" Pitch of Involute Gear,

B. WHEELER. Automotive Industries v57 Aug 6 1927 p 186-90 17 figs. Instruments designed to gage distance 235
between corresponding involute contours on consecutive

teeth measured along line perpendicular or normal to contours. Detailed description of use of a normal pitch

indicator, which is provided with a locating leg. Measurement of the Thickness of Involute Gear Teeth,

A. H. CANDEE, Am Mach v68 Mar 15 and Apr 5 1928 p 463-7 7 figs and 573-6 2 figs. For abstract see subsection 9.3. Laying Out and Checking Involute Tooth Forms, F. W. SHAW. Machy (London) v35 Jan 2 1930 p 441-446 Jan

16 p 513-9 11 figs. Jan. 2 : How spur tooth forms can be

set out or checked by their coordinate dimensions ; fallacy

of proposition that Grant Odontograph for 15-deg. involute might be usable for 20-deg. involute if contour arcs as tabluated were described from centers on base circles corresponding to obliquity of 20 deg. Trigonometrical

functions and the involute function, inv 0, (although not

yet designated by that symbol, coined by Buckingham in 1928) are used in calculations based on numerical tables given (with examples) in the second article (Jan. 16). For details of these tables see abstracts in subsections

10.1.3.1 and 10.1.3.3, p 217 and 220. The span measurement

of involute spur teeth is covered in both articles but with- out the benefit of special numerical tables. A Simple Method of Determining the Tooth Thickness of Spur and Spiral Gears. J. W. HAYES. Machy (London)

v36 Apr 17 1930 p 69-71 2 figs. Discussion Machy (Lon- don) v36 May 29 1930 p 279. Method is not as universally applied to measuring of above types of gears as its simplicity merits ; it eliminates the necessity of using pins or

rollers placed in tooth spaces, and abolishes tedious cal- culations involved in ascertaining distance over rollers

disadvantages of roller method ; advantages of present method. Checking Gear Teeth for Smoother Operation, E. N. TWOGOOD. Machy (London) v36 Apr 17 1930 p 82-3

3 figs. Describes methods and fixtures used in checking

the concentricity and uniformity of spaces and thicknesses

of teeth. Constant Chord Gaging, W. A. J. CHAPMAN. Am Mach

v72 May 8 1930 p 753-4 3 figs ; v73 n7 Aug 7 p 250-2 3 figs. Constant-chord method differs from means of tooth meas- urement now in use solely in computations involved ; substitution of constant for variable measurements of gears

since pitch and pressure angle are uniform in set or train

of gears, whereas tooth number usually differs, measure- ments are greatly simplified by possibility of using con- stant dimensions for ehordal length and depth. The Involute as a Conic Section, F. W. SHAW. Machy

(London) v36 June 26 1930 p 405-8 and July 17 p 492-5

13 figs. June 26 : How involute functions ; points on producing involute; relationships between circular and

rectilinear movement in involute cams ; varying stroke of involute cam. July 17 : Description of method for rectify- ing involute and relation of arcs and sectors ; kinematics

of involute cam ; notes on involute as parabola. Sykes Model E Gear-Tooth Comparator. Am Mach v73

July 10 1930 p 70-1. This gear-tooth comparator uses the ehordal method and eliminates the necessity of having to use an instrument with two scales. The instrument is a development of the Sykes gear-tooth vernier caliper. Both

jaws of the instrument are movable, but the dial indicator spindle is stationary. In addition, the dial gage is ad- justable in the holder. Consequently, it is not necessary

to change the plunger or spindle of the dial gage for gaging

fine and coarse pitch gears. Constant Chord Gaging. Am Mach v73 n6 Aug 7 1930

p 250-2 4 figs. Summary of comments received on W. A.

J. Chapman's article published in Am Mach v72 p 753. V-jawed caliper can be used with existing gear tables;

gear-tooth vernier is proposed to use constant chord principle without special computations. Gear Cutter Comparator, F. W. SHAW. Am Mach v75 n22 Nov 26 1931 p 803 1 fig. Cutter rolls in relation to

steel tapes upon its base circle instead of upon its pitch

circle; pressure angle is zero and angle of testing rack

tooth zero; device utilized also for testing accuracy of tooth spacing. New Gear Tester. Automobile Engr v23 n307 June 1933 p 198. Design of S. I. P. optical gear tester evolved for measurement of inaccuracies in pitch and eccentricity. Messen von Zahndicken bei Stirnraedern (Measurement

of Tooth Thickness of Spur Gears), H. HEINSSEN.

Maschinenbau vl2 nl7-18 Sept 1933 p 454-5. Indirect method by measurement of difference between teeth with

aid of cylindrical gages ; example of application. New Machine for Measuring Normal Pitch of Gears. Machy (N.Y.) v40 n9 May 1934 p 545. Semiautomatic machine built by Illinois Tool Works, Chicago, 111., for rapid measurement or normal pitch and space of spur,

helical, worm or bevel gears. Pitch Measurement of Gears I and II, F. W. SHAW.

Mech Wld v98 n2549 and 2550 Nov 8 1935 p 451-2 and Nov 15 p 475-6. Possible errors, measurements that can

be taken, and instruments that can be used, offer more ways of attempting to check accuracy than are useful

problem analyzed and practical methods discussed. Contribution a l'Etude des Engrenages (Contribution to Study of Gears), RENAUDIN. Arts & Metiers nl91 Aug

1936 p 161-4. Outline of method for measurements of tooth thickness. Neuartige kopfkreisfreie Zahndicken-Messungen fuer Schraegzahnraeder und Evolventen-Schnecken (Novel Method of measuring tooth thickness for involute helical gears and involute worms without use of addendum cir- cle), W. F. VOGEL. Werkzeugmaschine v41 nil June 15. 1937 p 253-61. Theoretical mathematical analysis of methods and their application to ball and span measurements. Deals also with pertinent involute spur gear measurements. Bibliography. See detailed abstract in subsection 9.3. Zur Messung des Smnmenteilungsfehlei-B an Zahnraedern und Teilscheiben (Measurement of Error in Overall Cir- cular Pitch Distribution on Gears), K. BUERGER.

Werkstattstechnik und Werksleiter v31 nl8 Sept 15 1937 p 406-8. Outline of methods and description of new test- ing equipment. Zur Praxis der Zahndicken- und Lueckenweite-Messverfahren fuer Evolventen-Stirnraeder (Practical Hints and

Outline of Methods for Measurement of Tooth Thickness and Spacing Between Teeth of Involute Gears). K. BUERGER. Werkstattstechnik und Werksleiter v32 n7 Apr 1 1938 p 169-76, 10 figs. Contents : The classification of the different common measuring methods. The concept

of the effective tooth thickness (influence of the eccentricity errors). The necessary basic equations for the single measuring methods. Method la: Direct measurement of the tooth thickness as a chord of a circular segment. II Direct measurement of tooth thickness with notched measuring piece. Ilia and I lib Direct measurement of the

tooth spacing with inserted plug gages. IV Measurement

of tooth span. Results of investigation. Conclusions. The Chordal Gaging of Spur Gear Teeth, R. PARKES.

Machy (N.Y.) v45 n5 Jan 1939 p 326-7. Deals with span measurements for a given number of involute spur

teeth, diametral pitch, and pressure angle for control of backlash. Includes selector-table and table of span dimen- 236
sions for 1 DP. For details see summary table under

subsection 10.1.3.5. Checking Spur Gear Teeth, F. W. SHAW. Mach Wld

vl05 n2725 Mar 24 1939 p 289-91. Base tangent system

described; method (sometimes designated as "span measurement") obviates uncertainties attendant on use of or- dinary tooth vernier caliper; measurement is unaffected by differences in diameters of blanks or their eccentricity

or by wear in instrument.

Application of Involute Trigonometry to Gear Gauging,

F. W. SHAW. Machy (London) v55 nl427 Feb 1940 p

545-7. Complementing information contained in E. Buckingham's "Manual of Gear Design" (Machinery Publishing Co.), article aims mainly at facilitating calculation

of caliper measurement of gears by certain of systems

therein described ; Buckingham's notation employed, but some additions have been made ; theoretical mathematical

study. Improved Method of Measuring Thickness of Spur Gear

Teeth. R. OLDFIELD. Machy (London) v57 nl471 Dec

19 1940 p 321-3. Details of system of tooth measurement

which will eliminate disadvantages of gear tooth caliper method ; diagrams given. Constant Chord Gear-tooth Caliper Settings for Corrected Gears at Standard or Extended Centres, E. E. DAVIES.

Machy (London) v58 nl507 Aug 28 1941 p 595-9. Explanation of method of finding correction factor for gear

to be measured ; from this correction factor, corresponding gear tooth caliper settings can be obtained from tables which are given. Measuring Gear Tooth Thickness, C. A. YOUNG, Am Mach

v86 n7 Apr 2 1942 p 278-9. Simple method described, which avoids errors resulting from variation in gear dia- meters ; two rolls, T-bar and conventional gear tooth cal- iper used and calculation necessary can be made in draft- ing room. Method of Measuring Thickness of Helical Involute Gear

Teeth, J. RELMER. Machy (London) v64 nl639 Mar 9

1944 p 266-8. Checking tooth thickness of helical gears

by method of measuring across number of teeth ; method

is independent of outside diameter; it does not require

special measuring instruments ; it can be applied easily without removing gear from cutting machine ; faces of

gage, and not corners of edges, are used for measuring. Improved Gear Tooth Vernier. Passenger Transport J

v91 n2305 Sept 8 1944 p 219-30 ; Transport Wld v96 n3073

Sept 14 1944 p 226; Engr vl78 n4625 Sept 1 1944 p 170. Illustrated description of simplified type developed by David Brown & Sons ( Huddersfield ) Ltd. for span meas- urement ; instrument has advantage of only requiring set- ting to linear dimension between fixed and moving anvils ; measurements are over number of teeth and, as anvils arc tangent to tooth flanks definite "feel" is obtained as in using micrometer on cylindrical object, no height meas- urement being involved. Gauging of Involute Gear Teeth. Eng vl58 n4116 Dec 1 1944 p 426 ; Engr vl78 n4640 Dec 15 1944 p 479. Illustrated description of micrometer for checking tooth thickness

of spur or helical gears, developed by David Brown and

Sons, Huddersfield ; method is commonly known as base

tangent method.

Chordal Measurement of Corrected Gears, F. A. BIRCHER. Machy (London) v70 nl799 Apr 17 1947 p

399-401. Explanation of geometry of engagement of en- larged or reduced gears, and use of standard tables showing how appropriate table sizes may be adjusted to suit corrected gears. Le "Ve-Comparateur" pour le Controle de l'Epaisseur des Dentures ( V-Comparator for Control of Gear Tooth Thickness), J. BERGERE. Pratique Indus Mecaniques v30 n8, 10 Aug 1947 p 235-42, Oct p 303-11. Description of device and method which can be applied without removing gear from machine; practical applications to various types of gear. Measuring Chordal Dimension of Helical Involute Gears,

A. BUDNICK. Machy (London) v73 nl870 Aug 26 1948 p 314-6. Equations and application of method based on

characteristics of circular involute, that normals to tooth

flanks are tangent to base circle of gear; measurement is made over definite number of teeth, and gives sum of

integral number of pitches and thickness of one tooth, measured on line of action or on base circle. Checking Gear Tooth Thickness with Variable Center- Distance Gage, L. D. MARTIN, Machy (N.Y.) v 60 n2 Oct

1953 p 205-6. Span Measurement of Involute Gear Teeth, J. E. VAN

ACKER. Machy (London) v86 n2200, 2204 Jan 14 1955 p 66-73, Feb 11 p 292-7. Before AGMA. Span system

of measurement involves measurement over two or more

teeth, and possesses universal application and high degree

of accuracy ; formulas presented which are applicable to

all spur and helical gears of all proportions and under

all conditions of operation ; tables of involute and trigono- metric functions provided to facilitate span measurement

calculations ; worked out examples show use of formulas and tables. See also numerical details under subsection

10.1.3.5. Inspection of Cumulative Circular Pitch on High-Precision

Gears, J. LOXHAM. Inst Meeh Engrs (advance copy Aug 6, 1958). Describes Sigma gear measuring machine. Base-Tangent Measurement of Gear-Tooth Thickness, W.

A. TUPLIN. Machy (London) v94 n2424 Apr 29 1959 p

948-50. Basic dimensions of involute, spur and helical gears ; derivation of base tangent measurement over pins

or rollers of given diameter ; converse problems ; caliper

settings ; formulas are expressed in terms of lengths that are either given or can be calculated and no reference to trigonometric tables is necessary. Hoefler Electronic Inspection Equipment for Gears. Machy (London) v98 n2526 Apr 12 1961 p 829-31. Description of German-built EVZM measuring head set up

on Lieherr L. 3200 hobbing machine for checking large diameter helical gear for tooth thickness and concentricity ; measuring head, and others in Hoefler range, is in- tended to be connected to electronic base unit incorporating paper strip recorder ; equipment may be employed also for checking spur gears, worms, bevel gears, and racks, for

pitch accuracy. Datchik dlya kontrolya izmeritel'nogo mezhtsentrovogo

rasstoyaniya na odnom zube (Gage for Checking Measured

Center Distance Over 1 Gear Tooth), I. V. MAZURENKO.

Stanki i Instrument n9 Sept 1962 p 19-21 ; see also English

translation in Machines & Tooling v33 n9 1962 p 22-5. Gage and electric circuit described are suitable for auto- mating inspection of center distance variations over 1 gear

tooth ; rejection errors during tests on gage did not exceed

plus or minus 3 /t; consequently, gage is suitable for inspecting gears with accuracy not exceeding 7th Class. 237
10.3. Bevel, Hypoid, Spiroid, and Worm Gears or Drives

For measurement of worms see also subsections 9.2, 9.3 and 9.4. German Bevel Gear Testing Device. Machy (N.Y.) vl4 Feb 1908 p 377. Protractor for testing the accuracy with which the teeth of bevel gears are cut. Comprises two

pivoted arms which are provided with sliding blocks carrying pivots on which are mounted the gears to be

tested. Testing Spur and Bevel Gearing. Internal Combustion Eng Oct 16 1912 p 341 4 figs. British machine by Parkinson and Sons in which bevel gear and pinion are run

together and errors are recorded on a chart. Making and Testing Bevel Driving Gears. Am Mach v38 June 5 1913 p 945-52 12 figs. Method of the White Co. on

large bevel driving gear of rear axle. Testing of parallelism of front and back faces is shown in fig. 7. Device

is an indicating fixture having a row of balls in a hori- zontal race just large enough in diameter to support the gear by its outer edge. Fig. 8 shows a fixture for testing tooth bearing of mating bevel gears. Fig 9 shows testing spur gears on bench centers with an indicating surface

gage. The Testing of Worms and Worm Wheels. Mech Engr Nov 14 1913. Illustrated description of apparatus designed by Percy Brown and Francis J. Bostock for the purpose

of ascertaining the accuracy of worms and worm wheels. Spur and Bevel Gear Testing Machine at the National

Physical Laboratory, T. E. STANTON. Eng vl09 Mar 12 1920 p 334-5 7 figs. Describes Daimler-Lanchester wormgear testing machine for direct measurement of ratio of torque of driving and driven shafts. Chordal Thickness of Tooth and Corrected Pitch Depth

of Bevel Gears, C. W. MAPES. Machy (N.Y.) v27 Oct

1920 p 169-70 1 fig. Diagram showing dimensions and

angles used in determining chordal thickness and corrected

pitch depth of bevel gear teeth. Testing the Accuracy of Teeth of Bevel Gears (Messrs, Saurer). Machy (London) vl8 1921 p 717. The Saurer Bevel Gear Testing Machine. Eng vll3 Feb 24 1922 p 228-9 9 figs. Bed of machine is heavy, cir- cular casting, upon which a pair of sliding heads can be

locked in any position, so that angle between axes of heads

corresponds to that of bevels to be tested, a range from 52

to 150 deg. being obtainable. The Normal Thickness of a Worm Thread, E. A. LIMMING. Machy (London) v20 Sept 7 1922 p 707-8 1

fig. ; v21 Dec 21 1922 p 360-2 4 figs. Apr 21 p 114 ; May 10 p

191 ; July 12 p 475 and Sept 20 p 795. See abstracts under

9.3. The Normal Chordal Thickness of a Worm Thread, A. FISHER. Machy (London) v21 Oct 26 1922 p 118-9 4

figs. Points out that problem of determining normal is not same as determining minimum chordal thickness, and

that common term, normal thickness, appears to have dif- ferent interpretations. Dial Gage Device Used with Success to Test Spiral Bevel

Gears, P. M. HELDT. Automotive Indus v48 May 17 1923 p 1088-9 4 figs. Machine developed to determine in- accuracy of tooth outline and errors of indexing adapted

to check correctness of curvature. Double Helical Bevel Gear-Testing Jig. Machy (London)

v23 Feb 28 1924 p 711 3 figs. Special jig for testing both

accuracy and truth of apex in double helical bevel wheels, as used in automobile back-axle drives. Testing and Adjusting Spiral Bevel Gear Drives for Automobiles. Am Mach v61 Nov 27 1924 p 848-9 14 figs. Printed by permission of The Gleason Works, Rochester, N.Y. Worm Gear Inspection and Testing, G. H. ACKER. Auto- motive Indus v57 Oct 29 1927 p 662-3 1 fig. Potential sources of error in worm gearing that must be guarded

against by suitable inspection are: eccentricity and cor- rect sizing of worm, index, lead, and profile of worm

thread, angle of gear, eccentricity of gear and silence. Gleason 90-Inch Bevel Gear Testing Machine. Am Mach

v67 Dec 1 1927 p 882 ; Machy (N.Y.) v34 Dec 1927 p 311 1

fig. ; Iron Age vl20 Dec 1 1927 p 1522 1 fig. Machine for

testing for quietness and proper tooth bearing of bevel gears up to 90-in. diameter. The machine is driven by

10 h.p. motor mounted on the drive head, and the spindle may be revolved in either direction. A friction brake on

the driven spindle permits testing the gears under load. Gleason Combination Lapping and Testing Machine. Machy (N.Y.) v35 Dec 1928 p 303 1 fig. Details of 18-in. combination testing and lapping machine developed by

Gleason Works, Rochester, for use in production of

spiral-bevel and hypoid gears ; gears are first tested in

this machine after being cut, to determine tooth bearing

after hardening, they are again tested, both for bearing and noise ; brake on gear or driven head enables gears to be tested under load. Gleason 3-In. Bevel Gear Testing Machine. Am Mach v73 Aug 21 1930 p 335-6. This machine is designed to test running qualities of straight and spiral bevel gears of smaller sizes whose shafts intersect at 90 deg. Bevel

gears are tested by running them together in pairs or with

a reference gear, to check the cutting machine for cor- rect set-up. Gears are also tested after hardening for both tooth bearing and noise, and to determine if the heat-treatment has made changes that must be compensated for in cutting. Gears can be tested with or without

load as desired. The pinion spindle is power-driven, and

is operated in either direction by push button control. The pinion head is adjustable horizontally on the frame

Gleason 18-in. Hydraulically Operated Testing and Lapping Machine. Am Mach v73 Oct 16 1930 p 642-3. Both

spiral bevel and hypoid gears can be tested and lapped on this 18-in. machine. After the gears are placed on the

spindles, the machine is entirely automatic in operation.

It is hydraulically operated, and the automatic features and timing are electrically controlled. The automatic

control mechanism reverses the direction of rotation of the gears after a predetermined length of time. Time of lapping may be adjusted from 30 sec. to 33 min. per side, and the total time may be varied. The driven head is mounted on a column adjustable horizontally on the frame. This driven head has a vertical adjustment also to permit lapping hypoids. An adjustable back-lash brake, operating on the gear spindle, is provided to maintain an

even load during lapping. Gleason No. 13 Universal Gear Testing Machine. Am

Mach v73 Dec 4 1930 p 903. Straight and spiral hevels with any shaft angle, hypoids, helicals, angular helicals, internal, herringbone and spur gears can all be tested on

the No. 13 universal testing machine. The driver or

pinion spindle can be run in either direction. It is mounted on a head which can be adjusted vertically. The gear or drive head has three adjustments. Specifi- cations : Capacity, 13 in., range of off-set, above center | 8 in., below center 2 in. ; max. center distance for spurs, 238
worms, and worm-wheels, 8 in. ; minimum and maximum

position of nose of drive spindle from cone center of gear

to be tested, 4 and 10 in. ; minimum and maximum posi- tions of nose of brake spindle from cone center of gear

to be tested —5 and +10 in., and net weight 3,500 lbs. Accuracy in Gaging Gears. J. v74 Feb 19 1931 p 325-7 8 figs, methods of determinin;

. POTTER. Am Mach

Detailed description of depth of tooth at pitch line of

spur, bevel, and helical gears by means of a micrometer

having a conical measuring contact. Also illustrates a

bevel-gear measuring device which uses a dial indicator with sine-bar angle adjustment.

Schranbgetriebe, ihre mogliche und ihre zweckmassigste

Ausbildung (Screw Drives, Their Possibilities and Their Most Suitable Development), F. G. ALTMANN. VDI

Verlag GMBH Berlin NW7 1932 30p 73figs 36 refs. See

abstract in subsection 10.1.2, p. 215. Compiler's comment: This paper contains the most complete bibliography on worm gear drives to an inel. 1932. Zeiss Gear Testing Machine. Am Mach v76 p 218 Feb 11 1932 2 p 5 illus. Measuring precision to 0.0001" combined

with rapid operation are features of this instrument. The gear tester will take spur, bevel, helical, and worm

gears and test the following elements ; Circular pitch,

eccentricity, uniformity of tooth spaces, and uniformity

of tooth thickness. The gear is placed between centers, where it can be revolved to bring successive teeth into

position. Analytische Untersuchung des zylindrischen Schneckentriebes mit gerader, die Achse Schneidender Erzeugender

i Analytical Investigation of Cylindrical Worm Drive with

Straight, Axial Worm Profile), W. F. VOGEL. Omnitypie-Gesellschaft, Stuttgart 1933. See abstract in subsection 10.1.2, p. 215. Eins neues Messgeraet fuer Waelzfraeser (New Measuring Gage for Worm Hob Milling Cutters) . A. FIESELER.

Werkstattsteehnik und Werksleiter v29 n 14 July 15 1935

p 276-8. Equipment and its application for measurement

of profile of pitch, circular pitch and testing of cutting

face.

1 Gauging of Worm-Gears, N. CUMBERLAND. Machy

(London) v60 nl536 Mar 19 1942 p 218-9. Description

of gage fixture in which component is held between centers, one fixed and other adjustable in use, work is placed between centers and roller or plug is passed between teeth

J of work and pad.

' Messeinrichtungen fuer den Austauschbau von Kegelraedern mit geraden Zaehnen. (Measuring Equipment for Interchangeable Manufacture of Bevel Gears with

Straight Teeth.) G. APITZ. VDI Zeit v87 n23/24 June

12 1943 p 366-7. Recommendations made for selection and operation of apparatus for this purpose.

Basic Relationships of Bevel Gears, E. WILDHABER.

" Am Mach v89 n20 21 22 Sept 27 1945 p 99-102, Oct 11

P 118-21, Oct 25 p 122-5. Analysis of bevel gear relation- -hips : characteristics, as compared to spur gears ; review

J !|of basic bevel gear formulas; gear generating principles

discussed. Oct 11 : Observation of tooth normals in pro- viding relative curvature analysis for estimating load

capacity of gear tooth surfaces. Oct 25 : Special analysis

'•t gear mesh for clarifying curvature conditions of spiral bevel gears wherein individual curvature radii at all points of line of contact are immediately apparent. Basic Relationship of Hypoid Gears, E. WILDHABER. Am Mach v90 n4 5 6 12 13 15 16 17 Feb 14 1946 p

108-11, Feb 28 p 131^, Mar 14 p 132-5, June 6 p 110-4, June 20 p 150-2, July 18 p 106-10, Aug 1 p 104-6, Aug 15 p 122-8. Feb 14: Relative motion, kinematic pitch

angles, relative translation and direction of instantaneous

axis and instantaneous turning motion about it, con- sidered and determined by geometrical calculations pointed out. Feb 28 : Required pressure angles for bal- anced tooth action indicated. Mar 14: Generation of hypoid pairs ; helical segment formulas. June 6 : Discussion of tooth contact and development of method for

finding required tooth profile curvature. June 20 : Conjugate action of hypoid gears, and its effect on their capacity explained. July 18: Gear tooth sliding. Aug 1: Screw hypoid gears. Aug 15 : Design for duplex cutting

formulas ; examples.

Universal Worm Gear Testing Machine. Engr vl84 n4788

Oct 31 1947 p 418 ; Eng vl64 n4269 Nov 21 1947 p 488 • Automobile Engr v38 n499 Mar 1948 p 117-8. Illustrated description of new machine being made by David Brown

Tool Co. to provide accurate yet rapid means of checking

all dimensions upon which performance and interchangeability of worm depends, and for testing finished wheels

in conjunction with master worm.

Pruefen und Tolerieren bei der Fertigung von Getriebe- schnecken (Testing and Gaging in Worm Gear Manufacture), H. M. HIERSIG. Werkstatt und Betrieb v81 n9 Sept 1948 p 242-7. Measurement of errors in profile, pitch and eccentricity ; accuracy conditions for inter- changeability, grinding of involute profiles by shaped and flat wheels ; pitch errors more important than tooth thickness errors ; backlash between worm teeth and wheel must be greater than in cylindrical wheels ; diagrammatic

drawings. Pin Measurement of Face Gears, J. SILVAGI, V. FRANCIS. Am Mach v96 May 12, 1952 p 183-7 4 figs

Van Keuren Catalog and Handb n36 1955 p 248-50 2 figs. See abstract under 10.1.4. Beveloid Gearing, A. S. BEAM, Mach Design v26 Dec 1954 p 220 (15 p) 23 figs 2 refs. The beveloid gear is an in- volute gear with tapered tooth thickness and, in most cases, tapered outside diameter. All sections normal to the axis have a common base-circle diameter and thus the same

involutes, but the tooth thickness at any diameter in- creases linearly from the front to the back faces of the

gear. Beveloid gears represent the most general form of involute gearing, and they can be engaged with spur gears,

helical gears, worms, racks, and other beveloid gears. They can be used with parallel, intersecting, or skew

shafts and offer advantages in precision, versatility, and

backlash control not previously anticipated. Compiler's comment: Beveloid Gears have been known as Conical

Involute Gears (Merritt 1955 and earlier editions, see subsection 10.1.2), but were exclusively proposed for meshing with each other in parallel-axes gearing with the purpose of eliminating backlash. Only for this type of mutual axis arrangement will beveloid gears yield line- contact. The Mathematical Background of Spiroid Gears, O. SAARI. Industrial Mathematics, Detroit, v7 1956 9 figs. Spiroid gears are considered as a generalized form of worm gearing. Develops the general first-order gear

tooth action law and its application to skew-axis gear

design. Design of Worm and Spiral Gears, E. BUCKINGHAM,

H. H. RYFFEL. Industrial Press, New York 1960 450 p

figs tables. Provides (1) a step-by-step guide to the de- sign of worm and spiral gear drives ( crossed-axes helical gears) with all-recess action and (2) presents certain basic principles and practices which enter into the suc- cessful design and manufacture of gears and gear drives

of several types. Chapter 1 deals specifically with worm

gear geometry.

Inspection of the Common Normal Generating Lines of Sraight Bevel Gears. P. M. DANILYUK. Meas Techn

1958 n6 Mar 1960 p 633-8 5 figs. Translated from Izmer 239
Tekh n6 Nov-Dec 1958 p 18. New method of common nor- mal checking, eliminating need for teeth faces to make

contact with fiat surface of measuring device, which re- duces accuracy of conventional methods by indirect in- spection of tooth thickness of spur gears ; suggested meth- od is suitable for measuring various types of small, medium

and large module gears. Checking Thickness of Straight-Tooth Bevel Gear Teeth By Their Edges, P. M. DANILYUK. Meas Techn 1960 nl Nov 1960 p 17-9 3 figs 2 refs. Translated from Izmer Tekh

nl 1960 p 14. Theoretical basis of new method-of checking

size of straight bevel gear teeth by using balls which run

over their edges and measuring distance between extreme

points of two balls, inserted into diametrically opposite

tooth spaces of gear wheel, these spaces being formed by

crossing of side bevel surfaces with additional external

bevel surface. Goulder Testing Machines for Worms and Worm-Wheels. Machy (London) v98 n2537 June 28 1961 p 1473-5. Three

machines described ; type 2H "long bed" lead tester for worms up to 8 in. diam, with integral shafts up to 54 in. long ; No. 3 testing machine for large-diameter hobs and worms ; No. 4/3 machine specially designed for checking worm drives which have wheels ranging from 3 to 48 in. diam ; light- and heavy-duty saddles are provided which

are brought into use as required, according to size of worm

gears to be tested. Mesure de L'Epaisseur de Dent des Dentures D'Engrenages

coniques droits (Measurement of Tooth Thickness of Straight Bevel Gears), H. L. DEBY. Rev M v8 nl 1962 p 1-6. How method used for cylindrical gears may be extended to bevel gears by changing one term in formula.

Narezanie vysokokaehestvennykh konicheskikh zubcha- tykh koles na stankakh mod. 5A27S3 i 5A27S4 (Cutting high quality bevel gears on model 5A27S3 and 5A27S4

machines), N. F. KABATOV. Stanki i Instrument nt4 Apr

1962 p 12-18 ; see also English translation in Machines &

Tooling v33 n4 1962 p 14-20. Machine setting calculations are given on which jobbing method developed by W.

Gleason is based, and that insures reliable cheek of width, height and inclination of field of contact when cutting

spiral bevel gears with teeth reducing in depth ; gear and

pinion are cut by cutters with alternating teeth, and having number of teeth considerably greater than calculated number. Mesure de l'epaisseur de dent des dentures d'engrenages

coniques droits (Measurement of tooth thickness of straight bevel gears), H. L. DEBY. Rev M v49 n4 1963 p 156-62. Reference is made to description of method in author's article indexed in Engineering Index 1963 p 804

tables are presented which make it possible to eliminate

all complex calculations, thereby considerably facilitating application of this method. Wormgear Standardization Envisages, W. A. TUPLIN.

Engr v215 n5603 June 14 1963 p 1066-9. Recently published

Brit Standard Specification for Worm Gearing (BS 721, 1963) is considered in relation to worm gear design with

regard to both form and dimensions, and in relation to earlier standards; advance made in present standard in defining worm-thread form in terms of basic rack of B.S. 436 is especially mentioned, but it is also noted that worms

of "preferred" and "second-choice" dimensions have 5600

different normal pitches. Addendum to Section 10

10.1.1. Standards and Nomenclature

Die DIN-Verzahnungstoleranzen und ihre Anwendung

(The DIN Gear Tolerances and their Application), G. APITZ, A. BUDNICK, K. KECK, W. KRUMME, H. K. HELLMICH. Friedr. Vieweg und Sohn, Braunschweig

4th ed 1960 31 p 25 refs plus 13 illus and DIN 3960 to 3964 and 3967. No. 13 of series of publications issued by Fachgemeinschaft Getriebe und Antriebselemente im

Verein Deutscher Maschinenbau-Anstalten. Contents: The economic significance of gear tolerance systems. Construction of the DIN-tolerance system. Gear qualities

in reference to transmission capability, quietness, and

accuracy of form. Gear qualities in reference to cost of manufacture. Influences of the gear fits : tooth thickness, tooth space, and axial distance. Establishment of the

quality and gear matching. Calculation of general toler- ance specifications in the DIN-System specifications. Relationship between tolerances and production processes. Comparison of the German standards for gear tolerances with those of other countries. Glossary. 10.2.5. Tooth Index Position Measurement

Gear Inspection, J. F. JONES, Jr. AGMA 129.15 June

1962 15p 19 figs. Fellows No. 8 tooth index measuring

instrument is illustarted in Figs. 1 to 5. It is stated that

the recording system in the machine has sufficient sensitivity and magnification to provide indications to 0.00001

in. The chart produced by the machine has graduations which can be calibrated to 0.000010 in. and obviously estimating is possible.

240
Section 11. Measurement of Thickness of Thin Films

CONTENTS

Page

11.1. Interferometric methods 241

11.2. Polarimetric methods (ellipsometry) 247

11.3. Miscellaneous methods 249 Addendum to Section 11 255

11.1. Interferometric Methods

Optisehe Experiniental-Untersuchen ; ueber Newton'sehe

Farbenringe und totale Reflexion des Lichtes bei Metallen

(Optical Experimental Investigations; Regarding Newton's Colored Rings and Total Reflection of the Light by

Metals) G. QUINCKE. Ann der Phys und Cheniie vl29 n2 1866 p 177-218 6 figs. To determine the thickness of a metal layer on a plane glass plate the author applied two

different methods, both of which are based on the obser- vation of Newton's rings. Experimental results using

silver and gold are given. Ueber die Bestimmung der Constanten ftir die Absorption

des Lichts in Metallischen Silber (Regarding the Deter- mination of the Constants for the Absorption of Light in Metallic Silver). W. WERNICKE. Ann der Phys und

Chemie 2ser v8 nl 1878 p 65-82 5 refs. Deals with the production of plane-parallel layers of silver, measure- ment of the absorbed light, and determination of the thickness of the thin layers, by interference methods. Ueber die Phasenanderung des Lichtes bei der Reflexion und Methoden zur Dickenbestimmung diinner Blattehen (Regarding the Phase Change of Light by Reflection and

Methods for Determination of Thickness of Thin La- minae), O. WIENER. Ann der Physik und Chemie 3ser v31 n8 1887 p 629-72 13 figs. Discusses previous methods

of Quincke and Wernicke for thickness determination of

thin laminae in general. Develops new methods for both

metallic and nonmetallic laminae. Investigates questions

as to whether phase change at perpendicular reflection is a

1 retardation or acceleration. Evaluates interference method and determines relation of thickness and color to the amount of phase change. Describes more accurate

experiments. Draws five conclusions. Ueber die Phasenanderung des Lichtes bei der Reflexion an Metallen (Regarding the Phase Change of Light by the

Reflection on Metals), P. DRUDE. Ann der Phys und

Chemie 3ser v50 nl2 1893 p 595-624, vol 1894 p 77-104 6

figs. See abstract in subsection 2.2.5. Ueber normale und anomale Phasenanderung bei der Reflexion des Lichtes an Metallen (Regarding Normal and Anomalous Phase Changes with the Reflection of Light by Metals), W. WERNICKE, Ann der Phys und Chemie

3ser v51 n3 1894 p448-59 6 figs. See abstract in subsection 2.2.5. Ein einfaches Interferometer zur Messung kleiner Schicht- dicken ( Simple Interferometer for Measuring Small Layer

Thickness), H. FROMHERZ, W. MENSCHICK. Zeit Phys Chem v2 abt B Apr 1929 p 399-404 2 figs. Apparatus and method of operation are described ; layer thicknesses

of 2 flat bulbs of about 10 and 50 microns thickness were measured to.0.2 per cent. Silica Gauge for Measuring Thickness by Means of Inter- ference Colors, K. B. BLODGETT. Rev Sci Instrum vl2 nl Jan 1941 p 10-4. Details of construction of gages for measuring thickness of monomolecular films by means of interference of light ; monolayers of various substances can

be deposited on top of silica film, and thickness of monolayer determined from change in intensity of reflected light produced by added thickness ; equations are given for calculating thickness. Measurement of Thickness of Thin Films, A. F. GUNN,

R. A. SCOTT. Nature (London) vl58 p 621 Nov 2 1946. Tolansky's technique was used to measure the "step" at the edge of films of collodion, silica and gold of thickness

of 100A and above, supported on a smooth glass plate

(e.g. lantern slide cover). Discussion by K. W. PLESS- NER, Nature (London) vl58 Dec 21 1946 p 915 1 fig 2 refs. Interferometric Determination of Apparent Thickness of Coatings, W. K. DONALDSON, A. KHAMSAVI. Nature

(London) vl59 Feb 15 1947 p 228-9 1 fig 6 refs. Describes

techniques for depositing film on a high-grade flat and

using the reflected film system for measuring thickness. Coating Thickness Measurement by Interferometry, M. F. BECHTOLD. J Opt Soc Am v37 Oct 1947 p 873-8. Thickness measurements of thin transparent coatings on thick transparent bases by reflection interferometry are made

possible through use of an immersion medium of the same

refractive index as the base to intensify interference. A

convenient interferometer comprising three essential parts, a "pocket" spectroscope, an incandescent lamp and a

cylindrical immersion tank, is described. Its use for rapid, precise measurements of thickness of single and double

layer coatings and films in the range of 0.2 to 50^ is illustrated with spectra. Thickness of Inhibiting Films on Glass Electrode Surfaces, D. HUBBARD, G. F. RYNDERS. J Res NBS v41 Sept 1948 p 163-8. The thickness of voltage-inhibiting films produced on glass surfaces by heat treatment after leach- ing has been studied by means of the glass electrode and

the interferometer. The glass electrode gave conspicuous

voltage departures (errors) and alternations (swelling)

of the surface that were just detectable by the interferometer. This corresponds to approximately 0.01 fringe, or 4X the unit cell dimension for cristobalite. The inhibiting

effect of films of electric conductors, such as metallic Ag, has been qualitatively compared with the inhibiting effect of films prepared from electric non-conductors, such as petrolatum and silicone stopcock grease. 241
Interferometric Determination of the Apparent Thickness

of Thin Metallic Films, D. G. AVERY. Letter in Nature

(London) vl63 June 11 1949 p 916. In connection with

the method for determining film thickness by depositing an opaque reflecting layer over the edge of the film and

then (interferometrically ) measuring the step, evidence

is presented showing that there is a "paeking-in" effect. Presumably this is due to filling up of the interstices in the film. It is suggested that use of this method may lead

to errors of up to 30%.

Interferometric Evaluation of Thicknesses of Thin Films,

S. TOLANSKY. J Phys Radium vll July 1950 p 373-4. A study is made of the validity of the multiple-beam in- terferometric method for measuring the thickness of thin

films. For a Ag film the deposit is made to cover part of an optical flat, and over this is evaporated a much thicker metal film. The step height is measured interferometrically. It is shown that the height measured is affected by

the nature of the superposed metal. When Ag is super- posed on an Ag film the final step value found is 25% less than that when Cr is deposited on an Ag film. The effect

is considered to be due to bedding in of the superposed

film on to the porous thin film. Studies are made with in- termediate films of cryolite and MgF2 . Interferometric Method for Accurate Thickness Measure- ments of Thin Evaporated Films, L. G. SCHULZ. J Opt

Soc Am v40 nlO Oct 1950 p 690-2. Fabry-Perot interfer- ometer used directly to measure thickness of uniform thin

films to accuracy of ±15A ; separation of D-lines of so- dium light used as standard of length ; method evaluated by comparison with other methods and in terms of appli- cations and limitations. The arrangement for the Measurement of Small Film

Thicknesses, G. C. MONCH. Optik v8 nl2 1951 p 550-60

in German. A description is given of optical arrange- ments for measuring thin film thicknesses by making use

of the interference double prism of Rosters. Methods are

described whereby the thicknesses of evaporated metal

films and also of thin celluloid films and varnish films can

be made. Full constructional details are supplied for the mounting. Measurements can be made with white light or with monochromatic light. The Investigation of "Thick" Metal Films and Their Surface Layers With the Aid of the Absolute Phases, H. SCHOPPER. Zeit Phys vl30 n4 1951 p 427-44 in German. A method is described for the determination of the re- fractive index within metal layers and by this means the

refractive index for Ag is found to be 0.11 for the green Hg line. In addition the thickness of the transition layer between the metal and support of the surface film on the

air side are evaluated. The surface layer can be followed down to thickness of only a few molecules. The method

described is an interference method using slits. Data are

reported for Ag on quartz and for silver-iodide surface

layers. Some Applications of Interferometry to the Examination

of an Electrodeposited Film, S. TOLANSKY. J Eleetro- depos Tech Soc v27 Paper 6 1951 8 p. Multiplebeam in- terference methods are applied to the examination of bright tin-nickel electrodeposit on polished brass. It is shown by precision interferometry that the electrodeposit contours surface irregularities as small as 1 micro-inch, although the deposit is thick as 200 micro-inches. The

thickness of the deposit can be measured by the fringes to within 1 micro-inch by visual inspection alone. Some

hardness micro-indentation tests are reported using a Vickers pyramid. Although the pyramid penetrates the deposited film yet an apparent increase in surface hardness is found. The Effect of Phase Changes in White Light Inter- ferometry, L. G. SCHULZ. J Opt Soc Am v41 Apr 1951

p 261-4. The phase change accompanying the reflection of white light from metal films was studied experimentally by interferometric methods. As predicted by electro- magnetic theory, the phase change was found to vary with

the wavelength of light. Corrections for this variation must be made in white light multiple-beam interferometry

if the full sensitivity of the method is to be used in making thickness measurements. Practical suggestions are given for making the required corrections. It is demonstrated experimentally and theoretically that these corrections are practically independent of the film thickness. Precise measurements of phase changes on Ag films gave results closely consistent with those calculated from

published values of the optical constants of Ag. No

such agreement was found for Al. Measurement of Thickness of Thin Films by Multiple- beam Interferometry, O. S. HEAVENS. Phys Soc-Proc v64 pt5 n377B May 1 1951 p 419-25. Study of measure- ments of thin films by multiple beam Fizeau fringes in order to assess accuracy attainable ; application of method

to examination of small scale irregularities on surfaces

of glass plates and flats used in thickness determinations ; measurements of films of lithium fluoride and of silver using five different metals as reflecting layers. The re- sults for the different reflecting layers show agreement to within the observational error provided that measure- ments are made within a short time of the preparation

of the film. With Ag as the reflecting layer an accuracy

of ±10 A can be expected if suitable precautions are

taken. Bibliography. The Measurement of Thin Film Thickness hy Inter- ferometry, S. TOLANSKY. Letter in J Opt Soc Am v41 June 1951 p 425-6. A critical analysis of a method re- cently proposed by Schulz for measuring thin film thick- ness by a Fabry-Perot interference method. A number

of optical defects are pointed out. These apply mainly

if the method is used in transmission with thin metal

films. A number of the objections raised do not apply if measurements are made on dielectric films, or on metal

films using reflection instead of transmission methods.

Interferometer for Thickness Measurement of Thin

Transparent Film, N. SIDJAK. Can J Technol v29 n7

July 1951 p 362-70. Interferometer described ; measure- ment involving only counting of dark interference bands

in continuous spectrum is particularly suited to measure- ment of mica and other thin transparent materials used

for windows on counters and apparatus employed in work on radioactive substances. The Interference of Thin Films and the Estimation of Their Thickness, G. C. MONCH. Optik v9 n2 1952 p 75-83

in German. A rapid estimation of the thickness of thin films from interference Colours is described. A

simple interferometric system involving slits permits the approximate thickness to be derived from the table of interference colours given. The table is calibrated by means of altering the angle of inclination of the light on

the thin film. Interference colours are given for films of thickness from 0-900 A. There is a good deal of ob- jective judgment required in estimating the colours. Measurement of Thickness of Microscopic Objects Using Three-Beam Interference, B. MENZEL. Note in Naturwiss

v39 nl7 1952 p 398-9 in German. A microscope modifica- tion of a technique formerly described, wherein the thick- ness of a thin object is obtained from change in localization of fringes produced by three slits. A microscopic reduced image of the three slits is projected on to the small object, on the microscope stage and by observing changes in localization of fringes with beams going through and missing the microscopic object, thicknesses can be measured as small as 100 A units. The Limit of Accuracy in the Measurement of the Thickness of a Thin Film Using the Kosters Interference Double 242
Prism, U. ZORLL. Optik v9 nlO 1952 p 449-55 in Ger- man. An arrangement permitting the application of photometric methods is described. Fringe width is nar- rowed by multi-photographic copying and this permits an

accurate measurement of fringe separation. Three photo- metric methods of evaluating displacements are described. The method permits the measurement of the thickness of

deposited thin films. A square centimetre film can be measured with the thickness down to about 20 m/i. A Discussion on Friction : An Optical Method of Measuring the Thickness of Adsorbed Monolayers. J. S. COURTNEY-PRATT. Proc Roy Soc A v212 May 22 1952 p 505-8. The interferometric techniques developed by Tolansky have been used to study films adsorbed on solid surfaces. A monomolecular layer of fatty acid was

spread by the retraction technique over part of a selected facet of a piece of mica. A highly reflecting layer of sil- ver was then deposited on both sides of the mica specimen, and the thickness of the acid layer determined by multiple reflection interferometry. The values so obtained were in agreement with X-ray data on the length of the

fatty-acid molecule. Examination showed that the

layers were uniform in thickness ; polymolecular layers were absent. The method provides direct and independent evidence that molecules of a fatty acid, spread by the

retraction technique, are adsorbed on a solid surface as a uniform monomolecular layer. Ein interferenzoptisches Geriit zur Messung der Dicke

diinner Metallschichten (An Interference Apparatus for Measurement of the Thickness of Thin Metal Layers), M. DUHMKE, G. GEORGI. Metall v7 n23/24 1953 p 1000-2

7 figs. 4 refs. Describes an interference method and ap- paratus for measurement of layer thicknesses in the range from several microns to a few millimicrons within an uncertainty of +1 rn.fi. An Interferometer Microscope for the Accurate Measure- ment of Optical Thickness. J. DYSON. Letter in Nature

(London) vl71 Apr 25 1953 p 743^. A polarization- interference microscope arrangement is described for the determination of the thickness of thin transparent films. The interferometric phase difference is determined with a

modified half-wave plate. Settings to within a quarter

degree can be made, corresponding to a path difference of

0.003 wave-lengths in interference film. Film Thickness Measurement for Grating Blanks, F. A. McNALLY. Letter in J Opt Soc Am v43 June 1953 p 540. A simple interferometric method for the measurement of the thickness of metallic films deposited on grating blanks

is described. The method can be applied to films greater than 500 A in thickness. Fringes of Equal Reflection Coefficient Ratio and Their

Application to Determination of Thickness and Refractive Index of Monomolecular Films, R. E. HARTMAN. R. S. HARTMAN, K. LARSON, J. B. BATEMAN. J. Opt Soc Am v44 n3 Mar 1954 p 192-206. Production of families of

spectral fringes by use of surfaces having equal reflection

coefficient ratios ; applications in determining thickness and refractive index of monomolecular films ; determination of thickness and refractive index of barium stearate double layers. Films prepared by the method of Blodgett, but using a different piston oil, were found to have a

thickness of 45.7 A and an ordinary refractive index of

1.508. Simple Interference Prisms for the Evaluation of the Thickness of Thin Films, G. G. MONCH. Optik vl2 n5

1955 p 226-32 in German. A variety of prisms in inter- ferometric arrangements is described using in each case

right-angled prisms. The systems are somewhat related but different from that of the Kosters double prism. The

prism mounts are described in detail and illustrated

schematically. Application of the interferometric system

to the measurement of thin films is considered and an example quoted. Tolansky Gauge for Rapid Measurement of Film Thickness, T. M. GREEN, L. N. HADLEY. Letter in J Opt Soc Am v45 n3 Mar 1955 p 228-9. A device is described which

speeds up the measurement of thin film thickness when

using the method of multiple-beam interference fringes. It

is based on the displacement produced by an inclined glass

plate. An image of the fringes is projected on to a glass

plate which is itself viewed by a lens system. The angle

to produce one fringe shift is determined. The angle to eliminate the fringe shift due to the stepped film is then measured. From these the mean fringe displacement from

several fringes is rapidly evaluated. An accuracy of 50 A in film thickness obtains. The Influence of Dispersion on the Optical Determination

of the Thickness of Thin Films, G. KOPPELMANN, K. KREBS. J Phys vl45 n4 1956 p 486-95 in Russian. The

dispersion in reflectivity measurements of vacuum-evaporated ZnS films was determined and the effect of the dis- persion on the thickness determination was investigated

theoretically and experimentally. The results are ex- pected to hold in general for any thin film showing inter- ference effects. Neuere optische Verfahren zum Bestimmen der Dicke

dunnster Schichten (New Optical Methods for Determining Thickness of Very Thin Films), H. SCHOPPER. For- schung auf den Gebiete des Ingenieurwesens (Ed B) v22 n2 1956 p 56-62. Includes corrosion films ; new interferometer arrangements, which include intensity compensation,

or with which phase can be measured by comparison of

intensity ; examples of thickness measurement of thin metal layers and tarnish films. Bibliography.

Interferometric Evaluation of Thickness and Shape Using

the Two-Sided Technique, G. SCHULZ. Optik vl3 n9

1956 p 404-10 in German. A method is described for measuring the thickness of transparent or opaque thin films using a Michelson interferometer type of arrangement

(interference microscope )with incident illumination. A

knowledge of the refractive index is not needed. The

interference pictures obtained are sharpened by the equidensity photographic procedure. Fringe patterns from

the two sides are copied on to one plate and this offers information about thickness variations from point to point. A CdS microcrystal is examined as an example. On the Thickness and the Dispersion of the Refractive Index of Thin Aluminium Oxide Layers, M. HENNIG.

Zeit Phys v!44 nl-3 1956 p 296-310 in German. The

dependence of the thickness of the layer of aluminium

oxide films on the oxidation voltage is studied interfer- ometrically. Measurements are made for different am- monium citrate concentrations. The relation is found be- tween the film thickness and the formation voltage. The

refractive index measurements are made for different wavelengths. The refractive index in the range 3600 to 6500 A decreases from 1.577 to 1.560. In the region 4360 A a dispersion anomaly is established. Measurement of the Thickness of Thin Films by Multiple- Beam Interference, C. WEAVER, P. BENJAMIN. Nature (London) vl77 June 2 1956 p 1030-1. Experiments have been carried out on the measurement of the thickness

of thin silver films, using both silver and chromium as

the overlayer material. A standard experimental pro- cedure was adopted for the deposition of these films, which

were evaporated on to selected glass microscope slides. The thicknesses of the silver films were measured by multipleJbeam interference fringes of equal thickness viewed

in reflection. The results indicate that when the chromium

overlayer is opaque, then there is no discrepancy in the

thickness of the silver films as measured by the two differ- 243
ent overlayers. However, when the chromium overlayer

is not opaque, then a discrepancy of the 'type found by Avery occurs. The discrepancy in the thickness measurement's when a non-opaque chromium layer is used may be caused by a difference in the phase change at reflection on the two sides of the step-edge since the underlying sub- stances are different. Recent Attempts to Determine the Thickness and Refractive Index of Unimolecular Films, R. D. MATTUCK. J Opt Soc Am v46 n8 Aug 1956 p 615-20. The Hartman

method for measuring the thickness and refractive index

of nonabsorbing unimolecular films is investigated. Both

theoretical and experimental evidence lead to unfavourable conclusions. A test experiment is reported in which

the Hartman method is used to measure the optical constants of barium stearate multilayers from 50 A to 250 A

in thickness. The results obtained disagree with the rela- tively wellknown properties of barium stearate films. To

determine the cause of the disagreement, the method is investigated theoretically. It is shown by numerical cal- culation and algebraic analysis that, in terms of the present accuracy of the optical measurements involved, the Hart- man method is too insensitive to be of practical use for

films of molecular thickness. The use of an Interference Microscope for Measurement

of Extremelv Thin Surface Layers, W. L. BOND, F. M. SMITS. Beil Systems Tech J v35 n5 Sept 1956 p 1209-21. A method is given for the thickness measurement of p-type

or w-type surface layers on semiconductors. This method

requires the use of samples with optically flat and reflect- ing surfaces. The surface is lapped at a small angle in order to expose the p-w junction. After detecting and marking the p-w junction, the thickness is measured by

an interference microscope. Another application of the equipment is the measurement of steps in a surface. The

thickness range measurable is from 5 X

10"6 cm to 10"3 cm.

Calculator for Thin Film Measurement, W. A. FEIBEL- MAN. J Opt Soc Am v46 nil Nov 1956 p 994-5. The

design and operation of a calculator for determining thin

film thicknesses measured by the multiple beam inter- ferometer method is described. A photograph of the in- strument and layout of the calculator dial are included. Thickness Measurement of Microscopic Objects by ThreeSlit and Two-Slit Interference (Probe Method), E. MENZEL. Optik vl4 n4 Apr 1957 p 151-64 in German. A

commercial microscope for direct and reflected illumination is adapted for the measurement of thickness by tripleslit interference. The object plane together with the re- duced image of the triple slit is projected to infinity and

observed by means of a telescope. The characteristic planes of interference are now equidistant and will appear

in the telescope after insertion of a cylindrical lens the

axial displacement of which may be read off. Phase contrast facilitates the required covering of the two slits. A filament lamp together with filters provide the light source. The arrangement may also serve to measure

longer path-differences using then the double-slit inter- ference. The two methods are particularly suitable for the measurement of the thickness of microtome sections and thin films. Corrections of Interference Thickness Measurements of Thin Films on Account of Boundary Reflections, P. J. LINDBERG. Optica Acta v4 n2 June 1957 p 59-68. Multiple-beam interferences show a remarkable effect owing to boundary reflections when a transparent film is interposed between the interferometer flats. Similar conditions occur in all interferometric thickness measure- ments of transparent films. The phase-shift so caused is calculated and represented in diagrams with rolling

circles. Measurements were made with multiple-beam

interference on zinc sulphide films deposited on silver, and the results agreed satisfactorily with the calculations.

If the boundary reflections are neglected in the case of multiple-beam interference, the error in the determi- nation of the film thickness is at most about \/2v, even if the difference in refractive index is small. The

consequences of this are considered for the interfer- ometric measurement of biological specimens. The Measurement of Thin Films by Interferometry, J. DYSON. Physica v24 n6 1958 p 532-7. In view of the high accuracy of comparison of path-differences attain- able in polarimetry, experiments were made to achieve some of this accuracy in thin film measurements. It is shown experimentally that setting accuracies are obtain- able corresponding to an error of thickness measurement

of ±1 A. Measurement of Thickness of Films Using Equal-Chro- matic-Order Lines, I. N. SHKLYAREVSKII. Optika i Spektrosk v5 n5 1958 p 617-19 in Russian. In 1945 Tolan- sky used equal-chromatic-order lines in the study of the topography of almost plane surfaces, using white light. Later Sinel'nikov and Rapp (1950) and the author (1954, 1956) applied Tolansky's method to the thickness measure- ment of films deposited in vacuo on glass plates. A

scratch is made across such a film. The film is then covered (by vacuum deposition) by an opaque layer of

silver which repeats the scratch contours forming a small

step. The height of this step is equal to the original film thickness. A second glass plate is covered by a semi- transparent layer of silver. The two plates are pressed

together and are placed in front of a spectrograph slit in such a way as to position the step, referred to above,

at right angles to the slit. These plates are illuminated with a parallel beam of white light. An achromatic lens

is used to focus the air gap between the glass plates on

to a spectrograph slit. In the focal plane of the spectro- graph camera objective two systems of equal-chromatic- order lines are observed and the separation between the two systems of lines is a function of the original film thickness. The paper gives formulae necessary for the

calculation of thickness from the observed interference

pattern. Remarks on the Three Slit Method, A. C. S. VAN HEEL.

Physica v24 n6 1958 p 529-31. The three-slit method of Zernike is adapted to the Francon crystal interferometer

for the measurement of the thickness of a thin film of area as small as 0.1 mm2

. The advantage of placing the

slits in the frontal focal plane is discussel. Thickness changes with time are reported for MgF2 films. The Determination of the Thickness, Dielectric Constant, and Other Properties of Anodic Oxide Films on Tantalum

from the Interference Colours, L. YOUNG. Proc Roy Soc A v 244 Feb 25 1958 p 41-53. The thickness of anodic

oxide (Ta»Os) films on chemically polished tantalum was

determined from the wavelengths of the minima in the specular reflectivity using a value of the refractive index

of 2.20 ± 0.02 at 5900 A which was measured on detached

flakes of the oxide by the immersion method. An auxil- iary measure of increments of thickness was required for the analysis of the spectrophotometrie measurements.

This was provided by the quantity (QAU/C) )%, where Q was the charge which was required to form the incre- ment of thickness, and A(l/C) was the corresponding

increase in the reciprocal capacity. This measure of thickness, like that provided by the colours, is independent of the area. The analysis gives the refractive index between 2800 and 6000 A, the net phase-change in the two reflections (with certain assumptions), and a value

of e/p, where e is the effective dielectric constant under

the conditions used, and p is the density ; p was deter- mined by weighing specimens in air and water. The

value obtained for p was 7.93 ( error ± 3% )

, which gives e=27.6 (error ±5%), at 1 kc/s. The effective surface area was then calculated, and was found to be very little different from the apparent area. The field strength dur- ing the formation of oxide at 9.55 mA/cm2 and 25.8° C

244
was found to be 6.61 X lOT/cm and to be constant within experimental error, independent of thickness. Optical Apparatus for Depth Sensing. U. GERHARDT.

Optik vl5 n2-3 Feb-Mar 195S p 132-4. in German. An

interference microscope was used to determine the dis- tance between two nearly coplanar parallel faces of two

metal end gauges wrung together. Using both white light and monochromatic light, accuracy of a fraction of a micron is claimed. Observations could be made at up to 70 cm from the gauges. Some Methods for Measurements on Thin Films, A. C. S. VAN HEEL. A. WALTHER. Optica Acta v5 n 1-2 MarJune 1958 p 47-52. Four modifications of Francon's inter- ference eyepiece are given which enable one to measure

the step in a wave-front and at the same time the lightloss. As it is possible to carry out measurements while

depositing the layer, the methods described can be used

for monitoring purposes, the non-optical windows not do- ing much harm to the appearance of the field of view. With the available apparatus a precision in the determi- nation of the light path of X/200 is easily obtainable for

all layer thicknesses. Nondestructive Interferometric Thickness Measurement

of Thin Transparent Films. R. L. SAUER. J Opt Soc Am

v48 n4 Apr 1958 p 275. The thickness of anodic oxide

coating of Al is measured interferometrically in the range

0.00005 to 0.01 inch. An Application of Tolansky's Method to the Measurement

of Films with Variable Thickness, A. HEISEN. Zeit InstrumKde v66 n5 May 1958 p 87-91 in German.

Multiple-beam fringes of equal thickness are applied to the evaluation of step heights (film thickness). It is shown how the method can be applied to a film of constant

thickness, or to a wedge film in which there is regular

increase of thickness, or an irregular change. It is de- scribed how measurements can be made when the steps are either perpendicular to, or alternately in the direction

of, the change in thickness. With thin films which are

not too absorbing the refractive index can be obtained. Eine Anwendung des Tolanskyverfahrens zur Messung

von Schichten mit sich aendernder Dicke (Application

of Tolansky Techniques to Measurement of Films with

Varying Thickness). A. HEISEN. Zeit InstrumKde v66

n5 May 1958 p 87-91. Thickness measurement by means

of multiple beam fringes of equal thickness on steps parallel and normal to direction of increasing thickness. Thickness Measurement of Epitaxially Grown Films. O. S. HEAVENS. D. C. PANDEYA. Nature (London) vl81 May 17 1958 p 1394. The thicknesses of Fe and Ni films grown on a rocksalt substrate were determined by float- ing the film off the rocksalt on to a glass flat where, by

silvering the film edge and using Fizeau fringes, the step- height was measured. The results agreed, within the accuracy of measurement ( ± 20 A), with those for similar films deposited simultaneously, but directly, on glass. The films were deposited at room temperature and were

130 to 450 A thick. Measurement of the Optical Constants of Thin Dielectric Films by Means of Frustrated Total Reflection, B. P. SAN- FORD. J Opt Soc Am v48 n7 July 1958 p 482-6. It is >hown that the transmission of light through a thin

dielectric film under conditions of frustrated total reflec- tion can be used to measure the refractive index and

thickness of the film. The refractive index and thickness were measured for each of several magnesium fluoride

films. The thickness was checked in each case by multiple beam interference and the refractive index compared

with the results obtained by other authors for similar

films. It appears that many present concepts on which

the theory of the optical properties of thermally evaporated films is based are inadequate for the problems

involved. The Interferometric Measurement of Metal Oxide Films,

J. C. KELLY. Optica Acta v5 n3-4 Sept-Dec 1958 p 75-8. A method is described for investigating oxide films in situ on the metal surface. The method yields the surface

finish of the inside and outside surfaces of a metal oxide

film, its volume ratio, its thickness and the location of the original surface with respect to the two oxide surfaces. All this information is contained in a single photo- graph provided the refractive index of the oxide is known. Some results for anodic oxide films on aluminium are

given. Errors in the Measurement of Film Thickness bv Multiple- Beam Interferometry, C. WEAVER, P. BENJAMIN. Nature (London) vl82 Oct 25 1958 p 1149-50. It is shown

that an error in estimating thin-film thickness by inter- ferometry can arise, if the step edge is produced on the

film by a scratching technique. The substrate (glass) can be deformed appreciably, to an extent depending on

the scratching load. Even light loads of as low as 5 gm

can induce error or as much as 18 A and a 100 gm load

leads to a 273 A error. This method of scratching the

film is considered unsatisfactory. Obtaining Low Orders of Interference in Measuring Film

Thicknesses by Multiple Beam Interferometry. G. D. SCOTT. J Opt Soc Am v48 nil Nov 1958 p 858. In

multiple-beam interferometry as used for the measure- ment of the thickness of thin films it is desirable to use low orders by bringing the surfaces very close together. A holder is described for mounting on a microscope stage which permits easy manipulation for this purpose. A Haidinger Interferometer with Linear Scale for Thickness Separation of the Plane Parallel Plates, R. RIEKHER. Optik vl5 nl2 Dec 1958 p 713-23 in German. An instrument for measuring separation between plane

parallel plates is described, using Haidinger's rings. By

employing a parabolic mechanical linkage the instrument works on a linear scale. Use of the system is described. Errors are discussed. Measurement of the Thickness of Very Fine Transparent

Films by the Interference Method, B. GADZUK. Slabo- proudy Obzor v20 n2 1959 p 85-7 in Czech. A beam of white light is directed, at an angle of less than 90°, on

to the film, and the interference fringes observed, the number of the fringes being directly proportional to the

thickness of the film. The method is suitable for the measurement of the glass foils in image orthicons having

a thickness of l-10/i. It can also be employed for the measurement of films up to 100/i. Zero Point One, A. M. DEXTER, JR. ASTE 59 Tech

Paper 195 1959 20 p. Presented at the April 29, 1958 meeting of the American Society of Tool Engineers, Hartford Chapter. Describes and discusses wringing films of various media between gage blocks and measurement of

film thicknesses. Control of Thickness of Evaporated Layers During Evaporation, G. PAPP. Rev Sci Instrum v30 nlO Oct 1959 p 911-12. Method for control of evaporated layer thick- ness for transparent substances ; progress of evaporation can be checked by method at any moment, simply by

counting number of interference fringes on control plate located in vicinity of target. A Thickness Measurement Technique Using a Three-Beam

Interference Arrangement for Objects of Thickness Less than 1 Micron, H. WESTMEYER. Exper Tech Phys v8

nl 1960 p 18-25 in German. It is often required to know

the thickness of an ultramicrotome section. An application of the Zernike three-beam interference method for 245
doing this measurement is described. The elementary

theory of the method is reviewed, adjustments are de- scribed and a simple setup is discussed. Measurement of the Optical Thickness of Absorbing Spe- cimens with the Three-Beam Interferometer, P. HARI- HARAN, D. SEN. J Sci Instrum v37 nil Nov 1960 p 417-

19. A simple modification of the three-beam interfer- ometer is described which permits measurements of the

optical thickness of absorbing specimens .with a high de- gree of accuracy.

Interference Method for Measuring the Thickness of Epitaxially Grown Films, W. G. SPITZER, M. TANENRAUM. J App Phys (USA) v32 n4 Apr 1961 p 744-5. Since the dielectric constant of semiconductors is de- pendent on the carrier concentration, radiation can be

reflected from the boundary between a heavily doped semi- conductor and a lightly doped layer deposited on it by an

epitaxial process. Interference effects will occur between

the radiation reflected at the boundary and that reflected from the surface of the epitaxial layer, and the thickness

of the layer can be deduced from the reflection spectrum.

Results are given for layers of germanium and silicon. Thickness Measurement of Epitaxial Films by the Infra- red Interference Method, M. P. ALBERT, J. F. COMBS.

J Electrochem Soc (USA) vl09 n8 Aug 1962 p 709-13. The infrared interference measurement has proved to be an accurate and nondestructive means for evaluating the thickness of epitaxially grown films on silicon. The

measuring technique is discussed and the necessary rela- tionships are presented. A fringe wavelength versus film chart is constructed, which enables rapid thickness deter- mination without calculation. The chart is derived for use with silicon films of relatively low carrier concentration deposited on silicon substrates of high carrier con- centration (0.007 ohm cm N-type). The chart is most

useful for low order interference fringes including 12th

order. Similar charts are applicable for other semicon- ductor materials. Ein Interferenzflaechenpruefer als Sehiehtdiekenmessgeraet (Interference Device for Surface Testing Used as Film Thickness Measuring Device), M. DUEHMKE.

Zeit InstrumKde v70 nl2 Dec 1962 p 300-2. Application

of interference microscope as multiple beam interferometer to measure thicknesses of thin films with accuracy of plus or minus 0.001 /on. Apparatus for the Determination of the Thickness of Thin Films, YU. A. DURASOVA, E. N. RYBAK. Pribory

i Tekh Eksper (USSR) 1963 nl p 195-6 Jan-Feb in Russian. English translation in : Instrum exper Tech (USA). Tolansky's fringes were used to determine the

thickness to within 10-15 A. Thin Film Thickness Measurement Using Silver-Modified Newton's Rings, B. J. STERN. Rev Sci Instrum v34 n2 Feb 1963 p 152-5. Interference technique for measure- ment of electric films is described that consists of silvered

lens placed over stepped film with silver overlay; re- sultant interference pattern, when viewed in reflection, is series of sharp dark rings against bright background

step in film to be measured causes shift in rings from

which thickness is calculated ; step heights in silver films, vacuum deposited on fire-polished microscope slides, of 160 and 780 A were measured . Interference Method of Measuring the Thickness of Thin

Transparent Flms, V. F. SHVETS. Meas Techns 1962 n7 Feb 1963 p 538-40 1 fig 1 ref. Translated from Izmer Tekh n7 p 5-6 July 1962. Method based on observing two

sets of white light fringes, one from the film and one from

the back surface. Various advantages are cited. Interferometric Evaluation of Thickness of Canada

Balsam and Collodion Films and Its Relation to Concentration of Solutions, N. BARAKAT, A. A. A. MOHAMED,

A. EL BIALY, K. A. AZIM. Brit J. App Phys vl4 n3 Mar 1963 p 144-6. Thin films of collodion and Canada

balsam were prepared on water surfaces. Their thick- ness was evaluated interferometrically over the range

1/£-%o^ and the relation between concentration and thick- ness studied. The effect of temperature on film thickness was evaluated at 25, 100 and 150° C. Very Precise Thickness Measurement of Thin Films, J. DYSON. Nature (GB) vl97 Mar 23 1963 p 1193. Equality of path length between two polarized light beams

in a modified interference microscope is detected photoelectrically, and film thickness may be determined to better than 1 angstrom unit. Comparaison de Deux Methodes de Mesure des Couches Minces d'Oxyde de Silicium (Comparison of Two Methods

for Thickness Measurement of Silicon Oxide Thin Films),

J. ENCINAS. Vide vl8 nl04 Mar-Apr 1963 p 95-9. Thickness determined from Newton's color scale using normal

incidence; interference order is obtained by counting green rings which appear when each pit is made by

fluorhydric acid droplet ; second method consists of measuring displacement of monochromatic interference

fringes; both methods are in very good agreement for thickness range C. 16-1.5 /i. Dichroic Multiple Beam Interferometer Microscope, M.

J. IRLAND, E. B. SCHERMER. Appl Optics (USA) v2 n5 May 1963 p 540-1. A description is given of the pre- paration of multilayers of high abrasive resistance suit- able for reflectors in multiple-beam interferometry es- pecially for the measurement of the thickness of thin

films. The reflector used for germanium measurement

consists of a triple layer built from Ti02 and Si02. This has a reflectivity of about 65% in the green and is almost

transparent near 4700 A. The abrasion resistance is found to be extremely good and is more satisfactory than any metal or dielectric film previously used, remaining unmarred after 100 applications, whereas other films have shown significant damage after this much use. Diffused Light Interferometry for Measurement of Iso- pachics. P. S. THEOCARIS. J Mech Phys Solids (GB)

vll May-June 1963 p 181-95. A simplified optical method, based on interference phenomena of diffused light, is described for the determination of isopachic patterns. The procedure consists in using a monochromatic diffused

light beam to illuminate the model surface. If an optically flat glass plate, used as datum plane, is brought in contact with the model front surface an interference pat- tern is produced related to the thickness of the air-film between the datum plane and the surface of the model.

Interference patterns before and after loading of the speci- men allow the determination of isopachics. Curves of variation of interference fringes throughout the surface

of the specimen, before their use for the determination

of thickness variation, must be readjusted in a convenient

scale as well as for the elimination of superimposed simple

interference patterns due to arbitrary inclination of the datum optical plane before and after loading. The

method does not necessitate a complicated equipment.

It is straightforward and very sensitive. It can be ap- plied to transparent as well as to opaque models made

of metal sheets. It can also be used as a supplementary means to measure thickness-strains in the birefringent coating method. The surface of the model, though

polished, could not be obligatorily optically flat. The

method was applied to several illustrative examples with

transparent and opaque models. The results obtained are

in good agreement with those yielded by theoretical or other experimental solutions. Interference Microscopy of Thin Films and Semiconductor

Structures, A. E. FEUERSANGER. Solid State Design v4 nlO Oct 1963 p 29-32. Operating principles of dual beam interferometer are outlined, and its potential for 246
applications in measurements on variety of electronic devices in solid state research is discussed, including

thickness and uniformity measurements of metallic and

dielectric layers. Nondestructive Determination of Thickness and Refractive Index of Transparent Films, W. A. PLISKIN, E. E. CONRAD. IBM J Res & Development v8 nl Jan 1964 p 43-51. Simple interferometric methods of determining thickness and refractive index of films on reflective substrates ; sensi- tive method of obtaining thickness of films less than 1

li by combined use of monochromatic filters and interfer- ence pattern chart ; color chart for thicknesses of ther- mally grown Si03 films up to 1.5 /i thick.

11.2. Polarimetric Methods (Ellipsometry)

Ueber Oberflaehenschiehten (Regarding Surface Films),

P. DRUDE. Ann der Phys und Chemie 3ser v36 n2 and 4, 1889 p 532-60, 865-97. Develops equations for relation- ships among optical constants and film thicknesses of transparent thin films, applying polarimetric methods. Eine Methode zur Bestimmung der Dicke und optischen Konstanten dursichtiger Metallschichten (Determining

Thickness and Optical Constants of Transparent Metal

• Films), W. BETZ. Ann d Physik vl8 n8 Nov 21 1905 p 590-605. (Extract from Dissert, Leipzig, 1905.) —The

I required quantities were calculated from the elliptic polarisation of the transmitted light and observations of

intensity, the method enabling the thickness, index, and

coefficient of absorption to be determined simultaneously. The author's formulae were derived from the theoretical investigations of VOIGT and DRUDE [Wied. Ann 25, p 25

: 1885 ; and 43 p 126 1891]. His measures of elliptic polari- sation were made with the spectrometer described by DRUDE [Optik p 238] and a banded compensator, as a compensator with homogeneous field gave too little light.

, A table of results for three silver and two copper mirrors

1 is given. With gold and platinum, consistent results could

i not be obtained. Under the microscope with strong homogeneous immersion, a grain-like structure was dis- covered in the gold films, the grains being apparently

j diffraction phenomena due to small holes.

' The Thickness of Spontaneously Deposited Photoelectrically Active Rubidium Films Measured Optically, H. E. IVES, A. L. JOHNSRUD. J Opt Soc Am and Rev

• Sci Instrum vl5 Dec 1927 p 374-81. Measurements were made of the thin films which deposit in a high vacuum

on polished platinum or glass, which are invisible, but

j which are photoelectrical^ sensitive to the same extent as

thick layers. Plane polarised light, polarised at an

1 azimuth of 45°, was directed on the surface, and the re-

- fleeted light examined with a Babinet compensator and

nicol prism, the shift of the azimuth or phase' caused by

the film being measured. The theory of the calculations

of the thickness has been given by T. C. FRY. The result

is that the layer of rubidium formed on glass is about one

- atom thick, but as the theory may not hold exactly for

: such thin films, it is possible that the actual thickness may

a be five or even ten atomic diameters. The effect of such

- a rubidium film on the optical behaviour of platinum is so small as to lie within the errors of observation, and this

. could not be measured.

Elliptical Reflexion and the Optical Study of Thin Layers,

R. DE MALLEMANN, F. SUHNER. Rev. Dpt (Theor

. Instrum) v23 Jan-Mar 1944 p 20-38 in French. A lengthy

; survey is given of the theory and the derivation of formuBae for the state of polarization of the reflected light in

t 5 the case of two media in contact. The general case is considered for both isotropic and anisotropic media, after which the special case of thin layers is dealt with (from

. a thickness of 10 A up to several microns) . The argument

i is on geometrical lines. Details are also given of the ex- perimental determination of the thickness and refractive index of thin layers, deposited on solids, using elliptically polarized light.

: Ellipsometer, Apparatus to Measure Thickness of Thin

I Surface Films, A. ROTHEN. Rev Sci Instrum vl6 n2

' Feb 1945 p 26-30. Apparatus designed to determine thickness of films deposited on metal slides is described ; based on measurement of change that takes place in ellipticity of light reflected after slide has been coated with film

apparatus is capable of measuring film thickness within ±0.3 A.

Optical Methods of Studying Films on Reflecting Bases Depending on Polarization and Interference Phenomena,

A. B. WINTERBOTTOM. Trans Faraday Soc v42 JuneJuly 1946 p 487-95. The optics of metals and of film- covered surfaces is discussed and a description given of

the techniques employed in polarimetric investigations. A detailed account is also given of the methods of computing thickness/reflectivity curves and interference thick- nesses based on strict film optics. The Reflexion of Light from Glass with a Transparent Homogeneous Surface-Layer, M. BRDIOKA. Bui Int Acad Tcheque Sci v48 1947 p 63-70. The electromagnetic

equations are applied to a beam of light incident upon a thin surface layer on glass. These equations are trans- formed into a 5th order algebraic equation which can be

solved to give the thickness and refractive index of the

layer from practical measurements of the angle of refraction, the elliptical polarization of the reflected beam and

the phase difference between the two components.

Polarimetric Methods for the Determination of the Refractive Index and the Thickness of Thin Films on Glass, A. VASICEK. J Opt Soc Am v37 Mar 1947 p 145-53 623. A

general method and various modifications are developed

for the determination from polarimetric measurements

of the reflected light, using plane polarized incident light. The mathematical problem involved cannot be solved in

explicit form but, as shown by numerical examples, exact

results can be obtained by graphical interpolation. The Reflexion of Light from Glass with a Natural Transparent Inhomogeneous Surface Layer, M. BRDICKA. Bui

Int Acad TchSque Sci v49 1948 p 81-9. The reflected beam from a glass-air surface shows elliptical polariza- tion which is believed to be due to the presence of a sur- face layer. The dielectric constant is assumed to vary

within the layer in a regular manner with the distance from its surface. The electromagnetic equations then

allow the mean refractive index and thickness of the

layer to be determined from the amount of elliptical pola- rization and the phase differences. Experimental results show good agreement with calculated values. Optical Determination of Thin Films on Reflecting Bases

in Transparent Environments, A. B. WINTERBOTTOM.

J Opt Soc Am v38 nl2 Dec 1948 p 1074-82. 'The classical theory of metal and film optics is recapitulated and its implications in connection with various optical methods

of studying films and surfaces are indicated. The experi- mental technique of determination of thin films in situ from the change produced in the reflection of a polarized wave is then outlined. Optical techniques are not advocated to supplant other methods of studying surfaces such

as weight increment, gas absorption, electron diffraction, X-ray diffraction and electrochemical analysis, but rather

to supplement these in selected cases. In particular, the

optical techniques are of value in making continuous

studies of films in situ in transparent environments when

771-846 O—66 17
conditions render the application of other methods diffi- cult. Examples of application are given. Optical Measurements of Surface Films. I. A. ROTHEN,

M. HANSON, Rev Sci Instrum vl9 Dec 1948 p 839-41. Practical information is given concerning the calibration of an instrument called the ellipsometer, which is used to measure thicknesses from 1 A up to >10G0 A of trans- parent films deposited on polished metal slides. It is a half-shadow instrument taking advantage of the ellip- ticity of polarized light reflected from film-eoated metallic

surfaces. The half-shadow is produced by depositing a

different thickness of transparent material on the lower and upper part of the slides, or by evaporating a thin layer of Au directly on the lower part of Cr slides. The Apparatus for Measuring the Thickness of the Thin

Film on Metal Plate, Y. YONEYAMA, K. IMAHORI. Sci Papers College Gen Education Univ Tokyo v3 Dec 1953 p 145-50. The thickness of a film of denatured protein (1-300 A) deposited on a metal slide is found by measure- ment of the change in ellipticity of light reflected from

the slide before and after deposition. Standard polarized

light techniques are employed using a half-shade analyser. Films of barium stearate of known thicknesses are used

to calibrate the instrument. Improved Method to Measure the Thickness of Thin Films

with a Photoelectric Ellipsometer, A. ROTHEN. Rev Sci Instrum v28 n4 Apr 1957 p 283-5. Describes the ad- vantages of a photoelectric ellipsometer over a visual in- strument for the measurement of the thickness of films from 1 A up to many thousand A. Experimental curves

are given showing the unambiguous correlation between

film thickness and position of two rotating elements, a X/4 plate and an analysing Nicol prism. Note on the Limits of the Polarimetric Method of Thin

Film Measurements, A. VASlCEK. J Opt Soc Am v47 n6 June 1957 p 565-6. Details are given to support the state- ment that the method is able to indicate the existence of

films having atomic dimensions and should permit accurate measurements for a film of thickness 10 A. Comment on the Rothen Photoelectric Ellipsometer, R. D. MATTUCK, A ROTHEN. Rev Sci Instrum v28 nlO Oct

1957 p 844-5. Mattuck states that to determine film thick- ness d by the Rothen method a value for the refractive index n is essential. Refractive indexes cannot be deter- mined for values of d less than 300 A, so that for such

thicknesses the Rothen method cannot be used. Refer- ence is made to a method that gives d and n simultaneously

for the range from 10 to 250 A. Rothen states that his method refers to optical thicknesses, and for these the instrument is sensitive to changes of 0.1 A in the range from 0 to 300 A. Application of the Standardized VaSicek procedure to Nonabsorbing Singly Evaporated Films on Glass Substrates, J. RASSOW. Zeit Phys (Germany) vl70 n4

1962 p 376-92 in German. The author modified Vasicek's polarimetric theory to a graphic method for determination

of optical constants of thick homogeneous films on glass

substrates. The method is verified for single layers de- posited by heating salts. The kind of salt determines the gradient of the refractive index. This gradient and the

state of the surface of the glass are responsible for deviations from the theoretical curves. A suitable method was

found for determining the refractive index and the thick- ness of the deposited film. In a modified form the method

can also be used for inhomogeneous films. Sometimes it is possible to determine a change in thickness less than

10 A during the deposition of the film. The thickness can

be calculated accurately only by measuring at three dif- ferent light-frequencies, because the curves are periodic. The values for the different light-frequencies agree well

with each other, differing only by about 5%. The agree- ment is much better for films thicker than 10 000 A. The

thickness of the films as obtained by applying this.method

is almost identical with the one given by an interference microscope. Testing the Standardized Vasicek Procedure, for Inhomogeneous Nonabsorbing Films on Glass Substrates. J. RASSOW. Zeit Phys (Germany) vl70 n4 1962 p 393-408

in German. In the use of Vasicek's polarimetric method

for a single layer, differences from the theoretical curves have been observed which can not be explained theoretically. These differences can be increased experimentally by the deposition of double films. The author suggests four rules, by which the inhomogenity of the films can be

calculated from the measured curves. It is possible to determine the thickness and refractive index quantitatively and the index gradient approximately. For the same salt all the four possible types of inhomogenity can

be produced. With the rules the differences in the results can be eliminated. The fifth rule limits the applicability

of the four other rules. Automatic Optical Thickness Gauge for Thin Film Measurements, T. P. MURRAY. Rev Sci Instrum (USA) v33 n2 Feb 1962 p 172-6. An automatic ellipsometer for meas- urement of the thickness of thin films in the monomolecular range is described. The instrument is capable of push- button operation by untrained personnel, and has been in use in an industrial laboratory for about two years. Theoretical Treatment of Ellipsometry, F. PARTOVI. J. Opt Soc Am v52 n8 Aug 1962 p 918-25. Exact expressions are obtained in closed form for the phase and amplitude

of the reflected light when a light beam is incident upon

a multilayer of a number of homogeneous media. The

assumption is made that Maxwell's equations and Ohm's

law hold. These equations are applied to the special ease of dielectric coated metals and the results are com- pared to ellipsometry measurements made in chromium

slides covered with barium stearate films of known thickness. When the conductivity and the dielectric constant

of the metal are allowed to assume complex values, and when precautions are taken to reduce the inaccuracy in- troduced by the residual oxide and gas layer on the metal, the agreement is good. Determination of the Properties of Films on Silicon by the Method of Ellipsometry, R. J. ARCHER. J Opt Soc Am

v52 n9 Sept 1962 p 970-7. The use of exact reflection theory to interpret data allows the application of ellip- sometry to the determination of the thickness and optical constants of surface films without the thickness limita- tions of approximate theory. Ellipsometer measurements

as a function of the thickness and optical constants of a

variety of different films on silicon substantiate the pre- dictions of exact theory and yield the properties of the

films. Theory of Frustrated Total Reflection Involving Metallic

Surfaces, T. R. YOUNG, B. D. ROTHROCK. J. Res NBS

(USA) v67A n2 Mar-Apr 1963 p 115-25; J Opt Soc Am

v51 n9 Sept 1961 p 1038-9. The theory for frustrated

total reflection was developed for the case where the

third medium is metallic of complex index. Using parallel polarized light a unique minimum in reflectance occurs

at a definite film thickness. Experimental verification of the theory is made and indicates the theory applicable

to the precise measurement of thin contact films existing between metallic and dielectric surfaces. Measurement of the Thickness and Refractive Index of Very Thin Films and the Optical Properties of Surfaces by Ellipsometry, F. L. McCRACKIN, E. PASSAGLIA,

R. R. STROMBERG, H. L. STEINBERG. J Res NBS

(USA) v67A n4 July-Aug 1963 p 363-77. The use of the ellipsometer for the measurement of the thickness 248
and refractive index of very thin films is reviewed. The

iPoineare sphere representation of the state of polarization of light is developed and used to describe the reflec- tion process. Details of the operation of the ellipsometer are examined critically. A computational method is pre- sented by which the thickness of a film of known refrac-

:ive index on a reflecting substrate of known optical instants may be calculated directly from the ellipsomeber readings. A method for computing both the refractive index and thickness of an unknown film is also developed. These methods are applied to the determination of the thickness of an adsorbed water layer on ?hromium ferrotype plates and on gold surfaces. In the former case the thickness was 23-27 A, and in the latter was 2 to 5 A. The measurement of the thickness and

refractive index of barium fluoride films evaporated on ohromium ferrotype surfaces is used as an illustration of

:he simultaneous determination of these two quantities. Some Observations on the Use of Elliprieally Polarized

Light to Study Metal Surfaces, F. P. MERTENS, P. THEROUX, R. C. PLUMB. J Opt Soc Am v53 n7 July

1963 p 788-96. Measurements and calculations using

elliptically polarized light to determine the thickness and index of refraction of barium stearate films on a

r ariety of substrates are described. Attention is focused

•especially upon problems associated with the study of very thin films, that is, films which are less than 100 A

chick. Measurements of the optical constants of metal

substrates are presented. An apparent dependence of the index of refraction n and extinction coefficient k and

independence of the absorption coefficient k upon the angle of incidence is observed and is discussed. Several

^effects, including accuracy and sensitivity, of the angle

:of incidence in studying film growth are noted. It is shown that there exists a characteristic angle of incidence

;at which the growth of a film produces a negligible change

in the ellipticity, and it is shown how advantage may be taken of this to facilitate measurements of rapidly [changing surfaces. It is demonstrated that extraneous

•films are satisfactorily accounted for in measuring thin

•films by means of the Drude equations through their

ieffects upon the apparent optical constants of the substrate. Advantage may be taken of this fact to extend

the thickness range over which the Drude linear equations are applicable by a computational procedure. The

problem of the anomalous index of very thin films as determined by the Drude equation is considered. It is concluded that the anomalies revealed by the Drude

Equations are associated with the system under study

•and are not caused by any inherent limitation in the 'Drude equations. It appears that at the interface be- tween a dielectric layer and metal system there is an

absorbing region which produces the anomaly in the

'refractive index calculated by the Drude equations and

; for which explicit allowance must be made in order to make accurate measurements of the thickness of very

thin films.

Photoelectronic Device for Measuring the Thickness of Thin Films, V. D. PEREVERTAEV, V. M. KUPRIYANOV,

M. S. METSIK. Pribory Tekh Eksper (USSR) 1963 n3 May-June p 193-5 in Russian. English translation in Instrum Exper Tech (USA) n3 May-June 1963 ; publ. Nov.

1963 p 568-70. Describes an improved modulation method

for anlyzing polarized light which is reflected from a material coated with a thin film. Ellipsometry—A Valuable Tool in Surface Research, K. H. ZAININGER and A. G. REVESZ. RCA Rev (USA) v25 nl Mar 1964 p 85-116. Ellipsometry is a technique that allows the determination of the optical properties of a

surface, or the optical properties and thickness of a thin

film, by measuring the effect of reflection on the state of polarization of polarized light. In this paper, the funda- mental equation governing ellipsometry is developed

starting from the problem of reflection and refraction of

light at a boundary between two homogeneous, isotropic media, and reflection from a film-covered surface. A pic- torial representation and the classical mathematical speci- fication of polarized light is given. Various solutions of the ellipsometry equation are discussed, the actual ellip- someter is described, and experimental techniques are outlined. Areas of applications are summarized and the value

of ellipsometry is examined in terms of possible errors and

obtainable accuracy. Finally, some of the deviations in the optical properties of thin films from those of the bulk

are briefly outlined. Ellipsometry for Frustrated Total Relection. T. R. YOUNG, J. M. FATH. NBS Misc Publ 256 Sept 15 1964 p 349-59 4 figs 7 refs. The practical length of a gage

block is dependent upon the thickness of the film between two contacting surfaces. The relationship between this wringing film thickness and its effect upon incident parallel and perpendicular polarization has been theoretically determined for the case where the light is incident upon

the first or transmitting surface at an angle greater than

the critical angle and where the second surface is metallic (complex index). The theoretical results indicate that when the optical constants of the two contacting surfaces and the wringing film are known, a polarization analysis

of the reflected light by the methods of ellipsometry offers an extremely sensitive and unique determination of the wringing film thickness. Attempts to verify the theory experimentally are discussed. Ellipsometry in the Measurement of Surfaces and Thin

Films, Symposium Proceedings Washington 1963, E. PAS- SAGLIA, R. R. STROMBERG, J. KRUGER. NBS Misc Publ 256 Sept 15 1964. A symposium on the Ellipsometer and its Use in the Measurement of Surfaces was held at NBS in Sept 1963. This volume contains 19 of the papers

included in the program, together with any discussions which followed oral presentation. Topics covered in- clude historical review, theory, computational techniques, measurement techniques, and the use of ellipsometry in measuring metal surface oxide films and organic films.

11.3. Miscellaneous Methods

Eine neue Methode zur Dickenbestimmung dtinner Blatt- chen (A new Method for Determining the Thickness of Films), C. H. SHARP. Ann Phys v3 n2 Oct 1900 p 210-

20. The thickness of a thin deposit is obtained by making

a model of it in a mixture of equal parts of colophonium and burgundy pitch. At the place where the thickness is to be determined, a small portion of the film is removed, and the mixture is laid on and warmed to 75° in a ther- mostat. It is lightly pressed in with the finger, after which

the whole is allowed to cool slowly, and the impression is lifted off. It has a brilliant black surface. It is pressed

on to a glass plate, and two systems of interference fringes are seen, one corresponding to the film and the other cor- responding to the blank space. The discontinuity between

the two systems is indicated by a displacement of the

fringes, and the amount of the displacement measures the

thickness. The author has devised a special spectrometer arrangement for exact measurements. He has measured

the thickness of various layers of gelatine by this method. When the impression is lifted off, it does not stick, owing

to a slight contraction on cooling. This contraction, while

sufficient to facilitate detachment, is not large enough to interfere with the correctness of the measurements, since the mixture remains practically liquid until it arrives at the ordinary temperature. New Method of Thickness-Measurement of Metal Films,

S. TANAKA. Tokyo Imperial Univ Aeronautical Re?, 249
Inst Rept v7 n91 Jan 1933 p 291-306 3 supp plates in English. Optical measuring methods and equipment for determining thickness of extremely thin sprayed on or chemically deposited metal films, applicable to thicknesses

of less than 0.01 micron. Thickness Measurement of Thin Coating by X-ray Absorption, H. FRIEDMAN, L. S. BIRKS. Rev. Sci lustrum

vl7 Mar 1946 p 99-101. The method is applicable to coat- ing thicknesses in the range 10~s-10~2 cm on crystalline

bases. An X-ray source and a Geiger counter are both

situated on the same side of the coating. The X-rays

pass through the coating and are reflected at a Bragg

diffraction angle from the base, back to the counter, their intensity being reduced by absorption due to the double

transmission through the coating. The thickness of the coating is computed from the measured absorption. On A Method for Measuring the Thickness of Thin Coating Films by Means of X-ray Reflex Photography, F. REGLER, Elektrotech und Maschinenbau [EuM] v65 July-Aug p 109-13 Sept-Oct 1948 p 148-52 in German. The general fundamentals of X-ray reflex photography and some known methods for the measurement of film thicknesses are discussed. A new method is described for measuring the thickness of a film deposited on a crystalline base. It utilizes the difference of absorption of Xrays diffracted by the base under different glancing

angles. The measurement is preferably made by photo- metric evaluation of pictures taken with a conical or

ring-film reflex system. The photometric method may be

replaced by ionometric intensity measurement. Dis- turbances caused by the coincidence of lines, by a coarse

grain structure or irregularities in the lattice structure

of the base, may be overcome by special experimental means which are described in detail. Direct Electron Microscopic Thickness Determinations of Ultramicroscopically Thin Crystals. J. H. L. WATSON,

W. HELLER, W. J. WOJTOWICZ. Chem Phys vl6 Oct 1948 p 999-1000. A procedure is described for measuring the thickness of platelets formed from a solu- tion of tungstic acid. Intense electron bombardment of the supporting film (Formvar) near the platelet selected for measurement generally results in the film rupturing

in a direction parallel to the major axis of the platelet. If the platelet adheres to the film, the net result is a ro- tation of the platelet about its major axis, from which

its thickness may be determined. For a particular speci- men the observed dimensions were 14.6/1 long, 5.0^ wide and 0.35/i thick. In certain cases, the method may be

used to compare the rigidity of colloidally thin crystals. X-ray Measurement of the Thickness of Thin Films de- posited on Microcrystalline Supports, C. LEGRAND, CR

Acad Sci Paris v227 Oct 27 1948 p 831-3 in French. The

method of Friedman and Birks is modified to avoid the

necessity of constant tube output. Two reflections from

the support are measured, the angle of incidence of the X-ray beam being chosen so that one emerges at a small angle ai (~3°), the other at a larger angle a2 . If the

ratio of the intensities for the bare support is R and for the coated support is R', the thickness e is given by Ate (sin

oi2— sin at) /sin ai sin a2 =log R/R', where /j. is the linear absorption coefficient of the coating. Method for Measuring Extremely Small Non-Uniformities

in Optical Thickness of Evaporated Films, A. E. GEE,

H. D. POLSTER. J Opt Soc Am v39 nl2 Dec 1949 p

1044-7. Methods for measuring half-widths of frustrated

total reflection filters of very narrow pass bands ; detec- tion of extremely small non-uniformities in spacer layers

of these filters. The latter method, permitting observation and measurement of thin film non-uniformities appreci- ably <1 unit cell provides a very sensitive means of studying thin film structures and the mechanism of formation.

The Determination of the Index [Refractive] and of the Thickness of Thin Transparent Films, F. ABELES. J Phys Radium vll July 1950 p 310-14 in French. Spectro photometric methods are surveyed ; although simple, thej are not generally applicable, failing for thicknesses below

A/4. A new method is described for evaluation of refrae

tive indices involving determination of reflectivities foi two different wavelengths. The method is applied tc evaluating the refractive index of Ti02. For a particulai

film the reflectivity as a function of wavelength is giver for the range W400-7 500 A. For a thickness of 19 m/t the index found is 2.48 for 5 000 <X <6 000. Calculations are made for both normal and oblique incidence. Data

are reported for MgFs, CaFz, LiF, cryolite and aluminium

fluoride. Polarimetric methods are also discussed. The methods developed can also be applied to films on an

base. A Method of Determining Concurrently the Thickness and

Refractive Index of a Thin Film or Lamina, P. D. FOCHS.

Letter in J Opt Soc Am v40 Sept 1950 p 623. On the Simultaneous Determination of the Optical Constants and the Thickness of Very Thin Metallic Films,

F. ABELES. CR Acad Sci Paris v231 Nov 6 1950 p 958-60

in French. For extremely thin films an approximation can be used permitting development of an expansion series in the theory formerly developed for the optical characteristics of thin films. It is shown that the reflectivities measured respectively from both sides of the film and the transmission are related. Further, it is shown how both

thickness and optical constants can be derived in terms

of transmissions, absorptions and the refractive indices of the media on either side of the thin film. The Determination of Optical Constants and Film Thickness of Absorbing Layers by Means of Measuring Absolute Phase Changes, R. FLEI SCHMANN, H. SCHOPPER.

Zeit Phys vl29 n3 1951 p 285-99 in German. By using j the complex amplitude which is derived from phase and

intensity measurements a new method can be developed

for the simultaneous evaluation of the optical constants and the thickness of an absorbing layer in which internal multiple reflection is disregarded. The determination of opaque layers by optical methods has so far not been possible. The new method is applied to antimony sulphide and the values of the constants and thickness determined

for various wavelengths in the visible regions of strong

absorption. Thicknesses up to about \/3 are studied. Be- cause the material is transparent in the red, optical controls on the thickness can be made and the newer tech- nique is confirmed as reliable. The method functions at normal incidence and is thus not affected by anisotropy! which might arise at other angles of incidence. The test |

is non-destructive, which is advantageous. The Thickness of the Helium Film, E. J. BURGE, L. C. JACKSON. Proc Roy Soc A v205 Feb 7 1951 p 270. A

description of an optical method for determining the

thickness of the He n film. Linearly polarized light is reflected from a stainless steel mirror, the upper part of which is coated with a layer of Ba stearate one molecule

thick and the lower part with a similar layer three molecules thick. The reflected light passes through a mica

compensating plate and a Nicol prism. Adjustment of the mica plate and Nicol gives equality of illumination on

the "1" and "3" areas. If now a film of He n covers the mirror the Nicol must be rotated to restore equality of

illumination. The rotation is a measure of the thickness

of the He film, the relation between the two quantities being calculated in terms of the angle of incidence and

the optical constants of liquid He, Ba stearate and stainless steel. The observed thickness at any given height above the liquid He was found to be nearly independent

of the temperature between 1-1 and 2-18 °K, but then decreased rapidly to zero at the \-point. In the formula 250
d=k/h1/I for the thickness d and height h cm for any

given temperature, the value of z varies from 3-5 at 1-1

:~K to 2-5 at 2-1 °K. The thickness at 1 cm and 1-5 °K

is provisionally given as 1 9X10""6 em. Determination of Thickness of a Thin Film Obtained by

Condensation of Artificial Radioactive Elements, M. DE- VTENNE. CR Acad Sci Paris v232 Mar 12 1951 p 1088-9

in French. A method of measuring the thickness of films

of radioactive Sb is described. The films were obtained by condensation from molecular beams on to a plate, precautions being taken to ensure a uniform deposit. The

- activity of the film is measured and compared with that

: of standards deposited on identical surfaces. These

• standards were prepared by evaporating a drop of a solu- tion of SbCl3 obtained by the action of aqua regia on a known mass of radioactive Sb. The plate was covered

with a very thin film of paraffin to ensure that the liquid spread uniformly over the plate. An Alignment Chart for Computing the Thicknesses of Evaporated Films, A. L. SCHOEN, R. H. DAVIS. Letter

in J Opt Soc Am v41 May 1951 p 362-3. Describes a

chart which serves as a convenient guide to the thick- nesses of evaporated films in situations where the evapo- ration material and geometry are subject to frequent

change.

!A Non-Destructive X-Ray Method for the Determination

;.©f the Thickness of Surface Layers, P. GAY, P. B. HIRSCH. Brit J App Phys v2 Aug 1951 p 218-22. The

intensity of reflection of a parallel, monochromatic X-ray

">eam is measured as a function of the angle (</>) between

:he lines given by the intersection of the plane of incidence With (a) the surface, and (b) the reflecting planes of

:he matrix crystal. If a surface layer is present, both

^incident and reflected beams suffer absorption. A general

-expression is quoted for the intensity ( which falls to zero

.Then <p = the Bragg angle) in terms of the geometrical,

absorption and intensity constants, it being shown how

i suitable plot of functions of the experimental values

Fields the layer thickness. Experimental procedure for

single crystal and polyerystalline bases is explained and

. >rief results are shown for an abraded surface on a LiF

crystal, and for an Al layer on polyerystalline Cu. The

. nethod is applicable to all layers with reflection co-

:* efficients different from that of the matrix.

-'"tfew Method for Liquid Film Thickness Measurement,

C A. M. PENNIE, J. Y. BELANGER. Can J Technol v30

i2-3 Feh-Mar 1952 p 9-19. Method employs micrometer

' :ieedle in conjunction with electric method for detection

>f point of contact; illustrated description of apparatus

.

( md test procedure ; results discussed.

k Tracer Method for the Thickness Measurement of Thin

5i Films, J. J. ANTAL, A. H. WEBER. Rev Sci Instrum

23 Aug 1952 p 424-6. The use of radioactive BrTM as a

racer in thin Bi films prepared by evaporation in a vacuum

'< las resulted in a simple and direct method for the measurei lent of film thickness in the range 1-300 A. The radioetivity of a standard, prepared by evaporating a weigh-

* jlble amount of active Bi on a piece of glass, is compared

5 |d that of a specimen of unknown thickness. For films

".00 A or less in thickness, the ratio of counting rates of

"be "unknown" and standard yields the mass of Bi on the nknown which, together with the film area (measured

"ith a planimeter) and the density of Bi, yields the aver- ge Bi film thickness. Two levels of activity occurring

i the standards were assigned after an electron diffrac- ion study to a difference in structure of the Bi films. The

lethod is accurate for extremely thin films (probable

Tror is less than 4% if counting statistics are carried to probable error of 3% ) , simple procedures and calculaions are used, calibration is continuous, and the specimen

8 not altered in any way.

On the Choice of Measurements to be Made for Simul- taneous Determination of the Optical Constants and Thickness of Thin Absorbing films, D. MALE. CR Acad Sci Paris v 235 Dec 22 1952 p 1630-1 in French. An approxi- mation formerly proposed by H. Wolter relating reflectivities, absorptions and transmission for thin films is re- examined graphically. Using existing experimental data

it is confirmed that the Wolter relation holds for thickness

less than 0.027 of the wavelength of the light used. Further

in the region of optical constants for Ag in the visible the

relation holds whatever the thickness. The method de- scribed enables constants and thickness to be obtained with only three measurements. Two New Methods Allowing the Determination of the Index and the Thickness of a Thin Transparent Film,

F. ABELES. CR Acad Sci Paris v236 Apr 8 1953 p 1412-3

in French. It is shown how one can derive the index and the thickness of a thin transparent film deposited on a transparent base by measuring the transmission factor

of the parallel and perpendicular polarized beams relative

to an incident vibration, polarized parallel and perpendicular to the plane of incidence, the two measurements being

affected at the same angle of incidence. Mathematical

relations are derived so that constants can be obtained having different angles of incidence. The effect of errors of measurements of the values calculated are discussed. The method has been applied successfully to titanium oxide

layers. Measurement and Control of Thickness of Thin Films, K. M. GREENLAND. Vacuum v2 n3 July 1953 p 216-30. Films may in general be measured by gravimetric, photometric, polarimetric, or interferometric methods ; princi- ples and some refinements of methods are described, to- gether with examples of some other methods (X-ray,

radioactive tracer, and electrical) of more limited appli- cation; how methods have been adapted for indication

or control of thickness of films deposited by high vacuum

or sputtering. Bibliography. The Determination of the Film Thickness and Optical Constants of "Thin" Films, C. VON FRAGSTEIN. Zeit Phys vl39 n2 1954 p 163-74 in German. Wolter's formulae

[Z Phys vl05 p 269 1937] connecting the optical constants n and k with the film thickness d are re-examined and

found to be valid only for very small values of d. It is shown that for very thin films the electric, but not the magnetic, vectors of the incident and emergent rays are

related as if d=0. The new expressions and (previous) values for n and fc of Ag, Pt, Pd and Cu show that the upper limit for d for which the theory is valid is 60-70 A. A New Method for the Rapid, Approximate Determination of the Optical Constants and Thickness of a Thin

Absorbing Film, F. ABELES. CR Acad. Sci Paris v238 Feb 22 1954 p 881-3 in French. The complex refractive index of a thin film and its thickness can be found rapidly from the positive root of a quadratic equation involving

the reflection coefficients and transmission of the film. A simplified equation is also given for the case of a highly absorbing film. Comparison of the values derived for a gold film by this and a more exact method shows that the

results are within the limits of experimental error. Film Thickness by X-Ray Emission Spectrography, H. A. LIEBHAFSKY, P. D. ZEMANY. Analyt Chem v28 n4 Apr 1956 p 455-9. When a polychromatic X-ray beam

excites the characteristic line of an element in a thin

film, the intensity of the line may increase with the thick- ness of the film, in which case a measurement of line intensity can be used to estimate the thickness. Owing

to absorption of X-rays by the film, however, the relation- ship of intensity to thickness is not generally simple. This absorption filters and attenuates the polychromatic beam, and attenuates the characteristic line. As a conse- 251
quence, the number of quanta per second contributed to the emergent beam by a layer of atoms decreases with

the distance of the layer beneath the surface. Further- more, quanta originating beyond a critical depth will have

no measurable effect on the detector because not enough

of them will reach it. For the measurement of film thick- ness by the method under discussion, this critical depth may be regarded as a critical thickness. Beta Gauge for Localized Measurements of Thin Films,

O. U. ANDERS, W. W. MEINKE. Rev Sci Instrum v27 n6 June 1956 p 416-7. Uses a narrow pencil of rays from

a 5 mc Pm1 " source mounted on a Lucite disk, a Lucite

collimator and a thin-window G. M. tube. An exploded diagram shows details of the source and collimator as- sembly. The gauge was developed to determine the thick- ness of films used as cyclotron targets and is most sensi- tive for films up to 6 mg/cm2

. The Measurement of Film Thickness with a Pneumatic Hypodermic Needle Mechanism, N. STOLOW. J Sci Instrum v33 n9 Sept 1956 p 333-7. An apparatus is de- scribed by means of which the measurement of film thick- ness may be made on supported polymer films in a nondestructive manner. This apparatus is based on the principle of flow of a gas, e.g. nitrogen, through the space formed by the tip of a cut-off hypodermic needle and a given surface. The theory, an extension of a previous one

for a swelling measurement apparatus, is presented and

appropriate sensitivity expressions are derived. Agree- ment with the theory is good except when the rate of flow parameter is high, and kinetic energy corrections must

then be applied. The r.m.s. error in the location, at a

fixed distance away, of a point on a surface is found to be ±0.2/x. The films are ordinarily cast on optically se- lected flat-faced glass plates which are mounted on the

flat base plate of the apparatus. By lateral sliding action

of the support on the base plate, a number of surface loca- tions are made on the film and around the film edge from

which the mean film thickness is obtained. The r.m.s. error in the mean film thickness is found to be ±0.4ft for

films ranging from 10/j, to greater than 200// in film thickness. The Measurement of the Thickness and the Optical Constants of Very Thin Metal Films, H. WOLTER. Zeit Phys vl47 nl 1957 p 1-23 in German. For a thin metal

film on a glass substrate one may calculate the reflection from each side and the transmission in terms of n, the

refractive index, fc, the absorption coefficient, and d, the

thickness. A phase change is associated with each of these intensities, and at normal incidence the six quantities depend, to a high accuracy, only on the product ndk. Measurement of any two of the quantities gives the other

four, as they are interdependent. The errors involved are discussed and tabulated. At non-normal incidence, with the electric vector parallel to the plane of the film, similar considerations apply. Using light at glancing in- cidence with the magnetic vector parallel to the plane of the film, a different combination of n, k and d can be measured. Photometric Determination of Thickness of Semitrans- parent Metal Layers, L. S. PALATNIK, G. V. FEDOROV.

Dokl Akad Nauk SSSR vll3 nl 1957 p 100—3 in Russian. Measurement of Thickness of Thin Carbon Films, A. W. AGAR. Brit J App Phys v8 nl Jan 1957 p 35-6. Refer- ence to use of evaporated carbon films prepared by method of D. E. Bradley widely used in electron micros- copy; nearly linear relationship has been found to exist between optical density and thickness of evaporated car- bon films ; determination of film thickness by density measurements is shown to have number of advantages

over measurement by interferometry particularly for very

thin films.

Different Methods for Determination of Thickness of Si ver Film, P. SEN, P. S. RAO. Glass Indus v38 n2 Fe

1957 p 89, 112. Comparison of methods for silver fin deposited on glass surface, including : volumetric anali I sis (by titration), direct weighing, and Fizeau's iodhn

crystal test. On the Reflection Coefficients of Thin Lacunal Film

P. DUMONTET, M. PERROT, J. TORTOSA. CR Aca

Sci Paris v244 n20 May 13 1957 p 2488-91 in French. 1 is pointed out that the observed variation, with thicknes; of the complex reflection coefficient for the substrate sid of a silver film deposited on a transparent support differ markedly for thicknesses less than 100 A from that <M

pected theoretically. A transitional layer at the substrat ! is suggested as the cause of the anomaly.

Optical and Electrical Methods of Measuring Thicknes

of Thin Metallic Films, Y. G. NAIK, E. M. BALSARA

Indian J Phys v31 nl2 Dec 1957 p 607-10. Measuremen

of thickness of chemically deposited thin films of silve; are made from (i) the study of the absorption of ligb and (ii) from the electrical conductivity of these films. I

is shown that the thicknesses determined by the tw j methods are of the same order. Film Thickness Determination From Substrate X-Ra

Reflections, D. T. KEATING, O. F. KAMMEREB

Rev Sci Instrum v29 nl Jan 1958 p 34-6. A method i given for the determination of the thickness of films usin X-rays diffracted from the substrate. The X-rays pas through the film and are diffracted by the substrate bac

to the counter, the intensity being reduced by absorptioi due to the double transmission through the film. N

assumptions need be made about the substrate reflection Unknown conditions of the substrate are eliminated b; measurement of the intensity of two orders of a reflec tion, or measurement of the intensity of a reflection usins two different incident radiations. The method is suitabl for all types of film, and is particularly useful in meas

urements of films containing elements of the substrate fo which cases X-ray fluorescence techniques are of littli value. The procedure is illustrated with a measuremen

of the thickness of zirconium nitride on a zireoniun

substrate. Swept Frequency Eddy-Current Device to Measure Over

lay Thickness, E. A. HANYSZ. Rev. Sci Instrum v29 n! May 1958 p 411-5. An instrument is described whici enables nondestructive measurements to be made of filn and overlay thicknesses. It utilizes the change in electri cal impedance of a composite sample resulting from dif ferences in the thickness of the material being measurec

to cut-off a swept-frequency oscillator at a frequency deter mined by that thickness. Operating frequencies frori 200 kc/s to 20 Mc/s have been used with frequency-sweei

widths, or deviations, up to 10% to measure overlay thick nesses ranging from 0.00005 to 0.007 in. on composite samples in which the eonduetivity-to-permeability ratk

of the base and overlay differ by at least a factor of two

Equations are developed to illustrate the conditions foi which a reactance-tube oscillator is employed in a uniqu* manner to make the measurement automatic. The Measurement of Critical Thickness of Aluminium

Films, V PUCALKA. Czech J Phys v9 n5 1959 p 668-9

in German. The critical thickness referred to is that

at which a finite electrical conductivity can be measured The value measured in vacuum is smaller than that in

air because oxidation will isolate particles which mak'

good contact in vacuo. In vacuo the critical thickness

is about 23 A and the transparency is about 73%.

Semiempirical Method of Determining Thickness Along Wedge-Shaped Thin Layer, M. P. LISITSA, V. M. MAEV- SKII. Instrum & Exper Techns (English translation of Pribory i Tekhnika Eksperimenta ) n3 May-June 1959 252
>_ P 459-66. Method makes it possible to determine thick-

- ;-t- ness distribution along wedge-shaped tbin layer deposited

Hi on bard base layer ; formulas, taking into account coeffic ient of substance accommodation on base layer, variation

it of layer density with thickness, imperfections of evaporar >r construction, and other factors.

-•'id Calculation of Thickness of Films Resulting From Vaporiafe zation in Vacuum, A. P. RUMYAXTSEV. Instrum &

- > Exper Techns (English translation of Pribory i Tekhnika

Eksperimenta ) no Sept-Oct 1959 p 802-5 17 refs. Distri- button functions for thickness of thin films, taking into account commensurability of dimensions of vaporizer and

-:•: distance from it to point of condensation, as well as spatial

distribution law for vaporization products. Measuring the Thickness of Thin Celluloid Films, I. S. DMITRIEV, TA. A. TEPLOVA, V. S. NIKOLAEV, L. N.

1 FATEEVA. Pribory i Tekh Eksper. (USSR) 1959 n6

"cefc P 131 Nov-Dec in Russian. A photometric method was

js- developed for measuring the thickness of organic films in st the range 2-20 g/cnr. Although their light-absorption

-_.'* coeflBcient is so small, use was made of the effects of

( interference in reducing considerably the transmitted

. intensity ; the transmitted intensity first falls with increas- ing thickness of the film, reaching a minimum at about

- v 0.1/t thickness, after which it begins to rise again and vary

njj a periodically. In addition, the colour of the reflected light

.^T; gives a guide to the particular absorption cycle corre- sponding to the measured intensity, thus eliminating in- "T determinacy. A formula relating the transmitted inten-

•tfj to ***e incident intensity in terms of film thickness, _*J refractive index, absorption coefficient, and illumination

Vt wavelength is given. [English translation in : Instrum

Exper Tech. (USA) n6 p 987-8 Nov-Dec 1959; publ. Sept

I960]. Measurement of the Thickness of Thin Foils, G. M. OSETINSKII, M. V. SAVENKOVA. Pribory i Tekh fUSSR) 1959 n6 p 114-6 Nov-Dee in Russian. The thick- ness of thin foil windows for gas target applications was

measured in terms of the sharp fall off in absorption of Po510 a-particles at the end of their range. The foils were

introduced into a vacuum chamber between a polonium

source and a ZnS crystal with photomultiplier detector. The particle count taken at various air pressures in the

• L range 100-760 Torr was plotted with and without the foil

Y

'T. in position to obtain complete absorption curves. The

'^r displacement of the curves in terms of differences in air pressure (at half height) could be interpreted directly

.~t in terms of the equivalent foil density in mg/cm2

. The

f« aPParatus was used for nickel foils from 0.8 to 1.5/t (0.9- JTe 1.6 mg/cm5 ). The achievable accuracy was investigated

:~Jl, by comparison with weighed samples and was estimated

'OL to be of the order of 1.5% for foils of similar thickness to a standard and 3-4% if samples are of considerably dif-

'7L ferent thickness. [English translation in : Instrum iT Exper Tech (USA) n6 p 971-3 Nov-Dec 1959; publ Sept "T I960]. A New Device for Measuring Thickness of Evaporated

Metal Film by Use of X-Ray Interference Fringes, T. FUJIKI, T. YOSHIDA. J Phys Soc Japan v!4 nl2 Dec

1959 p 1828. A modification of Keissig's method is described, in which a comparatively broad source of X-Rays

can be used. On the Possibility of Determining the Optical Constants and Thicknesses of Very Thin Metal Films Using Measurements at Normal Incidence, C. SCHWINK, H. PEHLAND. Zeit Phys vl58 nl 1960 p 12-25 in German. A

theoretical examination of the deductions possible from

a knowledge of the complex amplitudes transmitted, and

reflected from either side. If the thickness d is assumed

to be small with respect to the wavelength, the equations expanded in powers of d and the first terms only taken, then a complete solution is impossible ; by taking into ac- count higher powers, d and the optical constants n and

k can be calculated, but for small d the equations are

ill-conditioned ; in general only the product nkd can be

calculated with good precision when d is small. It is shown

also that Schopper's three-line method is invalid since the method involves taking only the first terms in the above

expansion. If d is known then n and k can be calculated. Messung kleiner Schichtdickenunterschiede in duennen

nichtmetallischen Schichten (Measurement of Small

Thickness Differences of Thin Non-Metallic Films),

G. KOPPELMANN. Ann Phys v5 n7-8 1960 p 397-404. Apparatus based on recording of reflections from various

points measured ; results for cryolite evaporation characteristics of particular furnaces ; application of method to multiple layers and to dispersion effect of film substances. Variation des Constantes optiques du Bismuth en Couche

Mince, en Fonction de l'Epaisseur, entre 2.5 et 10/i. (Variation of Optical Constants of Thin Bismuth Films

as Function of Thickness Between 2.5 and 10/i), R. BURTIN. CR Acad Sci v250 nil Mar 14 1960 p 1998-2000. X-ray and electron microscopic study of films evaporated

in high vacuo; thickness measurements; calculation of

indices n and k. Simple Method of Determining the Thickness or the Refractive Index of Thin Films, K. V. KRISHNA RAO. Am J Phys v28 n5 May 1960 p 447-9. A simple method

of determining the thickness or the refractive index of

thin films using double-slit Fraunhofer diffraction fringes

is described. To illustrate the method, the thickness of grey photographic film and the refractive index of a

cellulose acetate film have been determined. Measurement of Thickness of Thin Transparent Films Using Fluorescence, B. P. BUNT. Brit J App Phys vl2 n4 Apr 1961 p 175-7. Molecular fluorescence method of comparing thickness of transparent films (in range 3X10-6 to 102 cm) is described; instrument for use in middle of this range (10"' cm) is also described; results show that accuracy is better than plus or minus 2% ; applicability e.g. to organic coating of tinplate or etc. A Determination of Thin Oxide Film Thickness by In- tegrated Intensity Measurements, B. BORIE, C. J. SPARKS. Acta Cryst (Int) vl4 Pt6 June 1961 p 569-70. The thicknesses of thin single-crystal oxide films are determined by integrated measurements in absolute units. The method is illustrated with measurements of Cu2 0

films grown on copper single crystals. Thicknesses de- termined from two different Bragg maxima agree well with each other, and are reasonably consistent with the

thicknesses determined from the line shapes. The Use of X-Ray Fluorescence in the Nondestructive Measurement of Thin Film Composition and Thickness

over Small Areas, R. WEYL. Zeit angew Phys ( Germany

)

vl3 n6 June 1961 p 283-8 in German. The beam from a

tungsten fine-structure tube was reduced to about 1 mm*

at the specimen using a diaphragm. The fluorescence radiation was analysed in a vacuum using lithium fluoride crystal; a proportional counter was used as a detector. The intensity variation of the excitation radiation was

also analysed in the same way using a scintillation counter and pulse-height analyser. Calculations showed that the mass distribution of thin nonhomogeneous films could be determined by taking into account the intensity distribu- tion of the exciting radiation, the fluorescence field and

all losses in fluorescence radiation on the way to the

detector. The accuracy of the method was tested for

nickel-iron layers of thickness up to 1000 A. In a theoretical investigation it is shown that secondary excitation can be neglected in the case of thin films. In films consisting of two types of atoms the intensity ratio of the secondary to the primary fluorescence radiation of the

lighter element is proportional to the mass coverage of the heavier element and independent of the mass cover- age of the lighter element. 253
Measuring Thickness and Composition of Thin Surface Films by Means of Electron Probe, B. W. SCHUMACHER,

S. S. MITRA. Proc Electronic Components Conf 1962 p

152-61. Tests to show that thickness measurements with

electron probe, utilizing range-energy relations for elec- trons, can be of same order of resolution that can be

attained with multiple beam interferometry ; lateral reso- lution of electron probe may be even better; results of experiments with gaging probe are also of interest in con- nection with microprobe X-ray analysis of thin films. Measurement of the Thickness of Vacuum Deposits Using

the Electron Microscope, D. CHESCOE, J. S. HALLIDAY.

Nature (GB) vl93 Feb 3 1962 p 434-7. Shows that the

thickness of vacuum-deposited films ranging from 20 to 2000A can be determined accurately in the electron microscope. The method is that of Bradley in which a layer

of condensed hydrocarbon molecules is used as a marker

against which the deposited material piles up. The film thicknesses measured in this way are in good agreement

with those obtained by optical interference methods. A Note on Silicon Oxide Film Thickness Measurement,

H. M. ROBERTSON, J. E. MONAMARA, R. M. WARNER,

JR. J App Phys (USA) v33 n9 Sept 1962 p 2909. A

standard interferometric technique can be used to measure

the thickness of an unmetallized silicon oxide film if al- lowance is made for the film's optical properties. Use of Frustrated Total Internal Reflection to Measure

Film Thickness and Surface Reliefs, N. J. HARRICK.

J. App Phys (USA) v33 n9 Sept 1962 p 2774-5. When

total internal reflection of light occurs, radiation penetrates beyond the reflecting surface into the rarer medium

where the intensity decreases with distance from the

interface in an exponential manner. Since the degree

of coupling to this radiation can be controlled by adjust- ing the proximity of another object to this interface, it is possible to utilize this phenomenon in the measurement

of film thickness and to obtain high contrast images of surface reliefs. Film Thickness Determination with a Scintillation Counter, H. R. LUKENS, JR. Analyt Chem (USA) v34 nil Oct 1962 p 1396-7. A long-lived luminescence induced

in organic lubricant films by ultraviolet light has been employed to determine the thickness of the films. The

luminescence is measured and recorded with a multiplier phototube and scaler, and has been found to be proportional to film thickness. The phenomenon, long-lived luminescence, has been observed in many organic materials, which indicates that the method should be widely

applicable. The Use of Ferromagnetic Domain Structure to Deter- mine the Thickness of Iron Foils in Transmission Electron Microscopy, D. H. WARRINGTON, J. M. RODGERS,

R. S. TEBBLE. Phil Mag (GB) v7 Oct 1962 p 1783-90. The thickness of foils of f.c.c. metals can be determined

in the electron microscope by observations on slip systems

or twin boundaries. In b.c.c. metals these methods fail, and estimates from extinction contours are not very accurate. A method is proposed for iron which relies on the

deviation of the electron beam in passing through a magnetized layer. The specimen is positioned so that a do- main boundary is in the beam, which thus passes through two regions in which the orientation of the magnetic vec- tor differs. The beam is split into two parts, giving two

diffraction spots, the angular separation of which is a

function of the film thickness as well as of the angle be- tween the magnetic vectors. By selecting simple domain

configurations in which the magnetic orientation is clear, the film thickness can be found from the spot separation. The specimen must be placed outside the magnetic field of the electron lens. Results are given of a comparison between this method and the extinction distance method.

Examination. o£ Surfaces With A;d of X-Ray Reflection, i R. SCHEIDEGGER. Brown Boveri' Rev v49 nll-2 NovDec 1962 p 555-68. Description of asymmetrical X-ray

reflection method; calculation of layer thickness of dif- fracting surfaces; features of Legrand camera and use-i ! of counting-tube goniometer for examination of surfaces

examples of how method can be applied in practice; quan-;j ! titative investigations on crystalline powders.

| f Method for Measuring Thickness of Thin Bent Foils in Transmission Electron Microscopy, P. DELAVIGNETTE,

R. W. VOOK. Physica Status Solidi v3 n4 1963 p 648-53. New method of thickness measurement of thin monocrystalline foils in range of 1000 A; method is based on > observation of Kossel-Moellenstedt fringes in transmission electron microscopy ; it differs from classical Kossel- j Moellenstedt method by fact thatr no divergent beam is needed ; however, foil should be bent and method is based

on measurement of radius curvature.

I' E Nondestructive Method of Measuring Thickness of Trans- i parent Coatings, T. M. MANSOUR. Matls Res & Stand r v3 nl Jan 1963 p 29-32; Quality Engr v 27 n2 Mar-Apr

1963 p 46-9. Method utilizes commercially available: s optical instrument, Zeiss light-section microscope; it is t r, applicable to thickness measurement of transparent coat- ings of 0.1-10 mils, over both metallic and non-metallic

substrates; main limitation is its ineffectiveness with

substrates that are highly light diffusing; comparison ! with other methods is shown for aluminum oxide on Al, : clear synthetic enamel on steel, clear plastic and micro- scope slide glass on air.

|i I Activation Method of Measuring Thickness of Thin Films and Foils, F. P. DENISOV. Instrum & Exper Techns ! _ ; (English translation of Pribory i Tekh Eksper) nl Jan- i. Feb 1963 p 146-8. Simple method of measuring thick- ness of film, with and without backings, is based on use i of artificial radioactivity and can be used to measure films with thickness down to ljttg/sq cm.

ij Determination of the Thickness of Coatings by Recording

Scattered Beta Radiation, TU. S, ZASLAVSKII, G. 1 I SIIOR. A. I). STUKIN, E. D. STUKIN. Pribory i Tekh

Eksper (USSR) 1963 nl p 149-52 Jan-Feb in Russian. English translation in: Instrum Exper Tech (USA). At fj simple beta-ray back-scattering gauge, incorporating an end-window Geiger counter and a 1/ic source, is described.

8 IS A Simple Method for the Measurement of Small Thick- I nesses and Length Variations, A. H. BOERDIJK. Ned :' Tijdschrift Natuurkde (Netherlands) v29 n2 Feb 1963 p 53-5 in Dutch. The apparatus uses a convex lens and* 1 a glass plate—a sort of inverted spherometer—to measure the thickness of thin wires etc. Length changes can

also be measured.

Interferometric Evaluation of Thickness of Canada Bal- i sam and Collodion Films and Its Relation to Concentration of Solutions, N. BARAKAT, A. A. A. MOHAMED. ' A. EL BIALY, K. A. AZIM. Brit J App Phys vl4 n3 Mar 1963 p 144-6. Films prepared using fixed area of water surface; graphs and tables enable preparation of V thin films of known thickness for electron microscope tech- 1,1 niques in which exact thickness of carbon or silicon repli- cas deposited on films is required ; effect of temperature

on film thickness studied ; heating films enabled production of thinner films of known thickness.

? as Snr l'Epaisseur limite au-dessous de Laquelle on ne Peut *

Plus Determiner separement les constantes optiques et l'Epaisseur d'une Couche Mince Absorbante (Thickness

limit below which it is not possible to measure sepa-

"'' rately optical constants and thickness of absorbent thin

films), D. MALE. CR Acad Sci v256 n21 May 20 1963 p 4381-3. Method of normal incidence cannot be used below certain thickness because curves giving factors of -i 254
reflection, transmission, and phase change may be actually confounded with their tangent lines. Measurement of Thickness of Foils and Films by Means of

Soft X-Kays, S. I. LOBOV, V. A. TSUKERMAN. Instrum & Experimental Techniques (English translation of Pribory i Tekhnika Eksperimenta) n4 July-Aug 1963 p

757-61. Soft bremsstrahlung and characteristic X-ray

emission excited by tritium are used to measure thin

foils and films in thickness range lO^-lO"5 cm; Geiger

counter is used as detector; sensitivity of 3X10"6 g/sq cm

can be obtained with method when wavelength of characteristic emission is chosen to correspond with selective absorption at K, L, or M levels of foil material : method

is effective for measurement of metal foils and opaque

films in mass range ( 5-30) 10"6 g/sq cm. Method for Continuous Measurement of Thickness and

Deposition Rate of Conducting Films during Vacuum

Evaporation, J. A. TURNER, J. K. BIRTWISTLE, G. R. HOFFMAN, J Sci Instrum v40 nil Dec 1963 p 557-61. In method described, operational amplifiers are employed

I to monitor change in resistance of deposited layer, and

: their outputs used to serve control deposition rate and

I automatically cut off vapor stream, when deposit has

reached predetermined thickness ; equipment allows close control of deposition rate and thickness, thereby increas-

: ing uniformity of deposited layers during successive

; evaporations. Survey of Methods of Measuring Thin Film Thicknesses

• and Surface Irregularities, P. WRIGHT. Electronics

Reliability & Micro-miniaturization v2 n3 Dec 1963 p 227-

33. Methods of measuring thin film thickness and sur-

\ face irregularities are evaluated ; 2-beam interference

i microscope and multiple grid light profile technique are

- found to be most useful in research ; other methods and

- their properties are summarized in chart.

j Determination Simnltanee ries Indices et de l'Epaisseur

des Couches Minces Absorbantes, D. MALE. J de Physique v25 nl-2 Jan-Feb 1964 p 74-7. Simultaneous deterjj mination of optical constants and thickness of absorbent

thin films ; it is advanced that optical indices of metallic

thin films determined before 1950 are not valid ; graphical method is indicated for simultaneous determination of

optical constants and thickness ; method uses three

3 measurements at normal incidence of intensities and phase

i differences ; method cannot be applied to very thin layers

results are compared with those of other authors. Microscopic Observation of Film Cross Sections Having

•i -i Steep Contours, B. R. FRIEDEN. App Optics v3 n3 Mar

j 1964 p 395-8. New method is proposed for microscopic

observation of thickness distribution across thick (greater than about 12 n ) transparent film ; quality of observation

is analyzed by expressing resolution error, image intensity, and depth of focus in terms of refractive index and

geometrical constants of thickness distribution; constraints are derived governing design of viewing system by algebraically demanding that resolution error be suffi- ciently small, and image intensity and focal depth be

sufficiently large; constraints upon system parameters seem to be physically realizable. Instrument Measures Thin Film Thickness. Electronic Products v7 n6 Nov 1964 p 36 127. Probe and circuit design of measuring instrument for detection and thick- ness measurement of nickel, cobalt, aluminum, copper, and iron thin films; instrument has 0.001 in. full-scale reading with minimum increment of 20 juin. ; it is applic- able to nondestructive testing and can be used as flaw

detector to determine cracks and imperfections in metal

strips. Film-Thickness Measurements, J. G. COLLIER, G. F. HEWITT. ASME—Paper 64-WA/HT^ll for meeting Nov 29-Dec 4 1964 19 p 53 refs. Methods which have

been applied to estimation of thickness of liquid films in various types of film flow can be divided into two general classes—measurements of average thickness over con- siderable length of film—measurements of local thickness

both types of determination have been used to obtain temporal mean averages and second type has been used

to present information on time variation of thickness;

practical problems associated with application of various techniques are discussed ; relevance to lubrication is noted. Optical Constants of Thin Films, P. ROUARD, P. BOUSQUET. Progress in Optics, E. WOLF, North-Holland

Pub. Co., Amsterdam, v4 1965 p 145-97 26 figs 184 refs. A review article dealing with optical constants and

structure of transparent thin films and optical constants

of absorbing thin films. Routine Mass-Thickness and Nonuniformity Determinations of Thin Films, K. F. WYLIE, and G. R. HAGEE.

Nuclear Instrum Methods ( Netherlands) v32 n2 Feb 1965 p 201-3. A routine technique to rapidly determine the thickness and uniformity of thin plastic films and of thin

plastic films coated with beryllium was developed. The

thicknesses of Formvar films approximately 20 to 100 /ig/ cm2 and beryllium coated films (approximately 20 to 70 Mg/cm2 of beryllium) were determined using alpha-particle attenuation techniques. Film thicknesses were deter- mined by both alpha counting and destructive weighing. The difference between the two techniques was within

the experimental error of 7.5%. Addendum to Section 11

11.2. Polarimetric Methods (Ellipsometry)

Optical Measurement of Oxide Thickness on Titanium,

R. C. MINARD. General Mills, Inc., Electronics Group, Research Dept., Minneapolis, Minn. J Opt Soc Am v52 n4 Apr 1962 p 427-31 4 figs 18 refs. Reflectance of thermally

oxidized, mechanically polished titanium surfaces was

measured with a spectrometer at 5889-5895 A. The principal aim of the experiments was to furnish an optical means of measuring the thickness of thermal oxide layers on titanium. These measurements also provided a method

for determining the optical constants of the metal and the thermal oxide.

Error in Dielectric-Film Ellipsometer Determinations due

to Neglect of Film Absorption, D. W. PETERSON, N. M. BASHARA. J Opt Soc Am v55 n7 July 1965 p 545-50 13

figs 13 refs. The error in the calculated refractive index

of an absorbing dielectric film, which is determined by approximate equations that neglect absorption, is influ- enced by the true refractive index of the film and the controllable parameters—substrate and measuring wavelength. Such equations give two relations for calculation

of thickness. It is shown why one of these equations gives an insignificant error when small absorption is present and

an independently determined refractive index is used in the thickness calculation.

255
i

-

-
Section 12. Measurement and Production Techniques for Accurate

In-Process Control of Size and Form

CONTENTS

Page

12.1. General 257

12.2. Machine tools 259

12.3. Automatic control 262

12.4. Grinding 265

12.5. Lapping 266

12.6. Manufacture of precision measuring tools and components 268

12.6.1 General 268

12.6.2. Scales and gratings 270

12.6.3. Worms and power screws, including lead screws 271

12.6.4. Screw thread gages 273

12.6.5. Other gages 274 Addendum to Section 12 276 12.1. General

On Plane Metallic Surfaces or True Planes, J. WHIT- WORTH. Pub. in Miscellaneous Papers on Mechanical

Subjects, J. WHITWORTH, Longman, Brown, Green, Longmans, and Roberts, London 1858. Paper read at meeting of the British Association in Glasgow, 1840 p 3-19. Describes method of generating a true plane by matching

three surfaces. Problem of the Theoretically Correct Involute Hob, N. TRBOJEVICH. Machy (N.Y.) v25 Jan 1919 p 429-33

3 figs. Discusses interchangeable involute gears, generating an involute surface, analysis of involute tooth surface, theory of pressure angles, correct tooth curve of straight-gashed hobs, and hob versus spiral gear. Hobbing Spiral Bevel Gears, N. TRBOJEVICH. Machy

(N.Y.) v23 n582 Nov 22 1923 p 225-35 16 figs 6 refs. Describes a hobbing process for producing accurate spiral bevel gears or hyperboloidal gears having spiral teeth.

It is stated that gears produced by this method are more

nearly correct than any so far produced. The Pratt and Whitney Gear-Shaving Process, H. D. TANNER. Machine Shop Practice (ASME Trans) v50

n27 Sept-Dec 1928 p 17-22 22 figs ; Automotive Industries v59 nl8 Nov 3 1928 p 625-7 12 figs; Am Mach v69 n!7

Oct 25 1928 p 659-61 11 figs ; Iron Age vl22 nl6 Oct 18

1928 p 949. Practical method of generating involute spur

or helical gears at zero degrees which was invented by

J. H. BARNES, Dayton, Ohio. Active profiles of gear

teeth are generated by rolling gear in mesh with zero- degree rack ; active profiles of this rack are top edges of

its teeth, which coincide with cutting edges of tools ; tools have straight cutting edges slightly longer than face of gear to be cut. Mechanical Generation of Form. Eng vl56 n4049 Aug 18

1933 p 163-^. Definition of word generation in sense used by engineer ; author inclines to belief that true generation of forms other than primitive forms demands use

of mechanism involving nothing but link work and that

only those forms which are capable of being expressed by

combination of links are capable of being generated in true and proper sense.

Precision Workshop Methods, H. J. DAVIES. London, Edward Arnold & Co. ; New York, Longmans, Green & Co. 1935 306 p illus diagrs charts tables. Essential ideas upon

which precise machining of machine parts depends ; methods of setting out work, devices for setting work for machining, graduating and indexing, screw cutting, profiling, cutting gear teeth, and lapping and grinding limit gaging, testing machine tools, and related topics discussed. Eng Soc Library N.Y. Instruments in Machine Tool Industry, B. R. HILL. Western Machy & Steel Wld v27 n9 Sept 1936 p 328-9. Quantities which must be easily and quickly determined by

operator to obtain most from any motorized production

tool ; application of instruments ; selection of ratings

measurement of speed and position ; position shown electrically. From talk before representatives of 40 machine

tool manufacturers. The Honing Process for Cylindrical Bore Finishing, J. E. ANDRESS. Tool Engr v6 n2 June 1937 p 14-5, 26 28-9 4

figs ; Machy (N.Y.) v43 n8 Apr 1937 p 526-9. Work adaptable to honing ; preparation ; metals and holes honed ; honing angle of cross hatch ; hydraulic dwell ; strokes and

cycles; size and position of holes honed; connecting rod honing ; coolant. Bearbeitungsfragen der Feinmechanik (Machining prob- lems in precision parts manufacture), H. HEMSCHEIDT.

Masehinenbau vl6 nl3/14 July 1937 p 343-6. Illustrated description of modern methods and tools for machine

cutting and stamping operations on precision parts ; measuring and testing methods.

Materials for Precision Machinery, C. FUJIL. Japan

Nickel Rev v6 nl Jan 1938 p 53-76. In English and

Japanese. Requirements for precision machines and tools and properties required in materials for this purpose ; materials for beds of machine tools and measuring instru- ments, for spindles, guide screws, bearings, gears, standard

scales, gages, etc ; use of nickel in these materials emphasized. Generating Small Precision Gears, A. THOMPSON. Tool Engr v9 nl May 1940 p 9-12 85 14 figs ; Can Machy v51 n3 Mar 1940 p 70 72 74 116. Essentials of gear tooth generat- 257
ing considered; fundamentals of cutting teeth; cutting gears on turret lathes ; cutting precision gears. Tolerance and Dimensional Control—Its Effect Upon Air- plane Production, H. ADAMS. Mech Eng v65 nlO Oct

1943 p 739-40. Major problem confronting aircraft industry is attempt to eliminate rework required on assembly

to* make parts fit ; handwork is required because of cumulative errors in wrong dimensions and wrong tolerances

major part of solution lies in engineering, by designing to avoid overconstraint, exact dimensioning and application

of correct tolerances; tooling steps should be reduced in number and improved in accuracy. Generation of Conic Sections with Machine Tools, R. T. HINKLE. Prod Eng vl8 n8 Aug 1947 p 162-5. Application of two theorems from projective geometery duplicated by kinematic linkages, for generation of ellipse, hyperbola ; kinematic schemes for generation in accordance with these theorems are illustrated ; basic machine di- mensions are analyzed and conversion of design dimensions

of parts into machine settings for production is described. New Appliance for Measuring Angles of Pieces Being

Machined, G. KANN. Microtecnic v3 n5 Sept-Oet 1949 p 232-3. Illustrated description of appliance designed for checking dimensions and angles of pieces in course of manufacture without, separating them from machine. Modern Methods of Gear Manufacture. National Broach and Machine Co., Detroit. 3rd ed 1950 revised 1964 164 p 170 figs. Contents : Gear design principles ; gear formulas ; selection of gear steels ; heat treatment of gear steels : machining gears ; advanced production practices ; special gear problems and case histories ; red ring products ; gear

broaching. Chapter 6 on advanced production practices describes in detail the shaving process of finishing gear

teeth. Method of Controlling Profiles, A. MIRAU. Rev Opt v32

July 1953 p 418-22. In French. Control method for machining profiles, giving about 0.01 mm accuracy for pieces several centimeters in size. Zahnriider: Stirn- und Kegelrader mit geraden Zahnen

(Gear Wheels: Spur and Bevel Gears with Straight Teeth), W. LINDNER. Springer-Verlag 1954 133 p 183

figs 37 refs. Consists of two main parts: (1) the kine- matic and mathematical tooth cutting in the radial plane;

(2) application of the mathematical fundamentals. Contains a chapter (p 96-108) on the production of gears by form milling, form grinding, rolling, and lapping, and

the errors involved. Ein Beitrag fiir Ermittlung von Schleifscheiben- und Fraserprofilen zum Erzeugen geradflankiger Gewinde (A Contribution for the Ascertainment of Grinding-Wheel and

Milling-Cutter Profiles for the Production of Straight- Flank Screw Threads) , M. GARY. Werkstattsteehnik und

Maschinenbau, v46 nlO Oct 1956 p 510-3 2 figs 7 refs. With a given position of the grinding-wheel or millins- cutter axis with respect to the thread axis, the article develops the fundamental equations for calculating the workpiece profile in an axial section. The process is applicable to both straight and taper threads, external and

internal. How to do Precision Machining in Uncontrolled Temperatures, H. K. EITELMAN. Am Mach vl03 n21 Oct 5 1959

p 96-8. Problem of eliminating heat expansion which

can move part dimension completely out of tolerance; simple temperature correction method described which makes it possible to standardize machining and gaging when perfect temperature control is impossible ; how and when to compensate ; type of equipment needed.

Determination of Errors in Mechanisms with Lower Pairs. 1 V. A. SHISHKOV. Meas Techns 1958 n6 Mar 1960 r I 626-9 5 figs. Translated from Izmer Tekh Nov-Dec 195? I p 12. In the calculation of errors in a real mechanism I the permissible variations in the dimensions of its links I and the deviations in the positions of the centers of pin- or slots on the column are usually given. The errors in 1 position of other links for the given position of the driv- ing link have to be found. The method developed by the author makes possible the construction of a single poly- gon of small displacements without drawing the trans- formed mechanism. The polygon of small displacements provides the complete solution of the problem of deter > mining the effect of all links upon the position error ol the driven link (and also upon the position error of any

of the links of the mechanism)

Making Parts to Millionths, R. LeGRAN, H. SOKOLSKY

|

Am Mach/Metalworking Mfg vl06 n4 Feb 19 1962 p 105-8. :j How Raytheon Co. made sudden switch from experimental j: output to full-scale production of missile servos, to ac-W

curacies of 10 millionths in. for size, roundness, and taper : |l : major steps in making missile control valves. Development of Modern Electrical Instrument-Making. J A. M. DAMSKI, G. I. KAVALEROV. Meas Techns 1962 nl June 1962 p 4-9. Translated from Izmer Tekh nl Jan I 1962 p 4-8. Discusses many phases of the design and j

: production of electrical instruments. States that the 1 automation of production control raises a number of prob-1 lems in the production of specialized devices and systems j- which would provide, in addition to normal measurements | the control of complicated aggregate specialized measur

ing equipment operating with controlling computers. Die Fertigung von Genauigkeits-Grosszahnraedern (Pro- duction of large marine gears of high precision), W. DREYHAUPT. Werkstatt und Betrieb v95 nil Nov 1962 p 733-43. Details of gear hobbing machine and operating

conditions, manufacturing procedure and measuring and

safety devices employed ; numerous measurement results presented indicate accuracy of gears. Female Centers Influence True Roundness, G. L. DANNE- HOWER. Tooling and Production Jan 1964 3 p 7 figs. I Stresses the importance of true geometric center holes, i established alinement of axis, and close dimensioning

tolerancing between centers. Temperature Variation Effects on Dimensional Accuracy

in the Machining of Aluminum, D. WEISMAN. Tool and Mfg Engr v52 Feb 1964 p 91-6. This paper is ant investigation of temperature variation effects on di- 1 mensional accuracy in the machining of aluminum. Iti examines the thermal expansion differences between aluminum and steel and discusses the techniques of controlling the aluminum work-steel gage dimensional

difference. Tolerance ranges are presented for appraisal

of the dimensional error with reference to ±0.000050", ±0.0001", and ±0.00025". This investigation is signifij cant for manufacturing capability in the manufacture of

precision components.

Application of the Least Squares Method for Evaluating'

the Precision of the Technological Operation in the Process Control of Components' Dimensions, I. V. DUNIN-. BARKOVSKII. Meas Techns n5 Nov 1964 p 374-8 1 fig- 5 refs. Translated from Izmer Tekh n5 p 10-3 May 1964. | A method for evaluating the precision of technological j operations with process control of component sizes based on the least squares method is suggested in this article. I The method is convenient in practice and avoids the

theoretical difficulty in selecting the number of observa- j tions which would ensure a given precision and reliability j in evaluating for instantaneous distribution parameter . without at the same time distorting its value by variations with time in the position of the size dispersion center.

258
12.2. Machine Tools

i- Checking Lathes for Accuracy. American Tool Works. 2>Iachy (N.Y.) v30 Nov 1924 p 195-9 12 figs. Discusses

- eating lathe beds for straightness and parallelism, inspec- tion of lead screws, checking of headstock spindle, in- spection on the erecting floor, truing the faceplate and set- U ing the compound rest, alining the taper attachment, and

. -£»ther detail tests. >3jNPL Test on Carson Jig Boring Machine. Machy (London) v33 Nov 8 1928 p 186; Am Mach v69 1928 p 113. Jives results of tests on motion of table, motions of drill- ng head along slide, other motions, flexure of supporting

olumn, abutment faces for gages, squareness of drilling

.pindle to table, measurements of sample jig produced on

nachine. Refinements in Finishing Cylindrical Bores. J. W.

3INDES. J. G. YOUNG. ASME Advance Paper for meetg June 9-12 1930 9 p ; Automobile Engr v20 Aug 1930

303-4 : Abrasive Industry vll Aug p 25-7 and Sept 1930

28-30 6 figs. Limitations of boring, reaming, burnishig, and broaching; outline of grinding practice; operaion and advantages of hone ; coolant and abrasive.

)as Arbeiten mit Messeinrichtungen neuzeitlicher Caagerecht-Bohr- und Fraeswerke (Application of measring Equipment to Modern Horizontal Boring and Mill- Qg Machines), E. ZIEGENHALS. Werkstattstechnik

27 n6 Mar 15 1933 p 114-7. Accuracy obtainable with

pecial regard to application of end measures and recordlg scales ; examples of practical application.

recision Finish Machining. O. SCHLIPPE. Eng Progr

16 nl Jan 1935 p 29-32. Trend of development in design

f fine turning and boring machines, cutters, lapping and

oning machines ; illustrations. oring Equipment Adapted for Close Limit Machining of utomotive Pistons and Cylinders, W. F. WISE. Iron

ge vl35 n9 Feb 28 1935 p 20-3. Precision boring equiplent arranged for diamond turning of pistons with ellip- cal and tapered skirt to limit of 0.00005 in. on major

nd minor diameters and on taper, and set-up for single- pint finish boring of cylinders to unusually close limits. iternal Surface Finishing to Finer Limits, A. W. CHNEIDER. Can Machy v46 nil Nov 1935 p 13-5, 32. evelopment of standard precision boring machines due to gid requirements of manufacturers of automobiles, airi.anes and electric refrigerators for increased accuracy

ithout increased cost ; automatic control.

er heutige Stand der Feinstbearbeitung (Present status

" precision working) . C. BUETTNER. Zeit Metallkunde

IS n4 Apr 1936 p 91-6 ; (discussion) Metal Progr v30 n6

ec 1936 p 54-5. Results of investigation of precision

>ring. cutting, lapping and grinding ; purpose of precision achining demonstrated by examples of journal bearings,

iesel-engine fuel pumps, etc. ,:ude des Dispositifs de Mesure des Deplacements Lineres (Study of Equipment for Measurement of linear ^placement in Machine Tools), L. COMPAIN. Menique v22 n280 Sept-Oct 1938 p 205-12. With special ference to use of micrometer calipers in certain procses of precision production : as Mechanische Schaben von Flaechen ( The Mechanical

•raping of Surfaces). Werkzeugmaschine v43 n4 Feb

1939 p 86, 88. Mechanical scraping of surfaces in maine tool manufacture; advantages over manual opera-

)n ; description of scraping machines ; rotating table for ounting of work piece.

Optik an einum Lehrenbohrwerk (Optical gages on precision drilling machine) . E. ROTZOLL. Werkstattstechnik und Werksleiter v33 n9 May 1 1939 p 238-40. For

accurate centering of hole, discussed as example showing

usefulness of optics for practical application on machine

tools. Influence of Temperature on Lathes, G. SCHLESINGER. Am Mach v86 n9 Apr 30 1942 p 379-81. Observation on

changes in alignment of machine tools during warming

up period ; compensation for misalignments is discussed

illustrations show arrangement of dial gages for measure- ment of spindle movement during warming up tests, and

method of mounting dial indicator for testing alignment

of tool holes and recesses in turret faces by turn around

method. Accuracy Requirements for Heavy Machine Tools, J. H. RIVERS. Machy (London) v70 nl802 May 8 1947 p 486-

90 7 figs. Discusses spindle bearing design ; cambering mechanism used on a roll grinding machine ; instrument

designed to accurately measure roll camber. Measurement of Progressive Errors in Machine Tools by High-Speed Photography, C. TIMMS. NPL. Machy (Lon- don) v75 Dec 15 1949 p 27-31 6 figs 1 ref. Describes an

investigation of the errors in the linear movements of the hob saddles of a gear hobbing machine, using a camera

of simple design to record errors relative to a divided

scale of known accuracy by direct comparison. Describes

recording equipment and gives test results. Les Fabrications Mecaniques du Point de Vue de leur Precision (Machining from "Viewpoint of Precision), O. PETERS. Rev Gen Mecanique v35 n29 May 1951 p 160-

3. Influence of position of tool, and angle of projection

of cutter ; effect of control. Roll Generation of Approximately Plane Surfaces, P. GRODZINSKI. Mech Wld vl32 n3396 July 1952 p 12-5. Principle used hitherto mostly for describing ellipses has

been applied to generation of approximately flat surfaces by increasing ratio of elliptic axes ; method explained and

kinematic basis of method analyzed ; mechanism on Wick- man multiple spindle automatic ; extension of kinematic

principle to arbitrary number of cutting points and poly- gons ; Tellschow mechanism. Machine Tool Metrology, D. F. GALLOWAY, NPL. Eng

Dimensional Metrology, Proc of Symposium held at NPL,

2 vols, Her Majesty's Stationary Otfiee (London) 1955. Paper nl7 p 289-301 4 figs. Discusses deflection tests, temperature effects, spindle bearings, vibration, testing of

slides. Discussion. Testing the Accuracy of Jig Boring Machines, T. R. OAKLEY, NPL. Proc of Symposium held at NPL, 2 vols, Mer Majesty's Stationery Office (London) 1955. Paper

nl8 p 303-21 7 figs test chart. Discusses measuring equip- ment, testing site, temperature, preparation for tests, worktable, co-ordinate movements, and calibration. Discussion. Fixture Generates Large Radius. H. OSTRANDER. Am

Mach vlOO nl4 July 2 1956 p 118-9. Fixture constructed

of Meehanite castings generates true circular arc with good accuracy and reliability, and is adaptable to various standard machine tools ; fixture is designed so that work

will occupy position at arbitrarily convenient distance from center of large circle and be fixed to small circle so that it will rotate with it. Tough Problems Solved with Tricky Tooling, F. P. BROWN, C. E. PELANDER. Machy (N.Y.) v64 nl Sept

1957 p 149-55; Machy (London) v91 n2349 Nov 22 1957 259
p 1199-1204. Ingenious attachments developed in Shops

Division at National Bureau of Standards for producing

scientific instruments and equipment are described and

illustrated ; wide angle taper turning attachment ; verti- cal milling machine adapted to jig boring; roll forming

of thin wall conical components ; special tool holder and

base developed for ceramic tools. Practical Alignment of Machine Tools by Means of Optical Equipment, R. OSWALD. S African Mech Bngr v8

n6 Jan 1959 p 194-200. Alignment of machine tools, both

in initial setting and during course of their lives ; im- portance of sufficiently thick concrete foundations, and

use of vibration absorbers such as rubber, cork, or systems

of springs to reduce shock impact; principle of optical auto-collimator and its application in setting up and

maintaining alignment. Optische Moglichkeiten der Positionierung an Werkzeugmaschinen (Optical Possibilities of Positioning on Machine Tools), K. HBRKT. 4 FoKoMa, Munich Oct 1959 p B93. The advantages of embodiment of optical measuring equipment for positioning of machine tools were

placed under proof over a decade by the installation of

this equipment on a jig borer. Das statische und dynamische Verhalten von Werkzeugmasehinengestellen (Static and Dynamic Behavior of Machine Tool Frames), J. BIELEFELD. Acta Teehniea

(Prague) v5 n4 1960 p 311-29. Method for investigating

rigidity of elements of metal cutting machines ; optimum

design of machine frames. A Kinematic Method of Making Details with Curvilinear Cross Sections and a Technique of Evaluating Its Accuracy, N. M. KARELIN. Meas Techns 1959 n8 July 1960 p 586-92 4 figs 1 ref. Translated from Izmer Tekh n8 Aug 1959 p 9. The author aims to develop a method of constructing kinematic devices for nonduplicating machining of cylindrical details with curvilinear cross sections (such as cams, templets, outside surfaces of noneireular

wheels, polyhedrons, etc. ) Developing kinematic schemes

on this basis leads to a problem of the theory of function approximations.

Optical Oheck-Out of Machine Tools for Missile Production, G. W. DONALD. Machy (N.Y.) v66 n8 Apr 1960 p 149-51; Machy (London) v97 n2491 Aug 10 1960 p

333-5. In checking out machine tools such as horizontal boring mills and jig boring machines in Ordnance De- partment of General Electric Co, first bedway flatness is established with optical instruments ; flatness of table on

large boring mill checked with auto-collimator, corner

mirror, and mirror carriage; column squareness with

table determined by using alignment telescope, stride

level, pentaprism, and target attached to spindle. Machine Tool Research at the Technological University

of Munich, F. EISELE. Int J Machine Tool Design Res

vl 1961 p 249-74 35 figs. Discusses typical examples of vibration research and reports the scope, content, and the most important results on subjects as follows: stiffness investigations and their practical application, mechanisms

of excitation, the avoidance of vibration, disturbance re- search, investigation of structural groups and elements, foundation investigations, damping and stability investi- gations, research on cutting forces, methods of measure- ment and measuring instruments, and electrical analogies. Machine Tool Research, Design, and Utilization, D. F. GALLOWAY. Machy (London) v98 n2515 Jan 25 1961 p 196-204 ; Engr v210 n5475 Dec 30 1960 p 1081-2 : Chart- ered Mech Engr v8 n2 Feb 1961 p 72-83 95 133. Reference

is made to criteria of performance, terminology and specification, necessity for increased static and dynamic stiff- ness of machine tool structure, vibration, automation, and

ergonomics. Abstract of James Clayton Lecture before Instn Mech Engrs, Dec 14 1960.

A Kinematometer for Screw Cutting Lathes, Y. M. AN i DRUSHEVICH, M. K. KLEBANOV, M. Y. TSLAF, A. L RABHIN. Meas Techns 1960 n7 Feb 1961 p 588-9 2 figs Translated from Izmer Tekh n7 July 1960 p 27-8. De

scribes an instrument for measuring the degree to whicli the errors of separate elements of the screw-cutting lath< kinematic chain affect the accuracy of the thread. Ex j perimental investigations were made. UPPS for Ultraprecision Machining. Du Pont Eng Dep i Mech Development and Mech Res Labs July 1961 5 p 5 figs Defines ultraprecision machining and discusses importanci

of precision, program results, accuracy of motion, accurac;

of positioning, machining sequence, and applications. Graphical Method for Determination of Dynamic Stabilit: 1 of Machine Tools, J. P. GURNEY, S. A. TOBIAS. In] J Machine Tool Design & Res vl nl-2 Sept 1961 p 148-56-j Use of harmonic response locus, so far applied with mos j effect in electrical engineering is considered very useful t< describe characteristics of machine structure ; method be ing essentially graphical, is equally applicable when mode

of structure are not well defined, and it takes effect o rotational speed of tool or workpiece into account ; stabilit;

conditions for regenerative chatter determined by thi method are set out in form of stability charts. Zmniejszanie Obciazen Dynamicznych W Mechanizmacl

j Obrotu Maszyn Roboczych Ciezkich (Reduction of Dy

namic Loads on Drives of Machine Tools), H. HAWRY

LAK. Archiwum Budowy Maszyn v9 nl 1962 p 29-5-J: Analysis of dynamic overloads and possibility of reducin them toy introducing spring elements in drive ; choice o

j spring elements ; theoretical considerations are based o; I two-mass model; for experimental verification test standi has been constructed ; description of stand ; measuremen

methods and apparatus ; analysis of measurement result; English summary. Dynamic Acceptance Tests for Machine Tools, S. A. T( BIAS. Int J Mach Tool Design & Res v2 n3 July-Sep

1962 p 267-80. It is proposed that dynamic quality o machine tools, in particular of radial drilling machine.1 be measured toy coefficient of merit ; this coefficient is proc uct of static stiffness between tool and workpiece, in dim \ tion of cutting thrust, and nondimensional ratio deteii mined from harmonic response locus of machine structure determination of coefficient for radial drilling machine

is discussed and its relationship with stability chart o drilling process elucidated ; it is shown that coefficient o j merit is proportional to maximum drill diameter whie i is stable at all speeds. Ispytanie stankov obshchego naznacheniya na vibroustc

ichivost pri rezanii (Vibration Resistance of Genera- Purpose Machine Tools During Cutting) , V. A. KUDINO^

T. S. VOROB'EVA. Stanki i Instrum n8 Aug 1962 p 8-12 j see also English translation in Machines & Tooling v33 n 1962 p 11-15. Laboratory investigations and shop test are reported on basis of which method for investigatin vibration resistance of center lathes and kneejtype milling - machines was developed toy ENIMS.

Koroblenie chugunnykh basovykh detalei pretsizionnyk j stankov i metody ego ustraneniya (Warping in Mai|

Castings of Precision Machine Tools and Methods C Eliminating It), O. YU. KOTSYUBINSKII, A. M. GEEj ' CHIKOV, YA. I. OBERMAN, S. A. SHEVCHUK, E. Cl' I GINI. Stanki i Instrum n9 Sept 1962 p 1-5; see alsj English translation in Machines & Tooling v33 n9 19€| p 2-6. Investigation was carried out into warping of iro ; castings used in precision machine tools (aged natural! ; and artificially) ; fact that even in case of high levi! .jj of residual stresses iron casting may retain its dimension?

j |

stability, is extremely important in determining cond | tions for artificial aging; aging before rough machinin ,,: is inadvisable, because it does not insure subsequent stJ

j

bility in shape of machined components.
Irinienenie teorii podobiya dlya raseheta inetallorezhu- shchikh stankov na ravnomernost podachi (Applying Theory of Similarity When Calculating Working Traverses in Machine Tools), B. G. LUR'E. Stanki i Instrum nil Nov

1 >62 p 11-14; see also English translation in Machines

- & Tooling v33 nil 1962 p 13-16. New data on problem

of uniform slow motion of machine tool units are de- s.ribed; problem is solved on basis of experimental data,

>. with help of theory of similarity; method suggested for

" j\ experimental and theoretical analysis of nature of slow movements in machine tools, and for determining slide- way and feed drive parameters necessary for designing machine tool with small movements of required degree of uniformity and accuracy.

J. Role of Tracer Attachments in Contour Machining, L. S. 3 MAGOR. Automat vlO n5 May 1963 p 83-5. Discussion

of modern tracer attachments that can be mounted on

existing machine tools to control automatically contour

. " .machinery. u. I On New Feedback Controlled Precision Gear-Hobbing

Machine, T. NAKADA, T. MASUDA, S. MIWA, T. MATSUMOTO, Y. FUKUDA, Y. MORITA. Japan Soc Mech

Engrs—Bui v6 n23 Aug 1963 p 556-67. Basic analysis and design of new hobbing machine ; average and minip jffium of angular position error is 20 sec and 11 sec, 7yit respectively, when gear module is one pitch circle, diam-

TMfcjeter is 72 mm ; such accuracy is obtained by virtue of

electrohydraulic servomechanism that corrects error of

iriving worm wheel; mechanism performance is analyzed

i and experimental results discussed.

r Results Obtained When Using Vibrating Tools and In- ttformation on Energy Dissipation in Machine Tool Vibration from Russian Sources, R. WEILL. Int Prod Eng

"

j Res Conf Proc Sept 9-12 1963 p 459-64. Published by

I ASME. Variation of cutting forces during vibration is J discussed, and results obtained in this field reviewed

. ,4. Russian work on defining and measuring damping capacity

~_ Tof various machine tool components is discussed ; frac-

:ural energy loss per cycle of vibration was measured for

;T number of materials, and machine tool components; by J setting energy loss equal to energy input, due to rei -nerative copying of surface waves on workpiece, method

Ipf predicting stability is obtained.

S ability of Machine Tool against Self-Excited Vibration

, in Machining, J. TLUSTY, M. POLACEK. Int Prod Eng

Res Conf Proc Sept 9-12 1963 p 465-74. Published by

I A.SME. Influence of characteristics of machine tool on

occurrence of self-excited vibration is described, in order

:o be able to get higher stability of machine tools at minimal weight ; theory of self-excited vibration presented

ixplains all basic characteristics of this phenomenon, and

some of effects of changes in machine tool on vibration

?xample of change of orientation in case of boring bar with

"ectangular cross section is described. m -What Can Vibration Research Contribute to Machine Tool

Development, J. PETERS. Proc Int Prod Eng Res Conf

Sept 9-12 1963 p 486-93. Published by ASME. Surface

•oughness produced in turning operations is shown to be

-elated to natural modes of spindle and lathe bed ; struc- ural weaknesses contribute to surface roughness, especially when forced vibrations from gears, ball bearings,

( pte. are small ; chatter studies. Applied Vibration Research on Lathes, K. E. WETZEL,

3.. DORNHOFER. Int Prod Eng Res Conf Proc Sept «2 1963 p 494-501 23 refs. Published by ASME. Remits of dynamic studies of new lathe designs are reported, ncluding vibration behavior of lathe beds, and studies of

saddle and cross-slide and self-excited vibration on slide

svays ; methods of raising stability of headstock spindle

vibrational correct design of tailstock and center point

sources of severe vibrational disturbances are reviewed

including forced vibrations, vibrations from high speed

drives, belt drives etc ; chatter problems of boring tools and self-excited vibrations of gun drills. New Concepts Concerning Machine Tool Structures, F. KOENIGSBERGER. Int Prod Eng Res Conf Proc Sept

9-12 1963 p 535-42. Published by ASME. Effects of important parameters, such as design shapes and loads, materials properties, methods of manufacture, joint design and efficiency and stiffness-to-weight ratios are described, and problems of accuracy discussed, particularly that of alignment error correction; application of results to de- signs in past and present, and possible future develop- ments considered; some results of recent research work

are reported. High Precisiion Components-Analysis of Engineering Design and Manufacturing, J. LOXHAM. Proc Int Prod Eng Res Conf Sept 9-12 1963 p 634-^4. Conditions neces- sary for obtaining precision products within allowed tol- erances are discussed, including design of machine tools, as illustrated by design of grinding machine ; product measurement problems in design of machine and inspection. Osevaya zhestkost shpindel'nykh uzlov vysokotoehnykh

metallorezhushchikh stankov (Axial rigidity of precision machine tool spindle units), A. M. FIGATNER. Stanki i Instrument nl2 Dec 1963 p 1-5 ; see also English translation in Machines & Tooling v34 nl2 1963 p 2-6. It has

been established by calculations and by experiments that

axial rigidity of such units depends to great degree on

accuracy of manufacturing of bearings and adjoining

parts; methods of calculations and graphs for determi- nation of axial rigidity are given; high axial rigidity is assured by selection of high precision bearings with axial play not exceedng 1-3 n; recommendations for selection of bearings are given. Errors in Measuring Geometrical Accuracy of Machine

Tools by Means of Automatic Checking Devices,

A. SADOWSKI. Microtecnic vl8 n2 Apr 1964 p 45-53. Analysis of errors when measuring machine tool accuracy by means of dial gages, leads to conclusion that dial gages with 1/100 mm divisions have large intrinsic error and should be replaced by micro-indicators with error not exceeding two microns ; revision of international standards for testing machine tool accuracy should in- clude metrological indications relative to measuring

equipment such as dial comparators, precision squares and rules, test mandrels, and universal stands. Some East German Machine Tool Developments, R. E.- GREEN. Machy (Lond) vl05 n2698 July 29 1964 p 302-9. New designs of grinding, lapping, and honing machines shown at 1964 Leipzig Spring Fair; automatic

universal thread-grinding machine fitted with equipment

for automatic loading and unloading of taps of 0.394 in. diam; new design of shoe cencerless grinding machine

with automatic feeding and diameter size control ; machines for rough- and finish-grinding of ball raceways by

plunge-cut method; internal grinding machines fitted with recently developed HF spindles running at 24,000 rpm ; grinding machine for gears employing generating

principle; Naumburg flat-lapping machine; semiauto- matic vertical honing line. Optical Setting Devices for Machine Tools. Machine

Shop v25 nlO Oct 1964 p 484-6. Despite recent develop- ments in electronic measuring methods, optical devices are still favored for many applications ; direct reading microscope has now been replaced by projection type unit consisting of precision divided scale and micrometer projector; either element can be part of moving equipment 261
or remain stationary ; two units manufactured by Hilger & Watts are described. Das Multiprismat—ein neuartiges optisch-elektronisches Positioniersystem (Tbe Multi-Prism—A New Optical

Electronic Positioning System), W. SELIGER. Optik (Germany) v21 nlO Oct 1964 5 figs p 546-50 in German. The multiprism itself is a glass plate with a parallel

array of 90° prisms cemented to one face. A grating

is imaged by an optical system, via the multiprism, onto

a receiving grating and then to a photocell. Movement

of the multiprism then gives a sinusoidal output which

can be used to determine the position of the multiprism. The resolution of the system is about 10 fi. Some possible uses are described, particularly in the machine tool industry.

12.3. Automatic Control

Where Close Timing of Operations Rests on Machine Controls. Elec Mfg vl5 n6 June 1935 p 23-4. New gear- tooth lapping machine of Fellows Gear Shaper Co., for lap- ping gear teeth after heat treatment, is designed for

full electric control ; automatic timing of machine operations and shut-down upon completion of cycle of effective work are two control problems carefully developed in new

designs. Electronic Control and Its Relation to Machine Tool Operating Cycles, E. H. VEDDER. Steel vlOO n21 May 24 1937 p 64-5. Typical industrial applications of photoelectric control to indicate possible machine tool application. Before machine tool electrification forum, held under auspices of Westinghouse Elec & Mfg Co. Successful Electronic Controls, R. A. POWERS. Elec Mfg v20 n6 Dec 1937 p 50-4 96-7. General discussion of fundamentals of theory and application of photoelectric control machine tool operation. Steuerung von AVerkzeugmaschinen durch Fotozellen

(Control of Machine Tools by Photoelectric Cells), R. SPIES. Werkzeugmasehine v42 nl8 Sept 30 1938 p 391-9. Types and operating principles of cells ; replacement of mechanical control equipment by photocells ; control of

photocells and templets ; circuits. Air Size-Control, J. E. KLINE. Machine Design vl9 nlO

Oct 1947 p 88-91. Features of gaging device which measures workpiece during machining or other operations;

application to honing machines as exemplified by 6-spindle machine which simultaneously finishes all cylinders in block, or single spindle machine in which gaging control automatically indexes fixture, transferring operations through successive bores. Thickness Gage for Moving Sheets, J. W. HEAD. Electronics v21 n5 May 1948 p 90-2. How glass and other non-magnetic sheets ranging in thickness from % in. to

1 in. can be continuously gaged to close tolerances ; material is run between primary and secondary of measuring

transformer ; variations in material thickness change coupling, upset bridge balance and are directly indicated. Dimensional Control. Aircraft Prod vll nl32 Oct 1949 p 339. Technique developed by Sigma Instrument Co to provide operator with continuous dimensional information of component being produced and at economical price, consists of employing Sigma vertical comparator with

range of fixtures so constructed that all dimensions on component can be measured as distinct from being gaged, without resetting comparator; it is particularly intended

for checking of large quantities of parts produced on automatic machinery. Automatic Positioning Device Allows Precision Machining

of Delicate Optical Instruments, E. E. JEFFERY. Western Metals vlO nlO Oct 1952 p 54-6. Design of 340-T

Giddings & Lewis boring, drilling and milling machine in- stalled recently at Northrops Anaheim division ; number

of operations can be performed from single setup posi- tion ; machine used for manufacturing main housings of range finders, machining jigs and fixtures for production

of optical instruments, etc. ; how positioning cycle operates. Machine-Control Gaging, L. O. HEINOLD, JR. Machy

(N.Y.) v63 n3 Nov 1956 p 217-22; Machy (London) v90 1 n2308 Feb 8 1957 p 299-303. Discussion of gaging which

performs functions of inspecting work, changing speed or

direction of machine tool spindle or slide, and signaling needed resetting of machine tool member ; in-process and

post process gaging ; four available control systems in- clude pre-process gaging, combination gaging, electric and

air electric, and electronic and air electronic gaging

systems. Kontinuierliche Pruefmethoden in der industriellen Fer- tigung (Continuous Testing Methods in Industrial Manufacturing), M. DUEHMKE. Metall vll n.7 July 1957 p

579-82. Continuous testing methods in work shops, particularly in interchangeable manufacture ; statistical control by sampling ; built-in control apparatus in machine

tools ; examples of most recent developments in continuous automatic control. A Critical Evaluation of High-Precision Electromechanical Linear Measuring Systems, F. BROUWER. Elec Mfg

v60 n2 Aug 1957 p 128-11 28 figs 5 refs. Discussion of accuracy, linearity, resolution and sources of error in posi- tion measuring transducers suitable for closed loop machine tool controls, including: differential transformers and capacitors ; linear potentiometers ; ultransonic sys- tems; lead screw and rack systems with rotary signal

pickoffs ; optical systems : digitally coded scales ; and pro- prietary Pratt & Whitney "Electrolimit", Farrand "In- ductosyn" and Canadian Westinghouse "Nultrax." Dimensional Controlling Systems, R. A. SOULER. Auto- mat v4 nil 1957 p 76-80, v5 nl 3 Jan 1958 p 81-4, Mar

p 73—1. Nov 1957 : In-Process Gaging Provides Reliable Machine Control. Jan 1958: Post Process Gaging Provides Versatile Machine Control. Mar : Combination Gaging Systems. Basic Gages and Gaging Considerations for Automatic Machine Control, J. W. HOPPER. ASME-Paper n58- AUT-6 for meeting Apr 14-16 1958 4 p. Consideration of basic concepts of measuring manufactured parts, specifi- cally for purpose of controlling manufacturing machine

problems of compartor type gages and control systems

air gaging; electromechanical-type gaging; precision gaging. Gage Modules Advance Machine-Control Design. Elec Mfg v62 nl July 1958 p 110-13, 258. Adaptation of basic design principles, such as modular construction, plug-in component and connects, and sliding panel circuit sub

assemblies to gaging instruments and controls ; application of gages to machine tools, parts segregation systems, and automatic assembly machines. Instruments for the Control of Kinematic Accuracy of Linkages and Machine Tools, B. A. TAITS, V. P. KOROTKOV. Meas Techns 1959 n6 June 1960 p 406-10 7 figs. Translated from Izmer Tekh n6 June 1959 p 12. Describes instruments for the accuracy control of linkages
and machine tools and, especially, the method without

standards provides for a high-accuracy control of the kinematic accuracy of gears, lead screws, and kinematic

chains. However, a further improvement is necessary. An Automatic Method of Ensuring Accuracy of Dimensions in Centerless Grinding, S. S. VOLOSOV, G. B. TURBIX. Meas Techns 1960 n5 Jan 1961 p 379-81 2 figs 1 ref. Translated from Izmer Tekh n5 May 1960 p 7-9. Discusses limitations of self-adjusting systems of active automatic control and prerequisites to successful application.

i Automation Development—Machine Tool Trends, D. F. GALLOWAY. Machy Market n3140 Jan 19 1961 p 21-2. Example notes First State Ball Bearing Plant, Moscow,

- where automatic line comprises 150 machine tools, heat

, treatment furnaces, assembly presses, inspection equip-

: ment, and unit for greasing and packaging, all connected

- by handling devices ; problems in work handling, from

; machine to machine, with regard to feedback and numeriuj cal control systems, and design of tool elements in relation

:

.

'. to automatic control are considered. Abstract of paper

before Instn Mech Engrs. in Automatic Electronic Coordinate Measuring Equip- ment for a Heavv Boring Machine, E. L. ABRAMZOM,

. G. L. GRIN, A. Y. PELIKS, S. S. PODLAZOV. Meas

Techns 1960 n7 Feb 1961 p 579-83 6 figs. Translated from

Izmer Tekh n7 July 1960 p 20-4. Equipment for measur-

. ing displacement coordinates, both vertical and horizontal,

",. of heavy boring machine, by means of two circular induca tive transducers, and reversible electronic counter which

-

;

. operates with decatrons. Automatic Control of Dimensional Accuracy in Internal

Grinding, H. CH'ANGKEN. Meas Techns 1960 n8 Apr

; .1961 p 235-8 3 figs 2 refs. Translated from Izmer Tekh

*|;n9 Sept 1960 p 7-10. Describes method of measuring

lander optimum conditions by which it is almost possible

;o eliminate completely the effect of allowance variations

.^ '.ja the accuracy of the ground ring diameters. It is posI""

sible to grind details without subsequent precision grinding.

'Staveley Group Research Department, P. A. SIDDERS.

Machy (London) v98 n2534 June 7 1961 p 1309-12. Three

nain sections are concerned with mechanical engineering,

control systems, and electronics ; examples of work given

\

; nclude studies dealing with hydrostatic nut and lead- TM ('screw system for traversing machine tool slide, research

:onnected with stiffness of hydrostatic slides, use of Pers-

>ex models of machine tools to predict dynamic behavior

>f design, investigating hydraulic drives for machine tool

!eed systems, and tape-controlled contour milling machine. Terrodynamic Transducers for Automatic Monitoring and

Controlling Devices, M. D. GAFANOVICH. Meas

Techns 1961 n2 Oct 1961 p 100-4 3 figs 4 refs. Translated

| Tom Izmer Tekh n2 Feb 1961 p 8-12. Transducer de- eloped for angle of rotation into appropriate voltage, on

>asis of which new improved telemetering system has

•een designed and several computing circuits developed

dvantages of system, including better linear relationship

>etween output emf and angle of rotation, etc. developments in Moire Fringe Measurement Systems, A.

I. SHEPHERD. Machy (London) v99 n2562 Dec 10

961 p 1424-6. Machine tool control system is described

,-hieh gives digital subdivision of VJ0th of pitch and could

e extended to y2oth of pitch without use of carrier ; with

000-line/in. grating system affords digit size of 50 or

OO^in, which would meet all normal engineering requirements including jig borer applications ; principle of

peration. uccess of TV on Open-Side Machine Leads to Use

f Digital Read-Out, S. C. BROWN. Machy (N.Y.)

v68 n7 Mar 1962 p 89-91. Examples of machining jobs done at Waterbury Farrel Foundry & Machine Co. by

television read-out on Ingersoll open-side milling, boring, and drilling machine whose movable column provides 22

ft of longitudinal and 6 ft of cross travel, with 5 ft of boring-bar feed ; 78- by 78- by 24-ft split-table, planer type

milling machine, by employing Norden multiple-axis measuring system with digital read-out, eliminates guess- work as factor in setting machine positions. Automatically Controlled Machine Tools, C. A. SPARKES.

Chartered Mech Engr v9 n6 June 1962 p 298-305 40 refs. Review considers automatic features of machine tools in 3 broad groups ; single-purpose unit is often highly auto- mated; in various combinations, it is used for mass pro- duction; modern universal center lathes, milling and

planing machines, drillers and grinders are used for sev- eral types of operation but, to keep cost down, automatic

features are kept to minimum ; third range of tools, often high in capital cost, incorporate features intended to reduce to minimum cost of components produced. Wide-Range Pneumatic Instrument for Automatic Checking of Dimensions (during Machining) , E. I. PED'. Meas

Techns 1961 nl2 June 1962 p 949-51 3 figs. Translated from Izmer Tekh nl2 Dec 1961 p 12^. Presents experi- mental and theoretical investigation of a new pneumatic measuring system having wide measuring limits applied

for automatic checking of the dimensional parameters of components during machining.

Digital Techniques in Precision Dimensional Measurement, R. J. MARMORSTONE. Automatic Control vl7 nl

July 1962 p 32-4. Review of electromechanical shaft position encoders with sliding contacts: typical encoder

applications for measurement and control in machine tool industry and for general laboratory use. Some Performance Limiting Features of Machine Tool

Control System, A. COWLEY. Int J Mach Tool Design & Res v2 n4 Oct-Dec 1962 p 379-92. Simplified linear considerations, giving reasonable indication of system

response, are discussed ; effects of principal nonlinearities within servo loop considered ; describing function is useful

tool for dealing with single nonlinearities and will usually provide results with accuracies better than 50% ; if effect of several nonlinearities acting simultaneously is to be

predicted, then use of analog computer may be necessary and is certainly desirable. Automatic Position-Setting, Aircraft Prod v24 nlO Oct

1962 p 350-8. GSP-Matic machine, installed at works of Sperry Gyroscope Co, Ltd, is highly ingenious and un- orthodox example of numerically controlled machining

systems ; developed from jig-borer, it has two spindles and

is fitted with automatic tool changing system ; one spindle

is for heavy duty machining, other high speed spindle for

lighter work ; all machine functions, including tool changing, are programmed on 35-mm film. Computerless Programming vs Simple Control System and

Simple Computer, R. CLEGG. ASTME Creative Mfg

Seminars-Tech Paper SP63-12 Dec 1962 5 p. What nu- merical programmer must do to produce tapes required

features of computer routine ; computerless programming

is considered desirable at start of numerical control ; after using variety of numerically controlled equipment, computer may become useful by simplifyinng programming

for all numerically controlled machines; therefore, question is really computerless programming versus computer programming. New Photo-Optical, Random-Access Memory, W. RENOLD. Soc Photographic Instrumentation Engrs J

vl n2 Dec 1962-Jan 1963 p 44-8. New concept for high

capacity rapid access and readout photo-optical data stor- age system, combining recent advances in precision film movement with extreme accelerations, new optical-elec- tronic scanning methods, and digital positioning tech- 263

771-846, O—6€
niques developed for automatic machine tool control; integration of elements into system is described; immediate and potential capabilities are discussed; diagrams

are included. Ferranti Mk. IV Continuous Path Phase Control System,

D. F. WALKER. Int J Machine Tool Design & Res v3 nl Jan-Mar 1963 p 61-73. Background of Mk. IV system which was developed to supersede original continuous path tape control unit and to exploit benefits to be gained from use of transistors in place of thermionic valves; measuring system described; block diagram of complete

control system is shown along with some control waveforms ; design features ; continuous path system was de- signed to automate small quanity production work where

conventional mass production techniques are not applicable for economic reasons; applications indicated. Numerical Control of Machine Tools, D. F. WALKER. J

Instn Elec Engrs v9 Feb 1963 p 61-5. Discussion of nu- merical control as system particularly suitable for small

quantity production; error checking and correcting, and

measuring systems ; future trends. Pneumatic Contactless Instrument for Automatic Control

in the Course of Machining, E. I. PED', A. V. FEDOTOV.

Meas Techns 1962 n8 Feb 1963 p 639-40 3 figs 1 ref. Translated from Izmer Tekh n8 Aug 1962 p 16-7. Describes an automatic pneumatic instrument for production control which is equipped with a liquid manometer as an indicating device. Survey of Techniques Evolved for Measurement of Posi- tion in Numerically Controlled Machine Tools, R. BELL.

Radio & Electronic Engr v25 n3 Mar 1963 p 207-24 64 refs. Techniques employed in numerical control of machine

tools are reviewed ; they are classified into basic groupings

of analog and digital, and then according to mode of operation of transducer; inherent sources of error are

discussed. Big Tables Ride N/C "Cushion" for Accurate Positioning. Iron Age vl91 nlO Mar 7 1963 p 140-]. Numerical posi- tioning control system guides table along horizontal and

vertical planes ; it has already been applied to 30 ton Wiedemann press, where it positions large steel panels for

turret punching; system designed by Cutler-Hammer, Long Island, N.Y., moves 2-ton table mass from "dead

still" to speed of 600 ipm in only %o sec ; it places workpiece under right punch with positioning accuracy of

0.006 in. ; punched tape controls all machine operations in automatic, or normal mode.

Instrument for Automatic Control of Dimensions of Articles with Discontinuous Surfaces, B. N. MARKOV, E. I. PED'. Meas Techns 1962 n9 Apr 1963 p 722-5 1 ref. Translated from Izmer Tekh n9 Sept 1962 p 9-11. Contactless pneumatic instrument with large measuring range

developed toy Moscow Machine Tool Inst for automatic

control of parts during machining at low speeds. Magneto-Optic Positioning, R. J. MELTZER. IEEE Trans

Indus Electronics vIE-10 nl May 1963 p 46-56 27 figs 4

refs. For accurate production of scales and grids it was

necessary to develop device which would locate lines with

precision better than l/xin. ; system is described that ac- complishes this toy forming image of line with polarized

light, whose angle of polarization varies with position of line. Inside Mark Century Numerical Controls, J. T. EVANS,

L. U. C. KELLING. Control Eng V10 n5 May 1963 p 112-

17. Design of Gen Elec Co positioning and contouring numerical control system that uses binary-coded-decimal

computation throughout ; controls obtain high feed speeds

j (up to 500 in./min) with increments of 0.0001 in. ; absolute coordinates are used for positioning, and departure co-

' ordinates for contouring.

Effect of Servomechanism Characteristics on Accuracy of Contouring Around Corner, H. E. VIGOUR. IEEE Trans

on Applications & Indus v82 n66 May 1963 p 120-4. Servo- i mechanism errors in 2-dimensional contouring system are analyzed to determine position error of tool center nego- ! tiating corner formed by 2 straight lines ; results establish feed rate which will permit specified tolerance on path j error to be met; transient response information from i analog computer tests is summarized in nomographic form

to permit convenient consideration of maximum tool center path error during design of servomechanisms. Paper

62-250. Application of the Television Computing Technique in Automatic Control of Dimensions, V. S. VIKHMAN. Meas. Techns 1962 nil June 1963 p 904-8 6 figs. Translated from I Izmer Tekh nil Nov 1962 p 9-14. Describes a system J which amounts to the automation of known production | control methods. Tests have shown that the system oper- ates with stability and very few adjustments during 1 operation. Technological Requirements of Machine Tool Manufac- j turing System, R. R. WEBER. Int Prod Eng Res Conf

Proc Sept 9-12 1963 p 556-60. Published by ASME. Design, control, machining and part acceptance are con- sidered as necessary parts of fully integrated and auto- 1 matic system ; role of numerical control in element of de- sign is discussed ; some problems in area of control are considered where applications can toe made of current knowledge and where additional research is necessary to complete evolution of machine tool manufacturing system,

j Measurements and Control, V. Y. KNELLER. Meas i Techns 1963 n3 Sept 1963 p 181-4 11 refs. Translated from Izmer Tekh n3 Mar 1963 p 1-4. Conclusions derived j are that measurement and control (and correspondingly ! automatic measurement and automatic control) are dif- ferent processes distinguished by their objective and final results, and representing as a whole different forms of information transformation. The suggested definitions t of measurement and control reflect these characteristics. Measurement can form part of an intermediate trans- > formation in a control process. A clear conception of each of these processes, together with an understanding

of their common features, will help to systematize the j accumulated practical data, to understand the trends of s development in automatic measurements and control, and ! to determine the tasks of further research.

I \ Television Methods of Controlling Dimensions, O. D. BYCHKOV. Meas Techns 1963 n5 Nov 1963 p 372-5 2 i figs 21 refs. Translated from Izmer Tekh n5 May 1963 < k p 6-9. An article reviewing various methods.

a DIG, a Long-Travel Ultraprecise Absolute Reading Digital Linear Measuring Instrument. Bausch and Lomb,

Rochester, N.Y. 1964 8 p 4 figs. See abstract under 1.2.1. ]| k

l k The Use of Encoders in Machine Tool Control Systems, , F. J. ROBINSON. Machy (London) vl04 n2668 Jan 1 1964 p 12-9 7 figs. Discusses types of control systems, |i methods of feedback, the Baldwin encoder, coding, and f

, position control system using encoders. Measurement for Control, N. ANDERSON. Instrum Conj trol Syst (USA) v37 n8 Aug 1964 p 103-12. A review * of the most common types of transducers that have an TM output suitable for use in control systems.
Controlling Workpieee Accuracy, R. TILLEN, NPL.

Sept 1964 19 p 15 figs 24 refs in 2 parts. Part 1 is a

review of known commercial and experimental techniques, including direct in-process measurement of diameter, in- direct in-process measurement, and comparison of direct and indirect in-process measurement. Part 2 is a first report on work at NPL on measurements during turning, including design considerations applied to NPL prototype turning gage, experimental results obtained with

such gage, and conclusions. Air and Electronic Gaging, J. J. DWYER, JR. Am Mach

Special Rept n558 Oct 12 1964 16 p. Discusses the basics

of air gaging; typical manual air-gaging applications;

electronic gaging, automatic size control, gaging, and

sorting.

12.4. Grinding

Continuous Reading Grinder Caliper, H. K. SPENCER. Am Mach v25 Oct 5 1911 p636-8 6 figs. An amplifying

gage of which the table of a rotary surface grinder is the work support. The rotary work table carries the pieces, which are being ground, alternately under the wheel and

the measuring contact, so that each piece is measured

after evey pass under the wheel. Die Grundlagen des Schleifens (Principles of Grinding),

0. KRUG. VDI Zeit v71 Aug 6 1927 p 1109-16 36 figs. Classification of types of grinding, from rough to finest

physics and technology of grinding process studied with

aid of microscope ; structure and design of grinding wheel ; analytic and experimental study of details of grinding ; list of technical problems requiring study. Precision Surface Grinding, E. C. LARKE, F. C. SMITH.

Machy (London) v31 Dec 8 22 29 1927 Jan 26 Feb 2 23

1928 p 308-12 391-4 422-5 545-7 579-81 673-5 48 figs ; also v32 Apr 26 May 31 June 7 1928 p 105-7, 265-7 294-5 25

figs. Precision surface grinding dependent upon skill of

operator, accuracy of machine, and correct composition of

j grinding wheel ; fundamental rules governing choice of wheels ; grades of wheels ; form of wheels ; mounting of wheels ; hollowing and cornering ; wheel speeds ; feeds, preparation for lapping ; swiveling angle plate ; magnetic

chucks ; producing accurate angles on wheels.

: Precision Cylindrical Grinding, R. E. W. HARRISON.

Machine-Shop Prac (ASME Trans) v51 n24 Sept-Dec 1929

p 133-7 8 figs. Process of evolution through which preci- sion cylindrical grinding has passed during last eight years ; production dependent upon horsepower capacity

, of tool ; consequently its structure has been strengthened

i work handled on 5^hp. machines in 1921, today being pro- duced in proportionately reduced time on 20-hp. machines ; still considerable work to be done ; comparative methods

of metal removal; production possibilities on controlled

.center-type machine.

•Alignment Tolerances on Precision Grinding Machines. Machy (London) v35 n890 Oct 31 1929 p 141-2 7 figs. Description of range of special alignment test developed

by Churchill Machine Tool Co., Manchester, for all classes

of precision grinding machines; method of checking per- .pendicularity of wheelhead slideway vee; checking align- ment of table as it travels along ways ; checking alignment

of wheelhead spindles with bed slideways in both vertical and horizontal directions ; tolerances met on Churchill

Cincinnati grinding machines.

i Technique of Size Control in Precision Grinding Opera- :ions, R. E. W. HARRISON. ASME Advance Paper meet- ng Oct 3 1932 16 p 2 supp plates ; Am Mach v76 Oct 12

1932 p 1065-7 ; Iron Age vl30 Oct 13 1932 p 570-1 16 18

20; Machy (London) v41 Oct 6 1932 p 11^ Oct p 37-9;

Abrasive Indus vl3 Nov 1932 p 13-5 and Dec p 14-7 vl4

Ian 1933 p 15-7 22; Western Machy & Steel World v24

i2 Jan 1933 p 10-7 ; Indus Standardization v3 nl2 Dec

;L932 p 299-305 and v4 nl Jan 1933 p 10-7. Use of limit ystem as major key to cheap manufacture ; functions of

decision grinding machine and design factors which

; nake for ease of size control.

Profile Grinding Machine for Tools and Gages, O. P. VAN

STEEWEN. Machy (N.Y.) v39 n6 Feb 1933 p 411-3. Operating characteristics of grinding machines developed by Loewe Gesfuerel of Berlin, Germany, with particular regard to accuracy obtained by profile-copying system

using pantograph with ratio of 50 to 1. Electric Sizing in Grinding, A. V. MERSHON. Mech Wld

v93 n2414 Apr 7 1933 p 335-6. Automatic sizing control developed by Gen Elec Co., Schenectady, which has been adopted by sections of American machine-tool industry

single electric gage head has pair of coils which are used

to produce deflection on indicating instrument while workpiece is being ground to size. Precision Profile-Grinding Machine. Eng vl39 n3601 Jan 18 1935 p 58-9 supp plate. Machine made by Loewe

Gesfuerel, Berlin, it is claimed, reduces time required to form complicated profile on tool or gage to fraction of that required by usual methods ; principle is that of employing pantograph with tracing point on its long arm

and microscope, with cross lines in its field, on its short

one. Measurement During Machining and Automatic Sizing, H.

C. TOWN. Eng vl39 n3603 3606 Feb 1 1935 p 107-8 and

Feb 22 p 189-90. Feb. 1 : Details of automatic measuring

device introduced few years ago by H. W. Kearns and Co, known as Insulater dial traverse indicator ; with increas- ing accuracy demanded, Kearns now prefer to fit vernier

scales on high precision Ohesterman rules accurate to within 0.0005 in. in 4 ft. of length. Feb 22: Pneumatic

micrometer developed by Solex Ltd. Precision Grinding Machine for Small Cylindrical Parts. Eng vl40 n3627 July 19 1935 p 62-3. Machine made by Loewe-Gesfuerel A-G, Berlin, intended for work ranging from 0.02 in. to 1.18 in. in diam only; proportioned and

constructed that within these limits, very high degree of accuracy of 0.00039 in. in error can be consistently obtained. Five Theorems for a Mechanical Surfacer, C. DEVE. Rev

Opt vl5 June-July p 201-14 and Aug 1936 p 241-57. A

machine for grinding surfaces is described and its mech- anism provides means for realizing new parameters and

gives uniform use for the optical manufacturer. The

theory of the instrument is explained in a series of five theorems and their principal applications are set out. Extreme Precision is Required in Gage Grinding. Abrasives vl8 Sept 1937 p 9. Illustrated description of a few

of the grinding operations at tool making plant of Taft- Pierce Mfg. Co. giving the size, kind, and grade of grinding

wheel, and its speed for grinding a typical thread gage.

Size Controlling Device for Internal Grinding Machines,

H. A. DUDGEON. Machy (London) v60 nl537 Mar 26

1942 p 238-9. Description of device having light control wheel, attached to spindle running freely in bearings, which is placed in position close to end of work piece so that periphery of grinding wheel touches periphery of control wheel exactly when grinding wheel is in position

for finishing hole; contact between grinding and control 265
wheels causes latter to revolve, thus opening or closing

electric circuits which perform pre-arranged function. How to Secure Fine Surfaces by Grinding, H. J. WILLS,

H. J. INGRAM. Machy (N.Y.) v50 n5 6 7 8 9 10 11 Jan

1944 p 173-5, Feb p 167-70, Mar p 211-13, Apr 159-60, May

p 181-2, June p 173-5, July p 208-9 ; Machy (London) v64 nl640 Mar 16 1944 p 294-6, v65 nl661 1663 Aug 10 1944. pl49-52 Aug 24 p 210-2. Jan : Balancing grinding wheels

conditions responsible for chatter marks ; methods and

equipment employed to balance wheels; arbors equipped with balancing weights. Feb : Functions of coolants used

in grinding ; properties of different types of coolants and method for securing their most effective use. Mar : Fundamentals of lapping. Apr : Machine lapping operations. May : Details of lapping operations in tool room. June

Production lapping of ground internal and external cylin- drical surfaces. July : Lapping operations as applied to production of gears and worms.

Accurate Grinding Depends Upon Correct Location of Surfaces, S. H. NEADY. Am Mach v88 n21 Oct 21 1944 p 110-12. Difficulty in securing correct lateral dimensions

or correct relationship on ground parts is frequently due

to incorrect use of multiple locating points; article gives

specific case examples and illustrations showing methods

of locating surfaces correctly. Surface Grinder Attachment Generates Involute Gears. Iron Age vl70 July 31 1952 p 87 1 fig. Describes a new

universal involute gear generator for attachment on sur- face grinders. Only standard grinding wheels are re- quired. A wheel dressing unit is part of the attachment. Basic Gear Grinding Methods Compared, D. W. BOTSTIBER. Iron Age vl70 Aug 7 1952 p 118-21 6 figs. Grinding can correct gear tooth form and spacing errors.

It is particularly useful after hardening. Each of the

three basic methods—form, line, and point grinding, has

advantages and limitations. Hardened and ground gears can make transmissions 50 percent lighter, 40 percent

smaller, and cheaper than unground gears of equal

capacity. How to Calculate Exact Wheel Profiles for Form Grinding

Helical-Gear Teeth, O. SAARI. Am Mach v98 nl9 Sept 13

1954 p 172-5 3 figs 3 refs. In form-grinding helical gear

teeth the exact wheel profile is not reproduced anywhere

on the work. The article shows how the correct wheel

profile and its radius of curvature at. any point can be

calculated by an exact mathematical method. Formulas

are derived for computing the coordinates, pressure angle, and radius of curvature of the cutter form. A numerical example shows how to use the computed data in establish- ing the settings of the radius-dressing fixture. Grinding Round Within Millionths, R. LEGRAND. Am

Mach/Metalworking Mfg vl06 n26 Dec 24 1962 p 51-3 5

figs. New Highs in grinding accuracy—grinding round

within ten millionths on a revolving spindle headstock

are now possible with the hydrostatic bearing, a develop- ment which has been around since 1907, but which has come into its own as a metalworking tool relatively re- cently. Hydrostatic bearings, which support the headstock spindle by floating it on opposed pads of high-pres- sure oil, attain extremely high grinding accuracy through

counter-balancing of oil pressures. The slightest off-axis movement of the spindle builds up pressure in one pocket and reduces it in the opposed pocket. This fact buildup

of force limits the off-axis movement of the spindle to millionths of an inch. That is why, with the hydrostatic

bearings, it is possible to produce OD, ID and face di- mensions that are round, concentric and square within

plus or minus 10 millionths—or even less. At the moment,

such superfine grinding is more or less limited to manufacture of missile servos, gyroscopes, gimbals, gages and

the like. Here the idea is to attain the correct geometry and an ultrasmooth finish to closer limits and at a lower

cost through the use of hydrostatic bearings. But by now

enough field experience has been racked up with these bearings that their future potential in the fine grinding

field can be evaluated. Automatic Instrument for Combined Grinding, A. V. VYSOTSKII. Meas Techns 1962 nil June 1963 p 909-11

2 figs 2 refs. Translated from Izmer Tekh nil Nov 1962 p 14-5. Embodies a differential pneumatic pressure gage, one branch of which measures the diameter of a shaft during machining while the other branch is connected to a device for measuring the diameter of a hole to which the

shaft is to be matched.

12.5. Lapping

Laps and Lapping, W. A. KNIGHT, A. A. CASE. Trans ASME v37 June 1915 p 297-338. An investigation of the

cutting properties of abrasives when used with different laps and different lubricants. Comment, Aug 1915 p 976. Accurate Lapping, L. J. VORHEES. Am Mach v53 Aug 5 1920 p 263-5 3 figs. Instructions for gage lapping and for making laps. Material for laps, work speeds, lapping screw threads, plain plugs, and flat surfaces. Modern Lapping Practice. Machy (N.Y.) v27 Nov 1920 p 209-17 19 figs ; Machy (London) vl7 Nov 4 1920 p 129-

37 19 figs. Developments in lapping practice, including abrasives used in lap-charging methods, lapping thread

gages, snap gages, measuring wires, flat surfaces, ring

gages, die-casting dies and T-slots. Hand and Machine-Lapped Surfaces as Seen through a

Microscope. Machy (N.Y.) v28 Apr 1922 p 638-9 6 figs. Illustrated study by Pratt and Whitney Co. of the characteristics of different surfaces, as obtained by various methods of lapping. Machining and Lapping Very Deep Holes, J. B. ROSE.

Mech Engr v44 Dec 1922 p 807-12. Discussion of shop

operations in the forming of very accurate and highly

finished cylindrical holes.

Precision Lapping, W. E. HOKE. Machy (N.Y.) v31 Apr

1925 p 593-6 1 fig; Machy (London) v26 1925 p 4. Lap- ' ping abrasives and methods, and use of double type of lap for plane parallel surfaces. Precise Cylindrical Lapping, P. M. MUELLER. Mech

Eng v47 Sept 1925 p 701^r 11 figs; Machy (London) v27 1925 p 16 ; Am Mach v62 1925 p 749 and v63 1925 p 439. Method of production; preparation before lapping; preparation of laps ; lobing ; measurement, international tests. See also abstract in Machy (N.Y.) v32 Sept 1925 p 60-2

3 figs. Moline Automatic Cylinder Lapping Machine. Machy

(N.Y.) v33 Dec 1926 p 305-6 3 figs. Latest automobilecylinder lapping machine developed by Moline Tool Co. with view to making operation as nearly automatic as

possible. Maintaining Precision in Production Lapping, S. PLAYER.

Machy (N.Y.) v36 May 1930 p 686-8 4 figs ; Iron Age vl25 Mar 27 1930 p 943 ; Abrasive Indus vll May 1930 p 23-6 4 figs ; Automotive Indus v63 Dec 20 1930 p 906-8 5 figs

Machine Shop Practice (ASME Trans) v52 n24 Sept-Dec

1930 p 167-70 4 figs. Description of equipment and pro- cesses ; flat or cylindrical parts are lapped by machine to tolerance of 0.00002 in. ; 500 piston pins per hour being lapped ; limits of 0.0001 in. for straightness and round- 206
ness ; stock removed during roughing 0.0002 to 0.0004 in.

for finishing from 0 to 0.0002 in. over high limit of finished

piece. Progression of Commercial Accuracy—Turning, Grinding. Lapping. Grits and Grinds v22 n2 Feb 1931 p 1-8 9 figs. Origin and development ; fields for use ; advantages

methods. Zur Kenntnis des Schleif- und Polier-Torganges ( Study of

grinding and polishing process), L. HAMBURGER. Zeit Metallkunde v25 n2 Feb 1933 p 29-32 Mar p 58-62. Attention is called to deceptive appearance of polished sur- face ; comparison of grinding and polishing processes

deformations as result of polishing and grinding ; theoretical principles of polishing ; factors influencing process

change in properties of surface layers due to grinding and

polishing. Bibliography. Production of Optical Flats. Machy (London) v56 nl454 Aug 22 1940 p 625-8 : Eng vl50 n3905 Nov 15 1940 p385-6

[ and 390 supp plate. Methods employed at factory of Optical Measuring Tools Ltd ; primarily, optical flats are de- signed for gaging differences too small to be detected by

standard micrometer ; in practice it is possible to detect with ease differences of 0.00001 in. directly, or from

" 0.00001 in to 0.000005 in. by estimation ; preliminary opera1 tions on quartz crystal ; finish grinding. Optical Flats by Mass Production. L. P. JACKSON. Iron

; Age vl48 n9 Aug 28 1941 p 42-4. Elimination of hand lapj ping operations in making optical flats has effected con-

] siderable savings in their production time and cost, thus making manufacture of these surface gages practical for

j general industrial production. Lapping Center Holes for Accurate Grinding, R. N. CLARK. Grits & Grinds v34 n6 June 1943 p 8-10. Description of lapping machine for grinding center holes,

: which handles work up to 36 in. long and 10 in. diam, with spindle speeds varying from 665 to 4300 rpm : machine

operates similar to drill press, with work resting on

vertically adjustable center, while spindle which carries tapping stone is brought down by hand lever; entire moveable spindle assembly is eounterweighted to provide sensitivity to lapping pressure. Flatness and Parallelism in Quartz Plates, C. M. THURSTON. Bell Lab Rec v22 nlO 11 June 1944 p 435-9

July p 452-3. June : Description of lapping machine used

.for surfacing crystals. July : Design of hand lapper and

^utline of new technique which gives much improved

^results. Superfinishing by Lapping, F. M. BURT. Mill & Factory

,r,36 n3 Mar 1945 p 96-100 306 310. In superfinishing -measurements are made in millionths of inch; incredibly 3ne tolerances of this magnitude are generally produced py precision lapping methods and measurements are made

by light bands; superfinishing processes as performed by

. company with experience in this field, are explained.

Closer Dimensional Control, G. E. STEDMAN. Machine

Tool Blue Book v42 nl Jan 1946 p 149-50 152 154 156. •(Developments in precision and dimensional control as applied in manufacture of precision instruments and marines; detailed description of micrometer lapping ma-

•bines and precision thread lead finder developed and

employed at X. A. Woodworth Co. Ferndale, Mich ; construction, operation, application and performance dis- cussed. .3ow Russians Lap Carbides. Am Mach v90 n7 Mar 28

-946 p 138. Details of machine and methods developed for

• apping brazing face surface of cemented carbide inserts /or cutting tools ; machine operates on optical shop method

principles and batch grinds inserts by oscillated motion

of disks on eccentric driven swing frame; machine con- struction and operation illustrated. Investigation of Lapping Process, F. EUGENE. Indus Diamond Rev v7 n75 76 Feb 1947 p 35-^0, Mar p 67-71

Engrs' Digest (Am Ed) v4 n9 Sept 1947 p 403-8. Tests to determine : influence of period of testing ; influence of hardness of metal tested ; comparison between abrasives

influence of load and speed on abrasion ; abrasive properties of lap in relation to time and usage ; wear of laps

behavior of lap with reference to holding of abrasive ; comparison between smooth and grooved laps. From Travaux

et Memoirs du Laboratoire Central des Industries Mecaniques 1945 p 9-33. Precision Lapping Centerless Method, P. L. SOMMER, JR. Tool Engr vl8 n3 Apr 1947 p 33-4 5 figs. Data concerning typical, complete unit cabinet type lapping machine,

built by Size Control Co, Chicago; simple but positive operating principle produces uniform precision finish to

less than 2 microinches ; advantages of centerless over

previously used ring lapping. New Lapping Technique is Economical, Accurate . . . In- creases Lapping Production by 55%, W. F. SCHLEICHER.

Machine & Tool Blue Book v44 n8 Aug 1948 p 141-6. Features of process developed, by Crane Packing Co., Chicago, for superfinishing of faces of mechanical seals and

closures, including design and operating details of Lap- master used in process ; machine eliminates grinding operations between machining and lapping. Laeppen, die Grundlagen und ihre praktische Awendung

( Lapping, the Fundamentals and their Practical Application), W. LAETZIG. Carl Hanser Verlag, Munich 1950

185 p illus, diagrs, charts, tables. Book deals with process

of lapping all metallic materials with exception of cutting

tools ; it covers lapping material and media, hand and machine lapping, lapping time and defects, kinematics of lapping and other allied aspects; recommendations and

examples are generally based on practical experiences and

only in few cases on scientific research. Bibliography. Eng Soc Library, NY.

Lapping Technique ; To Improve Image Quality of Elec- tron Microscope Lenses, F. A. HAMM. J App Phys vl2 n4 Apr 1950 p 271-8. Magnetic asymmetry or astigmatism in objective lens is often due to imperfect machining,

localized defects or impurities in iron, or grain anisotropics; lapping technique is described which effectively re- duces effect of imperfect machining or misalignment of components ; electron micrographs illustrating value of lapping procedure. Machine Lapping With Continuously Fed Free Abrasives,

F. L. WHITE. Am Mach v95 nl2 June 11 1951 p 161-3. Important factors in machine lapping of flat surfaces to close tolerances for flatness and surface quality ; good re- sults obtained in short predetermined time controlled lap- ping cycles ; lapping machines arranged with wear rings providing continuous conditioning during lapping cycle

pressure on work ; recommended abrasives ; stock removal

rates indicated. Moderne Verfahren der mechanischen Feinbearbeitung von

Metallen (Modern methods for fine mechanical finishing

of metals), H. H. FINKELNBURG. Metall v8 nll-12 June 1954 p 459-62. Honing and lapping ; barrel grinding

lapping with compressed air pistol ; immersion lapping. Machine for Lapping Centre Holes. Eng vl78 n4621 Aug

20 1954 p 249. Pillar mounted machine introduced by A. A. Jones and Shipman, designed for lapping centers,

drilled in ends of shafts and other pieces, which have

suffered slight distortion at time of cutting or by subse- quent hardening. 267
Ultrafinishing—New High-Precision Lapping Process, T.

C. LEWIS, JR. ASME Trans v79 n7 Oct 1957 p 1699-

1706. Innovations which permit use of lapping for pro- duction of exceptionally smooth metal surfaces with precise geometrical control; technique includes necessary

variations in velocity to permit lapping of soft homogeneous and hard heterogeneous metals ; process can yield 0.3 to 0.5-microin. finish rms with overall geometry control equal to or better than any commercial finishing method.

Finishing Surfaces by Vibration, R. C. HITCHCOCK, J. P. MORAN. Tool Engr v40 n4 Apr 1958 p 127-30. Pro- duction type vibratory lapping machines generate surface

finishes as smooth as three ' microin. ; flatness is held to within three helium light bands; productivity is high as compared to manual lapping; application of new tech- nique to bronze and stainless steel rings for mechanical

shaft seals described. Whitworth Was Only Partly Right, R. J. RAHN. Am

Mach vl03 n8 Apr 20 1959 p 112-13. 119 yr old three- plate matching system of Sir Joseph Whitworth for pro- ducing flat surfaces considered incomplete; how this established method, if followed literally, might easily pro- duce sections of spirals instead of flats; best modern

method is to check with ten-millionths indicator. Investigating the Efficiency of Plane-Parallel Lapping of Gauges, A. M. VEDMIDSKII. Meas Techns 1961 n9 Feb

1962 p 642-4 1 fig 1 ref. Based on experimental data an

empirical formula is developed giving the mean amount

of metal removed per unit in plane-parallel mechanical

lapping of gage blocks. However, at the beginning of lap- ping a more intensive removal of metal occurs. Plastic-Fabric Lapping Discs for Diamond Compounds.

S African Min & Eng J v73 n3602 Feb 16 1962 p 367. Self- adhesive chemico-textile polishing disk, known as Hyprocel, introduced as improved vehicle for diamond and other abrasive compounds used in lapping or polishing of soft, hard and very hard materials ; introduction represents major advance over other lapping cloths ; Hyprocel is foam/fabric material composed of more than 50% chemicals; it is said to have excellent abrasive and lubricant retaining power.

Centerless Lapping Smooths Its Wrinkles, R. G. PIERCE.

Grinding & Finishing v8 n3 Mar 1962 p 42-4. Recent developments which helped to improve Centerless Lapper;

it can provide finish of 0.5 n in. rms and tolerances down

to 0.000005 in. ; recommended abrasives for centerless lap- ping ; 7 tips for improving quality of lapped work.

Preliminary Study of Lapping Process, G. A. ALLAN, K.

H. SUTHERLAND. Prod Engr v41 n4 Apr 1962 p 195-

202. Experiments on flat lapping carried out on 4 workpiece materials ; 60/40 brass, fully heat-treated aluminum

alloy HE 30 WP, and two annealed carbon steels EN 9 and EN 24b were tested in order to ascertain effect of load on workpiece and speed of lap on stock removal rate and

surface finish of workpiece; hardness of materials was

obtained in order to see if this value correlated with any

of results ; 36 in. Lapmaster machine was used for tests. Contribution Relating to Metallographic Study of Dis- turbed Metal Caused by Abrasion and Polishing, R. H. ATKINSON. Plating v49 n5 May 1962 p 485-9. Study

of surface of brass, steel, nickel and palladium, polished with abrasives such as diamond, chromic oxide, alumina and rouge has revealed presence, hitherto unsuspected, of

characteristic lines of very small "dots" which were found

to be tears; formation of tears can be avoided by hand

polishing; dark field illumination, which is particularly advantageous for detection of polishing tears with optical microscope, also enables much clearer pictures to be ob- tained of microstructures produced in disturbed metal by

abrasion. Machining to 0.0000005 in. Steel vl'53 n2 July 8 1963 p 58. Inside diameters are machined to half millionth surface

finish at Taylor Devices, North Tonawanda, N.Y. » job

in question concerns finishing cylindrical parts for liquid springs to be used in space programs of General Dynamics/Astronautics ; after honing and polishing opera^

tions critical, 2 stage lapping process on specially designed machine is carried out with patented, thin Teflon lap covered with diamond particles ; lap, moving linearly, ex- pands uniformly from hydrostatic pressure within, to pro- vide surface finish of 0.0000005 in. Fine Art of Flat Lapping, C. STEAD. Am Mach/

Metalworking Mfg vl07 nl6 Aug 5 1963 p 78-80. Rec- ommendations for obtaining maximum results in flat lapping on semiautomatic machine; importance of close control over such variables as size, shape, weight and re- quired surface finish is emphasized.

12.6. Manufacture of Precision Measuring Tools and Components

12.6.1. General

The Manufacture of Standard Thread Measuring Wires,

F. R. DANIELS. Mach (N.T.) v25 Mar 1919 p 606-7 4

figs. Table of values used for determining error in thread

angle by the three-wire system. Also describes method

of manufacture used by B. Seaboldt Corp. Gage Design and Gage-Making, E. OBERG, F. D. JONES.

Industrial Press, N.Y. 1920 310 p 235 figs. Contents : Developing a gaging system ; snap and plug gages ; contour

or profile gages ; flush-pin, sliding-bar, and hole gages

thread gages and their production ; making Whitworth

thread gages ; grinding and lapping thread gages ; lead and diameter measurements on thread gages ; microscopic measuring machines for testing accuracy of contour and

thread gages ; projection method of testing gage threads

general gage-making practice. Making the Almond Micrometer, E. VIALL. Am Mach

v53 nl4 Sept 30 1920 p 605-11 24 figs. Illustrates the mechanical processes of making the parts and discusses

the extreme care and workmanship required.

Accurate Tool Work, C. L. GOODRICH, F. A. STANLEY.

McGraw-Hill Book Co., Inc. N.Y. 1923 29 chapters 300 p

327 figs. Also pub. as Tool and Gage Work, 1922. Contains chapters on making : master plates, accurate tapers, accurate index dials, thread gages, plug and ring gages,

flat gages, and accurate squares. Manufacturing a Precision Tool, E. SHELDON. Ami Mach v59 n25 Dec 20 1923 p 903-7 12 figs. Describes manufacture of micrometer caliper, including preparatory

operations on frames and sleeve as one piece, threading

the main and adjusting nuts, rigid inspection methods. Der Laeppvorgang bei der Herstellung von Messwerkzeugen ( The Lapping Process in the Manufacture of Measuring Tools), C. BUETTNER. Werkstattstechnik v25 Mar

1931 p 113-6. Fundamental relations of various factors

in lapping necessary for obtaining measuring surfaces

of high quality ; relationship between tool and workpiece with particular regard to action of abrasive and lubricant. Balls for Bearings Are Last Word in Precision, H. T. MORTON. Metal Progr v35 n2 Feb 1939 p 149-55. Historical review of evolution of present day ball bearing, tracing materials used, lowered tolerances in last 25 yr 268
for balls 2 in. and under, improvement of ball surfaces, and " ' various stages in production of 3 in. steel balls for Grade

I ball bearings. Manufacture of Precision Measuring Tools. A. E. MORK RISOX. Machy (London) v60 nl531 Feb 12 1942 p 81-4.

B- Notes on state of precision tool industry in England ; dis- * ! cnssion on manufacturing methods, tolerances required.

inspection and checking of micrometers, try squares.

straight edges, etc; improvements in micrometer design. Mechanical Problems in Setting of Spirit Levels, F. GROVER. Instil Prod Engrs J v21 n3 Mar 1942 p 123-36. Author undertook investigation of problems involved in construction of levels in general, and attempted to evolve

simple technique for setting instruments of special form

described ; review of fundamental principles and their application to specific case. Precision Hole Location. J. R. MOORE. The Moore

Special Tool Co. 1946 448 p 309 figs. Discusses hole loca- tion and early practices relating thereto, development of the jig borer with accurate lead screws, jig boring practices, hole, grinding, and interchangeability in toolmaking. Notes on Gauge Making and Measuring. Metrology Division. NPL. His Majesty's Stationery Office. London 2d ed. May 1946 73 p 38 figs. 4 parts 2 appendices. Part 2 on

gagemaking. Covers selection of steel, machining the

blanks, hardening, stabilizing, grinding, and special workshop methods. On Sharpening of Microtone Knives for Ultra-Thin Sectioning. J. HILLIER. Rev Sci Instrum v22 n3 Mar 1951

p 185-8. Conventional methods of sharpening involve ex- tensive grinding primarily for removal of large nicks but

I which serves additional purpose of fitting knife to sharp- ening means ; since large nicks rarely occur in ultra-thin microtomy, grinding would become unnecessary if fitting of knife to sharpening means could be made permanent; Low this may be done. A Precision X-ray Diffraction Spectrometer Ring, D. C. BARNES. C. WAIXWRIGHT. XPL, Machy (London)

vS4 n2149 Jan 22 1954 p 189-92. 5 figs 1 ref. The rota- table member carries a scale divided into degree and half- degree intervals. The scale is subdivided by a graduated drum mounted on a worm drive-shaft. Overall accuracy

of angular setting is ±20" at any position of the rotatable member throughout 360° The design and construction

are described. Cam Design on a Visual Computer, W. HOFFMAX.

Indus Mathematics v9 1958 p 21-6 4 figs. The problem to be solved is the determination of the master cam outline

for the production of a cam having previously determined

lift characteristics on a cam grinding attachment. Anwendungsmoeglichkeiten von Lagerungen hoher Praezision (Possible Applications for High Precision Bearings), H. BECKER. VDI Zeit vlOO n29 Oct 11 1958 p

1398-1405. Increased accuracy required of modern in- struments leads to new combinations of structural parts

iby designer: some examples are discussed and illustrated,

( e.g., optical dividing head, micromanipulator, microtome

for ultrafine sections, etc. Determination and Correlation of Fundamental Instru- ment Bearing Parameters, T. P. BARXARD. R. S. GUYETTE. Lubrication Eng vl6 n2 Feb 1960 p 61-8. Paper

shows why measurement and evaluation of dimensional,

?eometrical and performance qualities of miniature in- strument ball bearings requires use of ultra-precise in- struments ; development of Running Torque Tester, torque

malyzer. and roundness comparator; use of supporting nstrumentation in determination and correlation of bearrig, geometry, retainer, and surface finish analysis ; dirt *nd lubrication analysis.

The Effect of Mandrel Eccentricity on the Aecuracv of Edge Cams. A. V. RUMYAXTSEV. Meas Techns 1960 n5 Jan 1961 p 384-7 3 figs 6 refs. Translated from Izmer Tekh no May 1960 p 11-4. Present a mathematical analysis which shows that the effect of mandrel eccentricity on

the accuracy of machining the working surface of a conoid amounts to a considerable and unavoidable quantity which must be taken into account when the cams are made.

High-Speed Master Cams Generated Mechanically, R. E. CHEXEY. Machy (N.Y.) v68 n2 Oct 1961 p 93-9. 148. Description of three-phase program by IBM Endicott, NY

Development Lab, to investigate and implement cam de- sign and cutting techniques ; new short run procedure en- ables hardened master cams for data processing machines

to be generated and finished to radial accuracies of four decimal places ; computers provide design capabilities for

establishing as many control points as needed to obtain necessary four-place accuracy in cam master model ; pro- cedure adopted as standard method for cutting master

Manufacture of Integral Ball Bearing Raceways, H. H. SHERRILL, Jr. Western Elec Engr v7 n4 Oct 1963 p 31-5. Method is presented for precision grinding and lapping in manufacture of bearing raceways for Nike Hercules guid- ance gyroscopes, to obtain design advantages of integral

ball bearings ; roundness checking instrument and elec- tronic vibration analyzer used for precision grinding are

described, along with lapping and grinding process, and

evaluation of raceway curvature, geometry and waviness. Spheres Turned to Millionths. Iron Age vl92 nl6 Oct 17

1963 p 90-1 ; Am Mach/Metalworking Mfg vl07 nl8 Sept

2 1963 p 80-1. Machine developed by Brown & Sharpe

especially for customer in atomic energy field, produces

spheres up to 18 in. in diam within roundness tolerance

of plus or minus 25 millionths; surface finish is very smooth ; spheres are sized with part-to-part repeatability

of 0.0001 in.; hydrostatic bearings used permit accurate

positioning of workpiece and cutting tool and provide very stiff support for machine elements while in motion

machine is reliable and very fast, turning out finished sphere in few hours. High-Accuracy Screws. Production Technology vl n8 Nov 1963 p 296-304. Procedures used in manufacture

of recirculating ball-screws by Rotax Ltd for use in air- craft undercarriage mechanisms, and in machine-tools where low power servo motor drives for numerical control and high resolution positioning are essential; assembly comprises shaft with semicircular helical groove, nut of corresponding threadform and steel balls; deflector plates in nuts, located between each complete

revolution of threadform cause free rolling balls at end

of turn to return to start of thread, thereby providing

recirculating path for each row of threadform in nut

thread whirling, hardening and thread grinding operations applied ; equipment used and method of inspection. Unusual-Precision Bearings, H. HANAU, L. BURGMEIER. Machine Design v36 n5 Feb 27 1964 p 148-53. Ball bearing systems are being produced that maintain

erratic angular deviation within 1 arc sec and predictable angular deviation within 1.5 arc sec; however, specifica- tions of airborne guidance devices and optical systems demand limiting these deviations to less than 0.1 and 1.0 arc sec, respectively ; new production and assembly tech- niques for such highest precision bearings are discussed. New Instrument for Generating Angles to High Accuracy

over 5-deg. Range, L. W. NICKOLS. Machy (Lond)

vl04 n2677 Mar 4 1964 p 554-8. To overcome limitations of instrument described previously, new instrument utiliz- ing same principle was developed at National Physical Laboratory, which enables angles up to 5° to be set out

in increments of few seconds of arc; diagram of kine- matic pivot arrangement for small-angle generator is 269
shown ; effect of errors on accuracy of angular measure- ment ; performance tests on instrument ; simplified method

of calculating values of x required to set out angle a. Making of Spacers for Fabry-Perot Etalons, F. M. PHELPS III. J Opt Soc Am v55 n3 Mar 1965 p 293-5. The Fabry-Perot etalon is a versatile device but it is not widely used because of the high cost of its components

if purchased from a commercial supplier. The author has developed a method of making spacers of excellent quality for a large diameter (60 mm) etalon for less than 10% of the typical price quoted by specialty houses which make them to order. While the spacers described here were made for use with the finest quality flats obtainable, the fact that 25.4 mm diam, 1/20 wavelength,

optical flats are available for less than $100.00 per pair, means that a Fabry-Perot etalon is now within the reach

of even the most impecunious physics department. Such an etalon can always be up-graded by purchasing better- quality flats ; no additional work on the spacers would

be required.12.6.2. Scales and Gratings

See also subsection 4.1. Automatic Circular Dividing Engine, W. R. STAMPER, E. R. HALL. Phys Rev v3 Apr 1910 p 492-505. Illustrated description of the apparatus and of the method of calibra- tion employed.

Precision in Instrument Making. Am Mach v33-2 July 7 1910 p 25-8. Illustrates and describes methods of extreme

accuracy in measurement and division used in the manufacture of standard scientific instruments. Building a Machine which Splits Millionths, D. M. LID- DELL. Am Mach v40 June 4 1914 p 969-73. A detailed description of the methods of making the screw, straight ways, and divided head of the Rowland dividing engine, with its maximum allowable error of two-millionths of an

inch. The Circular Dividing Engine of Edward Troughton, 1793, D. BAXANDALL. Opt Soc Trans v25 1923-4 p 135-9. History of development and description of construction. Bibliography, 8 refs from 1768 to 1923. Ruling 15000 Lines per Inch, F. A. STANLEY. Am Mach

v60 1924 p 161-6. Prepared by committee whose chair- man was Dr. Ames. A description of the dividing engines designed by Prof Rowland. Physical Papers of Rowland

collected by Johns Hopkins Univ p 691. 3 machines, no. of teeth in the ratchet such that they rule 14,438, 15,020, and 20,000 lines in an inch. The 3 machines are kept in the sub-basement of the Physical Laboratory of Johns Hopkins University. Untersuchungen an einer Kreisteilmaschine (Investigations of a Circular Dividing Machine), L. FRITZ. Zeit Instrumkde v46 June 1926 p 289-320 11 figs. Describes

dividing machine of Geodetic Institute of Technical High

School at Hannover; illumination, microscopes, axial ro- tation, formation of rosettes, improvement in diameter, systematic and accidental errors. Accurate Graduating in Mount Wilson Shop, J. HOMEWOOD. Machy (NY) v34 Mar 1928 p 540-1 1 fig. Machine for ruling diffraction gratings having 15,240 equi- distant lines per inch ; how diamond graduating tool is held and traversed ; obtaining indexing movement of 1/15,- 240 in. ; cross-slide which floats in mercury ; special thrust bearings and other constructional features. A Machine That Rules Fourteen Thousand Lines per

Inch, E. F. BARKER. Michigan Technic v41 Mar 1928 p 17-8 25 2 figs. Machine to rule optical gratings; distances marked off by parallel grooves of certain selected shape and depth with error of less than one millionth of inch ; machine resembles ordinary shaper ; two carriages

tests of butt bearing and of screw thread ; optical tests of gratings ; preparation of diamond ruling points ; experi- mental gratings adapted for measurement of spectra. The Rowland Ruling Machine. Mech Eng v50 Apr 1928

p 294-8 3 figs. Details regarding mechanism and working

of this historic precision dividing engine devised for en- graving lines of diffraction gratings; machine can be compared structurally to simple reciprocating steam en- gine; it has flywheel, two-bearing crankshaft, connecting

rod, crosshead, and slide which correspond in location to piston ; both technique of making mirrors and design of

ruling machines have been somewhat modified and im- proved of late. The Manufacture of Steel Measuring Tape, F. W. HOBBS.

Metal Indus (N.Y.) v26 Sept 1928 p 399-400. Manufacture of steel measuring tape is transfer and etching process, and consists briefly in filling etched surface of standard plate with acid-resisting paste, transferring it to etching tissue, and thence to blank steel line after which

line is immersed in acid bath which eats away exposed

parts having figures and lines in relief ; detailed descrip- tion of equipment and process is given. Graduating Machine for Special Rules and Gages, R. B. LOVELAND. Am Mach v73 Nov 20 1930 p 822 2 figs Hand-operated graduating machine and its operation. Machine for Dividing Scales of Varying Increment, B. M. DAVIES. J Sci Instrum vlO nlO Oct 1933 p 314-8. Di- viding machine incorporating special device for dividing thermometer and other scales of unequal increment; employs flexible metal strip which can be set in given curve

according to calibration of thermometer; curve of strip adjusts exact position of dividing tool in relation to work

details of operation ; typical scale is shown. Machines for Ruling Diffraction Gratings. W. STONE,

J Sci Instrum vl4 1937 p 309-11. The design of a type

of machine is described which will reduce to a minimum

the displacement of the lines being ruled, due to changes

of temperature of the machine and of the plate on which

the rulings are being made. Some suggestions for im- provements in the design and construction of machines for ruling diffraction gratings were made by the author in an

earlier paper. Further improvements, particularly as re- gards expansion of the parts due to changes of temperature, are suggested. Grayson Micro-Ruling Machine, W. STONE. J Sci In- strum vl4 Jan 1937 p 8-14. The principles involved in the design of micro-ruling machines are stated and it is shown how these principles were applied by Grayson in the design and construction of the machine which he made and used in ruling test plates with as many as 120,- 000 lines to the inch. The machine is described in detail. Rapid Calibration and Correction of Comparator Screws and Photographic Production of Scales, G. R. HARRISON.

Rev Sci Instrum v9 Jan 1938 p 15-8. An automatic re- cording and computing comparator has been adapted to the rapid construction of uniform and non-uniform scales on glass by photography. With such a scale, the record- ing attachment of the comparator can be used to determine

the correction curve for a screw in a few minutes. A

three dimensional correcting cam may then be shaped to correct the errors found, and fairly cheap screws can thus be made to serve for precision measurements. Details of a method of mounting the screw and the comparator car- riage so as to reduce friction are given. Dividing and Ruling Scales, R. P. ABRAHAMS. J Sci Instrum vl6 July 1939 p 205-9. A general outline is given

of modern methods of producing ruled scales, either singly 270
J

- or in quantity, on metal, glass, wood, or celluloid. The

: important elements of a dividing machine are discussed tos! gether with the provisions necessary to reduce or comf pensate for errors. Reference is also made to those scales, reproduced on glass by photographic means which are now

commonly employed as graticules in optical instruments. H Graticule Ruling in Australia, M. SHAW. Instn Mech

-! Engrs Proc vl60 n2 1949 p 145-52 (discussion) 152-3. * Production of graticules or reticles for range finders.

* predictors, gun sights, telescopes, etc. under conditions * prevailing in Dominion ; methods used in reproducing patiog tern, particularly ruling and etching process ; design of

! high precision machines which were made for ruling glass

i disks preparatory to etching pattern into glass ; machine

- accuracy tests. The Graduation of Precision Circles, B. L. PAGE, NBS.

: ; Surveying and Mapping vl3 n2 Apr-June 1953 p 149-61.

- See abstract in subsection 6.4. The Production of Accurate Linear Scales by Means of the Merton Nut, L. A. SAYCE. J. Sci Instrum v32 nl Jan 1955 p 11-2. A dividing engine is described for making linear scales of unusual accuracy. The scale is engraved photographically upon a plate carried by a Merton integrating nut riding upon a cylinder bearing

a very fine screw thread. The cylinder is carried by

bearings in which it is restrained from longitudinal move- ment by applying the principle of the Merton nut to a "thread" of zero lead. Interferometric Control of Grating Ruling with Continuous Carriage Advance, G. R. HARRISON, G. W. STROKE. J Opt Soc Am v45 n2 Feb 1955 p 112-21 10

figs 4 refs. See abstract in subsection 2.4.2. On Preparing Plastic Copies of Diffraction Gratings ; Extension to Merton-NPL Process, G. D. DEW. J Sci Instrum v33 n9 Sept 1956 p 348-53. Process whereby number of glass based plastic copies may be prepared from

. gelatine replica grating ; these copies, considerably more

! stable than gelatine replicas, may be employed as transmis-

: sion gratings or aluminized and used by reflection ; by

; using plate glass blanks it is possible to reduce production

: costs while obtaining optical quality almost indistinguishable from that of parent replica. Ruling of Large Diffraction Gratings with Interferometric

Control, G. R. HARRISON, N. STURGIS, S. C. BAKER,

G. W. STROKE. J Opt Soc Am v47 nl Jan 1957 p 15-

22 12 figs 14 refs. Describes mechanical features by which high accuracy has been attained.

\ Precision Circular Scales. Nat Eng Lab, East Kilbride, Scotland June 1958 2 p. Extension of the moire fringe ^technique to automatic angular control has shown the

\ requirement for circular scales having very large numbers of lines. Automatic machine installed ruling scales accurate to 1 sec of arc. capable of

Controlled Ruling of Diffraction Gratings, G. R. HARI RISON. Am Phil Soc Proc vl02 n5 Oct 20 1958 p 483-91. i-How, by using light waves to control diamond tool while

Hit engraves grooves on aluminum coated mirror to prof'duce diffraction grating, quality of resulting grating can

I be improved and, if desired, its size increased ; half dozen

| gratings of high quality, 10 in. in ruled width, have been

I- produced on such engine; resolving power of several of

I these gratings is found to equal that theoretically expected,

in all orders up to and including highest obtainable with

visible light. Interferometrically Controlled Ruling of Ten-inch Diffraction Gratings, G. R. HARRISON, N. STUYGIS, S. P. DAVIS, Y. YAMADA. J Opt Soc Am v49 n3 Mar 1959 p

-205-11 io figs 14 refs. Seven plane gratings of high

quality, having ruled widths of more than 10 in., have been

produced on the MIT servo controlled ruling engine, monitored with interference fringes. Discusses wavefront

shapes, ghost and satellite intensities, etc. Attainment of High-Resolution Gratings by Ruling under

Interferometric Control, G. W. STROKE. J Opt Soc Am

v51 nl2 Dec 1961 p 1321-39 83 refs. Theory of grating im- provements necessary for reduction of spectral-line imperfections in gratings made on MIT ruling engine ; im- provements made in interferometric control of grating

ruling give better performance by factor of 4 to 9 over

10-in. gratings described by G. R. Harrison and G. W.

Stroke ; precision replicas permit high-resolution spec- trometer studies. Multi-section Gratings for Linear Measurement, G. D. DEW, NPL J Sci Instrum v39 1962 p 141-4 6 figs 2 refs. Describes recent improvements in the techniques of pre- paring multi-sectional gratings for moire-fringe measuring application. The system enables adjacent sections to be phased with accuracy of 5-10 /tin. and is applicable to gratings of the finest pitch employed in this work. A

method of evaluating the phasing errors at the junctions is also described. Graticules and Fine Scales : Their Production and Appli- cation in Modem Measuring Systems, E. BOVEY. J Sci Instrum (GB) v39 n8 Aug 1962 p 405-13. See abstract under subsection 5.1. Ruling, Testing and Use of Optical Gratings for HighResolution Spectroscopy, G. W. STROKE. Progress in Optics v2 North-Holland Publishing Co, Amsterdam,

1963 p 1-72 115 refs. Quality of gratings required for

high-resolution spectroscopy, and means for obtaining such gratings by ruling under interferometric control are

discussed ; high-resolution grating spectrometers and

spectrographs are described ; contemporary methods for obtaining plastic replicas of gratings are briefly examined

further improvements in quality and blaze of diffraction gratings, as well as in speed of ruling, are being made

using electron microscopy and other control methods. Some New Advances in Grating Ruling, Replication, and

Testing, R. F. JARRELL and G. W. STROKE. App

Optics (USA) v3 nil Nov 1964 p 1251-62. A report on some significant recent advances in the art of grating rul- ing, blazing, replication, and testing, with a more detailed description of the construction and performance of a newly

completed interferometrically controlled ruling engine re- cently put into operation. Ruling Engine with Hydraulic Drive, W. R. HORSFIELD.

App Optics ( USA ) v4 n2 Feb 1965 p 189-94. The carriage

of a ruling engine is driven by a hydraulic system servo- controlled by an optical interferometer, so that the posi- tion of the carriage is determined in terms of the wavelength of light. The arrangement is free from the errors of the conventional lead-screw system and is far cheaper

to construct. A Method for Making Very Accurate Line Patterns for Photographic Reproduction, U. PICK. J Sci Instrum (GB) v42 n2 Feb 1965 p 120-1. A method is described

for cutting a parallel line pattern in very thin metal

films. The width of the cut lines is constant to less than 4X10"* cm and the edge definition is better than 2X10"* cm. Photographic negatives of similar accuracy can be produced by contact printing from the cut film. 12.6.3. Worms and Power Screws, Including Lead Screws (Leading Screws, Guide Screws

[Leitspindeln], and Feed Screws)

On a Practical Solution of the Perfect Screw Problem, W.

A. ROGERS. Trans ASME v5 Paper nl46 1885 44p vl2 Paper n446 p 725-8. Discusses three classes of errors to 271
which screws are subject; a survey of the accuracy that had been attained ; and a new method of cutting screws. Das Friisen von Sehraubengewinden (The Milling of Screw Threads), E. STUEBLER. Zeit fur Mathematik

und Physik v57 1909 p 271-9 2 figs. Develops the geo- metric theory of producing a screw thread of a given form

by means of a milling cutter. Screw, H. A. ROWLAND. Encyclopedia Britannica 11th ed v24 1911 p 477-82 10 figs. With reference to lead screws the article contains sections on testing screws,

errors of screws, and mounting of screws. Describes Rowland's machine for ruling gratings. Refers to Holtzapffel's "Turning and Mechanical Manipulation" for early

history of manufacture of screws. Cutter Shapes for Milled and Ground Threads, E. WILD- HABER. Am Mach v60 nl8 May 1, 1924 p 645-9 4 figs 1 ref. Presents an analysis of the relationships between

the cutter and the thread which is important for worms

and long-lead screws. Presents table of formulas for curvature radii for various threads and cutters. Cutting a Lead-screw of Unusual Accuracy, WM. GAERTNER. Machy (N.Y.) v31 June 1925 p 808-10 5 figs. Methods used in producing precision screw about 4 ft. long with lead accurate within 0.00004 in. in entire length. Die analytische Berechnung des Gewinde-Drehstahlprofils

fiir steilgangige Schrauben und Schnecken mit geradem

Achsenschnitt (The Analytical Calculation of the Thread

Lathe Tool for Long-Lead Screws and Worms with

Straight-Line Axial Section), W. F. VOGEL. Werkstattstechnik v27 nl4 July 15, 1933 p 275-9. Classical equations proved to be only approximate; data on exact

profile equations ; results of analysis ; relation between

principal dimensions of thread and of cutting profile. Analytische Berechnung des Fingerfraserproflls fur steil- gangige Schrauben und Schnecken mit geradem Achsenschnitt (The Analytical Calculation of End-Mill Profile for Long-Lead Screws and Worms having Straight-Line Axial Section), W. F. VOGEL. Zeit VDI v78 n5 Feb 3

1934 p 156-8 and discussion Oct 20 p 1222; Betrieb vl3

n9/10 May 1934 p 252 2 figs 3 refs. Error indicated in usual method for graphical determination of profile and

correct method pointed out ; exemplification. Konstruction eines Frasers der eine gegebene Gegenflanke erzeught (Construction of a Milling Cutter which

Generates a Given Counterflank ) O. BAIER. Zeit fiir angew Mathematik und Mechanik vl4 n3 Aug 1934 p 248-

50 4 figs. Presents the principle of construction and a

practical explanation of the construction ; also the proce- dure of the construction of the milling cutter by an

example. Der Geradflanken-Drehstahl fiir steilgangige Schrauben und Schnecken mit geradem Achsenschnitt (The Straight- sided Lathe Tool for Long-Lead Screws and Worms with

Straight Line Axial Section), W. F. VOGEL. Werkstattstechnik und Werksleiter v29 n6 Mar 15 1935 p 121-6 n7 Apr 1 p 135-40. Practical mathematical analysis for de- sign and making of tools ; limits of application. Gesetze und Berechnung der Mutterdrehstiihle und

Schlagmesser fiir steilgangige Schrauben und Schnecken

mit geradem Achsenschnitt (Rules and Calculation of Internal Lathe Tool and Fly Cutter for Long-Lead Screws and Worms with Straight-Line Axial Section), W. F. VOGEL. Werkstattstechnik und Werksleiter v29 n20 Oct

15 1935 p 399-400. Theoretical design analysis and exemplification. Berechnung der Schneidflanken von Gewindedrehstahlen

fur steilgangige Schrauben und Schnecken mit geradem

Achsenschnitt (Calculation of the Cutting Flanks of

Thread Lathe Tools for Long-Lead Screws and Worms of Straight Line Axial Section), W. F. VOGEL. Zeit VDI

v79 n45 Nov 9 1935 p 1370-2 7 figs 7 refs. Consolidated

report. Discusses lathe tools and impact tools with

crooked cutting flanks ; the plane straight-sided tool ; the

cross tool. Gewindedrehstahle und Schlagmesser fiir Schnecken und

steilgangige Schrauben mit geradem Achsenschnitt. Er- mittlung und Verlauf der Schneidflanken. ( Thread Lathe

Tools and Fly Cutters for Worms and Long-Lead Screws

with Sraight Line Axial Section. Calculation and Analysis of the Shape of Cutting Edges), W. F. VOGEL. Ma-

•schinenbau — Der Betrieb vl5 nl/2 Jan 1936 p 27-30 13

figs 11 refs. Consolidated summary of the author's four

pertinent papers. Se abstracts above, in 1933 and 1935. On Cutting and Hobbing Worms and Gears, D. W. DUDLEY, H. PORITSKY. ASME Trans (J Appl Mechanics)

vlO n3 Sept 1943 p A139-46, 197-201. Two problems are

treated in this paper: (1) given the shape of a milling

cutter tooth or of a hob tooth, to find out what is the re- sulting shape of worm or gear surface; (2) given the

desired shape of a worm or gear tooth, what shape of mill- ing or hobbing tooth will produce it. Discusses four common types of worms : straight-sided axial section ; that produced by cutter or grinding wheel of straight-sided axial section ; straight-sided normal section ; involute

helicoidal worm.

Grinding Lead Screws, J. R. MOORE. Iron Age vl53 n22 June 1 1944 p 42-6 June 8 p 66-70. Description of elabo- rate techniques worked out by Moore Special Tool Co, Bridgeport, Conn, over period of years to achieve ultimate

in accuracy in manufacture of micrometer screws for small

jig borer ; highlights of method is use of electronic thermostat to maintain temperature of coolant and hence work at constant differential with respect to master lead screw

of thread grinder; unusual methods of checking product

are illustrated. Interferometric Calibration of Precision Screws and Control of Ruling Engines, G. R. HARRISON, J. E. ARCHER.

J Opt Soc Am v41 n8 Aug 1951 p 495-503 12 figs 14 refs. A new device is described with which screws of any

length can be calibrated rapidly for both periodic and

cumulative errors in terms of interference fringes. It can

also be used to plot correction cams to remove fixed errors

of translation or rotation, and to monitor the operation of an engine while ruling diffraction gratings or scales, cor- recting by automatic feedback differences between the

actual carriage position and its proper position as shown

by an optical interference field. This so-called "Commensurator," whose name arises from its function of over- coming the incommensurability of the wavelength of the

light used for calibration and the lead of a screw, consists principally of a screw drive system, eight-figure dials, and

a generator, geared together in ratios that can be controlled to one part in 10s

. Fringes produced by a Michelson

interferometer mounted on the ruling engine (or having

one mirror moved by the nut of the screw being calibrated) are changed photoelectrically to a wave train that measures

translation to within 0.1 microineh. A second wave train of almost identical average frequency is produced by the Commensurator generator to measure screw rotation, and

the two trains are continuously compared by means of a phase-sensitive amplifier and motor to within 1/100 cycle or fringe. Any error in carriage translation appears as a

lag or lead which produces a torque in the motor until synchronism is re-established by a relative shift of the two wave trains, and thus makes possible automatic

plotting of the screw error curve on a moving chart. Precision Screw Thread Corrector Lathe. Eng vl96 n5099

Oct 16 1953 p 489-90 ; Engr vl76 n4578 Oct 23 1953 p 524-5. Essential element for accurate operation of gear hobbing 272
ad riniachines is hob slide feed screw ; new high precision lathe ^Uror finishing of such screws as developed by Craven

.^Brothers (Manchester); on this machine screw thread

^tl;pan be accurately measured in position after cutting and

it - >rreetor mechanism can be directly adjusted to precision gage readings as required.

ad it raven Precision Screw Thread Corrector Lathe. Machy

Br . (London) v83 n2142 Dec 4 1953 p 1111-3. Lathe especially

ale constructed for correcting gear hobbing machine hob slide

: - ;feed screws, after they have first been cut by normal

methods ; special measuring head mounted on top of tool

j- .ipost carries single stylus point and spigot type dial gage

B reading to 0.00005 in.

;.:>5 Method of Recording the Pitch Errors of Screw Cutting

Lathes, F. H. ROLT, XPL. Eng Dimensional Metrology,

. Proc of Symposium held at NPL, 2 vols, Her Majesty's

; ; Stationery Office (London) 1955. Paper nl9 p 323-8 3

;yj;figs. Describes equipment by which lathes can be tested 1^ :ln the works and an autographic record obtained showing

. e complete periodic and progressive errors over any

:. .ength of traverse required. Discussion. ^ -Special Lathe at the National Physical Laboratory for

itting and Forming Fine-Pitch Screw Threads, V. W.

. . STANLEY, NPL. Eng Dimensional Metrology Symposium

'. a-ld at NPL, 2 vols, Her Majesty's Stationery Office (LoniBon) 1955. Paper n20 p 329-45 10 figs 3 refs. A high

precision lathe is described capable of producing fine1 ten screws ranging from about 1 00 to 30,000 threads per

~

[ nch. Reference is made to the application of these fine

[r4 jtecrews to the production of diffraction gratings for use in

1 L

:5pectrochemical analysis and for measurement of linear Misplacement.

. .(.Precision Lead-Screws Ground from Solid, M. C. SU- LANDER, W. F. SPIERLING. Machy (N.Y.) v62 n9 May

1956 p 146-9; Machy (London) v89 n2285 Aug 31 1956 p

SO6-6. Lead screws produced by Precision Thread & Gear

Torp, Chicago, have variation in thread pitch diameter

. not exceeding 0.0002 in., and max lead error between any _ -,wo vees at 1-in. intervals of 0.0003 in. ; importance of

~r naterial selection, with good results obtained with Sparta, m

Universal Cyclops air hardening tool steel; ultra-precise H r.hread grinding operations described; continuous inspecIcion of threads.

~\ 40,000 Threads to Inch, J. F. BELL. Am Mach vlOO nl6

; Inly 30 1956 p 112-3. Modification of 50 yr old Rivett

• a the at Johns Hopkins University has made it possible to TM 'nake very accurate screws of 10,000 threads to inch;

-

""• :hread is used as diffraction grating and is also of value

^9 jfor very accurate measurement of lineal displacement

«t frhrough relatively large distances ; methods of making

{ H ?screw.

,-

: -Mechanical Engineering Research Laboratory : Work of J .:he Mechanisms, Engineering Metrology and Noise Control

division, C. TIMMS, Nat. Eng. Lab. Trans Instn Engrs

uid Shipbuilders in Scotland 1958 p 317-68. On p 334 is lescribed and illustrated the master-screw correcting lathe

~j -ecently transferred from NPL, which has a history dati . ng back to 1900. Screws to 10 ft. in length may now be

' Corrected. Reference is made to "Standard Leading

. .Screws for Screw-Cutting Lathes" 1905 (Stationery Office, London). W 'k Comparison between Different Tooth Forms on Ground

Bj Worm Gears, G. ZEISE. Klingelnberg News, W. Ferd. » Klingelnberg Sohne. Remscheid Dec 1961 5 p 5 figs. ToothI 'forms are designated in DIN 3975 as A, N, and E in which

the generatrix of the toothfiank is a straight line and as K when the straight line generatrix is on the tool itself.

. J .The paper shows the difference of the various profiles, and

'. particularly the results obtained in relation to grinding

•' >vheel parameters.

Finishing Worm Profiles on Universal Thread-Grinding

Machine, B. SMITH. Machy (London) vl02 n2621 Feb 6 1963 p 304-8. Setup for fly-cutting teeth in worm wheel

on hobbing machine ; description of Matrix generating

dresser for forming wheel on universal thread grinding machine; Matrix dresser eliminates need for time-con- suming calculations and greatly facilitates dressing re- quired form; example of calculating, producing and

checking involute helicoid worm ; grinding fly-cutter for machining worm-wheel teeth ; development of dressers. See also H. KALUZKA subsection 9.2, 1963, p. 205. 12.6.4. Screw Thread Gages

Making Thread Gages, A. L. MONRAD. Machy (N.Y.) vl4 Feb 1908 p 387. A thorough description of the manufacture of thread gages ; tables of ball diameters to be used in determining angle of thread for V, USS, Briggs

Standard, and Whitworth threads. The Production of Screw Thread Gages, W. RICHARDS.

Mech Wld v59 1915 p 134-5 146 158-9. Methods of turn- ing on lathe ; measurement by three-wire method. The Manufacture of Screw Gages, J. E. SEARS, NPL. Eng vl03 Feb 9 1917 p 137. Various developments and

refinements in the measuring of screw threads at NPL.

Producing British Screw Gages, I. W. CHUBB. Am Mach

v46 nl4 Apr 5 1917 p 593-1 3 figs. Gives brief description

of screw thread plug and ring gages, methods of manufacture, accuracy, composition of material, and method

of hardening. Measurement of pitch diameter. Making Precision Thread Gages, E. A. SUVERKROP. Am Mach v47 Aug 16 1917 p 265. Describes manufacture. Comment by J. BOLKOVAC, v47 Nov 1917 p 938. The Manufacture of Hardened Thread Gages, G. DOORAKKERS. Eng vl24 n3222 Sept 28 1917 Oct 5 12 26 Nov 2 p 263 290 308 354 390. Gives details of manufacture of master tool, thread cutting tool, checks for thread plug gages, laps. Making Whitworth Thread Gages, W. D. WOODWORTH,

H. W. BENDER. Machy (N.Y.) v24 n6 Feb 1918 p 483-93

17 figs. Reviews practice of a successful manufacturer. Making Whitworth Thread Gages. Machy (London) vll Mar 14 1918 p 645-9, Mar 21 p 676-81. Elements of Whit- worth thread ; machining gage blanks ; preliminary annealing process ; rough machining thread ; carburizing ; finish- machining ; hardening ; advantages of grinding thread be- fore lapping; special grinding machine; use of wires for measuring pitch diameter ; measuring core diameter ; heat treatment to prevent future distortion ; finish grinding

operations ; timing lapping periods ; lead and angle checking gage. Gage Making in a Shell Plant, F. D. JONES. Machy

(London) vl3 Sept 21 1918 p 197-202. Practice used for gaging of 75 mm shell ; materials used for thread gages

thread gage cutting, grinding, and lapping; testing ac- curacy of thread gages. Making Thread Gages, T. H. FENNER. Can Machy v20 Nov 7 1918 p 529-32 7 figs. Description of plant and

methods of a Canadian firm. Present Practice in Thread Gage Making, F. O. WELLS.

Trans ASME v40 paper nl666 1918 p 809-25 ; Am Mach

v50 Jan 23 1919 p 153-8. Manufacturing difficulties ; lead

errors in lathes ; approved methods of thread lapping, grinding, and testing ; gage tolerances. Advance of Thread Gage Making during the War, C. B. COLE. Machy (N.Y.) v25 Aug 1919 p 1153^. Practices used during the war in thread gage making ; difficulties 273
experienced in cutting Whitworth threads ; choice of material ; annealing and pack-hardening ; laps ; checking ring gages using four check plugs. Thread Gage Standards, J. E. COLLINS, Machy (N.Y.) v26 Jan 1920 p 427. A complete system of thread plug and

ring gages ; tolerances and their application, three-wire method of measurement, effects of heat treatment, lapping, and shadow projection method of measuring threads. Making Whitworth Thread Gages, C. E. ALLEN. Machy

(N.Y.) v26 Aug 1920 p 1157-60 5 figs; Machy (London)

vl4 July 1919 p 504. Method which utilizes disintegration

of grinding wheel during grinding operation to produce

final thread form. Hardening Screw Gages with Least Distortion in Pitch, W. J. LINEHAM. Am Mech v53 Sept 1920 p 547 ; Mech Wld v67 May 7 1920 p 291, May 14 p 307, May 28 p 339

Engr vl29 Apr 30 1920 p 443. Report of the procedure

used at Goldsmith's College, London, to give least distortion. Discusses cutting, measurement, and heat treatment. The Manufacture of Hardened Screw Gages. Engr v!30

Sept 24 1920 p 310-1 5 figs. Manufacturing process fol- lowed at plant of Coventry Gauge & Tool Co., Coventry, England. The Manufacture of British Association Screw-Thread

Gauges, T. F. DAVEY. J Inst Mech Engrs Apr 1921 p

191-6. Design, methods, and apparatus used in measurement, compensation and correction for errors in lathe, cut- ting tools, lapping, and heat treatment. Some Notes on Hardening Various Screw Gauges, F. A. LIVERMORE. Can Machy v28 July 13 1922 p 26-7. Results of experimental work ; effort to obtain process that

will eliminate warpage and change of shape; methods of heat treating and quenching; expansion and contraction. Heat Treatment of Screw Gauges. Eng Prod v5 Aug 10 1922 p 138. Resume of experimental work conducted over

period of nine months with view to determining best conditions for production of hardened screw gages to satisfy stringent tests of NPL.

Special Apparatus for Tapering Thread, W. O. RUSSEL. Am Mach v60 Mar 1924 p 480. Description of apparatus

used in place of taper attachment for cutting taper thread

gages. Die Herstellungsgenauigkeit der Gewindelehren und ihre messtechnische Erfullung (The Production Accuracy of Thread Gages and their Metrological Performance), G. BERNDT. Werkstattstechnik v22 n'5 Mar 1 1928 p 131-6

5 figs. Describes special microscopes, gages, and measuring devices; methods used in making thread gages in accordance with German DIN standards.

Nitriding Oil Tool Gages, F. W. CURTIS. Am Mach v70 n22 May 30 1929 p 863-4 5 figs. Description of nitriding process for large thread gages which eliminates difficult grinding operation ; and produces hard surface free from

scale; tool joint made by Doheny Stone Drill Co. is dis- cussed ; case hardening by nitriding process can be done by

small shop with inexpensive equipment.

Tools for Hartometer Production, C. R. RANNEY. Am

Mach v71 n25 Dec 19 1929 p 1001-2 6 figs. Discussion of how problems of aligning multiple starting points for threads of different pitch and diameter in Hartometer

screw-thread gage are solved. Herstellung und Priifung von Normal-Gewindelehren (Manufacture and Inspection of Standard Thread Gages),

O. KESSLER. Werkzeugmaschine v38 Jan 1934 p 3-6. Detailed description of machines, instruments, and

methods used. Illustration of special microscope.

Typical Operations on Ford Gages, C. O. HERB. Machy

(N.Y.)*v43 July 1937 p 706; Machy (London) v50 Sept

16 1937 p 749. Grinding and thread-lapping accurate thread gages and methods of checking and measurement.

Plating of gages. Aus der Fertigung von Gewindedorn und Lehrringen (On

the Manufacture of Thread Plug and Ring Gages), F. MATTHEES. Werkstattstechnik v33 May 1939 p 262. Discussion of the methods with particular reference to lapping. 12.6.5. Other Gages

See also subsection 3.1. Making Spherical End Gages, C. W. WRIGHT. Am Mach

v26 Aug 13 1903 p 1148-9. Illustrates and describes in- ventions of the writer for grinding spherical end gages and a lapping rig for The Making of a Knife Edge Square, T. MILLER. Machy

(N.Y.) vl7 Mar 1911 p 519 5 figs. Detailed description with line drawings. Gage Making and Lapping. Machy's (N.Y.) Reference Book No. 64. Principles of gage making, the manufacture

of gages, lapping flat work and gages, the rotary lap, miscellaneous lapping. The Manufacture of Gages at the L. C. C. Paddington

Technical Institute, A. G. COOKE, W. J. GOW, W. G. TUNICLIFFE. Proc Inst Mech Engrs Jan Feb Mar 1917 p 45-108 ; Eng vl03 Jan 26 1917 p 89-91 5 figs ; Mech Wld

v61 Jan 26 1917 p 46 ; Feb 2 p 57-8. Discusses work of

Institute on standardization of Gages. Discusses accuracy and the tolerances on limit gages, position gages, screw

gages. Discusses instruments devised there for measuring

pitch and diameters of screw gages and an optical ap- paratus by which screw cutting tools could be shaped and

the sections of screw threads examined. Gives results of some of tests in form of curves; the optical apparatus

consisted of a light source giving a parallel beam of light freed from heat rays by passage through saturated solu- tion of alum, a rigid optical adjustable bench carrying tool or gage and projecting lenses, a screen at a distance of about 16 feet. In final projection of screw thread in sil- houette a careful examination for symmetry is made.

Magnification up to 400 diameters was obtained. Discussion which followed paper took up more in detail such

points as pitch errors in lathe, the optical apparatus used,

lenses used for magnification, method of lapping (much in detail) the importance of an accurate lead screw, materials, methods of hardening quenching and annealing of

gages, the alum bath used, sequence of operations in manufacture of case-hardened mild-steel gages, method of inspection of gage, pitch measurement, etc. Grinding Accurate Profile Gages by Means of Master

Plates, H. M. DARLING. Am Mach v50 Jan 16 1919 p

105-6 3 figs. Description of operation. Making Some Difficult Duplicate Gages, E. A. DIXIE. Am Mach v50 Jan 23 1919 p 162. Describes method of making a special taper plug gage. Discussion by A. MOSES on p 706. Manufacture of Hoke Precision Gages at the Bureau of Standards, H. L. VAN KEUREN. Am Mach v50 Apr 3

1919 p 625-30 6 figs; Mech Eng v41 Mar 1919 p 289-90. Gage blocks are being produced at the Bureau with an

accuracy limit of a few millionths of an inch. Apparatus

used in testing flatness and parallelism to one millionth

of an inch. Development of process for their commercial manufacture has taken place within period of six months.

Special reference is made to light-wave interference method for determining accuracy. Angular Plug-Gage Making, H. PUSEP. Am Mach v50 Apr 3 1919 p 635-40 15 figs. Lays emphasis on elimination 274
of errors in preliminary operation, in order to prevent

- their accumulation and the appearance of serious defects which will be difficult to eliminate in later operations. How Precision Gage Blocks are Made, F. D. JONES.

• Machv (X.Y.) v26 Apr 1920 p 697-708 27 figs; Machy

! . London) t16 June 3 1920 p 253-63 27 figs. Practice of

£> Pratt & Whitney Co., Hartford, Conn.

i ti

' Generating Precision Tools, W. E. HOKE. Machy (N.Y.) t31 Feb 1925 p 421-5 7 figs; Machy (London) v25 1925 p

613. Fundamental or natural methods of obtaining precision in toolmaking, gagemaking, etc. by application of generating principle.

luk

'

-• Lapping Micrometers. H. L. VAX KEUREX. Am Mach

v64 June 3 1926 p 871. Describes procedure for reconditioning micrometer calipers to high degree of accuracy.

~ Manufacture of Wickman Gages. Machy (London) v33

' Xov 29 Dec 27 1928 p 257-62 397-402 24 figs. Methods

employed by Coventry Gauge and Tool Co. Ltd, in manufacture of adjustable limit plain and thread snap gages, wickman gage details ; operations on frame ; drilling holes _ f or anvils ; seasoning process ; sizing anvil holes ; operations on anvil; hobbing threads; grinding operation by which finished form of thread is generated; checking

rt finished anvils ; method of assembly ; tests for alignment

of teeth as between two opposing anvils. Der Laeppvorgang bei der Herstellung von Messwerkzeugen (Lapping Procedure in Manufacture of Gages).

C. BUETTNER. Werkstattstechnik v25 no Mar 1 1931 p 113-6 10 figs. Fundamental relations of various factors in lapping necessary for obtaining measuring surfaces of high quality; relationship between tool and work piece with particular regard to action of abrasive and lubricant. Anleitung zur Herstellung einer Praezisions-Rachenlehren-Schleifmaschine ( Design of Special Grinding Machines

for Precision Grinding of External Gages), O. LICH.

Maschinen Konstrukteur v65 Mar 5 1932 p 29-31. .Production of Dial Indicators. Machy (London) v41 Oct

1932 p 6-9. Machining operations and equipment used

y T. and F. Mercer, St. Albans, in manufacture of dial

. indicators giving readings up to 0.0001 in. Heat Treatment of Gage Steel, F. A. W. LIVERMORE.

Mech Wld v92 Oct 21 1932 p 381-3. Ideal conditions would be realized if it were possible to transmit simul- taneously to each molecule of steel given amount of heat in

: given time; in efforts to approach as nearly as possible

this ideal, certain phenomena in connection with mass

occur ; in heat treatment of steel for gages, these alternations are of great importance ; results obtained ; construe-

: tion of special furnace. How to Make Accurate Multi-Spline Gage, W. C. BETZ.

Machy (X.T.) v40 nl Sept 1933 p 22-3; Machy (London)

v43 nll03 Xov 30 1933 p 245-6. Difficulties in obtaining

precision spacing of blade slots are overcome by simple and ingenious method ; simple ring gage used for precision spacing; equipment used for making final inspection of

I slots in gage body.

1 Facts to Know in Gage Grinding, H. J. CHAMBERLAXD.

Abrasive Indus vl7 n4 Apr 1936 p 8-10. Form of physical adjustment which steel must undergo, between heat treat- ing and finish grind, which is known as seasoning period

procedure to be followed ; gages ground to size.

Typical Operations in Making Ford Gages, C. O. HERB.

Machy (X.Y.) v43 nil July 1937 p 706-8; Machy (Lon- don) v50 nl301 Sept 16 1937 p 749-51. Commentary on some of grinding and thread lapping operations carried out in gage plant of Ford Motor Co. Extreme Precision is Demanded in Gage Grinding. Abrasives vl8 n9 Sept 1937 p 9-11 62-3. Brief illustrated de- scription of few of grinding operations carried out at toolmaking plant of Taft-Peirce Manufacturing Co. Woonsocket, R.I. Production of Dial Gauges. Machy (London) v74 Feb 22 1949 p 227-32. Methods employed by British Indicators, Ltd. St. Albans, for making "John Bull" gages;

punching, boring and plating; machining operations are few ; production of gear train components ; assembly. Zur Frage des Feinschleifens und Laeppens von Lehren

(Fine Grinding and Lapping of Gages), O. RICHTER.

Werkstatt und Betrieb v82 n5 May 1949 p 160-1. Conclusions based on replies to circular letter sent to gage manufacturing firms ; problems discussed include : accu- racy of gages, their uses, costs, and manufacturing

problems. How Gage Blocks Are Made, R. GIERLICH. Am Mach

v94 nl Jan 9 1950 p 85-9. Importance of surface finish

wear on gage block surfaces ; manufacture of gage blocks

lapping procedure and importance of interchanging blocks during lapping ; inspection of finished gages including

calibrating for exact size and inspection for flatness. Producing Gage-Blocks To "Millionths", R. A. GIERLICH.

Machy (X.Y.) v59 n6 Feb 1953 p 147-56; Machy (London)

v83 n2121 July 10 1953 p 59-67. Techniques employed

in Savage, Minn, plant of Continental Machines, Inc. for manufacturing DoAll gage blocks ; 131 sizes of gage

blocks, ranging from 0.010 to 20 in in length produced;

grinding, heating and inspection operations; lapping of gage blocks. Lapping Anvils of Micrometer Calipers, H. M. BUCK.

Machy (London) v88 n2251 Jan 6 1956 p 14-5. Description of apparatus and techniques which were applied suc- cessfully for generating accurately flat and parallel measuring faces on micrometer calipers ; method involves

first rectification of measuring face of micrometer spindle, after which anvil face is lapped in fixture. "C.E.J." 4- "B. & S." = Precision Gaging. Machy (X.Y.) v64 n8 Apr 1958 p 132-5. Manufacture of "Jo" (after Carl Edward Johansson) gage blocks at Brown & Sharpe Mfg Co, Providence, R.I. ; details of making "Thrift"

blocks which is new class of blocks produced to better than

Class B accuracy; lapping operations indicated. Gage Inspection in Millionths—Xot Guesswork, G. ASH- MEAD. Machy (X.Y.) v70 n5 Jan 1964 p 104-6. Del- tronic Corp, Costa Mesa, Calif manufactures Class "X"

cylindrical plug gages exclusively in over 6000 sizes ; with

each plug gage certificate is supplied which unconditionally guarantees that gage is within size tolerance of plus 0.000,040 in. minus 0.000,000 in. and that it has sur- face finish of approximately one /iin ; manufacturing methods described and illustrated.

275
Addendum to Section 12.

12.6.2. Scales and Gratings, Manufacture of

Preliminary Notice of the Results Accomplished in the Manufacture and Theory of Gratings for Optical Purposes, H. A. ROWLAND. Phil Mag ser5 vl3 1882 p 469-74. Refers to previous work of Rutherford in making gratings. Describes progress in making a highly accurate screw

the ruling of 160,000 lines on a surface or 29,000 per inch, and the making of concave gratings.

See LOEWEN, pll9. See TAYLOR pl66, and ZEISS, p!66. 12.6.5. Other Gages, Manufacture of

See KNOYLE, pl63, on manufacture of combination angle

gages. Addendum to Section 2 (continued from page 90)

flection within a plane-parallel plate, by means of which

interferences can be investigated for much larger path

differences than previously. Green rays from a mercury lamp pass into a glass plate 6 cm thick through a slit in the opaque silvering which covers the face of the plate. The opposite face is half-silvered, and the rays which

emerge pass into a telescope focused at infinity. A

movable shutter at the eyepiece can cut off the rays in succession, and the change observed on cutting off the ninth

reflected ray shows that the latter is still in a condition to interfere. The corresponding path-difference is 2,600,000 wavelengths,—a limit which could be extended by the use

of a thicker plate. tiber cine Kadmiumamalgamlampe aus Quartz ( Regarding

a Cadmium Amalgam Lamp of Quartz), O. LUMMER, E. GEHRKE. Zeits InstrumKde v24 n 10 Oct 1904 p 296-8 6

refs. Lamp produces eight strong visible Cd and Hg lines from 644 to 436^. Construction is described. 2.4.1. Length and Diameter Measurements —General

Methode pour Mesurer en Longueurs d'Onde de Petites Epaisseurs (Methods of Measuring Small Thicknesses in Wavelengths), J. M. De LEPINAY. Ann Chim Phys ser6 vlO 1887 p 68-85. The method adopted was based on the use of Talbot fringes, the advantages of which were set forth by Mascart. Presents numerical data ; corrections for temperature and pressure ; description of apparatus

preliminary experiments and calculations ; conclusion. Mesures Optiques D'Etalons D'Epaisseurs (Measurement

of the Thickness of Optical Standards), J. M. De LEPINAY. Ann Chim Phys ser7 v5 May-Aug 1895 p 210-

55 10 figs. Contents : measurement of index ; measure- ment of thickness; determination of the equal-thickness

curves. 2.4.2. Fringe Count Interferometers and

Dilatometers

Measuring Device Employing Light Interference Fringes,

E. ROOT III. U.S. Patent 2 604 004 July 22 1952 8p

20 refs. Provides an apparatus for making absolute meas- urement of an article of any size by an actual count of the succession of interference fringes. Reversible Interference Fringe Counter with a Small Measurement Range, L. Ya. KVASKOV. Meas Techns n8

Mar 1965 p 675-8 4 figs 3 refs. Translated from Izmer Tekh n8 p 16-9 Aug 1984. Describes a Michelson inter- ferometer, photocells, and an electronic unit consisting of a photo multiplier, a dc two-channel amplifier, a reversing

stage, and a counter. The apparatus has a range of 50

fringes and a precision of one interference fringe. 2.4.4. Interference Comparators

New Interferometer for Measuring Block Gauges. V. P. GOLUBKOVA, V. P. KORONKEVICH, E. I. FINKEL'

SHTEIN. Meas Techns n8 Mar 1965 p 672-4 3 figs 4

refs. Translated from Izmer Tekh n8 p 14-6 Aug 1964. Describes a new interference comparator for measuring

the lengths of gage blocks from 3 to 100 mm without wringing them to auxiliary surfaces. 2.4.5. Measurement of Long Lengths

(by Interferometry)

Sur les Phenomene des Interferences entre deux Rayons

de Lumiere dans le cas de Grandes Differences de Marche

( Regarding the Phenomenon of Interference of Two Rays

of Light in the Case of a Large Path Difference), H. FIZEAU, L. FOUCAULT, CR Acad Sei v21 1845 p 1155-

8; Ann de Chim Phys ser3 v26 1849 p 138--18, v30 1850| p 146-59. Discussess interferences produced by an array j

of mirrors, by reflection on thin plates, and by means,

of double refraction. 2.4.6. Measurement of Line Standards jj (by Interferometry)

Automatisches Vermessen und Protokollieren von Pra- 1 zisionmasstaben dureh fotoelektrisches Interferometer

j und fotoelektrisches Mikroskop (Automatic Measurement;! and Programming of Precision Measurement Standards i by Means of the Photoelectric Interferometer and Photo- jl electric Microscope), F. HOCK, K. HEINECKE. j 1 Maschinemarkt v71 n37 May 7 1965 p 27-37 25 figs 14jl

refs. Describes apparatus for fast, completely automatic

length measurements of line standard intervals in rela-Jl; tion to the wavelength definition of the meter, millimeter ji graduations are calibrated to 6.1/x as the result of many 1 years of development work. Graduation lines are-l scanned photoelectrically by an oscillating light beam, and if a punched tape is used for recording.

276
AUTHOR INDEX

Note. References showing names of firms or organizations, but not naming authors, are indexed in italics. A AA Gage Co, Abadzhi, K_

Abbe

Abbott, E. J.

Abeles, F

Subsection/Year Page __6.3/1958 163

..7.1/1961 180

..1.1/1940 7

I. 2.1/1963 10 2.2.1/1964 48

2.3.7/1964 68

..1.7/1936 36

.11.3/1950 250

II. 3/1953 251

11.3/1954 251 Abrahams, R. P 12.6.2/1939 270 Abramzom, E. L 12.3/1961 263

Abrikosova, I. I 1.7/1957 38

Acker, G. H 10.3/1927 238

Ackerl, F 6.4/1926 165

Acquista, N 2.3.1/1952 57

Acton, F. J 8.2/1943 195 Adadurova, M. A 4.3/1960 123 Adam, N. K 1.7/1941 36 Adams, A.R 5.2.4/1963 141 Adams, H 12.1/1943 258 Adams, J. R 2.1/1956 43

2.3.1/1956 58

2.3.4/1956 64 Adams, K. B 2.3.4/1950 64

Adderley, E. E 3.1/1943 93

Afanas'eva, V. A 2.4.4/1961 83

Agar, A. W 11.3/1957 252

Ahearn, J 6.1/1947 154

Airborne Instruments Lab. Div 2.4.5/1964 86

Airy, G. B 1.5/1846 40

Aitchison, P. M 2.2.5/1950 54 Akhmatov, A. S 3.1/1961 93

Aksyuk, Y. F 3.6.2/1960 113

Albert, M. P 11.1/1962 246

.Albrecht, S 1.3.4/1920 26

5.2.3/1936 138

Alciati, C. J 6.2/1955 158

Aldis, A. C. W 8.1/1911 189

j. H. Alexander Mach., Ltd 2.4.1/1939 70

Alexander, W 5.2.2/1951 135

Alford, L. P 7.1/1911 175

Aliab'ev, D. V 1.3.3/1959 25

Alig and Baumgartel 1.2.3/1930 13

plan, E. R 1.2.1/1957

,^Uan, G. A 12.5/1962 268

[fen, C E 12.6.4/1920 274

Uler, W. F 3.4/1944 101

5.2.1/1952 132

Ulsopp, H. F 1.4/1958 29

\lpar, G 6.7/1964 171

Uquist, H 7.3/1936 181 Utmann, F. G 10.1.2/1932 215

10.3/1932 239

an Mfg. Co 3.6.4/1912 115

erican Gear Manufacturers

Association 10.1.1/1945 213

10.1.1/1947 213

10.1.1/1955 214

10.1.1/1956 214

10.1.1/1958 215

10.1.1/1959 215

10.1.1/1962 215

10.1.3.4/1962 221

10.1.4/1962 228

10.2.2/1956 231

10.2.2/1964 232

American Grinder Co 10.2.1 American Instrument Co 6.2 American Society of Mechanical

Engineers 1.2.1 3.6.1 American Society for Testing and

Materials 3.3 American Standards Association 10.1.1 10.1.1

10.0.1

10.1.1

10.1.1

10.1.1

10.1.1

10.1.1 10.1.3.4

10.1.3.4 10.2.4

10.2.4 American Tool Works 12.2 Ames 3.3

3.5, 3.6.4 Ames, J. S 2.3.1 Ammco 7.4, Anders, O. U 11.3 Anderson, G. M 1.3.2 Anderson, J. S 3.4 Anderson, M. E 9.1 Anderson, N 12.3 Anderson, N. A 5.2.3 Anderton, P 1.2.2, Andrade, E. N. da C 1.7, Andrae, W. C 1.1 Andrejev, E. M 1.2.3 Andress, J. E 12.1 Andrew, K. L 2.4.3 Andrews, H. I 3.2 Andrews, J. P 1.5, 7.3 Andrushevich, Y. M 12.2 Angles, J. W 1.1 Angus, H. T 5.6 Antal, J. J 11.3 Aoki, S 3.5

10.1.1 Apitz, G 10.3 Appleby, A. N 5.6

7.- Archer, J. E_._ 9.1 10.6.3 Archer, R. J_-- 11.2 Arecchi, F. T 2.4.5 Aregger, A 6.4 Armand, G 1.7 Armstrong, L. D 5.4 Armstrong, W. E

Armstrong, Whitworth & Co 3.5 Army Tank Automotive Center 10.2.2 Arnulf, A 6.1

8.1 Aronson, M. H 5.2.2 Arregger, C. E 3.1 3 2 Arrow Tool Co 9.2 Arthur Knapp Eng. Corp 9.1 Arutyunov, V. O 1.1

Subsection/Year 1923

1948

1963 1958

1961 1946

1950 1954

1955 1956

1958

1960

1962

1956 1960

1956 1960 1924

1929 1930 1930

1897 1930 1956

1962

1923 1909 1964

1956

1964

1953 1930

1961 1937 1964

1947

1931 1928

1961 1919 1955

1952

1963 1960

1943 1945

1958

1951

1951 1962 1964

1921 1964

1955

1958

1918

1962

1929 1928

1953

1945 1945

1919 1919

1961 277
SubseclionlYear Page Asanov, V. V 1.3.2/1965 40 Ashby, H.F 1.4/1961 30 Ashmead, G 12.6.5/1964 275

Aspinwall, D. M 1.3.3/1960 25

Astin, A. V 1.1/1961 4 Astrop, A. W 3.5/1961 108

4.4/1961 127

Atkins, H. F 3.6.4/1911 115

Atkins, W. F 3.2/1964 116

3.3/1957 99

9.1/1964 202

Atkinson, M. P 2.5/1959 88

Atkinson, R. H 12.5/1962 268 Attwood, C 10.1.3.1/1947 218

Atwell 6.2/1915 157

7.3/1915 181 Aubertin, A 6.3/1936 162

Austen, A. E. W 1.3.3/1946 23 Automation Gages 8.2/1962 196 Averbach, B. L 4.3/1951 173 Averv, D. G 2.2.5/1950 54

11.1/1949 242

Avril, J 5.2.2/1956 136 Axman, B 1.1/1961 4 Ayre, V. E 3.4/1920 101

9.3/1921 206 Azim, K. A 11.1/1963 246

11.3/1963 254 B

Bacon, R. H 1.3.3/1953 23 Baeckstroem, A 5.2.2/1934 133 Baeckstroem, H 1.3.1/1930 17

1.3.4/1933 27

Baier, O 12.6.3/1934 272

Bainbridge, N. W 1.4/1963 30

Baird, D. C 1.1/1962 4

1.2.2/1961 12

Baird, K. M ..--2.1/1957 43

2.3.1/1960 59

2.3.1/1963 59

2.3.2/1958 62

2.3.3/1959 62

2.3.3/1962 63

2.3.3/1963 63

2.3.4/1956 64

2.3.4/1957 64

2.3.4/1959 65

2.3.7/1963 68

2.4.1/1958 71 2.4.3/1954 79

2.4.6/1961 87

2.4.6/1963 87

4.1/1961 119

Baivel, L. P 5.2.2/1964 138

Baker, D 3.6.4/1916 115

5.7/1959 150

6.6/1916 169

Baker, E. B 3.5/1951 107

5.2.2/1951 135

Baker, H 3.5/1922 105 Baker.-H. D 1.4/1953 28

Baker, H. W 3.6.4/1958 116

Baker, J. B 1.2.2/1962 12 Baker, K. E 1.3.4/1949 27

3.6.3/1949 114

Baker, L. R 2.2.3/1953 50

6.2/1961 160

Baker, M. I 6.1/1964 156 Baker, N. H 1.4/1953 28

Baker, S. C 12.6.2/1957 271

Baker, W. C 8.1/1915 189 Baker, W. H 5.1/1945 130 Bakos, J 5.1/1961 131 Baldwin, R. R 6.2/1964 162

Ballik, E. A 2.3.7/1963 68

Subsection/Year Page Balsara, E. M 11.3/1957 252

Banfield, A. C 8.2/1919 193 Banhart, A 10.1.4/1962 228

Banwell, I 9.3/1914 206 1 Barakat, N 2.2.1/1963 48

2.2.5/1963 55

6.5/1949 167

11.1/1963 246

11.3/1963 254

Barany, N 5.4/1959 145

6.1/1958 155

6.1/1960 155

6.5/1960 168 Barash, M 10.1.4/1959 227 Barber-Colman 10.1.2/1954 216

Barber, C. R 1.4/1954 29 Barber, D. L. A 2.5/1959 88

Barer, R 4.4/1960 127

Barford, J 2.4.2/1963 77

5.2.2/1963 136

Barger, R. L 2.3.3/1961 63

2.3.6/1958 65, 66

2.3.6/1960 66

Barinberg, A. D 6.1/1960 155

Barker, A. J 1.2.3/1964 15 Barker, E. F 12.6.2/1928 270

Barker, G. H 1.3.2/1938 20 Barker, S. G 8.1/1930 190 Barlow, B. L 6.2/1963 161 7.3/1963 184 Barnard, G. P 6.1/1945 154 Barnard, T. P 12.6.1/1960 269

Barnes, C 3.3/1950 99 Barnes, D. C 2.4.1/1953 70

3.5/1954 107

6.7/1950 171 12.6.1/1954 269

Barnes, J. H 12.1/1928 257

Barnes, W. P 1.6/1963 35 Barnet, E. J 6.2/1957 159 Barnett, C 3.5/1954 107 ! ' Barr, G 3.4/1923 101

Barrell, H 1.1/1957 4 1.1/1965 6 1.2.2/1959 12 1.2.2/1962 12 2.1/1948 42

2.1/1951 43 2.1/1954 43

2.2.4/1951 52

2.2.5/1929 54

2.2.5/1951 54

2.3.1/1932 57

2.3.1/1947 57

2.3.2/1933 60

2.3.2/1944 60

2.3.3/1957 62

2.3.4/1951 64

2.4.5/1950 84

3.1/1927 92

3.3/1927 97

6.1/1947 154

6.3/1947 163

7.1/1948 177

7.1/1950 177

Barret, P 5.4/1956 145 Bartholdy, M 3.3/1927 97

3.3/1929 98

Bartley, A. J 6.1/1956 155 Barus, C 2.2.3/1918 50

2.4.2/1919 73

2.5/1900 87

6.5/1919 167

Barwell, F. T 1.7/1953 37

Barz, E 5.2.3/1938 138

Bastien, P 1.7/1946 37 278
Batarchukova, N. R.

Subsedion/Year Page ..2.1/1963 44

2.3.2/1942 60

2.3.2/1956 60

2.3.3/1963 63

2.4.5/1963 85, 86

2.4.6/1963 Batchelor, L. E 6.2/1960 Batemen, J. B 11.1/1954

Bates, W. J 7.3/1947 Bath, J 3.4/1921 John Bath & Co 3.6.2/1921 9.1/1917 Baty, J. E 9.1/1928 Bauer and Schaurte 3.4/1939

Bauerle, K. E 9.3/1938

10.1.3.4/1938 Bausch and Lomb 1.2.1/1964

1.2.3/1926 3.3/1930

4.4/1926

6.4/1930

8.2/1922

8.4/1923 12.3/1964 Baxandall, D 6.4/1923

12.6.2/1923

Bayle, F 1.2.2/1923

Beals, L. S. Jr 4.1/1951 Beam, A. S 9.3/1962

10.1.3.1/1962 10.2.1/1962

10.2.4/1962 10.3/1954 Bean, H. S 8.2/1919

Bearce, H. W 1.2.2/1926

1.2.2/1932 Beardsley, R 10.1.4/1935 Bechtold, M. F 11.1/1947 Beck, G 5.2.2/1958

Becker, E 3.6.2/1924

Becker, G. C 4.4/1946

Becker, H 4.1/1951

12.6.1/1958

Becker, L 3.5/1928

Becker, P. W 2.3.7/1962 Becker, S. E 2.3.7/1962

Beers, Y 1.3.3/1957 Behar, M. F 1.1/1951 Behrens, D. J 3.4/1941

Beilby, G 1.7/1959

Belanger, J. Y 11.3/1952

Bell, J. F 12.6.3/1956

Bell, R 12.3/1963

Belyi, M. I 3.3/1963

5.2.2/1963 Bender, H 6.1/1951 Bender, H. W 12.6.4/1918

Benedict, R. P 1.3.1/1961

I. 3.1/1964

1.4/1954

1.4/1961 Benedikt, E. T 1.3.2/1949 Benford, R. L . .6.1/1962 Benjamin, P 11.1/1956

II. 1/1958

'Bennett, F. D 2.2.3/1951 2.2.3/1952 Bennett, G. T 5.1/1905 ' Bennett, J. M 2.4.4/1959 4.4/1961

Benoit, J. R.

9.2/1961

.2.3.1/1913 2.3.2/1895

2.4.1/1934 3.2/1902

4.1/1895 4.1/1900

4.2/1883

87

160 243

182

101

111 198

199

101 212 220

10

1398

125

166 194

194 264

165 270

10 118 212

219 230

234

239

193

10

11 224

241

137 112

126

118 269

106

67

67243 10138

251 273 264

100

137 154 273

18

192930

20

156 243

245

5050

12983

127 204

56

59

7094

117 117

121

Subsection/Year Benoit, R 2.2.2/1897 2.2.2/1898

2.3.2/1907

2.4.2/1897

2.4.2/1898 Bensimon, R 5.2.5/1937 Benson, J. M 1.4/1962 Bentley, G. P 5.1/1939 Bentley, H 3.6.2/1926 Bergere, J 10.2.1/1949 10.2.6/1947 Bergmann, H 10.1.3.4/1961 10.1.4/1959

10.2.4/1961 Berkeley 7.1/1915

Berlin, G. S 5.2.1/1961 Berndt, G 1.1/1925

1.2.1/1932

1.2.1/1941 1.2.1/1952 1.2.1/1954

1.3.1/1925

1.3.2/1922 1.4/1921 1.5/1922

1.5/1928

1.5/1938 2.4.1/1924

2.4.4/1921 2.4.4/1924 3.4/1941 3.5/1921 3.5/1932

3.6.1/1934

3.6.1/1935

3.6.2/1921 3.6.2/1922 3.6.2/1932

3.6.4/1953 5.1/1929 5.1/1930

5.2.3/1921 5.2.3/1932

5.2.4/1932 6.1/1953 6.2/1928

6.3/1927

6.6/1961 6.8/1958

7.2/1927

7.2/1928

8.1/1958 9.1/1922

9.1/1929

9.1/1930

9.1/1932

9.1/1933 9.1/1936

9.1/1952

9.3/1931 9.3/1932

9.3/1935 9.3/1937

9.3/1939 9.3/1940

9.3/1942

10.1.2/1938

10.1.4/1937 10.2.5/1925

12.6.4/1928 Bernhardson, R 6.6/1917 Bernolak, K 5.4/1953

Berring, H 4.2/1954

Bessel, F. W 4.1/1839 4.2/1826

6.4/1822 6.4/1844

Page 48

9059

72

73

14!30

130

112 230

237

22 

227

•233 175 132177

17 20

2S

3232

32

69

S'J 82

101

L05 L06 110

110

L12 112 1 13 L15 129

129 138

L38

L40

L54

L57 1 62

170

173 L80

ISO

102 198

199 1 '.»'.> 1119 199 200

201 20S 208 208 2 OS 200 209

209 216

224 234 274

169 144

122

12S 120

164

164

771^846 O—66 19 279
Subsection/Year Page Bethel-Player 3.5/1924 106

6.7/1924 171

Betz, W 11.2/1905 247

Betz, W. C 6.6/1918 169

12.6.5/1933 275

Beuret, P 8.2/1921 193-4

Bhalla, M. S 2.4.2/1959 76

Bialy, A. El 11,1/1963 246 1L3/1963 254

Bielefeld, J 12.2/1960 260

Bigg, P. H 1.2.2/1964 13 Bingham-Powell, H. J 9.1/1917 198 Bikermann, J. J 1.7/1949 37

Billings, J. H 9.3/1917 206

Binder, R. C 1.3.3/1955 24

Biondi, M. A 2.4.3/1956 80

Biot, A 7.1/1932 176

8.1/1929 190

8.1/1931 190

8.1/1953 191

Birch, A. J 1.3.4/1948 27

Bircher, F. A 10.2.6/1947 237

Birdsall, F. W 6.3/1944 163

Birdsall, G. W 10.2.2/1945 231

Birge, R. T 1.3.3/1934 22 Birkebak, R. G 1.7/1964 39

Birks, L. S 11.3/1946 250

Birtwistle, J. K 11.3/1963 255

Biryukov, G. S 7.4/1964 187 Biryukov, L. I 2.4.5/1962 85 Bjerhammar, A 1.2.4/1960 16 Bjornberg, S. O 10.1.4/1923 223

10.1.4/1938 224

Black, A 1.2.2/1947 11 Blackburn, D. H 2.4.1/1961 71

Blaise, J 2.4.3/1958 80

Blake, D. V 6.7/1950 171 Bland, J. R 1.2.1/1938 40

Blank, J. M 2.3.4/1950 64

Blaschke, A 4.4/1907 124

Blet, G 2.3.4/1942 63

Block, W 1.1/1925 1 1.2.1/1930 6

I. 3.1/1924 17 3.5/1924 106

5.4/1922 143

6.7/1930 171 Blodgett, K. B 11.1/1941 241 Blomstrom, L. C 6.6/1916 169 Blumova, V 8.1/1956 191 Board of Trade, Westminister 9.2/1901 202 Bochmann, G 9.1/1932 199 Bochmann, H 1.5/1927 32

9.1/1932 199

9.3/1927 207

9.3/1929 208

Bock, E 9.1/1930 199 Bock, R 10.1.4/1937 224

Bodart, E 1.2.1/1961 9 Bodner, C. H 10.2.1/1947 229

Boeckel, F. W 9.1/1945 200 Boehm, K 10.1.4/1959 227

Boella, C 10.2.2/1912 230

Boerdijk, A. H 6.1/1955 155

II. 3/1963 254

Bogros, A 2.2.1/1937 45

Boguslavskii, M. G 1.3.2/1964 40

1.4/1964 31 Boguslawski, M 3.2/1956 96

Bohle, F 10.1.4/1955 226

10.2.2/1952 231

10.2.2/1957 231

Boisvert, M 5.2.2/1949 135

5.2.2/1950 135 Bokin, M. N 10.2.2/1960 231

Bolbrinker, E 10.2.1/1939 229

Boldin, L. A 7.4/1959 186

Subsection/Year Boldrini, M 1.3.3/1946

Bolf, J 6.2/1963 Bolkovac, J 12.6.4/1917 Bolotov, B. E 7.3/1961 Bonanomi, J 2.3.1/1962 Bond, G. M 3.1/1884

3.1/1886 3.5/1884 Bond, W. L 11.1/1956 Bond, W. N 5.2.4/1928

5.2.4/1929 Bonetti, A 1.4/1958 Bonnell, D. G. R 5.2.4/1950 Bonsdorff, J 6.7/1908 Boonshaft, J. C 1.3.2/1953 Booth, S. F 1.1/1961 Bopp, F. H 7.3/1926 Bordewijk, J. L 1.1/1947

Borie, B. P 11.3/1961 Born, M 1.5/1946 Borneman, C. H 3.1/1938 Bornemann, W 5.4/1939

Boss, L 6.4/(1900) Bostock, F. J 10.3/1913 Boston, O. W 5.1/1945

Botstiber, D. W 12.4/1952 Bottcher, K 3.1/1928 Bottema, M 2.2.1/1958

2.2.1/1960

2.3.1/1960 Bottomley, S. C 3.2/1959 4 1/1959 Bouasse, H 6.4/1917

Boulet, J. H 3.6.4/1907 Bousquet, P 11.3/1965 Bovey, E 5.1/1962

12.6.2/1962 Bowden, F. P 1.7/1953 Bowen, H. W 1.2.1/1938 Bowker, A. H 1.3.3/1959 Bouzitat, J 1.5/1951 Boyd, H. S 2.2.2/1922 2.4.1/1920

2.4.1/1922

2.4.3/1922 7.1/1920 Boyer, J 1.1/1921 Bracey, R. J 6.2/1943

Bradsell, R. H 1.2.4/1961

I. 2.4/1964

2.4.5/1962 Bradshaw, E 5.2.2/1944 Brangaccio, D. J 2.3.7/1962 Branin, F. H. Jr 2.4.2/1953 Braune, G 3.4/1962 Braybon, J. E. H 2.1/1950

Brd'icka, M 11.2/1947

II.2/1948

Breazeale, E. N 5.7/1958

Bredin, H. W 1.2.3/1961 Breene, R. G. Jr 2.3.1/1957 Breithaupt, W 3.1/1913 Brewer, W. B 1.4/1965

Bricout, P. A 5.2.2/1949 5.2.2/1950

Briggs, C. A 1.5/1918

Bright, R. J 2.4.3/1949

Brillouin, M 6.5/1903

British Indicators, Ltd 12.6.5/1949

British Standards Institution 1.2.2/1962 3.2/1961 3.3/1939 3.3/1942

3.4/1941 3.6.2/1938

3.6.2/1950

3.6.3/1940 4.1/1964

Page 22

162 1 273

18359

10391

91 244

140

14029

140

170204

1812 l 253

32

92: 144

164 238

130 1$

4747

5996

11!) 165

114 255

131 27137724

78

17.

157

16

1686 134

6774

103, 42 247

247

150

1458

9131 135

135

3179 167 275

1296

101 113

113 114

280
Subsection/Year Page Subsection/Year Page British Standards Institution— Continued

5.2.3 5.2.3

5.3,

6.7 7.4

9.3 10.1.1

10.1.1

10.1.1

10.1.1 10.1.1

10.1.1

10.1.1 10.2.2

6.2

3.1

4.2, 2.4.1 2.4.2; 6.2

9.1

3.1 2.3.1

7.3

1.2.4 2.4.5

9.1 5.2.1 12.3

: Brower, E. 0 8.1

:! Brower, F 3.5 Brown, A. F. C 2.4.2

. Brown, C. C 4.2

-.: Brown, E. B 5.2.2

6.2

.: Brittan, K. W

* : Broch, 0. J ... Brockman, R. H.

Brooker, A...

Brookes, A. J

Brooks, D. E.

Brossel, J Broussaud, G

Brousseau, H.

Brouwer, F_ _

6.2 Brown, F. P 12.2 Brown, F. W. Ill 2.4.2 Brown, J. H 2.5 Brown, P 10.3 Brown, R. W 3.5 Brown, S. C 12.3 and Sharpe Mfg. Company.

David Brown and Sons, Ltd.

jl David Brown Tool Co.

Bruce, C. F.

.3.6.1 3.6.2

3.6.2

3.6.2 3.6.2

3.6.2

3.6.3 12.6.1

12.6.5, .10.1.4 10.2.1

10.2.6,

.10.1.4, 10.3

.10.1.4 ...2.1

2.2.1

2.2.2,

2.2.3,

2.2.3, 2.3.1

2.3.1

2.3.2, 2.3.3

2.4.5, 3.1 6.5

6.5 Bruce, R. A 9.2 Brunnow, F 6.4

1 'Bruno, M. S 10.2.2,

1939 1940

1964

1951 1959

1941 1964

1964

1937

1940

1949

1951 1952 1958

1963 1963 1960 1890

1886 1962

1962

1949 1917

1924

1954

1946

1956

1956

1957

1921 1957

1958

1883

1951 1955

1956

1957 1948

1955

1913 1927

1962

1909 1900 1907

1927

1928 1932 1928

1963

1958

1944

1932

1944

1955 1947

1948 1954

1962

1953

1955

1957

139 139

143 166

170

171 187 212

213 213

213 214 214

214

215

232

159

91 12172

77 158

19792

57

181

1684 202

132 262

189 108

75

121 135

159

159 2597488

238

106 263

109 110

111 112

112

113 114

269

275 225

229 237

226

239 225

4348

49 50-1

51 1956 57, 58

1961 1961 1962

1956 1956

1949 1950

1952 1904

1865

1963

59

616384

93

115

167

168 202

164 232

Bruns, H 6.6.4 Brutti, C 1.6 Bryan, J. B 1.4, Bryant, CD 5.1 Bryant, E. J 3.5,

6.6, Brzhezinskii, M. L 2.4.6, Bubert, J 5.7, Buck, H. M 12.6.5, Buckingham, E 3.6.1

9.3,

9.3, 10.1.2,

10.1.2, 10.1.2

10.1.3.1 10.1.3.1 10.1.4

10.2.6, 10.3 Budgett, H. M 3.1 Budnick, A 9.1 10.1.1

10.1.1 10.1.4

10.2.6, Buettner, C 5.4 12.2

12.6.1 12.6.5 Buisson, H 2.2.5

2.3.1

2.3.1

2.3.1 2.4.1 Buman, H 5.4 Bunch, J. M 6.2 Biinnagel, R 7.1 7.3 Bunt, B. P 11.3 Burch, J. M 2.5 Burge, E. J 11.3 Burger, K 9.1 10.1.4

10.2.2,

10.2.2,

10.2.6,

10.2.6, Burgess, E 6.1 Burgess, G. K 1.2.1

1.2.1 1.4 Burgmeier, L 12.6.1 Burguburu, P 1.1 Burley, G. W 3.4

3.6.2, 3.6.4

10.2.6, Burlingame, L. D 3.6.1

3.6.2, Burkhart, L. E 2.3. Burmistrow, F 2.5, Burns, K 2.3 Burt, F. M 12.5 Burtin, R 11.3, Burton, A. E 4 Busch, A. E 1.2.4, Busch, T 1.2.1 3.6.1 Butler, C. T 6.4,

6.6, 10.2.5, Butrick, F. M. Jr 9.2,

9.2,

1892

1912

1962 1965

1962

1917

1917

1963

1947

1956 1928

1938 1945

1928

1935

1949 1928

1935

1927

1921 1960

1911 1949

1955 1960

1959

1948

1935

1936

1931

1931 1908

1908

1912 1913

1902

1938

1958

1956

1956

1961 1963

1951 1953

1944 1940

1942

1937 1938

1959

1924

1928

1928 1964

1932

1913

1912

1911 1913

1914

1915

1949 1936

1950

1945

1960

1902

1963 1964

1965

1953

1953 1953

1951 1953 281
Page

76 204

tionlYea Biittner, C 5.4/1935 9.1/1922 Buza, J. A 2.4.2/1960 Bychkov, 0. D 12.3/1963 C

Cabrera, N 2.2.1/1941 45

2.4.5/1951 84

4.2/1944 122 Cadwell, J. H 1.3.3/1950 23 Callame, J 3.5/1923 105 Camargo, M. C 1.3.3/1956 24

Cambridge Scientific Instrument Co 4.4/1903 124

5.1/1931 129

9.1/1904 197

9.1/1918 198 Cameron, A 1.7/1949 37 Cameron, C 2.4.2/1963 77 Cameron, J. M 1.3.1/1960 18 Campbell, N 1.3.3/1920 22 Campbell, N. R 1.1/1928 1 Canac, F 1.7/1937 36 Canada, Topographical Surveys 4.3/1921 123

6.4/1923 165 Candee, Allan H 9.3/1928 207

10.1.2/1959 216

10.1.2/1961 216

10.1.3.1/1961 218

10.1.3.4/1928 220

10.2.4/1928 233

10.2.6/1928 236

Candler, A 2.1/1951 42

Candler, A. C 2.2.1/1946 45

Canfield, W. G 7.4/1958 185

Cantelo, W

9.3/1903

205

9.3/1907 205 Canzek, L

8.2/1964

196 Carbone, P. E 7.1/1959 179

7.4/1958 185-6

Carey, M. C 2.5/1965 90

Carl, R 5.2.5/1959 142

Carlstedt, R. L

1.6/1963

35 Carman, P. D

7.1/1955

178 Carmichael, C. M 1.4/1959 29

Carson, P. A 4.3/1911 173 Carson, R. W 3.3/1947 99

3.5/1932 106

3.5/1941 107

5.2.2/1931 133

5.2.2/1936 133

5.7/1937 148

Carter, B. C 5.2.2/1944 134

Cartwright, B. W 10.2.4/1952 233

Cartwright, R 7.1/1940 176

Case, A. A 12.5/1915 266

Casey, J. P., Jr 2.5/1952 88

Cassignol, C 2.3.4/1963 65 Cau, M 2.1/1937 41 Cave, E. F 2.1/1955 43

Caville 6.4/1893 164

Ceely, F. F 1.2.4/1960 16

Cerni, R 1.3.2/1961 21

1.3.2/1962 21

Cerni, R. H 1.1/1962 4 Chabbal, R 2.4.3/1958 80 Chalmers, S. D 7.3/1917 181 Chalvet, M 1.1/1950 3 Chaman, V. S 6.1/1961 156 Chamberland, H. J 3.1/1950 93

12.6.5/1936 275 Chambers, R. G 1.7/1953 37 Chaney, L 1.7/1954 38

Ch'angken, H 12.3/1961 263

Ch'ao-tseng, L 3.1/1961 93 Chao-wang, H 2.3.1/1943 57 Chapin, W. C 1.5/1918 31 Chapanis, A 5.3/1955 143 Chapman, W. A. J 10.2.6/1930 236

Subsection/Year Page Chappell, A. W 10.2.4/1914 232

Chappell, F. A 8.1/1952 191 Chappie, M. A 1.7/1957 38

Charbal, R 2.4.3/1958 80 Charman, W. N 1.3.4/1963 27 Chekhonadskii, N. A ,1.3.2/1963 22

1.3.3/1959 25 Chen, H. S. C 8.1/1954 191 Ch'en, S 2.3.1/1957 58

2.3.2/1958 61 Cheneveau, C 3.5/1923 105 Cheney, R. E 12.6.1/1961 269 Cherna, J. C 7.4/1956 185 Cherry, R 5.2.2/1947 135 Chescoe, D 11.3/1962 254 Chesley, W. L 9.3/1937 208

10.2.4/1937 233

Chesterman-Sogenique 3.6.3/1964 114 Chieherova, A. S 6.8/1960 173

Childs, W. H. J 2.4.3/1926 78

Chitayat, A. K 2.4.2/1964 78

Chittleburgh, R 3.4/1954 102 Chiverton, H. A 3.6.2/1955 113 Chree, C 1.5/1901 31

Christoff, P 5.7/1951 149

Christoph, W. P 1.2.3/1958 14 Chubb, I. W 12.6.4/1917 273

Churchill Machine Tool Co 12.4/1929 265 Churchman, C. W 1.1/1959 4 Cichon, J 4.1/1960 119 Ciddor, P. E 2.2.5/1960 55

Clark, J. A 1.4/1955 29

Clark, J. S 4.1/1951 118

4.2/1956 122

4.3/1950 123

4.3/1951 123

4.4/1956 126

Clarke, K. A 9.1/1948 200

Clark, R. N 12.5/1943 267

Clay, R. S 5.2.3/1940 139

Clay, W. E. R 1.7/1945 36

Clayton, D 1.7/1945 36

Clegg, R 12.3/1962 263

Closson, H. T 4.2/1958 122

9.2/1958 204

Clunie, D. M 2.4.5/1964 86

Clusius, K 1.2.1/1963 40

Coales, J. F 1.1/1956 3 5.1/1956 130

Coats Machine Tool Co 9.2/1918 203 Cobb, E. T 3.2/1938 95

Cochet, C 1.4/1918 28

Cochin, L 1.3.3/1963 26

Cocks, M 1.7/1954 37: Coffman, M. C 3.1/1938 92 : Cohen, M 4.3/1951 173

Cole, C. B 12.6.4/1919 273 Colebourne, R 1.2.1/1956 8

Collart, K. S 1.7/1957 38

Collet, E 2.4.3/1953 79

Collett, C. T 3.4/1950 102

Collier, J. G 11.3/1964 255

Collins, J. D 5.6/1963 148

Collins, J. E 12.6.4/1920 274 Combs, J. F 11.1/1962 246 Compain, L 1.2.1/1952 8'

10.1.2/1952 216 ( 12.2/1938 259 " Compudex Eng. Co 10.2.5/1946 234 Comrie, L. J 10.1.3/1962 217 Conaty, A. L 3.6.1/1919 109 Condon, E. U 5.2.1/1949 132, Conners, E. R 9.2/1908 202 Connes, P 2.4.3/1958 80

Connolly, T. F 4.4/1920 124 6.7/1923 170 Conrad, E. E 11.1/1964 247

Constans, M 2.4.1/1961 71 282
u

Subsection/Year Page H. H. Controls 6.2/1961 160 Cook, A. H 1.1/1957 4

1.2.2/1957 12 2.2.1/1957 47

2.2.1/1962

2.2.5/1959 55

2.4.3/1959 80

4.1/1953 119

4.2/1956 122

4.4/1956 126

6.1/1954 154 6.3/1954 163 Cook, H. D 2.3.7/1964 68

2.4.2/1961 77

2.4.6/1961 87

4.1/1961 119 Cooke, A. G 12.6.5/1917 274

Cooke, Troughton and Simms 4.4/1942 126

6.2/1962 161

8.2/1935 194

Cornelius, J 5.2.2/1945 134

Cornelius, J. R 9.3/1932 208

CorneU, S 10.1.4/1944 225

Corner, W. C 5.2.2/1954 136

Corson, A. J 5.2.1/1948 132

Cos, A 5.4/1948 144

Cotton, A 2.2.1/1911 45

Cotton, P 2.2.5/1945 54

Couling, S. A 10.1.4/1956 226

Courtel, R 1.7/1963 39 Courtney-Pratt, J. S 11.1/1952 243

Coventry Gauge & Tool Company 3.4/1957 102

3.6.1/1949 110

6.6/1958 170

7.1/1950 177

10.1.4/1950 225

12.6.4/1920 274

12.6.5/1928 275 Cowee, R. L 10.1.4/1956 226

Cowell, P. H 6.4/1901 164 Cowley, A 12.3/1962 263

Cowlin, W. H 10.1.3.4/1920 220

10.2.6/1920 235

Cox, A. J 4.4/1907 124

Cox, R. J 3.5/1942 107

5.2.2/1942 134

Crain, C. M 2.2.4/1950 52

Craven Brothers 12.6.3/1953 272-3

Crede, C. E 1.6/1961 34 Crompton Parkinson, Ltd 5.7/1962 150 Culmann, P 2.3.2/1902 59 Culshaw, W 2.1/1950 42

2.1/1960 44 Cumberland, N 10.3/1942 239 Cuninghame, W. A. F 6.4/1950 167

6.4/1952 168 Cunningham, H ' 1.5/1962 33

10.1.3.6/1962 222 Cuny, B 7.1/1948 182

Curry, C 5.2.2/1947 135

Curtis, F. W 12.6.4/1929 274

Curtis, H. E 3.6.3/1909 114

Curtis, H. J 5.4/1931 144 Cutkosky, R. D 1.1/1961 4

5.2.2/1961 137 Cutler-Hammer 12.3/1963 264

Czerski, Z 8.1/1956 192 Czygan, W 6.2/1957 159 D

Dacus, E. N 5.7/1958 150

Daeves, K 1.3.4/1930 27

Dallas, D. B 1.2.2/1962 12 Damm, T 3.6.1/1931 109 Damski, A. M 12.1/1962 258

Daniels, F. R 1.2.1/1923 6 12.6.1/1919 268

Danielson, W. E_

Danilevich, F. M.

48 Danilyuk, P. M.

Subsect 4.2

9.2 4.4

5.2.2 10.2.4 10.2.4

10.3

10.3 Dannehower, G. L 12.1 Dantu, P 2.5, Darling, H. M 12.6.5, Darmody, W. J ..1.3.1

1.3.1 7.4 Darwin, C 1.1

1.1 Dauber, J 2.1 Dauphinee, T. M 5.2.4 Davey, T. F 12.6.4 Davies, B. M 12.6.2, Davies, E. E._ 10.2.6 Davies, H. J 12.1 Davis, E. P 6.6 Davis, R. H 11.3 Davis, R. J 4.4 Davis, S. P 12.6.2 Davis, W. O 5.1 Davison, C. St. C 1.2.2 Davydov, B. S 2.1 Dawney, W. H 9.3

10.1.2, Dawson, G. W 3.6.2 Dayton, R. W 5.2.2, De, M 2.2.1, De Baufre, W. L 3.5, de Bruin, T. L 2.3.3, 2 3 3 de Bruin, W ^6.2

10.1.4 Deby, H. L 10.3

10.3 de Gramont, A 6.7 de Jong, A. N 6.2 De Juhasz, K. J 5.2.4 Delavignette, P 11.3 de Leiris, H 5.2.5 de Lepinay, J. M 2.4.1

2.4.1

2.4.1

2.4.1 2.4.3 Delhomme, F 4.1 Deloffre, G 5.2.2 Delyunov, N. F 1.2.1 3.2 De Mallemann, R 11.2 Deming, W. E 1.3.3 Denisov, F. P 11.3 Denisov, P. V 3.1 Denis-Papin, M 1.1 Denton, P 5.4 Desch, C. H 1.7 de Senneville, C 1.7 Desvignes, F 2.3.1 Detroit 9.2 Deutschen Normenausschuss 1.1 5.1 5.6 5.6 Deve, C 6.1 6.2 12.4 de Veer, J. D 6.2

7.1 Deverall, G. V 2.4.3 Devienne, M 11.3 de Villemeur, Y 5.6

on/Year 1958

1958

1963

1963

1961 1962

1958 1960

1964

1962

1919 1956

1962

122 204

127

138 233

234 239

239 25S

89 274

18

18 1958 185-6

1944 2 1945

1943

1955

1921

1933

L941 1935

1917

1951

195S 1959

1955

1957 1963

194!) 194S 1946 1946

1956 1916

1921

1931 1955

1957

1962 1963

1928

1963

1940

1963 1937

1887

1895 1899

1902 68, 69

1899 78 1948 118

2 42

140 274

270

237 257

169 25

126

271

130

1

44 210 216

113

13446

105

6161 158 226

24(1 240

171

Hi I 140 254

141 276

276

1953

1961 1962 1944

1934

1963

1959

1946 1952

1946

1946 1949

1931 1962 1962 1949

1950

1941

1941 1936

1961

1961 1953

1951

136996 247

22

254

93

2 144

3737

57 203

» 5 131 147 147

153 157 265

160

179

79

251 1962 147- 283
Subsection/Year Page DeVos. L 10.2.1/1962 230 Dew, G. D 2.4.1/1964 72

2.5/1962 89

12.6.2/1956 271

12.6.2/1962 271

Dexter, A. M., Jr 11.1/1959 245

Dicke, R. H 2.3.1/1957 58

Dickson, J. H 5.1/1953 130

Diederichs, H 1.1/1930 1 Dieffenbach, A. P 7.1/1954 178

Diettrich, G 3.2/1958 96

9.1/1939 200 Dimmer, G 1.5/1920 31

Dixie, E. A 12.6.5/1919 274

Dixon, H. D 1.4/1960 30

Djurle, E 1.2.3/1958 14 Dmitriev, I. S 11.3/1959 253 The DoAll Co 1.2.1/1953 8

7.1/1953 177 Dobrowolski, J. A 3.3/1957 99

4.4/1957 126 Dobson, G. M. B 8.1/1911 189 Doekes, J. G 6.2/1955 158

Doi, V 2.4.6/1962 87 Dolgushev, A. N 3.6.2/1959 113

Dolinskii, E. F 1.3.2/1959 21 Donald, G. W 12.2/1960 260

Donaldson, W. K 11.1/1947 241

Doorakkers, G 12.6.4/1917 273 Dorey, S. F 10.1.4/1947 225 Dornenburg, G 2.2.5/1951 54 Dornhofer, R 12.2/1963 261

Dorsey, E 1.3.1/1953 17 Dort, S. T 10.2.4/1914 232

Douglas, R 4.4/1932 125

Douglas, R. W 2.5/1952 88 Dovey, D. M 1.7/1953 37

Dowell, J. H 1.5/1926 32

2.4.1/1960 71 2.4.4/1960 83

4.4/1926 125

5.6/1932 146 Dowling, J. J 5.2.2/1920 151 Draper, C. S 1.1/1953 3 5.1/1939 130

Dratz, H. R 5.4/1942 144 Draudin, A. T 10.2.1/1960 230

Dress, K 7.4/1940 185

Dreyer, C. F 5.7/1930 148 Dreyhaupt, W 10.1.4/1962 228

12.1/1962 258

Drinkwater, J. W 9.1/1943 200

9.1/1944 200

9.1/1946 200

9.2/1942 203 Drude, P 2.2.5/1893 53

2.2.5/1894 53

11.1/1893 241

11.2/1889 247

Dubinovskii, A. M 4.4/1964 128 du Bois, H 2.1/1911 41

Dubrovskii, G. B 2.3.2/1956 60

Duckert, P 3.6.2/1924 112 Dudgeon, H. A 12.4/1942 265

Dudley, D. W 10.1.2/1954 216

10.1.2/1962 216

10.1.3.1/1962 218, 219

10.1.3.4/1962 221

10.2.1/1947 229

12.6.3/1943 272

Duffieux, M 7.1/1932 176

Duffieux, P. M 2.2.1/1939 45

Dufour, C 2.2.1/1948 45

2.3.1/1946 57

2.4.3/1946 78

2.4.3/1950 79

Subsection/Year Dueit, M 6.1/1920 Diihmke, M 2.4.2/1957 2.4.4/1957

2.4.5/1957

2.4.5/1961 3.6.4/1962 7.2/1959 11.1/1953

11.1/1962

12.3/1957 Dukhopel, I. I 7.3/1956

7.3/1961 Dumanois 5.2.5/1937 Dumontet, P 11.3/1957 Dunaev, B. B 1.3.1/1963 Dunin-Barkovskii, I. V 1.3.3/1960 12.1/1964 Dupeyrat, R 2.4.3/1957 DuPont Eng. Dept 12.2/1961 Dupuy, O 2.4.1/1962 Duquesne, M 1.3.3/1963 Durand, W. F 7.4/1899 Durasova, Y. A 11.1/1963 Durbin, E. J 1.3.3/1959 Durfee, W. C J 3.6.2/1906 Duston, F. C 10.2.5/1929 Dwyer, J. J. Jr 12.3/1964 Dymott, E. R 3.4/1948 Dyson, J 3.3/1959

5.4/1959

5.4/1961 6.2/1960

6.2/1961 6.2/1964

7.3/1955

10.1.4/1955 11.1/1953 11.1/1958

11.1/1963 Dziobek 4.2/1903 E

East, F. G 10.1.1/1954 Eastman, F. S 5.7/1935 Eastman Kodak Co 10.2.2/(1953) Eastmen, H 1.2.1/1963 3.1/1963 Eastwood, E 1.3.4/1948 Eaton, G. M 10.2.4/1926

10.2.6/1925 Ebbeni, J 2.5/1964 Eberhardt, E 3.3/1951 Eckert, E. R. G 1.7/1964 Eckerkunst, W 1.2.1/1964 Eddington, A. S 1.3.3/1933 Edensor, K 9.1/1960 Edlen, B 2.2.4/1953 Edmundson, D 5.2.2/1949 Edush, V. Y 5.2.2/1963 Efimov, A. A 6.4/1960 Efremov, I. P 2.2.2/1960 Efremov, Y. P 2.2.3/1960

2.3.3/1960

2.3.3/1963

Efros, I. E 7.4/1964 Egen, P. N. C 4.2/1827 Egudkin, A. S 2.4.4/1963 Egy, W. L 6.2/1955 Ehrenburg, W 1.3.3/1958 Ehrenhaft, F 1.3.2/1937

Eichler, F 5.1/1932 Eidinov, V. Y 5.2.3/1962 6.1/1963 Einsporn, E 1.5/1929 7.1/1950 Einthoven, W 1.6/1895

Eisele, F 12.2/1961

Page 153758284

85

116

181 243 246

262

182

186

141 252

19 25 258

80

260

72

26

1X5 246

25

110 234

265

102 100

145 145

159

1(30 162

182 226

243 244

246

121

214

148

231994

27 232

235

90

9939

10 22 202

52

135

137

5162

63

187 120

83

15924

20

130

139

15632

17734

260 284
Subsection/Year Page Eisenhart, C 1.3.1/1953 17

1.3.1/1962 18

1.3.3/1952 23

1.3.3/1962 25

1.3.3/1963 26

1.3.3/1964 26

Eisner, R. L 2.4.2/1958 75

Eitelman, H. K _' 12.1/1959 258

Elberty, R. S 5.2.5/1948 141 ElBialy, A 11.3/1963 254

Elkins, E 6.8/1940 172 Ellingham, B 3.3/1959 100

Elliott, A 5.1/1953 130

Elliott, A. J 7.1/1949 177

Elliott, K. W. T 5.4/1957 145

Elliott, R. M 2.4.3/1940 78 Emara, S. H 2.3.4/1961 65 Embleton, T. F. W 2.1/1955 43 Emde, F 8.1/1938 190 Emel'yanov, A. P 6.6/1963 170 Emerson, C 5.4/1949 144 Emerson, W. B 2.4.1/1950 70

7.1/1952 177

Encinas, J 11.1/1963 246

End5, O 9.1/1961 201 Engelhard, E 1.2.2/1961 12 2.1/1957 43

2.3.1/1959 58

2.3.1/1960 58

2.3.3/1954 62

2.3.3/1959 62

2.3.3/1960 62

2.4.5/1959 85

Entin, L. P 1.3.2/1959 21

Eppenstein, O 1.2.1/1925 6 9.1/1924 199

9.3/1922 206

Erdoekuerti, Z 2.2.1/1963 48

2.2.3/1963 51, 52

2.4.3/1964 81

Erdokuri, Z 5.1/1961 131

Erickson, E. C 9.1/1937 200

Erickson, K. E 2.2.4/1962 53

2.4.5/1962 85

Esclangon, F 2.1/1937 41

Essen, L 1.2.2/1957 11 1.2.2/1959 12

2.2.4/1953 52 Esserman, N. A 3.1/1943 93

Estabrook, M 10.2.2/1923 230

Estey, M. E 7.4/1948 185 Eugene, F 12.5/1947 267

Evans, J. C 1.1/1946 2 1.2.3/1962 15 3.3/1957 99

5.2.5/1951 141

5.2.5/1956 142

5.2.5/1957 142

5.2.5/1964 143

6.1/1961 155

6.1/1964 156

Evans, J. T 12.3/1963 264

Evans, U. R 1.7/1953 37

Eversole, W. G 4.4/1941 125

Evich, E. M 3.6.4/1962 116 Ewald, W 3.6.4/1926 115

Ewell, M. D 3.6.2/1907 110

Ewles, J 5.2.2/1947 135

Fabish, E. F.

?abry, C

.10.1.4/1963 -_-2.1/1897

2.1/1899

2.2.5/1908

2.3.1/1900

2.3.1/1908

2.3.1/1912

2.3.1/1913

228

41

4154

5656

56

56

SubsectionlYear Page Fabry, C.—Continued

2.3.2/1907 59

2.3.2/1934 60

2.4.1/1899 68

2.4.3/1899 78

2.4.3/1901 78

2.4.4/1898 81

2.4.5/1899 84 Fainerman, I. D 1.3.4/1963 27

Fairchild Aircraft Div 1.2.3/1952 14

3.2/1952 96

Fairey Aviation Co 5.6/1951 147

Fairfield, D. J 1.2.3/1963 15 Fano, U 1.1/1950 3 Farago, F 7.4/1964 187

8.1/1964 193

Farrar, W. A „ 3.6.2/1907 111 Fath, J. M 11.2/1964 249

Fastie, W. G 2.3.1/1958 58

Fateeva, L. N 11.3/1959 259

Faust, R. C 2.2.1/1955 46

Fawssett, E 3.4/1943 101 Fayet, G 6.4/1907 164

6.4/1910 164

Fayolle, P 5.2.2/1947 134

Federal Products Co 3.3/1923 97 Federov, A. V 12.3/1963 264

Federov, G. V 11.3/1957 252 Fedotov, A. V 5.2.2/1965 151 12.3/1963 264

Fedukin, V. A 10.1.4/1962 228

Feibelman, W. A 11.1/1956 244

Feklistov, E. M 6.4/1961 167

Fellows Gear Shaper Company 10.1.2/1957 216

10.1.4/1932 224

10.2.1/1943 229

12.3/1935 262

Fennell, K 9.3/1916 206

Fenner, T. H 12.6.4/1918 273

Ferguson, J 7.3/1964 184

Fergusson, P 1.5/1957 33

Ferranti Ltd 1.2.3/1963 15

Ferris, C. D 1.1/1962 5

1.3.4/1962 27

Feuersanger, A. E 11.1/1963 246

Field, J. C 2.3.5/1960 65

Field, R. H 1.2.1/1951 8 3.3/1947 99

6.8/1947 172

Field, T. H 4.1/1939 118

Fields, T. H 1.2.3/1960 14

Fieseler, A 10.3/1935 239

Figatner, A. M 12.2/1963 261

Finch, G. I 1.7/1945 36

5.6/1950 147

Finch, J. M 3.5/1943 107

Findlay, V. R 2.2.2/1953 49

Findley, R. W 1.2.3/1960 14

Fink, G. A 2.4.2/1933 73 Finkelnburg, H. H 12.5/1954 267

Finkel'shtein, E. I 2.4.4/1965 276

4.4/1961 127

6.4/1960 166

10.2.5/1959 234

Finckelstein, L 1.1/1963 5 Thos. Firth & John Brown 9.1/1946 200

Fischer, L. A 1.1/1925 1 1.2.1/1915 6 4.1/1898 117

4.1/1906 117

8.2/1920 193

Fischer, W 3.6.4/1962 116

Fisher, A 9.3/1922 206

10.2.6/1922 235

10.3/1922 238

10.3/1923 207

Fizeau, H 2.4.2/1866 72

2.4.5/1845 276 285
Flanders, R. E_.

Fleischmann, R_

Subsection/Year Page 10.1.4/1922 223

2.2.5/1951 54

11.3/1951 250

Fletcher, A 10.1.3/1962 217

Fleury, P 6.2/1947 157 Fochs, P. D 11.3/1950 250

Folds, W. H 10.2.4/1924 232

Foley, G. M 5.2.2/1945 134

5.2.2/1946 134 Fok, M. V 2.2.1/1953 46 Fomicheva, M. K 8.1/1963 192 Fomina, O. P 7.3/1959 183

Forestier, M 7.1/1962 180 Forshaw, J. R 5.2.2/1944 134

Forster, G 6.4/1913 165

Fortney 9.3/1918 206

Forsyth, G. H 10.1.4/1947 225 Fortuna-Werke Spezialmaschinenfabrik A-G 5.2.3/1931 138 Forward, E. A 8.1/1919 189

Foster, C. E 5.5/1930 146

Foster, J 3.6.2/1948 113

Foster, L. E 1.1/1962 4 Foucault, L 2.4.5/1845 276

Fox, A. G 2.3.7/1961 66

2.3.7/1963 67

Fox, G. W 2.4.2/1933 73

Fraichet, L 1.3.1/1929 17 9.3/1928 207

Francis, V 10.1.4/1952 226

10.3/1952 239

Frankel, A. B 6.6/1960 170

Franklin, C. H. H 5.1/1946 130 Frankzenburg, W 6.2/1938 157

7.3/1938 181 Fraunthal, A. H 7.4/1923 185

Fred, M 2.3.1/1958 58

Fredericks, P. A 9.3/1922 207 Freeman, D. H 4.4/1964 128

Freise, H 6.2/1948 158

Frieden, B. R 11.3/1964 255 Friedman, H 11.3/1946 250

Frisch, O. R 4.4/1960 127

Fritz, L 6.4/1928 165

12.6.2/1926 270

Froboese, E 5.2.2/1939 133

Frolov, F. P 9.2/1961 204 Fromherz, H 11.1/1929 241 Frommer, J. C 5.2.2/1943 134 Froome, K. D 1.2.4/1961 16 Fruedenstein, F 10.1.4/1958 227

Fry, T. C 11.2/1927 247

Fujiki, Y 11.3/1959 253

Fujil, C 12.1/1938 257

Fujiwara, S 6.2/1962 161 Fukuda, Y 12.2/1963 261

Fullmer, I. H .1.2.1/1935 7 1.2.1/1960 9

1.4/1960 30

3.2/1959 96

Fultz, A. R 6.2/1949 158

8.2/1954 195

Funnell, H. M 9.3/1918 206

Furey, M. J 1.7/1963 39

Furse, J. E 8.2/1962 196 G

Gabriel, G 4.2/1823 120 Gadzuk, B 11.1/1959 245

Gaertner, W 12.6.3/1925 272

Gafanovich, G. Y 10.2.1/1961 230

Gafanovich, M. D 12.3/1961 263

Galassini, A 3.6.2/1903 110

Gale, B 7.1/1962 180

Gale, H. G 2.1/1901 41 Gallagher, D. R 3.4/1919 101

Subicction/Ycar Page Gallo, P. M 10.2.4/1925 232 Galloway, D. F 12.2/1955 259

12.2/1961 260

12.3/1961 263

Gardner, G. F 1.1/1948 2 Gardner, I. C 1.3.2/1955 21 2.1/1955 43

2.3.1/1955 57

2.4.1/1957 71

2.4.5/1960 85

Garner, W. R 5.3/1949 143

Garrett, P. L 6.4/1964 167

Gary, M 4.3/1956 123

9.1/1953 201

9.3/1955 210

9.3/1956 210

10.2.1/1957 230

10.2.4/1956 233

12.1/1956 258

Gaskill, D. M 6.2.2/1955 136

Gates, J. W 2.2.3/1956 51 7.4/1960 186

8.1/1954 191 Gates, T. S 10.1.4/1955 226

Gauss, H. E 8.1/1934 190 Gay, P 1.7/1953 37

11.3/1951 251 Gear Grinding Co 10.2.1/1933 229

Geary, P. J 5.7/1954 149

5.7/1958 150

5.7/1960 150

Geballe, R 5.7/1958 150 Gebhard, J. W 5.3/1949 143 Gee, A. E 11.3/1949 250

Geer, R. L 1.1/1946 2 Gehlhoff, G 6.2/1922 157 Gehrke, E 1.6/1931 34

1.6/1932 34

2.2.1/1902 44

2.3.1/1902 90

2.3.1/1904 276

2.3.1/1906 56

Geiger, F. E. Jr 2.4.3/1949 78

General Electric Co 5.2.2/1931 133

Georgi, G 3.6.4/1962 116

11.1/1953 243 Gerasimov, F. M 2.5/1961 88

2.5/1963 89 Gerchikov, A. M 12.2/1962 260

Gerhardt, U 11.1/1958 245

Gerlach, W 1.1/1937 2 1.3.1/1937 17 Germansky, B 1.3.3/1933 22 Gershman, G 6.8/1960 173 Gertsbakh 1.3.2/1962 22 Giacomo, P 2.4.3/1952 79

Gibbs, D. F 1.4/1958 29

Gidel, A. Y 1.3.2/1960 21

Gielessen, J 4.4/1962 127

Gierlich, R. A 3.1/1962 94

12.6.5/1950 275

12.6.5/1953 275

Gieseler, E. A 4.1/1888 177

Giesler, H 9.2/1959 204

Giessbart, R 8.1/1938 190

Gigas, E 2.4.6/1934 86

Gilet, P. M 1.3.3/1953 23

10.1.4/1951 226

Gill, D 4.2/1889 121 6.4/1888 164

Gillilland, K. E 2.3.7/1964 68

Gilson, J. R 8.1/1963 192

Gini, E. C 12.2/1962 260

Gladilina, T. S 1.2.3/1961 14 Glazebrook, R 1.2.1/1923 6 3.1/1920 92 Glazebrook, R. T 1.1/1919 286
Subsection/Year Gleason Works 10.2.2/1930

10.2.6/1926 10.3/1927

10.3/1928 2 I 10.3/1930 Glennan, T. K 1.1/1961

Glover, J. H 9.3/1961

10.2.4/1961 Glover, L. E 2.4.1/1951 Godfrev, C 4.1/1959

fl Godfrev, G 3.2/1959 Godfrev, J. R 7.1/1926 Godfrev, \V 3.3/1957 4.4/1957

Goetze, S 5.7/1962 Gogate, D. V 2.3.2/1938 Gogava, L. A 7.1/1965

33 Goldberg, J. L 2.2.1/1963 2.4.1/1962

2.4.2/1962 4.4/1964 Goldberg, M 7.4/1960

Goldes, L 6.6/1963 6.8/1964 Goldsborough, J. P 6.2/1693 Gollnow, H 4.4/1962

Golod, S. D 3.3/1965

Goloul'nikov, E. M 6.1/1961

19 Golubkova, V. P 2.4.4/1965

7.2/1961 7.2/1962

7.2/1965 & Goncharskii, L. A 5.2.2/1952

5.2.2/1955 2 Gondik, S. L 4.4/1963

7.4/1963 4 Gonnessiat 6.4/1907 U Good, C. H 1.7/1954 y 1.7/1959 X Goode, B 7.4/1956

71 Goodeve, T. M 3.5/1877 i Goodier, A .3.6.4/1959 Goodman, J 1.5/1923 3 Goodman, L. E 1.5/1962

[j Goodrich, C. L 12.6.1/1923 g Goodwin, H. M 1.3.1/1913 1.3.1/1920 • Gootschau, C. M 4.4/1925

Gopel, F 1.2.1/1926 1.4/1912

2.4.4/1919 3.3/1914

3.3/1920

3.5/1910

3.5/1917

6.1/1926 6.4/1926

9.1/1920

9.1/1929 9.1/1929

9.1/1930

10.2.6/1913 Gorbacheva, V. V 6.1/1963

6.2/1963

7.3/1963 ! Gordon, E.I 2.4.3/1963

;G6thel, E 5.2.5/1947 ; Gough, V. E 8.2/1953 - Gould andEberhart 10.2.2/1922 Gould, G 2.3.7/1963 Goulder 2.4.3/1962 10.1.4/1964 10.2.2/1964

10.3/1961

Gouzil, J 1.1/1961 Govorkov, V. G 5.4/1959

Page 231 235 238

238

2384 210

233

70 119

96 176

99

126 150

60 18848

72

77 128

186

170

173

162 127

116

156 276

181

181 188

135

136 127

187

16438

38

185

103

11632

33 268

1740

12439

28

82

97

97

104

105

153

165 198

199 199

199 235

156

161 184

81

141 195 230

67

81 228

232

2394

145

Subsection/Year Gow, W. J 12.6.5/1917 Gradenwitz, A 3.6.4/1910 Gran, G 1.2.3/1958 Grand, P 1.4/1952

1.4/1955 Graneek, M 5.2.5/1951 Grant, G. B 10.1.2/1958 Graux, L 1.4/1927 Gray, A. W 1.2.1/1919 4.4/1914 Gray, J. B 6.6/1919 Grayson, H 1.2.1/1940 Green, A. E 1.5/1951 Green, C. J 8.1/1963 Green, D. R 1.1/1962 Green, R. E 9.2/1962 12.2/1964 Green, S. E 2.4.3/1930 Green, T. M 11.1/1955

Greenfield Tap & Die Corp 9.1/1917 Greenland, K. M 1.1/1956 11.3/1953 Greeye, J. W 10.2.1/1962 Gregor, H 10.1.4/1936 Grether, W. F 5.3/1948 Gribben, W 4.3/1896

Greiss, E. C 8.2/1918

Griffin, P. M 2.3.4/1949

Griffiths, R. B 2.3.1/1957

Griggs, H. J 1.7/1945

Grigor'ev, I. A 3.4/1956 Grim, E. D 5.4/1962 Grimod, Y 2.4.2/1955

Grin, G. L 12.3/1961 Grodzinski, P 12.2/1952 Grohe, W 1.2.1/1960 Groocock, W. G 6.6/1916

Groosfield, K 1.2.4/1952 Gross, F. L 7.1/1959 Groth, W 3.1/1948 Grover, F 12.6.1/1942 Grozinskaya, Z. P 7.4/1961 7.4/1963 Grudzinski, R 2.3.7/1963 Gruenberg, I. J 10.2.4/1934 Grunberg, L 7.1/1961 Gruneisen, E _2.4.2/1907 GSP-Matic 12.3/1962 Guenther, A. H 2.3.1/1957 Guenther, N 8.2/1939

9.3/1934

9.3/1939

Guild, J 2.2.1/1920 2.5/1956 2.5/1960

5.2.4/1924 8.1/1919

8.1/1920 Guillaume, C. E 1.1/1921 1.4/1928

2.3.2/1895 3.1/1918

3.2/1902

3.2/1913 4.1/1895

4.1/1921 4.2/1886

4.2/1889

4.2/1907

4.3/1903 Guillaume, H 6.3/1956 Gulbransen, E. A 1.7/1946 Gumenyuk, V. S 2.4.3/1961 Gunn, A. F 11.1/1946 Gunn, R 3.5/1940

5.2.2/1939

Page 274 1 141428

29

141 216

124

16933

1925 204

26 

78

243

L973 251 230

224

143

122 193

6358

36

102

14C,

7.->

15 17993

26!)

ISC, 187

68 233

17973

2(13 58

194

21 IS 20045

139 1 89

1S91 28

59

91,9294

94 117 117

121

121 121 128

16337

80

241

107

133 287
Subsection/Year Page Giinther, N 8.2/1939 194

9.3/1939 209

Gunther, C. 0 ...8.1/1930 190 Gupta, S. C 1.6/1962 35 Gurney, C 1.7/1953 37 Gurney, J. P 12.2/1961 260

Gustafsson, G 3.5/1948 107

Gustafsson, O 7.4/1960 186

Gustyr', L. Y 6.4/1961 167

8.2/1962 196

9.1/1963 202

Gutzwiller, J. E 10.1.1/1960 215

Guyette, R. S . 12.6.1/1960 269 H

Haake, H 9.3/1962 211 Haas, H 5.2.4/1958 140

5.3/1958 143 Haas, L 3.6.4/1909 114

Habell, K. J ..5.4/1948 144

6.2/1960 159

8.1/1954 191 Haber, H 2.4.3/1949 79 Hadley, L. N 11.1/1955 243

Haertel, A 9.1/1929 199 Hagee, G. R ..11.3/1965 255 Hagen, W 10.1.4/1955 226

Halis, F. W 10.1.3.4/1951 220

10.2.4/1951 233 HaU, C. E 9.3/1962 212

10.2.4/1962 234

Hall, E. R 12.6.2/1910 270

Hall, G. A., Jr 1.1/1961 4

Hall, J. A 3.6.1/1929 109

Hall, R. G. N 2.5/1961 88

3.5/1960 108

7.3/1961 183

Halle, G 8.1/1902 189

Hallert, B. P 4.4/1963 127

Halliday, J. S 11.3/1962 254

Halpern, C 1.4/1961 30

1.4/1963 30

Halsey, F. A 3.6.1/1909 109 Hamburger, L 12.5/1933 267 Hameed, A. S 7.1/1959 179 Hamilton, D. T 3.5/1916 105

9.1/1917 197

10.1.4/1917 222

10.1.4/1932 224

10.1.4/1935 224

10.1.4/1941 224 Hamm, F. A 12.5/1950 267 Hammond, R . 1.6/1959 34 Hamon, J 2.2.3/1951 50

2.3.3/1957 62

2.3.4/1957 65

2.4.1/1956 71 2.4.5/1954 84 Hamy, M 2.3.2/1897 59

2.4.2/1898 72 Hanau, H 12.6.1/1964 269

Handel, S 2.5/1963 89 Handley, R 1.4/1954 29 Haneman, G. C 3.6.2/1919 111 Hanes, G. R 2.2.1/1959 47

2.2.1/1963 48

Hanley, D. S 1.6/1960 34 Hanold, J. I 6.2/1958 159 Hansen, G 2.2.3/1958 51 Hansen, J. R 6.6/1957 169 Hansen, P. A 4.2/1879 120

3.6.1/1921 109 Hanson, B. M. W 9.1/1923 198 Hanson, M 11.2/1948 248 Hanson-Whitney 3.5/1925 106 Hanysz, E. A 11.3/1958 252

Hara, K 2.4.2/1959 76

Subsection/Year Page Hard, C. G._ 5.2.5/1949 141 Hariharan, P.. 2.4.1/1959 71

2.4.2/1959 76

2.4.3/1961 80

2.4.4/1960 83

2.4.4/1961 83

2.4.5/1959 85

6.5/1959 168

6.5/1961 168

7.3/1961 183

11.1/1960 246

7.1/1959 179 Haringx, V. J. A. 1.5/1949 33

1.6/1949 34

Harkness, Wm -- .1.1/1887 1 Harle, G. A 2.2.1/1955 46

Harrick, N. J 11.3/1962 254

Harries, R . 3.6.1/1944 110

Harrington, J. A ..1.3.2/1954 20

.1.6/1961 34

Harris, F. K 1.1/1961 4

5.2.2/1961 137

Harris, N. L__ . _ 2.3.1/1950 57

2.3.3/1950 61 . . 3.2/1963 97

3.5/1963 108

Harrison, G. R. . 2.3.1/1946 57

2.4.2/1955 75

9.1/1951 201

12.6.2/1938 270

12.6.2/1955 271

12.6.2/1957 271

12.6.2/1958 271

12.6.3/1951 272

Harrison, P. W 1.3.1/1961 18

1.3.1/1962 18

1.3.1/1963 19 3.2/1953 96

3.2/1955 96

3.4/1959 102

3.4/1960 103

6.2/1954 158

7.3/1960 183

8.1/1956 192

8.2/1962 196

9.1/1953 201

9.1/1961 202

9.3/1961 211

Harrison, R. E. W 1.7/1936 36

12.4/1929 265

12.4/1932 265

Harrison, W. H ... 9.3/1952 210

Harrisson, E. R__ 3.2/1963 97

3.5/1963 108 Harrold, B. P 6.1/1948 154

6.1/1953 154 Hart, K. H -.-1.2.2/1961 12 2.2.2/1960 50

2.3.1/1963 59

2.3.4/1956 64

2.4.6/1963 87

Harting, H 2.3.5/1907 65 Hartman, R. E__ 11.1/1954 243 Hartman, R. S . 11.1/1954 243 Hartmann, J ._ — 1.1/1947 2 Hartmann, L_ 3.5/1895 104

Hartness, J 8.2/1919 193

Hartridge, H_. 1.3.4/1923 26 226

Harzer, P__ . . 6.4/1914 165 Hathaway, C. M . ... . 5.2.2/1937 13S

6.4/1936 165

Hauseler, E 2.5/1965 90 Haven, C. E _ .6.3/1953 163 260 Hayes J W 10 2 6/1930 236 Hayford, J. F 4.3/1902 122 288
SubiectionlYear Hayward, H. N 5.1/1940

Hazi, T 7.4/1962 Head, J. W 1.1/1953 12.3/1948 Heavens, 0. S 1.7/1957 2.1/1950

11.1/1951 11.1/1958

Hefft, K 2.4.3/1963

Dr. Johannes Heidenhain 2.5/1963 4.1/1963

5.4/1964

6.4/1963

Heil, H. G 1.5/1918 Heinecke, K 2.4.6/1965 Heinemann, E 8.1/1952

Heinold, L. 0. Jr 3.4/1962 12.3/1956

Heinssen, H 10.2.6/1933 Heinz, A 5.2.2/1935 Heisen, A 11.1/1958

Heldt, P. M 3.6.4/1934 10.3/1923

Heller, W 11.3/1948 Hellmich, H. K 10.1.1/1960 Helmert, F. R 6.4/1907 Hemscheidt, H 12.1/1937 Henderson, G 2.2.5/1964 Henderson, G. A 5.2.4/1963 Hennert 4.2/1758 Hennig, M 11.1/1956

Henrici, E. O 6.4/1923 6.7/1918 Henry, J. M 9.3/1922 Herb, C. O 12.6.4/1937 12.6.5/1937

Alfred Herbert, Ltd 1.2.3/1920 4.4/1918 9.1/1920

Page 130

1863 262

38

42 242

245

8189

120

146

167

31 276

191 103 262

236

133 245

115 238 250

240

164 257

56

141 120 243

165 170 206

274

275

13 124

197, 198 235

29 260

223

67

180

31

10.2.6/1921 Herington, E. F 1.4/1954

!J I Herkt, K 12.2/1959 : Hermann, K. L 10.1.4/1922 J Herriott, D. R 2.3.7/1962 7.1/1961

Hertz, H 1.5/1896

:: Hessen, V. B 3.2/1953 96

:: : Heughebaert, D 5.4/1958 145 ; Heughebaert, J 5.4/1958 145

Heuvelink, H. J 6.4/1913 165 ..Hewitt, G. F 11.3/1964 255 ' Heyde, G 6.4/1929 165 . Hiatt, H. D 5.1/1945 130 ' , Hidiegan, M. E 10.2.2/1909 230 ^idnert, P 4.3/1953 123

'Hiersig, H. M 10.3/1948 239

<- Hight, E. K 9.1/1941 200

Hildebrand, K 6.2/1961 160

Hildebrand, S 5.7/1956 149 Adam HUger Ltd 2.4.1/1924 69

2.4.1/1942 70

6.1/1944 154

6.2/1944 157

8.2/1941 194 HUger and Watts, Ltd 2.4.1/1947 70

2.4.1/1951 70

2.4.4/1939 82

6.2/1948 158

6.2/1949 158

7.2/1944 180

8.2/1951 195

8.2/1953 195

12.2/1964 261-2

12.1/1936 257 Hill, B. R.

SubiectionlYear Page

Hill, R. M 2.2.1/1962 48

2.3.1/1961 59

2.3.2/1961 61

2.3.3/1962 63

2.4.3/1963 81

Hill, W. J ...1.3.1/1959 18

Hillier, J 12.6.1/1951 269

Hillman, M. H 5.6/1955 147

Hindes, J. W 12.2/1930 259

Hinkle, R. T 12.1/1947 258

Hire, M. de La... 6.7/1897 170

Hirsch, P. B 1.7/1953 37

11.3/1951 251

Hirsl, P 1.2.3/1961 14 Hisakado, T 1.7/1964 39

Hitchcock, R. C 8.1/1934 190

12.5/1958 268 Hoadley, H. O 5.2.4/1949 140 Hobbs, F. W 12.6.2/1928 270 Hock, F 2.4.5/1961 85

2.4.6/1965 276 Hodsman, G. F 8.1/1952 191

Hoeiler 10.2.6/1961 237

Hoersch, V. A 1.5/1930 32

Hoffman, G. R .11.3/1963 255 Hoffman, W 12.6.1/1958 269

Hoffrogge, Ch 2.2.2/1954 49

2.4.5/1957 84

2.4.6/1956 86

2.4.6/1961 87

4.1/1955 119

4.1/1961 119

4.3/1955 123

4.3/1958 123

5.6/1961 147 Hofmann, W.. ...5.l/l932 130 Hogland Eng. and Mfg. Co 10.1.3.1/1954 218 Hohenner, H 6.4/1910 165

Hoitz, H 6.4/1959 166 Hoke, W. E 12.5/1925 266

12.6.5/1925 275

Holden, J 2.2.1/1949 46

Holecek, K ..8.2/1942 195

Hollis, W. W 2.4.4/1957 83 Holman, S. W 1.3.1/1887 17

1.3.1/1901 40

6.1/1898 153 Holmes, P 3.2/1963 97

3.5/1963 108 Holmes, W. G 8.1/1921 189 Holroyd, L. V. 2.1/1955 43

Holt, W. L 3.5/1933 106

Holtwijk, T 1.2.3/1960 14 Homewood, J.. 12.6.2/1928 270

E. H. Hones, Ltd.. 3.6.2/1946 113 Hopkins, H. H... 2.2.1/1957 47 Hopper, J. W 12.3/1958 262 Hopper, V. D 7.1/1946 176

7.1/1947 176

Hori, S 1.2.3/1959 14 Home, R 1.4/1962 30

Horner, F 5.1/1937 130

Horner, J 3.6.1/1905 108

Horsfield, W. R 12.6.2/1965 271 Horton, J. W... 1.2.2/1952 11 Horton, W. L .1.1/1962 5 Hoshina, N 9.1/1961 201 Hoskins, M 8.1/1959 192

Hoskins, M. S 2.1/1956 43 Hosmer, G. L 6.4/1930 165 Hough .6.4/1904 164 Hough, J 1.3.1/1951 17 Houghton, J. L 8.1/1941 190

Houston, P. L 3.6.4/1922 115

5.2.3/1922 138 Houston, W. V 2.3.5/1927 65 Howard, J. E. ...3.5/1893 104 289
lion/Year Howden, P. F 1.3.3/1962 Howell, E. A 5.5/1951 Howlett, L. E 1.2.2/1961 2.3.3/1963 Hoyt, A 2.4.2/1936

Hrdlifika, J 8.1/1956 Hsu, B. S 7.3/1962 Hsueh, C. W 2.3.2/1946 Hubbard, D 11.1/1948 Hubbell, C. A 3.6.2/1920 Huber 1.3.3/1936 Hudson, F. C 1.7/1922 Hudson, W. S 10.2.4/1918 Huetz, J 5.2.2/1953 Huff 2.3.1/1897 Hughes, H. A 1.3.1/1946 Hughes, J. C 3.4/1950 Hugo, S. W 7.1/1956

7.1/1961 Hiihn, H 1.4/1959 Humbert, B 3.3/1947 Hume, K. J 1.2.1/1950

1.2.1/1956 6.1/1949 Hume, K. S 6.2/1955 Humphreys, C. J 2.3.3/1929 2.3.3/1930

2.3.3/1931 2.3.1/1934 Humphreys, H 7.3/1925 Humphreys, W. J 2.3.1/1897 Hunt, G. H 5.2.2/1954 Hunt, I. A 3.6.4/1949 Hunt, R. W. G 5.4/1946 Hunter, J. J 1.4/1962 Hunter, M. C 5.5/1944 Hunter, P. H 1.4/1959

5.2.2/1946 Huntoon, R. D 1.1/1950

1.1/1965

2.4.2/1954 Hunzinger, J. J 2.1/1957

2.4.4/1955 Hupe, K 3.2/1941 Hurtt, L 1.2.4/1964 Hwang, H 1.4/1963 Hyler, J 5.6/1954

Ichikawa, M 9.2/1964

Ickert, J 1.3.1/1955

Ido, M 7.4/1962

Idrac, J 5.1/1960 Ignatenko, V. V 1.6/1963

Iizuka, K 3.6.4/1962 Ikeda, I 2.4.2/1958

Her, W. T. Jr 9.3/1917

Illinois Tool Works 9.2/1934

9.2/1935

10.1.4/1928

10.1.4/1954

10.2.2/1952 10.2.6/1934 Imahori, K 11.2/1953 Imaizumi, M 2.3.2/1928

2.4.5/1929 Imbusch, G. F 2.4.5/1963 Indian Government 3.2/1915

Industrial Press 9.4/1964

10.1.3.2/1964

10.1.3.4/1964 Ingelstam, E 2.2.3/1958 Ingram, H. J 12.4/1944

Institute of Metals 1.7/1953

International Bureau of Weights and

and Measures 2.4.5/1961 4.1/1889

International Business Machines 1.2.1/1952

Page 25

146

12

6373

191 18460

241 111

2236

232 136

90

17 102

178

179

29

154

15860

6060

57

18190

136

115 14430

14629 134

339

75

4482

95

1730

147

205

17

1 86 13034

11676 206

203

203 223

226

231 236 248

59

8486

95

212

219

221

51 266

3785

117

Subsection /Year Page International Comm. on Weights and

Measures 1.2.2/1963 13 International Organization for Standardization 1 0. 1 . 1 /l 953 21

10.1.1/1957 214

10.1.1/1961 215

Irland, J 11.1/1963 246

Isa, S 9.2/1963 205

Isakower, R 1.3.3/1963 26

Isard, J. O 2.5/1952 88

Isebeck, K 1.4/1964 31 Ishikawa, J 10.1.4/1962 228

Iudin, S. P 5.2.5/1960 142

Ivanov, Y, V 10.1.4/1963 228

Ivantsov, A. I 1.3.2/1965 40

Ives, F. E 4.4/1902 123

Ives, H. E 11.2/1927 247

Iaotov, S. I 7.2/1963 181

Jackson, C. V 2.3. Jackson, D. A 2.4 2.4 Jackson, L. C 11 Jackson, L. P 12

Jacobs, S. F 2.4 Jacoby, H 4

4 Jacquinot, P 2.2 Jaeger, J. J 10.1.3

Jaffe, H 2.4

Jaffe, J. H 2.2

2.4

2.4 James, P. R 5.2 Jansson, A 9

Jarrell, R F 12.6

Jaseja, T. S 2.3 Javan, A 2.3 Jeans, L. E 10.1

Jeffcott, H. H 9

Jeffery, E. E 12

Jeffree, J. H 5

Jeffreys, H 1.3. Jenkins, I 1 Jennings, W. O 3

Jensen, H 8

Jewell, R. G

Jimbo, Y

Jobst, C

Johansen, F. C

Johansson, C. E

C. E. Johansson, Ltd.

Johansson, L. P.

Johnson, J Johnson, K. L

Johnson, K. W...

Johnson, L. J Johnson, L. O. C.

Johnson, S. G

Johnson, S. J Johnsrud, A. L

John-Sons

Johnstone-Taylor, F

A. A. Jones and Shipman.

Jones, A. B

Jones, A. G

Jones, D. E

E. H. Jones, Ltd

,2/1936

.3/1949

.3/1963

,3/1951 .5/1941 ,3/1962

.2/1895 .2/1896

.1/1948

.2/1959 .1/1950

.1/1956

.1/1950

.3/1951

.2/1961 .2/1946

.2/1964

.7/1963

.7/1963 .4/1948

.3/1907

.3/1952 .4/1932

.3/1932

.7/1953 4/1948

1/1947

1/1950 1/1954 2/1935

6/1962

.6/1947 7/1945

2/1933

3/1953

.3/1954 3/1958

3/1919

3/1958

.1/1948 6/1959

6/1962

.2/1906

.1/1952

.1/1951

.3/1951 .1/1957

.3/1957 2/1927

2/1924 4/1924

.5/1954

.5/1946

.3/1959

.5/1896 .5/1943

.1/1943

60

79

81 250 267

81 121 12145

220

7046

70

79

137 204

27167

67 225

205

262

144

22

37

102

177

191

191 122 , 35

147

36

11 139

139

139

162

118

123

201

211 247 , 203 223 267

32

14

31 107

154 290
Subsection/Year Jones, F. D 3.1/1922 8.2/1918

12.6.1/1920 12.6.4/1918

12.6.5/1920

Jones, R. V 1.5/1961 5.1/1962

5.2.4/1951 5.2.4/1959

5.2.4/1961 5.4/1956

5.6/1961

5.7/1951 5.7/1955

5.7/1956 5.7/1959

5.7/1962

Jones, T. E 3.4/1948 Jordon, W 6.4/1923

Jotzoff, A 3.2/1940

Joyce, A. H 5.2.5/1958 Judge, A. W 1.1.1/1957 Judson, L. V 1.2.2/1956 1.2.2/1959 1.2.2/1960 4.1/1960

4.2/1934 4.2/1960

4.3/1926 4.3/1927

4.3/1960

6.4/1927

Julius, W. H 1.6/1895

Juran, J. M 1.3.4/1935 Jurek, B 8.1/1948 8.2/1954

Juricic, H 6.2/1959 K

Kaatz, K 3.2/1958 Kabatov, N. F 10.3/1962 Kadikov, G. M 1.2.3/1961 Kahl, G. D 2.2.3/1952 Kainer, G. B 1.4/1963 3.4/1965

.52.3/1962

Kaiser, F 6.4/1870

Kaiser, H 1.3.3/1936 Kaluzka, H 9.2/1963 Kamada, A 1.4/1952 Kamilov, I. K 2.4.2/1962 Kammerer, O. F 11.3/1958 Kaneko, T 2.3.2/1958 2.3.4/1958 Kanevskii, Y. P 2.2.3/1960 Kann, G 12.1/1949 Kans, N. F 1.4/1958 Kantor, K 2.2.1/1963

2.2.3/1963

2.4.5/1961 5.1/1961

Karelin, N. M 8.1/1962 12.2/1960

Karolus, A 1.2.4/1960 Karovic, K 6.2/1963 Karpasheva, A. N 1.3.3/1960 Kartacheff, A. I 2.4.3/1935

Kartaschoff, P 2.3.6/1962 Kartashev, A. I 1.3.2/1962 2.3.2/1942

2.4.5/1960

2.4.5/1963

2.4.6/1963 Kartashova, A. N 3.6.4/1963 Kartcher, H. S 6.8/1927

Kashirin, V. B 5.5/1961 ! Kasper, R. H 3.6.1/1921

Page 92

193 268

273 275

33

131 140

140

140

145 147 148

149

149

151 150

102 16595 1428

1140

12 119

121 122

123

123 123

16534

27

190, 191 195

159

96 240

1450

31 116

139

164

22 204

28

77 252

62

65

51 258

29

48

51,5285

131 192

260

16 162

25

78

66

2160

8585

87

116 172

150

109

SubsectionI Year Page Kastler, A 2.3.7/1962 66

Kater, H 1.3.2/1830 40 Kath, H 2.2.5/1897 53 Katsman, F. M 9.2/1963 205 Kaufman, V 2.3.4/1962 65

2.3.6/1959 66 Kautsky, F 8.1/1948 190

Kavalerov, G. I 1.1/1963 5 12.1/1962 258

Kaverkin, I. Y 1.1/1963 5 Kavle 10.2.1/1920 228 Kawamura, C 9.2/1963 205 Kayak, L. K ^ 1.3.2/1963 22

1.3.2/1964 40

2.4.1/1961 71

3.2/1956 96

4.4/1960 127 Kaye, G. W. C 3.1/1911 91 Kayser, H 2.3.2/1904 59 Keane, C. B 6.21(1948) 158

Keating, D. T 11.3/1958 252

Keck, K 10.1.1/1960 240

Kedrov, S. S 1.6/1962 35

Keil, E 2.4.1/1908 69

Keinath, G 1.2.1/1958 9

1.3.2/1935 20

4.1/1934 117

5.2.1/1932 131

Kelling, L. U. C 12.3/1963 264

Kellner, H 4.4/1923 124

Kelly, J. C 11.1/1958 245 Kennedy, C. W 1.2.1/1962 9

1.3.2/1958 21 Kennedy, J. T 6.1/1962 156 Kern, R 2.4.3/1963 81 Kern, W. F 1.2.1/1938 40

Kerns, D. M 2.1/1960 44

Kessler, K. G 2.3.3/1961 63

2.3.4/1950 64

2.3.6/1958 66

2.3.6/1960 66

Kessler, O 12.6.4/1934 274

Khairov, A. A 9.1/1961 202

Khalebskii, N. T 9.3/1963 212 Khamsavi, A 11.1/1947 241 Khanna, B. N 2.2.4/1962 53 Khomazyuk, V. G 2.2.2/1960 49 Kickman, L 8.1/1959 192

Kiehne, H 3.6.2/1919 111

Kienzle, O 1.2.1/1954 8

1.7/1937 36

3.6.2/1920 111 6.8/1922 172

10.1.1/1949 213

Kimble, R 2.5/1963 89

3.2/1963 97

Kinder, W 2.2.3/1958 51

2.4.5/1962 85

2.4.5/1963 86

2.4.6/1963 87

King, A. A 10.1.4/1948 225

King, H. M 5.2.3/1962 139

King, L. E 8.2/1921 193

King, R. J 6.1/1961 156

King, R. P 6.7/1903 170

Kinzel, A. B 1.1/1961 4 Kirby, R. K 4.3/1953 123

Kirchner, W 3.4/1962 103

Kirchhofer, K. F 3.1/1942 93

Kirichenko, A. P 2.1/1962 44

2.1/1963 44

2.4.1/1962 72

2.4.5/1963 85, 86

2.4.6/1963 87

Kirillova, T. S 9.2/1963 205

Kirk, D. B 5.2.5/(1945) 141 Kirkham, E. E ..10.1.3.2/1959 220 291
Subsection/Year Page Kirkpatrick, P 1.3.4/1922 26

Kirner, J 7.4/1922 185 Kissam, P 1.2.4/1949 15

1.2.4/1962 16 6.2/1963 161 Klapper, E 1.2.2/1929 10

1.2.2/1930 11 Klawe, C. H 1.2.1/1945 7 Klebanov, M. K 12.2/1961 260

Kleintov, N. A 4.4/1960 127 Klemm, W. F 1.7/1945 36

Kline, J. E 1.7/1935 36

12.3/1947 262 W. Ferd. Klingelnberg Sdhne 10.2.1/1956 230

Klucher, T. M 2.3.7/1963 67 Kluwe, P 10.1.4/1940 224

1.1/1963 5 Arthur Knapp Engr. Corp 9.1/1919 198 Knedel, W 9.1/1935 200

9.3/1935 208

Kneller, V. Y 12.3/1963 264 Kniehahn, W 5.1/1928 129 Knight, W. A 6.1/1908 153

12.5/1915 266 Knott, R. D 2.3.3/1951 61 Knowles, T. R 10.2.5/1956 234

10.2.5/1957 234

Knoyle, C. H 2.4.4/1926 82

6.3/1950 163 Koana, Z 2.1/1951 43

Kobler, H 2.4.3/1963 81 Kobold, H 6.4/1914 165 Koch, W 4.1/1945 118

4.2/1945 122 Henry Koch & Son 3.6.4/1908 114 Kochenov, M. I 6.1/1961 156

Koehler, H 6.2/(1963) 162

Koehler, O. E 9.3/1938 208

Koehler, W. F 2.2.2/1958 49

2.2.5/1953 55 Koenig, E. H 2.4.4/1959 83

6.2/1964 162 Koenig, F 4.4/1944 126 Koenigsberger, F 12.2/1963 261

Koester, C. J 2.2.5/1958 55

2.2.5/1960 55 Kogan, G. I 10.1.4/1960 227

Kogelnik, H 2.3.7/1962 67 Kohn, J. P 1.3.1/1962 18 Kolomiitsov, Y. V 2.4.4/1963 83

7.3/1956 182

7.3/1959 183 Kolomitsova, T. S 2.4.2/1960 76 Kolpakov, D. I 8.1/1963 193 Kondo, Y 2.4.1/1961 71 Konejung, A 1.3.3/1933 22 Konig, F 2.2.2/1928 49 Kon'kova, E. M 3.5/1965 151 Kono, T 2.4.6/1962 87 Koop, H. A 9.2/1962 204

10.1.4/1962 228 Koppelman, G 2.4.3/1961 81

2.4.3/1963 81

7.3/1961 183

11.1/1956 243

11.3/1960 253 Kornhauser, M 1.5/1951 33

Koroleva, A. N 2.4.2/1963 77 Koronkevich, V. P 2.4.2/1960 77

2.4.4/1961 83

2.4.4/1965 276

7.2/1961 181 7.2/1962 181

7.2/1965 188

8.2/1962 196

9.1/1963 202 Korotkov, V. P 12.3/1960 262 Korwien, H 1.2.1/(1950) 7

Subsection/Year Korsunskii, M. I 5.2.2/1964 Koster, G. F 2.3.7/1962

Kosters, W 2.3.2/1935

2.4.1/1922

2.4.1/1926

2.4.4/1925

2.4.5/1938 3.1/1912 3.5/1908

3.5/1923

4.4/1913

Kostich, B. E 1.2.4/1960

I. 2.4/1965

5.2.2/1962 Kostin, V. E 4.4/1960 Kostrov, B. D 5.2.5/1960 Kotsyubinskii, O. Y 12.2/1962 Kottas, H 5.2.2/1935 Kouno, T 2.4.6/1964 Kozma, A 1.5/1962

10.1.3.6/1962

Kragel'skii, I. V 7.7.1/1965 Krasnoperov, N. K 5.4/1961 Krause, G 2.2.1/1916 Krause, H 2.4.3/1963 Krebs, K 2.4.3/1961 7.3/1961

II. 1/1956

Kreis, E 9.1/1925 Kremen', Z. I 3.1/1963

Kress, K 1.2.1/1942

Kreusler, H 2.4.1/1932 Krug, C 12.4/1927 Krug, W 6.4/1938

7.3/1956 Kruger, J 11.2/1964 Krumme, W 10.1.1/1960 Krupp, N. Y 1.3.1/1963 Kruszynski, M 1.3.3/1957 Kubacek, L 6.2/1963 Kudinov, V. A 12.2/1962 Kuebler, K. H 9.1/1952 Kuehni, H. P 5.2.2/1942 Kugler, C 8.1/1926

9.3/1931 Kuhlmann-Wilsdorf, D 5.2.3/1954 5.7/1954 Kuhn, H 2.1/1951

2.4.3/1949 2.4.3/1950 Kuhne, C 6.4/1960 Kuhne, K 7.1/1958 Kuhne, P 3.2/1937 Kuhnen, F 3.2/1913 Kumagai, I 9.2/1963 Kuokkanen, P. E 5.2.2/1934 Kupriyanov, V. M 11.2/1963 Kuptsov, I. A 3.4/1960 Kurochkin, A. P... 5.2.5/1962

5.2.5/1963 Kurrein, M 3.6.4/1922 10.1.4/1923 Kurtz, H. F 4.4/1925

5.4/1925 8.2/1938 Kutay, A 3.3/1933 Kvaskov, L. Ya 2.4.2/1965 L

Laborde, A 3.6.3/1946 4.2/1946

Laessker, F .9.2/1939

Laetzig, W 12.5/1950 Lafay, A 2.4.4/1901 Lagunov, A. S 5.2.2/1964 Lakshminarayanan, S 1.2.2/1955 LaMarre, D 2.4.1/1956

Page 13467

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19994770

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1924

162 260

201 134

189 208

139

14942

79

79

167

17895

95 205

133 249

103

142

142 115 223

125

144

19498 276

114

122 203 267

81 138

1171 292
7.3, 7.3

7.4

8.2,

.2, Langer, R. E 1.1 Lapujoulade, J 1.7 Larke, E. C 12.4, Larmor Eng. Co 9.3, Larson, K 11.1 Lasnier 1.7, LaTourrette, J 2.3.7 Laurent, P. A 9.3, Lawrence, T. R 2.3.7 Lawson, J. L 2.3.4 Lea, F. C 1.2.1 Le Bourhis, C. A 9.1 Lede, W 1.3.3 Lee, A. J 9.2 Lee, E. S 5.2.2 Lee, J. W 6.8

9.3, Lees-Bradner Co 9.2, 10.1.4

10.2.1 Lees, E. J 10.2.6, Lees, S 1.1 Legallais, V 1 5.2.2, Legav, F 2.2 Legrand, C 11.3, LeGrand, R 6.2, 12.1 12.4 Lehmann, H 2.4.2 Lehmann, R 1.2.1 1.2.1

1.7, 9.1 Leibfried, G 5.2.3 Leighton, R. B 8.2, Leinweber, P 1.2.1

1.3.1

1.3.2,

1.7, 2.4.2

2.4.4

3.2, 10.1.3.1 Leman, A _.3.5

4.2 Lement, B. S 4.3 Lenkova, G. A r 6.2 Lennuier, R 2.3.4 Lepper, E 3.3 5.4

Leslie, R. T 1.3.1

1.3.3, 1.3.3 3.1

4.1

4.2,

5.4, _ - 2.5, 10.2.5, Lethersich, W 1.5,

Subsection/Year Page 1956 49

1958 51 1959 51 1949 177 1958 178-9

1959 183

Subsection/Year Page

Leslie, W. H. P.

Levesque, G. N.

Levin, B. M_-

Levina, Z. M.

Lewis, A

Lewis, C. R1962 1958

1958

1959

1959 1964

1927

1945 1954

1945 S 1963 e 1929 207-

184

185

196

19639

39 265

209

243

1963 1936

1946

1953

1948

1917

1937

1951 1947

1934

1934

1923 1903

1953 1947

1956

1948

1958

1962

1962

1936 1940

1956 1957

1932

1950 1956

1954 1964

1964 1944

1960 1963

1944 1954

1913

1906

1951 1964

1963 1959

1959 1963

1947

1954 1963

1963 1963

1955

1962

1961 1944

1953

1952 1962

1959 1959 1950

1952

67637 20123 202

133

172 210

203

224

229

2353 13552 250

159 258 266

737

199

139

1922

36

7683

95 218

104

121 173

162

65

100

145

1923

2394

119 122

14589 234

32

182 154

148 155

16837

37

Lewis, E. A 2.5, Lewis, H. B 2.4.6,

6.6, Lewis, R. E__ 1.2.3, 3.6.3, Lewis, T. C. Jr 12.5

Li, T 2.3.7 2 3 7

Lich, O 12.6.5, Lichtenauer, G 10.2.2, Liddell, D. M..-. 12.6.2, Lieberman, G. J 1.3.3, Liebhafsky, H. A 11.3, Liem, S. H 6.2, 7.3 Lieneweg, F 1.4 Liggett, J. V 1.2.3

Lily, J. C 5.2.2 Limming, E. A 9.3

'• ' • 3 9.3

9.3

9.3 10.3 ..11.1

_3.6.1 .1.3.3 --12.1

...1.1

12.6.4 ...2.5

Lindberg, P. J_. Lindholm, A. C.

Lindley, D. V_.

Lindner, W

Linebrink, O. L. Lineham, W. J_

Linge, J. R

Linnik, V. P 7.1

9.1 Linsley, H. E 3.6.1 Lion, K. S 5.2.1 Lippmann, G 6.2

Lisitsa, M. P 11.3

Littlefield, T. A 2.3.3 Litvin, F. L 9.3 Livermore, F. A 12.6.4

12.6.5, Lloyd, H 6.5, Llovd, W. A 8.2, Lobe, F 10.1.4 Lobell, D 3.5 Lobov, S. I 11.3 Lochte-Holtgreven, W 2.4.4 Lodge, A 1.1 Loewe Gesfurel 12.4 Loewen, E. G 1.2.1 4.1 6.2 Loewy

Lofton, R. E

Logacheva, L. N

Lohmann, A 2 Lohse, O

Lokhmatov, A. I London, F. H 2 Longwell, J 2 Lopovok, T. S

Lorents, E. V.

Lorentzen, I__ Lotmar, W

Louckes, F. I. Jr Love, R. J

Loveland, R. B ...12

Lovins, G. H 2 Lowczynski, L 1 Lowe 3

1952

1924 1917

1950

1950 1957

1961 1963

1932

1963

1914

1959

1956

1961 1961 1952 1962

1947 1922

1923

1924

1928

1929 1922 1957 1910

1946

1954

1961 1920 1957

1942

1960

1951 1956

1902

1959

1946 1950

1922 1932

1950

1948 1960

1958

1963 1957

1895 1935

1958

1963

1963

1906

1932 1959

1962 1959

1910 1964

1964

1950

1961 1963 1963

1962

1893

1894

1962

1956

1953

1930

1964 1952

1914 293
Subsection/Year Page Loxham, J 1.2.1/1962 9

10.2.6/1958 237

12.2/1963 261 Liidemann, K 3.6.3/1929 114

4.1/1922 117

5.5/1931 146

6.7/1928 171 Luders, G 1.1/1951 3 Ludovici, B. F 2.3.7/1962 67

Luers, G. A 10.2.6/1924 235

Lufkin Rule Co 3.6.2/1930 112 Lukacs, E 1.2.4/1951 15 Lukens, H. R. Jr 11.3/1962 254

Lukin, I. V 2.4.5/1962 85 Lummer, O , 2.2.1/1902 44

2.3.1/1902 90

2.3.1/1904 276

7.2/1884 188

Lur'e, B. G 12.2/1962 261 Lush, A. J 5.5/1931 146 Lynch, E. E 5.2.1/1948 132 M

Maag Gear Wheel Co 10.1.2/1963 216

10.1.3.1/1963 219

10.1.3.5/1963 222

10.1.3.6/1963 222

10.1.4/1928 223

10.2.1/1926 229 Maag, M 3.4/1952 102 Mabboux, G 6.7/1928 171 Macabrey, C 10.1.4/1947 225 MacDonald, D. K. C 1.3.4/1948 27 MacGahan, P 5.7/1944 148 MacGeorge, W. D 5.2.2/1950 135 Mach, L 6.7/1894 170 Machabey, A 1.2.1/1959 40 Machine Shop Equipment, Ltd 9.1/1946 200

Macinante, J. A 1.6/1963 35 Maclndoe, R. C 5.7/1959 150 Mack, J. E 5.4/1942 144 Mackay, D. M 1.3.3/1958 24 Mackensen, O 7.1/1926 176 MacLachlan, D. F. A 6.7/1962 171 Maevskii, V. M 11.3/1959 252 Magor, L. S 12.2/1963 261 Magyar, G 2.3.7/1963 68

Mah'lmeister, R 7.4/1958 185-6

Mailey, G. C 4.4/1941 125

Maitre, J 6.1/1921 153 Makishima, S 2.1/1951 43 Male, D 11.3/1952 251

11.3/1963 254

11.3/1964 255 Mandel, J 1.3.3/1946 22

1.3.3/1954 24

1.3.3/1962 26 Mandel, L 2.3.7/1963 68 Manke, H. R 6.1/1961 156

Mansfield, D. L 6.1/1962 156 Mansour, T. M 11.3/1963 254

Manzotti, M 5.2.1/1956 132 Mapes, C. W 10.3/1920 238

Marcotte, E 2.4.4/1928 82 Marechal, A 2.4.1/1962 72

6.2/1961 160 Marek, W. J 4.2/1879 120 Mark, A 10.1.4/1964 228 Markov, B. N 12.3/1963 264 Markov, N. N 1.4/1963 31 5.2.3/1962 139

10.1.4/1960 227

10.1.4/1963 228 Markov, P. U 3.4/1962 103

Maries, D 5.6/1955 147 Marmorstone, R. J 12.3/1962 263 Marrman, H. J 2.2.1/1955 46

Subsection/Year Marriner, R 7.1/1947

7.1/1948 Marriner, R. S 8.1/1953 9.3/1958 Marsh, D. M 5.7/1962 Marsh, M. C 3.5/1929 Martin, J 4.1/1948 Martin, L. D 9.3/1958

10.1.1/1958

10.1.4/1948

10.2.2/1949

10.2.2/1950

10.2.2/1964

10.2.6/1953 Martin, P 1.2.1/1964 4.1/1960 Martin, W. C... - .2.3.5/1960 Martynov, A. D 5.2.1/1960 Marzetta, A .4.1/1961 Marzetta, L. A 2.4.2/1961

2.4.6/1961 Mason, G. W 1.2.3/1964 Mason, W. P. 5.2.2/1957 Masui, T 2.3.3/1957

2.3.4/1957 Masuda, T 12.2/1963 Mateos, M 1.2.2/1963 Mathews, G. G - _2.4.2/1963 Matsumoto, T 12.2/1963 Matthees, F 12.6.4/1939 Matthew, J. A 3.3/1932 Matthews, G. G 2.4.2/1963 Matthews, J. W 5.2.2/1929 Mattuck, R. D 11.1/1956

11.2/1957 Matveev, V. V 5.2. 1/1962

7.4/1960

8.1/1963 Maudet, L 3.1/1912 3.1/1927 4.1/1944 Maurer, H__ 1.2.2/1935 4.1/1937

6.1/1935 Maurice, D. M 5.2.2/1954 Maxwell Motor Corp 10.1.4/1926 Mayer, A. E 7.4/1932 Mazur, M 1.3.3/1957 Mazurenko, I. V 10.2.6/1962 McArdell, W 6.6/1916 McCain, G. L 10.2.4/1946 McCallum, W. B 1.3.1/1965 McCaw, G. T 6.4/1909 McClure, E. R 1.4/1965 McCombie, C. W 1.1/1953 McConnell, D 1.7/1945 McCrackin, F. L 11.2/1963 McCubbin, T. K. Jr 2.2.4/1958 McCutchen, C. W 7.3/1964 McDermott, J. V 7.1/1964 McDowell, C. H 10.1.4/1964 Mcllraith, A. H 2.5/1963

2.5/1964 Mcllwraith, C. G 5.7/1958 McKee, S. A 1.5/1947 McKay, W 1.1/1953 McKeown, P. A 2.3.3/1960 McKewen, G. E 1.5/1962 McKinley, W. A 1.2.2/1960 McNally, F. A 11.1/1953 McNally, J. R., Jr 2.3.4/1949

2.4.3/1956 McNamara, J. E 11.3/1962 McNicholas, H. J 5.4/1931 McNish, A. G 1.1/1958

1.1/1963 1.1/1965

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153

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24 237

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19 164

31336 248

52

184

180 228

903 6240

12 24363

80 254

1444539 294
SubsedionlYear Page McNish A. G.—Continued

1.2.2/1959 12

I. 3.1/1960 18

2.3.7/1964 68

McPharlin, L. M 1.7/1927 36 Meadows, J. J 9.3/1946 210

Medhurst, C. W 7.3/1951 182 Medvantseva, L. L 6.1/1963 156

6.2/1963 161

7.3/1963 184 Meggers, W. F 2.2.4/1918 52

2.3.1/1921 56

2.3.1/1934 57

2.3.1/1942 57

2.3.3/1929 61

2.3.3/1931 61 2.3.4/1948 63

2.3.4/1949 63

2.3.4/1950 63, 64

2.3.4/1951 64 Mehdahl, A 10.1.4/1942 225

Meili, J 5.7/1962 150 Meinke, W. W 11.3/1956 252

Meissner, K. W 2.3.6/1958 65

2.3.6/1959 66

2.4.2/1929 73

2.4.3/1942 78

2.4.3/1953 79

Meister, G 1.2.1/1963 9 4.1/1960 119

Mellor, H 6.8/1940 172 Melson, E. W 2.1/1935 41 Meltzer, R. J 4.1/1963 119

4.4/1963 127

12.3/1963 264

Mendenhall, T. C 1.2.2/1892 10 Mennesson, M 5.2.5/1932 141 Menschick, W 11.1/1929 241 Menzel, B 2.2.1/1952 46

II. 1/1952 242

Menzel, E 11.1/1957 244

T. and F. Mercer 12.6.5/1932 275

Mergol'd, M. M 6.4/1960 166 Merriam, R 7.1/1955 178

Merrill, P. W 2.3.5/1917 65

Merritt, H. E 9.3/1922 207

9.3/1923 207

9.3/1924 207

10.1.1/1956 214

10.1.2/1955 216

10.1.3.1/1946 218

10.1.4/1923 223

10.2.4/1923 232

Mershon, A. V 5.2.2/1929 133

5.2.2/1932 133

12.4/1933 265

Mertens, F. P 11.2/1963 249

Merz, L 5.5/1950 146

Meslin, G 2.4.4/1904 82 Mesnager 2.4.4/1904 82

Metsik, M. S 11.2/1963 249

Metz, A 1.1/1950 3 3.3/1961 100

4.4/1954 126

5.1/1950 130

6.2/1954 158

8.1/1939 190

Meurers, J 1.3.3/1948 23 Meyding, L 1.3.2/1958 21 6.5/1962 168

10.1.4/1959 227

Meyer-Arendt, J. R .2.5/1963 89

6.5/1963 168 Meyer, F., Jr 7.4/1958 185

9.1/1920 198 Meyerson, M. R 3.1/1960 93

3.1/1961 93

3.1/1964 94

Subsection/Year Page Michalec, G. W 10.1.4/1956 226

Michalet, G 3.6.4/1949 115

Michelson, A. A 2.3.1/1888 56

2.3.1/1894 56

2.3.1/1903 56

2.3.2/1895 59

4.4/1924 124

5.4/1924 143

6.5/1890 173 Michigan Tool Co 9.2/1931 203

Middleton, S. P 6.1/1961 156

8.1/1954 191 Mielenz, K. D 2.3.7/1964 68

2.4.1/1964 72

Mielich, R 5.3/1936 143 Mikhailova, M. G 5.4/1963 146 Mikryukov, V. E 2.4.2/1962 77

Miller, D. C 1.2.1/1903 6 5.2.4/1909 139

Miller, D. R 3.6.4/1922 115

5.2.3/1922 138

Miller, F. J 3.5/1892 103

Miller, H. W 9.3/1919 206

Miller, J. C. P 10.1.3/1962 217

Miller, J. M 6.2/1963 161

Miller, J. R. Ill 1.3.1/1961 18

1.3.1/1964 19

I. 3.2/1964 20

Miller, L 1.2.1/1962 9

Miller, T 12.6.5/1911 274

Milner, S. R 7.1/1908 175

Minaire, C 6.8/1955 172

6.8/1958 173

7.1/1957 178

7.1/1958 179

8.1/1949 191 Miner, E. D 2.5/1963 89

6.5/1963 168 Mirau, A 7.3/1951 182

12.1/1953 258

Mirkin, M. S 1.3.3/1960 25

Misener, A. D 1.4/1959 29

MitcheU, C. A 3.6.1/1930 109

Mitchell, R. F 7.1/1952 177

Mitra, S. S 2.2.1/1958 47

II. 3/1962 254

Mitrovich, V. P 8.1/1963 192 Miwa, S 12.2/1963 261 Miyasato, I 2.3.3/1958 62

2.3.4/1958 65 Mivazaki, K 8.1/1958 192 Moen, W. K 1.4/1960 29

Moffat, R. J 1.4/1961 30

Moffit, G. W 8.1/1919 189 Mohamed, A. A. A. 11.1/1963 246

11.3/1963 254 Mohler 2.3.1/1897 90

Mohorovicic, S 8.1/1954 191 Mokhov, A. V 8.1/1959 192 Mokhtar, S 2.2.1/1963 48

2.2.5/1963 55

Moles, A 1.1/1953 3 Moline Tool Co 12.5/1926 266

Molle, R 5.2.5/1950 141 Mollenauer, L. F 2.4.5/1963 86

Mollet, P 1.1/1960 4

2.2.1/1960 47

Molstead, O ..2.5/1964 90 Monarch Tool Co 10.1.4/1941 244

10.2.2/1941 231 Monch, G. C 11.1/1951 242

11.1/1952 242

11.1/1955 243

Moncrieff, D 10.1.4/1946 225 Monrad, A. L 3.6.2/1903 110

3.6.2/1904 110

9.3/1908 205

12.6.4/1908 273

771-846 O—66 295
Subsection/Year Montgomery, D. J 1.1/1954

Montilla, J 9.2/1963 Moody, J. C 1.2.1/1963 1.3.1/1963 1.4/1957

1.4/1960 6.1/1963 6.2/1955 6.2/1958

7.1/1953

7.1/1955 Moon, C 3.1/1933

3.5/1925 Moore, C. B 5.2.5/1945 Moore, J. R 12.6.1/1946

12.6.3/1944 Moore Special Tool Co 1.2.3/1960 Moos, H. W 2.4.5/1963 Morais, C 2.5/1958 Moran, J. P 12.5/1958 Moreau, H 4.2/1944 Moreau, T 6.2/1948

7.3/1948 Moret, H 3.4/1962 Morey, F. C 3.4/1950 Morgan, I. G 3.3/1955

3.3/1962

3.3/1963

3.4/1959 3.4/1960

5.2.5/1956

5.2.5/1964 Morin, J. 0 5.2.1/1960 Morimura, M 1.3.3/1958 Morita, N 1.2.3/1959 Morita, Y 12.2/1963 Morley, E. W 2.3.1/1888 Morokuma, T 2.3.7/1963 2.3.7/1964

2.4.2/1962

Morrelli, D. A 3.5/1942 Morrison, A. E 12.6.1/1942 Morrow, J 2.4.2/1905 Mortonand, F. G 8.2/1953 Morton, G. F 3.4/1954 Morton, H. T 12.6.1/1939 Moses, A 12.6.5/1919 Mosman, A. T 4.1/1893 Mossoux, R 1.2.1/1961 Mottu, A 1.2.1/1947

1.3.2/1949 4.4/1964

Mueller, F 3.5/1939

Mueller, P. M 12.5/1925

Mueller, R 1.6/1929 Mugridge, E. G. V 2.4.3/1962 5.2.1/1962 Muhlig, F 4.3/1949 6.4/1933 Muirhead, D. P 8.2/1925 Muller, J. M 3.4/1964

Minister, C 7.2/1932 Murase, Z 9.3/1962 Murdock, G. J 3.5/1909

3.6.2/1909 Murray, D 5.2.2/1959 Murray, T. P 11.2/1962

Murrell, K. F. H 5.3/1963 5.4/1963 Murty, M. V. R. K 2.1/1964

2.4.2/1960 7.1/1962 Musk, A. W 3.1/1949 N

Nabiev, M. A 5.2.2/1962 Nagaoka, H 2.2.1/1915

2.4.3/1917

Page3 20510

1929

29

156

159

159 177 178

92 106

141 269

272

14

2GN

122

1 58

1S2

103 10299

100

100

102

io;{ 142

143

13224

14 26156

6768

77

107 269

73

195

102 26S

274

12M

9

7 20

I2S 107

34

81 132 123 166 194

103

180

211

104 111

137 248

143, 14644

76

ISO93

13745

78

Subsection/Year Nagata, R 7.4/1962 Naik, Y. G 11.3/1957 Nakada, T 1.2.1/1964 12.2/1963 Nakata, T 10.1.4/1939

Nalle, D. H 1.4/1963

Nassal', V. I 5.2.2/1963 National Broach and Machine Co 10.1.2/1964 12.1/1950 National Bureau of Standards 1.1/1961

1.1/1963

1.2.1/1912

1.3.3/1954 2.1/1957

2.2.2/1961

2.3.4/1951 2.4.2/1963

2.4.4/1957

2.4.4/1958 2.5/1963 3.1/1945

3.4/1960

4.1/1927

4.2/1927

6.3/1953 6.8/1920

7.2/1958

8.1/1919

8.2/1921 9.1/1919

9.1/1923

9.3/1923 9.3/1957

9.4/1957 National Cash Register Co 8.1/1927

National-Cleveland 9.2/1931

10.2.1/1926 10.2.1/1930 National Engineering Laboratory,

G. B 1.6/1963 12.6.2/1958 National Physical Laboratory, G. B 1.1/1946

1.1/1951 1.1/1952

1.3.1/1953

1.3.1/1962 2.1/1960

2.4.1/1922 3.1/1920

3.5/1925

3.5/(1955) 4.1/1906

5.2.4/1920 5.7/1956

6.7/1919 8.2/1917

8.2/1918

8.2/1920

9.1/1920

9.1/1922

9.1/1951 9.2/1906

9.3/1916

9.4/1951

10.1.4/1923

12.6.1/1946 National Screw Thread Commission 9.1/1929

Natrella, M. G 1.3.3/1963 Neady, S. H 12.4/1944

Nefflen, K. F 2.3.7/1963 2.4.5/1960 Nelson, L. M 7.4/1962 Nemirovskii, A. S 4.2/1961 Neumann, F. E 4.2/1879 Newall Engineering Co 3.5/1903

3.5/1906

3.5/1937

Page 186 252

10 261 224

30

138 216

258

4

5

624

43

50

64

73

82

8390

93

103 117

121 163

172

181 189

193 198

198 207

211 212

189 203

229

229

35 271

2

17

1944

6992

106

108 117

139 149 170

193

193 193

198

198 201 202

206

212

223

269

199

26 266

6785

186

122 120

104

104

107 296

tl,
Subsection/Year Newbound, K B 2.2.4/1949 New Departure Engineering Data 10.1.3.6/1946 Newman, S. B 3.6.2/1952 Ney, W. R 3.1/1960

3.1/1961 Nezhurin, I. P 9.3/1961 9.3/1963

10.2.4/1961

Nichterlain, P 8.2/1937

Nicolau, P 1.1/1936 1.7/1937

5.2.5/1937

Xickols, L. W 1.2.2/1955

1.3.1/1962 1.3.1/1963

1.3.2/1961 1.5/1961 3.2/1956 3.3/1955

3.5/1955

5.1/1957

5.7/1951 6.4/1962 6.6/1962

9.1/1957

9.2/1960 9.3/1957 12.1/1964

12.6.1/1964 Xidey, R. A 6.1/1958

Xieberding, O 3.3/1961

5.2.5/1942 5.2.5/1957 5.2.5/1960

7.1/1961

Nielsen, R. J 4.2/1958

9.2/1958

Niepel, H 5.2.5/1946 Xigge, K. E 1.2.4/1963

Xikiforov, V. V 5.2.2/1963

Xikitin, B. D 7.3/1957

Xikitin, V. A 3.3/1965 4.4/1963

5.2.2/1963 5.2.4/1963 Xikolaev, V. I 6.1/1960

6.6/1960 Xikolaev, V. S 11.3/1959

Xishijima, Y 2.5/1963 Xishimura, G 1.6/1962

Xiu, H 2.3.3/1958 2.3.4/1958 Xoble, P. J. W 6.2/1964 Noch, R 1.3.3/1959 1.4/1959 6.1/1962

6.4/1961 7.4/1959

10.1.1/1956

10.1.4/1962

10.2.2/1961 10.2.2/1964

, n

10.2.5/1961 Xoldeke, G 2.4.3/1963 Xoltingk, B. E 5.2.1/1960

5.2.2/1955 5.2.2/1959 Nomarski, G 2.2.5/1954 Xorbury, J 5.2.2/1958 Xordon, P 1.4/1963

Norris, M. H 8.1/1930 Noskin, A. P 5.2.5/1963 Xourse, F 1.7/1945 Xourse, J. H 8.1/1965 Xovikova, I. V 2.4.2/1960

Xovitskii, P. V 1.3.3/1963

Nuttall Gear Works.. 10.1.4/1941

Page 52 222

1139393

211 212

233

194

236

141

1118

19

2133

108 130

149

167 170

201 204

211 258

269

155 100

141 142

142 179

122 204

14116 138

183

116 127

138

141 155 170 253

89

35

6265

16224

29

156 167

186 214

228

232 232 234

81 132

136 137

55

13730

190

14236

193

7626 224

O Subsection/Year Page Oakley, T. R 12.2/1955 259

Oakley, T. R. J 1.3.2/1961 21

1.5/1961 33 Obata, J 5.2.2/1931 151 Oberg, E 3.6.1/1928 109

9.2/1908 202

12.6.1/1920 268 Oberman, Y. I 12.2/1962 260

Obetz, S. W 2.4.2/1953 74 Ockenden, F. E. J 8.2/1939 194

8.2/1954 195 O'Donnell, T. J 2.1/1960 44

2.4.1/1960 71

Offner, F. F 3.6.4/1954 115 Ogawa, M 9.3/1951 210

Ogden, H 2.5/1962 89 Ohmura, H 10.1.4/1962 228 Okamoto, Y 1.2.3/1959 14 Okun', I. Y 5.2.5/1963 142 Oldenbourg, R 1.1/1932 2 1.2.1/1932 7 Oldfield, R 10.2.6/1940 237

Olson, C. G 10.1.4/1921 222

10.2.1/1953 229 Omar, M 7.1/1953 177

8.2/1952 195 Omel'chenko, A. I 8.1/1959 192

9.1/1960 202 Omer, G. C, Jr 2.3.4/1936 63 Omptimeter 3.3/1940 98

Onions, W. J 3.3/1959 100 Oppenheim, U 2.2.1/1956 46

Optical Measuring Tools Ltd 12.5/1940 267

Orshanskii, D. L 1.3.2/1962 21 Osanov, B. A 5.2.2/1960 136

Osetinskii, G. M 11.3/1959 253 Oshchepkov, P. K 5.2.2/1960 137 Oshima, K 2.1/1951 43 Osmick, H. R 6.2/1958 159

6.2/1963 161

Oster, G 2.5/1963 89

2.5/1964 90

Osterberg, H 2.4.1/1956 71 Ostrander, H 12.2/1956 259

Oswald, R 12.2/1959 260

Ota, K 2.4.2/1959 76 Otryashenkov, Y. M 6.4/1960 166 Otterman, J 5.1/1959 130

Outin, J 5.2.5/1937 141

Oxley, A. J 4.4/1960 127

Oxley, P 10.1.4/1959 227 P

Paananen, R ..2.3.7/1962 67 Packard, W. B 1.3.3/1963 26

Page, B. L 2.4.4/1925 82

4.1/1955 119

4.2/1934 121 6.4/1953 166

7.1/1925 175

12.6.2/1953 271

Paigne, J 1.7/1964 39

Paillette, M 2.3.7/1963 68

Palatnik, L. S . 11.3/1957 25

Palei, M. A 7.4/1962 186 Palmer, A. deF 1.1/1912 1 Palmer, D. A 2.5/1960 88 Pampel, H 9.1/1929 199 Pandeya, D. C 11.1/1958 245

Paoli, A. R 6.2/1956 159 Papp, G 11.1/1959 245

Papworth, Ltd 6.1/1943 154

Parker, E. R 1.7/1944 36

Parkes, D. H 2.4.1/1963 72

Parkes, R 10.2.6/1939 236

Parkhurst, D. L 6.7/1957 171 Parkinson, A. C__ 9.3/1949 210

10.1.2/1948 216 297
Subsection/Year Page Parkinson and Sons 10.2.2/1912 230

10.3/1912 238

Parks, J. R 1.3.4/1947 27 Parkson 10.2.2/1934 231

Parnet, A 5.2.2/1947 134

Parratt, L. G 1.3.3/1961 25

Parsons, R. T 9.3/1961 211

10.1.3.1/1962 219

Parsons, S. A. J 1.2.1/1960 9 Partovi, F 11.2/1962 248

Passaglia, E 11.2/1963 248

11.2/1964 249 Pastukhov, I. M 8.1/1963 192 Paton HawksJey Electronics 2.5/1960 88

Paul, M • 1.2.1/1955 8

1.2.3/1955 14 Pearce, D. C. K 5.6/1959 147

Pearse, D. J 1.4/1955 29

Pearse, W. H 5.5/1948 146

Pearson, H. A 9.3/1919 206

9.3/1920 206

Pearson, J. W 1.4/1965 31 Peck, E. R 2.1/1948 42

2.2.1/1948 46

2.2.1/1955 46

2.2.1/1957 47

2.2.4/1958 52

2.2.4/1962 53

2.3.1/1949 57

2.4.2/1953 74

2.4.2/1955 75

6.5/1949 167

Ped', E. I 12.3/1962 263

12.3/1963 264

Pefhany, J 5.2.5/1961 142 Pehland, H 11.3/1960 253

Pelander, C. E 12.2/1957 259

Pelika, A. Y 6.1/1961 156

Peliks, A. Y 12.3/1961 263

Pelphrey, H 10.1.4/1942 224

10.1.4/1947 225

Pelzer, H 1.3.3/1946 23

Pen'kov, V. V 7.4/1964 187 Penn, R. G 3.6.4/1959 116 Penndorf, R 2.2.4/1957 52

Pennie, A. M 11,3/1952 251 Pennington, E. W 1.3.2/1944 20

4.4/1940 125

7.1/1958 178

7.4/1958 185 Pennington, W. A 3.1/1964 94

Penselin, S 2.4.3/1955 79 Pepper, P. M 4.2/1961 122

Perard, A 1.2.2/1956 11 1.4/1927 28

1.4/1928 28

2.2.2/1920 49

2.2.2/1922 49

2.2.2/1947 49

2.3.2/1934 60

2.3.3/1932 61 2.3.4/1950 64

2.4.1/1912 69

2.4.1/1920 69

2.4.1/1922 69

2.4.1/1930 70

2.4.1/1934 70

2.4.1/1944 70

2.4.2/1932 73

2.4.4/1921 82

3.1/1912 91 3.1/1927 92

3.2/1913 94

4.1/1923 117

4.1/1939 118

4.1/1941 118

4.1/1944 118

4.1/1952 118

Subsection/Year Page P6rard, A.—Continued

4.2/1917 121 5.4/1923 143

Peres, N. J. C 9.3/1950 210 ! 10.1.4/1954 226

10.1.4/1959 227

10.2.4/1950 233

Perevertaev, V. D 11.2/1963 249

Perfect, D. S 5.2.3/1944 139

6.7/1928 171 7.2/1948 180

Perkins, F. C 5.2.3/1918 138

Pernet, J 3.2/1900 94

Pernet, M. J 4.1/1884 117

Pernetta, C 5.3/1957 143

Perot, A 2.1/1897 41 2.1/1899 41

2.2.5/1906 54

2.3.1/1900 56

3.2.1/1913 56

2.3.2/1907 59

2.4.1/1899 68

2.4.3/1899 78

2.4.3/1901 78

2.4.4/1898 81

2.4.5/1899 84

Perrier, A 6.1/1936 153

Perrigo, O. E 3.5/1908 104

Perrin, E 6.2/1947 157

Perrot, M 2.2.5/1945 54

11.3/1957 252

Peters, C. G 2.2.2/1922 49

2.2.4/1918 52

2.4.1/1920 69

2.4.1/1922 69

2.4.1/1950 70

2.4.2/1919 73

2.4.3/1922 78

2.4.4/1925 82

2.4.6/1924 86

7.1/1920 175

7.1/1925 175

Peters, J 2.4.2/1953 74

10.1.3.1/1937 218

10.1.3.1/1951 218

12.2/1963 261

Peters, O 12.2/1951 259

Petavel, J 4.1/1960 119

Pettavel, J 4.4/1960 126

4.4/1964 128

Pettitt, C 9.3/1923 207'

Pfleiderer, N 5.2.3/1924 138

Phelps, F. M. Ill 12.6.1/1965 270"

Philbert, M 7.1/1958 179 1 Phillips, H. W. L 1.7/1953 37 ' Philpot, A. J 5.2.1/1948 131'' Physical Society of London 1.1/1919 1 Picca, R 2.4.3/1946 78

Piccord, A 1.2.2/1947 11 Picht, J 8.1/1953 191 8.1/1954 191

Pick, U 12.6.2/1965 271

Pierce, R. G 12.5/1962 268

Pierre, E 5.2.2/1953 136

Pietzsch, H 2.2.2/1928 49 ' Piggott, M. R 2.5/1965 90

Pippard, A. B 1.7/1953 37

Pisharoty, P. R 1.5/1940 32

Pitter Gage & Precision Tool Co., Ltd 3.2/1923 95

3.2/1944 95

3.5/1944 107 3.6.1/1944 110

Plagnol 1.7/1945 36

Plainevaux, J. E 4.4/1954 126

5.7/1953 149

5.7/1956 149

Planer, G. V 6.7/1962 171

Player, S 12.5/1930 266 ' 298
Subsection/Year H 3.5/1959

Plessner 11.1/1946 U Pliskin, W. A 11.1/1964

Plourde, A. J 1.3.1/1963

)fi Plumb, R. C 11.2/1963

271 Plyler, E. K 2.3.1/1952

33 ;{ Pocklington, H. C 2.2.1/1902 a Podlazov, S. S 12.3/1961 . Poett, H. H 6.2/1956 • Pohl, R. W 2.2.1/1960

Polacek, M 12.2/1963 ; Polidor, E. C 8.2/1947

8.2/1951 8.2/1962

(j Polk, L 1.3.2/1960 . Polkova, A. Z 3.1/1960

jj PoUard, A. F. C 5.1/1922

5.1/1928

5.2.3/1938 5.6/1934 . Pollok, J 2.5/1965 ; , Polster, H. D 11.3/1949

•; Ponce, A 2.5/1961

fj Poole, S. P 2.4.1/1960

2.4.4/1960 3.3/1962

.5.1/1962 -.-2.5/1959

.2.3.3/1963

-1.2.3/1961 12.6.3/1943

.1.2.2/1961

Popp, H. P...

Poppa, H

Popov, G. S... Popov, M. I. Poritsky, H-.

Pose, R 3 Post, D 2.2.1/1958

53 i Potter, J. A 6.1/1930

10.3/1931 • Powell, E. F 3.4/1954

Powell, R. W

Powers, R. A

Pratt & Whitney Co.

1.7/1957 12.3/1937

1.2.3/1963 3.1/1886

3.3/1922

3.3/1932 3.4/1944

3.5/1927 6.4/1958 6.7/1923

10.2.6/1922 12.5/1922

jj Precision Grinding, Ltd 1.2.3/1955

Preger, E 1.5/1927

'• Prescott, J 1.5/1924

..Presto Machine Works 6.6/1918 - Preston, J. S 2.1/1951 \ Pribylev, A. A 7.1/1965

Priest, I. G 2.4.2/1920

.] Primak, W 2.2.1/1958 : Proschan, F 1.3.3/1953 ; :Pruliere, A. C 1.1/1947 9.1/1948 • Pucalka, V 11.3/1959

Pulfrich, C 2.2.1/1898

2.2.2/1898 2.4.4/1898 4.4/1907 Purman, H. V 3.6.4/1912 I Purvis, R. D 3.6.1/1963 5.6/1963 Pusep, H 12.6.5/1919 ;Pusep, H. F 3.6.2/1918 Putschbach, R 1.2.3/1951 Puttock, M. J 2.2.2/1962 2.4.1/1953

2.4.1/1965

2.4.5/1950 3.4/1948 7.1/1950 7.4/1948 | Pyle, L 3.6.2/1919

241 247

19 249

57

44 263

15947

261

195

195

129

12'.) 13S

146

7183

100

1318863

14 272

1447 153 239

10238 262

15

919798

101 105

166 170 235

266

143232

16943

18873

47232 200

252

4448

81 124

115 110

148 274

111

1450

70

7284

102

177 185

111 Q Subsection/Year Page Quentin, J 5.2.2/1960 137 Quincke, G 6.4/1873 164

11.1/1866 241 R

Rabhin, A. L 12.2/1961 260

Rabinovich, V. I 1.1/1963 6 Rabinowitz, P 2.3.7/1963 67

2.4.3/1962 81 Radford, G. S 1.3.1/1921 17 Raentsch, K 1.2.1/1963 10

3.5/1947 107

6.1/1952 154 Rahn, R. J 7.1/1953 177 7.1/1954 178

7.1/1959 179

7.1/1960 179

12.5/1959 268 Ramsauer, C 1.1/1936 2 Ramsay, B. P 2.2.1/1934 45

2.2.1/1941 45 Ramsay, J. V 2.4.3/1962 81

5.2.1/1962 132

Randall, K. C 1.7/1953 37

Rang, O 2.5/1959 88 Rank, D. H 2.2.4/1954 52

2.2.4/1958 52

2.3.1/1957 58

6.1/1946 154

8.1/1946 190 Rankin, B 6.1/1954 154 Rankin, R. L 3.1/1919 92

3.6.1/1919 109

4.4/1919 124

7.1/1919 175

8.1/1919 189 Rank Taylor Hobson 7.4/1963 187 Ranney, C. R 12.6.4/1929 274

Rannie, J. L 6.4/1930 165

Ransford, G.-D 1.3.3/1951 23 Rantsch, K 1.2.1/1963 10 3.3/1959 100

3.5/1947 107

3.5/1959 108

4.2/1960 122

5.4/1941 144

5.4/1949 144

5.4/1959 145 Rao, I. R 6.1/1947 154 Rao, K. N 2.4.3/1963 81 Rao, K. V. K 11.3/1960 253

Rao, P. S 11.3/1957 252

Rao, S. V. S 6.1/1947 154 Rao, V. V. L 1.2.2/1955 11 Rasmussen, E. K 7.1/1945 176 Rasmussen, R. E. H 7.3/1953 182 Rassow, J 11.2/1962 248 Rassudova, G. N 2.5/1961 88

2.5/1963 89

Ratoosh, P 1.1/1959 4 Rausch, R. H 6.6/1924 169

10.1.4/1922 223

Rawling, R. E 10.1.3.4/1952 220

Rayleigh, Lord 2.3.1/1906 56

2.3.5/1908 65

2.4.3/1906 78

3.1/1936 92

7.1/1893 175 Razuvaev, A. N 9.1/1963 202

Reading, O. S 1.2.4/1953 15 3.2/1953 96 Reason, R. E 1.7/1945 36

1.7/1951 37

7.4/1959 186 Redepenning, W 5.2.2/1943 134 Reeb, O 1.2.2/1954 11 1.2.2/1955 11 Reed Small Tool Works 3.6.2/1922 112

Regel, V. R 5.4/1959 145 299
Subsection lYear

11 3 / 1 Q48 250

T?^i"/-1 M TP 8 1/1 QK4- 1 93

xveiiiyy, T? oil loir Pvjt. P 1U. 10 1 . 4/1Q9"i i . 1 <3£tiJ in 9 t ; / 1 < 1 1 l 237

xteinai, J Qy.o/iyiy "i /I Q1 Q 206 Q A 

1 Q 1 Q

212 K 9 9/1Q^1 133

D.L.Lj K 9 9/1Q^lft iyoo 1 ?>'> t> l n a ft ft/1 Q1 ft 169 Renaudin 1 n 9 A/1U^R

Renault, IVI OJl ^.^t.i/iyo.5 /1Qft9 72 S 9 tcj 1 OftQ

I> ari ~1 J AIT 19^/1 Qft^ y"

RevesZj A. G 1 1 2/1Q04 249 1 *i /I QftO 25

ft 1 / 1 QftH Q ft 1 /I OflA L08 PlnUnUo T P Q o.^.t;/ H 9 4/1iyoy Q^Q 140

o. 7* / 1 a so / iyoy

ft 8/1Q4R 1 72

fi 8/1Q47 172 Q ^{/1 Q1 S 206 Q S/1Q98 207 Qy.o//liyzy Q9Q 207

19 ft 4/1 Q1 K 273 9 4 A/iaw 1 "i ^li Qfin

T? ir>Vi a rrlarm TT AT 9 9 S 1 1 Q SQ 5 5 9A.tx.oi 4 ^ / 1 Q SQ iyoy 80

T>Krcnarclson, • i j JT . HIM _ 9•"•i/1/1 OAA lyou 44

"RipViorHann CI P 1.1/1961

I) + or- C\ 19 ft S/1 OAO i i 

» Q 1 / 1 QQ 

y.o/ iyoi 20S

-Q • i n ^ SO 1 /IQfiO 1 32

T?i'/-1o-q W P Q a/1 OA9 l(t(i Riekher, R 11.1/1958 245

Rienitz J 9 9L . 1y /1QS1 / iyoi 9 9 1 /1 Qft1 4048 Rieth ftU.I7/1 887 / loo 1 1 70

^iftUy, o ^ 9 9/1 QftO 137 Rigden J D 9 4. "}/1 QftQ 81

T?itrrii A 1/1 OQ7

Rights, H. T 9 2/1944 204

rugrou, w . w — 9 O 7/1 ofiO l.o.i i iyoz 07 9^7/1 z.o. Qft*2 / / iyoo 67 Rimrott U 7 4/1 Qftfl Rin/r W A Ifl 1 All Q/1 O 22.) Ritphio T 9 4 9/1 QS7 75

Ritter, H. J. 4 4/1 Qft/1 i 2K

Ritter, R

lilvclo, *J . 1 1

in i 9/1 asn

""i 4/1 OQC 0.4/ iyoo 1 44

19 9/1 QA"7 L&.ttj 1 J i i 259 Rivot P. M 1 1 /lOftQ

i.o. 1 Q 1 /I OAQ 1/ iyoo 19

T)r>KKiii TVT A e o Q / 1 flQ9 1 38 Robbrecht G. G 9 4 *i /1 Qft9 L.'k.oi iyo<s 81

T?ohprt« TT C R 9 9/1 ClA A 134 c o O/IAilR o.i.Li iy40 1 34 t, , , TT T\T 11 Q /I OA9 254 Robida L 30 Robinson, F. J 12 3/1964 204 Robinson, I. R 1 7/1953 37 Robinson, S L 3 4/1953 102 Robinson, T R 6 4/1835 104 Robson, R. S 3 6 4/1959 1 10 Rock, N. H 2 4 5/1964 SO

Rockefeller, J. W. Jr S 7/1Q"?fi 1 48

5.7/1951 1 41) Rockwell, H 6 2/1948 158 Rodgers, J. M 11 3/1962 254

Roehler, R 5 1/1962 131

Roesler, F. L 7 3/1962 184

Rogers, G. L 2 5/1959 88

Rogers, M.D _ 4.4/1962 127

8.1/1963 193

Subsection/Year Page Rogers, W. A 1.2.2/1879 49

3.1/1886 91

4.2/1893 121

12.6.3/1885 271

Rohlin, J 6.5/1963 168. Rohmann, H 5.2.2/1920 133

Roig, J 2.2.1/1938 45

2.4.3/1953 79

5.2.2/1953 136 Rokhman, D. E 3.4/1960 103

Rolt, F. H 1.2.1/1929 6

1.2.1/1937 7 1.2.1/1952 8

2.1/1957 43

2.2.5/1929 54

2.4.1/1955 70

2.4.4/1926 82

3.1/1927 92

3.1/1938 92

3.2/1959 96

5.1/1929 129

6.4/1937 166

9.1/1938 200

9.2/1938 203

9.2/1951 204

10.2.5/1937 234

12.6.3/1955 273 Romanova, M. F 2.1/1957 43 1 i! 2.3.2/1942 60

2.3.2/1957 61 Romerskirch, W 10.1.4/1961 228

10.2.1/1959 230 Ronan, H. R 10.2.5/1962 234

Ronchi, V 2.2.1/1964 48

2.5/1958 88 • Root, E., Ill 2.4.2/1952 276

Rose, J. B 12.5/1922 266

Rosenberg, H 3.6.2/1902 110 !l Sl Rosenfeld, G. H 1.2.3/1963 15 H

Hi Rosenhauer, K 8.1/1956 192 ;a 8.1/1957 192 > v Rosenhead, L 10.1.3/1962 217 \i k Ross, G. S . 1.4/1960 30 1 I Ross, I. M 5.2.2/1956 136 ] l Ross, R. J 10.2.5/1958 234

Rosson, J. W 6.1/1962 156 Rostovykh, A. Y 5.2.5/1963 143 s f Rotax, Ltd 12.6.1/1963 269

Rothen, A 11.2/1945 247 ! fa 11.2/1948 248

11.2/1957 248

Rothrock, B. D 2.2.1/1963 48

11.2/1963 248

Rotzoll, E ..12.2/1939 259 Rouard, P 11.3/1965 255

Rowell, H. S 8.1/1924 189

Rowell, W. S 6.8/1930 172

9.1/1918 198

9.3/1918 206

9.3/1932 208 Rowland 12.6.2/1928 270 Rowland, H. A 12.6.2/1882 275

12.6.3/1911 272 ! Rowley, W. R. C 2.3.7/1963 68

Rozenberg, E. I 1.2.1/1961 9 3.2/1962 96

7.4/1964 187

Rubin, L. G 1.4/1964 30 Rubinov, A. D 7.4/1959 186

Riicker 4.2/1882 120 Rudberg, F 4.2/1837 120 k

Ruffino, G 2.4.2/1957 75

2.4.2/1960 76 Rugg, K. E ..5.2.5/1958 142 ! j % Ruggaber, W 1.3.2/1948 20 i * Ruble, H 1.3.4/1938 27 j Rumiantsev, A. V 6.8/1959 173 I 300
Subsection/Yea Rummert, H 4.3/1958 Rumyantsev, A. P 11.3/1959 Rumyantsev, A. V 12.6.1/1961 Runge, I 3.3/1928

Russel, W. 0 12.6.4/1924

Russell, A. M 1.3.3/1956

Russell, H. N 2.1/1921

Russell, H. W 1.1/1961 Ryaskov, V. L 7.4/1960 Rybak, E. N 11.1/1963 Ryder, E. A 1.4/1953

Ryffel, H. H 10.3/1960 Rynders, G. F 11.1/1948 S

Saari, 0 10.3/1956

12.4/1954

Sachs, H. K 1.6/1964

Sachs, S 1.4/1963 Sadowski, A 12.2/1964 SaegmuUer, G. N 6.7/1922 Safonov, L. N 6.1/1962 Sagaspe, P 1.3.3/1937 Saha, M. N 2.3.1/1917

Saker, E. W 5.2.2/1956 Saksena, G. D 2.2.4/1958

Sakurai, T 7.1/1949

Sakurai, Y 2.4.2/1958

2.4.2/1959 2.4.5/1963

2.4.6/1960

2.4.6/1961 4.1/1961

5.2.2/1951 Samal, E 5.7/1959 Samuels, L. E 1.7/1959

1.7/1961 Sanborn, G. H 10.2.2/1945 Sanders, J. V 1.7/1959

Sanford, A. C 7.4/1952

Sanford, B. P 11.1/1958

Santer, L 3.4/1948

Sappet, C. L 1.1/1963

Sasaki, N 1.4/1952 Satserdotov, P. A 1.4/1964

Satterthwaite, I. H. R 2.4.2/1963

Sauer, R. L 11.1/1958 Saunders, J. B 1.2.4/1963 2.1/1957

2.1/1963

2.2.1/1957

2.2.2/1960

2.4.2/1939

2.4.2/1944 2.4.2/1945

2.4.4/1960

2.4.5/1960 6.1/1961

6.2/1961 6.2/1963

7.1/1951 7.1/1954

7.1/1959

7.1/1964 7.2/1958

7.3/1951 7.3/1961 7.3/1962 Saurer 10.3/1921 10.3/1922 Savenkova, M. V 11.3/1959 Sawabe, M 9.1/1961 Sawin, N. N 1.7/1937 3.2/1944

3.2/1947

Page 123 253

269

97 27424

414 186 24628

239

241

239 266

35

30

261 170

15622

56

136

52

177

7576

86

8687

119 135

150

23138

185 245

102528

3177 245

76

4344

4750

74

747483

85

156

160

162 177

177

179 180

180, 181 182 183

184 238

238 253

2013695

95

Subsection/Year Page i,L.A 12.6.2/1955 271

Saylor, C. P 3.3/1965 116

Schaffer, R. R 8.1/1963 193 Schawlow, A. L 2.4.5/1963 86

Scheidegger, R 11.3/1962 254

Schendell, G__ 4.4/1950 126

Schepler, H. C 8.1/1944 190 Schermer, E. B 11.1/1963 246

Scherr, G 3.5/1928 106

Geo. Scherr Co 3.4/1932 101

10.1.4/1932 223

Schiebel, A 10.1.2/1930 215

Schilling, F 2.4.5/1957 84

Schimz, K 1.3.4/1930 27

Schleicher, W. F 12.5/1948 267

Schlesinger, F 9.2/1917 202

Schlesinger, G 1.7/1951 37

5.2.3/1939 139 12.2/1942 259

Schlueter, D. J 2.2.4/1958 52

Schlink, F. J 1.1/1924 1 1.3.2/1918 19 5.2.3/1919 138

Schlippe, O 12.2/1935 259

Schloss, F 1.6/1961 34

Schmerwitz, G 1.7/1933 36

Schmidt, H 1.3.1/1942 17

1.3.2/1943 20

1.3.3/1942 22

3.2/1928 95

3.2/1942 95

3.2/1958 96

3.3/1928 97

8.1/1928 189 Schmidt, H. W 3.2/1956 96

Schmidt, K_._ 6.1/1953 154

Schmidt, W 1.7/1957 38

Schneider, A. W 12.2/1935 259

Schneider, D. B 1.3.1/1963 19

I. 3.4/1962 27

Schneider, E. J 7.4/1958 185-6

Schoeffler, F 1.4/1943 28

Schoen, A. L 11.3/1951 251 Schoenbacher, K 5.2.2/1939 133

Scholetzer 5.7/1937 148

Schonrock, O 1.5/1929 32

7.1/1905 187

7.1/1939 176

Schopper, H 11.1/1951 242

II. 1/1956 243

11.3/1951 250

Schorsch, H 3.4/1940 101 3.5/1959 108

9.1/1935 200

Schott, G. H 1.5/1896 31

Schreiber, O 6.4/1886 164

Schroder, R. P 1.3.2/1922 19

3.1/1922 92

3.2/1939 95

3.6.2/1920 111 Schulthess, E 10.1.4/1958 227

Schultz, H 6.2/1956 159

Schultz, T 2.4.3/1962 81 Schulz, G 2.2.1/1954 46

2.2.3/1954 50

2.4.1/1956 71 11.1/1956 243

Schulz, H 1.3.4/1920 26

2.2.1/1922 45

5.1/1929 129

6.2/1956 159

8.1/1952 191

Schulz, L. G 2.2.5/1951 54

2.4.3/1950 79

11.1/1950 242

11.1/1951 242

Schulze, B 3.3/1931 98

Schulze, M. T 2.4.2/1936 73 301
Subsection/Year Page Schulze R 3 5/1951 107 A 9 /I QftQ 161 Dcnumacner, a. w __

11 9/1 OAO ii.o/iyoz 254

Schuster, A. 2 2 1/1924 45 bcnwartz, J ^ 9 9/1 QAA 135

bcnweitzer, w . <j 66 O Q fl/1 G£Q

11 3/1960 253

Scoles C A 7 4/1960 1 86

*7 /i /i nfii /.4/iyoo 187 ino k/1 ncc 2.' > i Scott, D - - 179

bCOtt, d. LJ 11.1/1958 Scott L W 6 2/1947 157

(J„„(t P A 1 1 1 /1 QAA 241

Searle G F C 8 1/1911 189

Sears J E Jr 1 2 1/1924 6

1.3.2/1926 20

2.3.1/1932 57

2.3.2/1933 ('»(» 2.3.2/1934 60

2.3.2/1935 60

2.4.1/1923 69 2 4 1/1927 69

/I /I /I fl/1 1 1 25 1 9 A A /l 01 7 273

Sedoric J 6 2/1955 1 5S

oegeietz, xt. 7.1/1956 178 r o /1 one o. 3/ 1908 162

Seliger, W 12 2/1964 262 Sen D 2 4 1/1959 71

2.4.2/1959 76

2.4.3/1961 80

2.4.4/1960 S3

2.4.4/1961 83

2.4.5/1959 S5

6.5/1959 1 6S

6.5/1961 168 7.3/1961 184

11.1/1960 246

oen, r .... 11.3/1957 252 _ .. .9.1/1963 202

Series, G. W 2 3 5/1960 65

Server F 3 6 2/1917 1 ! 1 Severn, G. M__ . . _ .3.4/1959 102 3.4/1960 1 03 Sewig, Jti _ 

4.1/1936 l 1 s Shaevich A B 1 3 1/1963 19 coo/1 C\A A 134

ftl-iarr^-ira TP. TP. A 9 / 1 QA 

1 63 Sharp, C. H 11.3/1900 249 Sharp G H 1 2 1/1956 g

Sharp, K. W. B 8.1/1954 L91 Shaw F W 7 4/1932 1 85 207

10.1.3.1/1930 217

10.1.4/1931 223

10.2.6/1930 236

10.2.6/1931 '2,','Ai 10.2.6/1935 236

in 9 A/1 QQQ 237

10.2.6/1940 237 Shaw H 1 85

7.4/1932 1 X5 Shaw, M . . 12.6.2/1949 271 Shaw, P. E 3 1/1911 91

3.5/1903 1 04 3.5/1905 1 04

3.5/1906 104

3.5/ 1

'.) 1 2 104

3.5/1913 104

3.6.2/1 '.HI-! 110 5.2.2/1900 132

7.1/1912 175 9.1/1919 198 Shchipacheva, N. M 3.2/1964 97 Shchukin, L. D . 3.6.3/1962 114

Subsection/Year Page Shearer J N 2 2 4/1954 52

2.3.1/1957 58 The Sheffield Corp 1 2 3/1964 15 9 9/1918 203 Sheldon E 3 6 2/1921 112

10.2.6/1923 235

12.6.1/1923 268

Shelley C P B Q K/1 C77 103 Shenbrot I M 1 3 3/1964 26

Shenfield S 6 1/1961 156 Shepard C D 4 3/1932 123 Shepherd A T 2 5/1963 89

12.3/1961 263

Sherrill H H 19I_.u.A 1 /1QRQ 1/ lifUO 269 Shevchuk S A 12 2/1962 260 Shewhart W A 1 3 1/1926 17 5 2 2/1958 137

Shield, A. H 6 6/1915 169

Shield, R T

Shilova E A 1 5/1951 33 9 2/1963 205 2 4 6/1962 87

2.4.6/1964 87

Shipilevskii B A 7 4/1963 187

Shishido K 7 1/1949 177

Shishkov, V. A 12 1/1960 258

Shkly*irpvskii I N 2 2 5/1956 55

11.1/1958 244 Shlyandin V M 5 1/1962 131 3 5/1965 151 Shokhtin A P 6 7/1963 171 Shor G I 11 3/1963 254

Shost'in N A 1 1/1963 5 Shtein V G 5 2 1/1960 132 6 4/1793 164

Shultz T 2 4 3/1962 81 Shvets A D 5.7/1961 150 Shvets V F 11 1/1963 246

Siadbei G 6 7/1932 171

Sir>Viirr>lln A TP, 1 4/1958 29

Sidders P A 3.6.3/1962 114

12.3/1961 263

Sidjak N 11.1/1951 242

Sieker, K. H 5 2 4/1932 140 Sigma Instrument Co 3 3/1943 99

3.3/1946 99

3.3/1950 99

6.1/1943 154

12.3/1949 262

Sillitto, G. P 1 3 3/1948 23 9 3/1958 211

10.1.4/1952 226

10.2.1/1949 229

10.2.4/1949 233

lo!2!4/1955 233

10.3/1952 239 Sim P J 3.1/1959 93 2 2 1/1924 45 SimHn Ci S 1.3.3/1959 25

1.3.3/1960 25

1.3.3/1962 25 2A5/1962 85

7^3/1959 183

10.2.1/1961 230 Simmons A T F 6 5/1920 167 Simnarl M T 1.7/1953 37 2 4.1/1928 69

3.3/1929 97

4.1/1928 117 Simonenko, G. L .. . . 7^2/1962 181 6.5/1950 167

9.2/1959 204

9.3/1958 211

rt- j 9 2/1942 203

Siprikov, I. V 5.2.2/1960 137

Sittner W R 2 3 1/1949 57

6.5/1949 167 Skidan, V. V 2A4/1961 83

Skinner, N. P 6.6/1946 169 302
Subsection/Ye Skvortsov, B. N 5.2.2/1960

Slater, P. N

T ... . . ..3.3/1957

4.4 1V.7

Slatis, H 4.4/1958

Slevogt, H_ . .2.2.1/1954 Slocomb, J. T 3.6.2/1901 3.6.2/1915

Sluis, K. L. V ... . 2.3.2/1956

2.4.3/1956 Smirnov, V. V 1.2.3/1961 Smirnova, E. P ._ 3.2/1962

5.2.4/1963 Smirnova, L. I . 6.3/1961 Smith, B__ ..12.6.3/1963 Smith, C. F 2.3.1/1926

2.4.1/1933 3.5/1927 7.2/1932

8.2/1926

8.2/1931 9.1/1935 Smith, D. S 2.3.1/1963

2.3.3/1958

2.3.3/1959

2.3.3/1962

2.3.4/1957 2.3.4/1959

2.4.1/1933

2.4.2/1959 2.4.2/1960 Smith, F. C. 12.4/1927 Smith, W 2.4.2/1954 Smith, W. M 6.2/1963

Smits, F. M _ 11.1/1956 Smohichowski. R 1.7/1944

Sociit6Genevoi.se d' Instruments de Physique. 1.2.3/1928

1.2.3/1930

1.2.3/1963 3.2/1914

3.3/1923 3.3/1930

3.3/1931 3.4/1927 3.5/1914

3.5/1920

3.5/1939

4.1/1950 4.4/1924

4.4/1926 4.4/1928

4.4/1931

5.2.3/1930 6.4/1930

6.7/1924

8.2/1949

8.2/1962

9.2/1927 9.3/1938

10.1.4/1924 10.1.4/1928

10.2.6/1933 Soderberg, E. F 6.1/1961 Sodha, M. S ._ ... ...2.2.1/1958

2.4.3/1953

Soffel, A. R 1.3.3/1959 Sokolov, S. S 1.1/1963

Sokolov, S. Y 5.4/1953

Sokolsky, H 12.1/1962

Sola, M. C__. 3.1/1964

Solov'ev, A. I 1.2.1/1963

Somervaille, L. J 5.2.1/1954 Sommer, A _______ 9.1/1929 Sommer, P. L., Jr 12.5/1947

Sona, A__ 2.4.5/1964

Sorber, G. E 1.3.2/1960

Sosnovskii, V. I _ _ _ 6.2/1964

Souder, W 3.6.2/1952 8.1/1920

Page 13799

126

126

46 110

11160

80

1496

141 163 273

5670

106 180

194

194 200

5962

626364

6570

76

265

75

161 244

36

1313

1595

97

101 104

105

107

118 124

125

125 125

138

165 170

195

196 203 208

223

223 236

156

4779

25

5 145 258

94

9 132

199 267

8621 162

113

189

Subsection/Year Souers, R. C 3.6.4/1954

Souler, R. A 12.3/1957

Soulet, M 2.4.3/1958 Spaeth, W 1.1/1949 Spannuth, J 6.4/1913 Sparkes, C. A 12.3/1962

Sparks, C. J 11.3/1961

Spear, P 1.7/1953 Spear, W. E 5.2.4/1963 Speen, G. B 5.5/1964 Spence, J 10.1.4/1964 Spencer, H. K 12.4/1911 Spencer, J 1.3.2/1961 5.3/1961 Spencer-Smith, J. L 1.3.3/1937 Sperry Gyroscope Co 12.3/1962

Spierlingi W. F 12.6.3/1956

Spies, R 12.3/1938 Spikowski, R. J 7.4/1964

Spitzer, W. G 11.1/1961

Spotts, M. F 10.1.3.1/1962

Spring, K. H 1.3.3/1950

Squire, A. M 6.7/1962

Stabe, H 5.7/1939

Stabel, J. M 9.3/1904

Stacey, D. S 6.1/1958 Stadthagen, H 1.3.1/1911 Stamper, W. R 12.6.2/1910 Stang, A. H 3.5/1935

Stanley, F. A 3.6.1/1907 4.4/1907 4.4/1908

12.6.1/1923 12.6.2/1924

Stanley, R. W 2.4.3/1964

Stanley Rule & Level Plant 3.6.1/1932

Stanley, V. W 1.2.1/1956 2.5/1961 3.5/1960

4.1/1951

12.6.3/1955 Stanton, T. E 10.3/1920

Stark, R. M 2.4.6/1957

Starling, S. G 6.7/1922

L. S. Starrett Co 3.6.2/1928

3.6.2/1931 3.6.2/1932 6.7/1930

Statz, H 2.3.7/1962

Stead, C 4.4/1963

12.5/1963

Stearn, J. L 1.3.3/1960

Stecher, M 2.5/1964 Stedman, G. E 12.5/1946

Steel, W. H 2.2.1/1962

Steele, H. B 9.2/1917

Stegner, C. B 5.7/1962

Steinberg, H. L 11.2/1963

Steiner, K 4.4/1962

Steinle, A 3.4/1923

4.4/1926

10.1.4/1924

Steiskal, F 5.2.2/1950

Stejskal, F 5.2.2/1950 Stepanek, K 10.1.4/1963 Stephens, R. B 2.3.7/1964 Stephens, R. W. B 1.7/1957

Stern, B. J 11.1/1963

Steudel, A 2.4.3/1955

2.4.3/1957

2.4.3/1963 Stevens, F. L 1.2.1/1943 Stewart, B 4.2/1882 Stewart, J. J 9.3/1912

Stiehler, R. D 1.3.3/1954

Page 115 262

80

2 L65 25337

141 146 22S

265

21

L4322 263

273

262

1 87 246

2 IS23

171 L48 205

155

17

27(i 106

L09

124

124 26*

27n

81

L09

IDS

1 IS 273 238

86

17(1 112

112 112

17167

12s

2 (is 25

90 267

4S 202

150 248

127

101 125 223

135 135 22S68

38 240

7980

81

7 120 206

24 303
SubsectionI Year Page Stale, U 1.1/1957 39

1.1/1959 14

1.2.2/1955 11

I. 2.2/1959 12

Stiller, B 4.4/1956 126 Stimson, G. H 9.1/1958 201

Stimson, H. F 1.4/1962 30

Stocker, W. M 9.2/1958 204

Stolar, G 5.7/1962 150

Stolow, N 5.2.5/1955 142

II. 3/1956 252

Stone, N. W. B 1.1/1957 4

Stone, W 12.6.2/1937 270

Storey, C 1.5/1960 33

Storey, J. E 3.5/1905 104

3.5/1906 104

Strakun, G. I 6.3/1961 163

Strang, A. G 1.7/1957 38

6.3/1953 163

Stratton, S. W 4.3/1916 122

Street, C. C 3.4/1941 101

Stribeck, R 1.5/1901 31

1.5/1907 31

Stroh, H 6.8/1925 172

Stroke, G. W 2.2.1/1957 47

2.4.2/1953 74

2.4.2/1955 75

2.4.2/1957 75

2.4.2/1958 75

6.2/1961 160-1

6.5/1961 168

12.6.2/1955 271

12.6.2/1957 271

12.6.2/1961 271

12.6.2/1963 271

12.6.2/1964 271 Stromberg, R. R 11.2/1963 248

11.2/1964 249

Struve, W 6.4/1838 164

Stryker, J. D 3.6.4/1907 114

Stuebler, E 12.6.3/1909 272

Stukin, E. D 11.3/1963 254

Stulla-Goetz, J 1.2.2/1961 12 2.4.1/1932 70 Stumpp, E 7.4/1941 185

Sturgis, N 12.6.2/1957 271

12.6.2/1959 271

Sturkey, L 2.2.1/1941 45

2.4.3/1940 78

Sugg, R. E 6.5/1957 168 Suhner, F 11.2/1944 274

Sukigara, S 9.1/1961 201

Sulander, M. C 12.6.3/1956 273

Sully, J. R 5.4/1960 145

Sutherland, K. H 12.5/1962 268

Suverkrop, E. A 12.6.4/1917 273

Suvorov, A. I 3.6.2/1962 113 Svensson, K. F 2.2.4/1960 53 Swain, E 1.7/1945 36

Sweet, J. E 3.5/1906 104

6.3/1908 162 Sweetman, L. R 3.5/1935 106

Swift, E. A 6.8/1926 172

Swindells, J. F 1.4/1965 31 Sykes 10.2.6/1921 235

10.2.6/1930 236

Sykes, A. O 1.6/1960 34 T

Tabor, D 1.7/1953 37

Taft-Peirce Mfg. Co 12.4/1937 265

12.6.5/1937 275

Tagg, G. F 5.5/1951 146

Taits, B. A 10.1.4/1960 227

12.3/1960 262

Takahashi, S 2.4.2/1959 76 Takeo, M 2.3.1/1957 58

Subsection/Year Page Tako, T 2.3.2/1960 61

2.3.3/1958 62

2.3.4/1958 65

2.3.4/1960 65 Tanaka; S 11.3/1933 249

Tandler, W. S 10.1.4/1954 226 Tanenbaum, M 11.1/1961 246 Tangerman, E. J 3.4/1949 102 Tanner, H. D 12.1/1928 257

Tarasov, K. I 2.4.3/1956 79 Tarczy-Hornoch, A 6.7/1964 171

Taylerson, C. O 1.2.3/1962 15

1.3.2/1954 20

3.4/1953 102

6.1/1961 155

6.1/1964 156

6.3/1947 163

6.3/1948 163

6.4/1937 166

10.2.5/1937 234

Taylor Devices 12.5/1963 268

Taylor, E. W 6.4/1943 166

Taylor, H. E 10.2.6/1913 235

Taylor, J. B 8.2/1916 193

Taylor, J. E 6.2/1963 161 Taylor, M. H 5.4/1941 144

Taylor, M. J 2.3.7/1963 68

Taylor, Taylor and Hobson 4.4/1942 125

7.4/1952 185

8.2/1942 194

8.2/1954 195

Taylor, W. G. A 2.1/1957 44

2.2.1/1957 47

Taylor, W. T 9.3/1943 209

10.2.4/1945 233

Teasdale-Buckell, P 2.2.5/1951 54

Tebble, R. S 11.3/1962 254

Templin, R. L 3.5/1921 105

3.5/1928 106 Tennant, R. M 7.3/1953 182

Terpstra, J 2.4.2/1955 75

Teplova, Y. A 11.3/1959 253

Terrana, E 6.1/1952 154

Terrien, J 1.1/1963 5

1.1/1965 5

I.2.2/1962 12

2.2.1/1941 45

2.2.1/1958 47

2.2.3/1959 50

2.2.4/1965 53

2.2.5/1954 55

2.3.3/1957 62

2.3.3/1958 62

2.3.3/1959 62

2.3.3/1960 62

2.3.4/1950 64

2.3.4/1957 65

2.3.4/1958 65

2.3.5/1960 65

2.4.1/1956 71

2.4.2/1959 76

2.4.4/1952 82

2.4.5/1954 84

2.4.6/1954 86

6.2/1948 158

7.3/1948 182

Tesa, Ltd 3.4/1953 102

3.6.2/1952 113

3.6.3/1951 114 J Tetens, O 6.4/1914 165

Theocaris, P. S 2.5/1962 89

II. 1/1963 246

Theroux, P 11.2/1963 249 Theime, B 3.6.2/1912 111 1 Thiesen, M _ 4.2/1879 120 Thomander, V. S 5.7/1959 150 Thomas, A. E 3.4/1948 102 Thomas, D. E_. 7.1/1915 175 304
Subsection/Year Thomas, H. A 2.4.2/1928

5.2.2/1923 Thomas, H. R 1.5/1930 Thomas, P. A 4.3/1919 Thompson, A 12.1/1940 Thompson, I. M. G 6.1/1961 Thomson, A. G 4.1/1953 Thomson, J 5.2.2/1957 Thornton, B. S 2.2.1/1955

2.2.3/1957 2.2.5/1959 3.1/1956 Thorpe, T. E 4.2/1882

Thrasher, L. W 1.3.3/1955 Thuesen, H. G 10.2.4/1925

Thulin, A 2.3.4/1955 Thurston, C. M 12.5/1944 Thurston, R. N.

Thwaite, E. G.

5.2.2/1957

1.3.1/1963 3.1/1963

4.1/1963 4.2/1963

4.4/1964

Tienstra, J. M 1.3.3/1948

Tiffany, H. E 5.6/1963

TiUen, R 12.3/1964

Tillen, R.J 6.2/1963

Tilton, L. W 2.2.4/1934

2.2.4/1935 6.4/1929

7.1/1945 Timken Roller Bearing Co. Timms, C 1.7/1945 8.2/1964

10.1.4/1947

10.1.4/1948

10.1.4/1950 10.1.4/1954

10.1.4/1958

10.2.5/1955 12.2/1949

12.6.3/1958 Timofeeva, A. A 5.7/1958

Tinaut, D 2.2.2/1964

Titsch, J 3.6.1/1944 Tittmann, O. H 4.1/1893

Tlusty, J 12.2/1963

Tobias, S. A 12.2/1961 12.2/1962

Todd, H. A. C 1.3.3/1937 Todd, T 3.5/1925

1.2.1/1939 1.7/1937

1.3.4/1960

1.7/1953

1.7/1957

1.7/1961 2.1/1950

2.2.1/1946 2.2.5/1950

2.4.2/1950

2.4.3/1943 7.1/1953

7.1/1963 8.2/1952 8.2/1954 11.1/1950

11.1/1951

1.7/1949 3.3/1962

3.3/1963 3.4/1959 3.4/1960

3.5/1962

3.5/1963

5.6/1959 7.3/1959

8.2/1951

Toernebohm, H. a Tolansky, S

rolley, G

[olmon, F. R.

Page 73

15132

122 257

156

118

13646

515593

12024

23264

267

136

1994

119

122

12823

148 265

162

52

52 165

17636

196

225

225 225

226

227 235

259

273 150

50

110

128

261 260

260

22

106736

273738

38

42

45

54

7478 177

180

195 196

242 242

37 100

100

102

103

108 108 147

183

195

SubteetionlYear Tolstoj, N. S 1.2.3/1961 Tomascheck, R 5.7/1956 Tomaszewski, A 1.2.1/1952 3.6.1/1949 Tomkins, F. S 2.3.1/1958 Tomkins, J. A 5.1/1928 Tomlinson, G. A 3.3/1926 3.3/1927

5.2.2/1929 6.3/1940

8.2/1926 9.3/1926

9.3/1927 9.4/1926 Tomonaga, Y 2.4.4/1961 Toropin, S. I 4.4/1960

Tortosa, J 11.3/1957 Town, H. C u..- 1.2.1/1956 12.4/1935 Townes, C. H 2.3.7/1963 Towns, V 6.7/1926 Trautschold, R 10.1.3.4/1918 10.2.4/1918 Trbojevich, N 6.3/1938

12.1/1919 12.1/1923 Trimbath, S 9.3/1932

10.1.4/1931 10.1.4/1933 10.2.4/1930

10.2.4/1932 Troeger, H 5.7/1962

Trost, S 3.3/1961 7.1/1961

Trott, J. J 5.2.2/1952

Trotter, A. P 5.3/1916 Trowbridge, R. P 1.7/1950 Trulev, Y. I 2.4.2/1960 Truten', V. A 3.3/1963 Tsapenko, M. P 1.1/1962

1.1/1963

Tschirf, L 3.5/1942

6.8/1941 9.1/1939

Tseitlin, Y. M 5.7/1964

Tsidulko, F. V 5.2.5/1962 5.2.5/1963

Tslaf, M. Y 12.2/1961 Tsuboi, T 2.4.6/1962 2.4.6/1964 Tsukerman, V. A 11.3/1963 Tsukizoe, T 1.7/1964 Tucker, M. J 5.2.2/1952 Tucker, R. H 6.4/1895 Tuckerman, L. B 5.2.4/1923

Tunicliffe, W. G 12.6.5/1917 Tuplin, W. A 1.7/1945 7.1/1942

10.1.1/1948

10.1.1/1952

10.2.6/1959 10.3/1963 Turbin, G. B 12.3/1961 Turlan, C 3.6.3/1946 4.2/1946 Turnbull, L. G 7.2/1947 Turner, A 3.1/1938

3.4/1953

4.4/1941 9.1/1938 9.2/1938 Turner, J. A 11.3/1963 Turner, R 2.3.7/1963

Turrettini, F 5.2.2/1952

Turrettini, J 8.2/1953

Turrettini, M. F 5.1/1937

Page 14 1498 110

58 129

9797 133

163

194 207

207 212

83

127 2528 265

67

171 220 232

163 257

257 208

223 224

233

233

151 100

179

L36 143

37

77 100

107

172 200

151 142

142 260

87

S7 255

39

136

L64

139 274

36

176 213 214

237 240

263

114

122 180

92

102 125 200

203 255

68

136

195

130 305
Subsection/Year Tuttle, C 5.4/1939 7.1/1940

Tuttle, L 1.1/1916 Tutton, A. E. H 2.3.1/1931 2.4.2/1898

2.4.2/1910

2.4.2/1923 Twogood, E. N 10.2.6/1930 Tyr, V. R 3.4/1960 U

Uhink, W 6.4/1928

6.4/1932

Ullrich, R 2.4.4/1957 U.S. Army, Office of Chief of Ordnance 9.1/1944 Utumi, H 1.2.3/1959

Uverskii, I. T 1.3.2/1959 V

Vaganov, I. P 1.4/1963 3.2/1962

3.2/1963

Vaisala, Y 2.4.1/1927

2.4.5/1923 2.4.5/1930

Vale, L. B 3.6.2/1963

Valedinskii, A. S 5.7/1962

Valentine, A. L 9.1/1927

Vallot, J 1.1/1946 Van Acker, J. E 10.1.3.5/1954 10.2.6/1955 Van der Breeggen, J. C 5.2.2/1960 Vanderman, E. J 5.2.2/1951 Vanet, P 3.3/1919 Van Heel, A. C. S 6.2/1946

6.2/1949 6.2/1950

6.2/1960

6.2/1961 6.2/1962

7.1/1961 11.1/1958

11.1/1958 The Van Keuren Co 3.5/1932

7.1/1920

7.1/1955

10.1.3.4/1955 Van Keuren, H. L 2.4.4/1920 7.1/1920 8.2/1918

9.1/1918

9.3/1918

9.4/1948

12.6.5/1919

12.6.5/1926 Van Outryve, E 2.4.3/1962 Van Soest, J. L 1.1/1947 Van Steewen, O. P 5.4/1931 12.4/1933 Van West 10.2.6/1923 Vargady, L. O 2.5/1964 Varnum, E. C 9.3/1957

10.1.3.1/1962 Vasicek, A 11.2/1947

11.2/1957

Vasilenko, I. S 3.4/1960

Vasil'ev, V. G 1.1/1963 Vedder, E. H 12.3/1937 Vedmidskii, A. M 12.5/1962 Verhaeghe, J. L 2.4.3/1962 Verkhoturov, B. Y 3.4/1963

10.1.4/1963 Vernotte, P 1.3.3/1959 Vernotte, P. C. R 1.3.3/1946

Verschoffel, A 6.4/1916

Viall, E 12.6.1/1920

Vickers 9.2/1924

10.2.6/1922

Page 144

176

1 56

73

73

73 2m

103

165

16683

200

14

2130

9697

69

84

84

113

150

1992 222 237

137 135

97 157

158

158 160

11,0 161

179 244

245

106 175

178 221

82

175 193

198 206

212

274 275

81

2

144 265

235

90

211 219 217 248

1(135 262

268

81

103 228

24

23 165 268

194 235

Subieet ion/Year Vidal, J. M. T 1.4/1951 Vienot, J. C 2.4.1/1956 8.2/1956 Vieweg, R 1.2.2/1961 Vigman, B. A 1.3.1/1963 Vigness, I 1.6/1965 Vigour, H. E 12.3/1963 Vikhman, V. S 12.3/1963 Vinco Corp 10.2.5/1960

Visser, A 7.4/1960

Vittoz, B , 2.2.1/1960 Vlahos, C. J 1.6/1962 Voeneky, G 9.3/1962

Vogel, W. F 9.3/1937 9.3/1945

9.3/1947

9.3/1955 9.3/1957

10.1.2/1933 10.1.2/1945

10.1.3.1/1936 217

10.1.3.1/1945 217, 10.1.3.2/1943 10.1.3.2/1945 10.2.4/1937

10.2.6/1937 10.3/1933

12.6.3/1933 12.6.3/1934

12.6.3/1935

12.6.3/1936

Vogl, G 7.3/1958

Vogl, J. G 6.2/1947

7.1/1946 Vogt, W 1.5/1938 Voight, W 3.3/1954

Voigt, B 1.6/1931 1.6/1932

Voigt, W 3.3/1954

Volet, C 1.6/1952

2.4.5/1951 4.1/1939

4.1/1941 4.1/1942 4.1/1944

4.1/1948

4.1/1952

Volger, J 1.3.4/1948 Volkonskii, V. A 4.2/1961 Volkova, E. A 1.2.2/1963 Volosevich, F. P 3.2/1959 4.4/1960

6.4/1960

Volosin, Y. P 3.6.2/1960 Volosov, S. S 12.3/1961 Von Fragstein, C 11.3/1954 Von Geldern, O 6.7/1897 Von Hofe, C 5.4/1925 Von Keussler, V 9.1/1948 Von Weingraber, H 7.3/1960

8.1/1960 von Weiss, A 1.6/1956 Vook, R. W 11.3/1963 Vorhees, L. J 12.5/1920 Vorob'eva, T. S 12.2/1962 Vorontsov, B. N 3.6.1/1960

Vysotskii, A. V 7.4/1960

12.4/1963 W

Wade, H. T 4.1/1906 Wadsworth, F. L. O 6.4/1894 Wagner, E 10.1.4/1956 Wagner, G. H 4.4/1941 Wahl, A. M 5.7/1939 Wahrlich, G. V 2.3.2/1942 Wainwright 12.6.1/1954 Wait, E. V 7.1/1941

\i

2Qt 25

17.

14; 20(

18:

19:

11

16' 22< 12

14;

306
JW SubsectionI Year Page . Waite, B. C. Jr 5.2.2/1929 133

i] Waldersee, J 1.6/1963 35

•e Walker, D. F 12.3/1963 264

Walker, H 10.1.1/1952 214

10.2.2/1941 231

10.2.6/1926 235

'M Walker, J 2.2.3/1898 50

•:4 Waller, M. D 1.5/1940 32

-U Walter, L 3.3/1958 99

ic Walther, A 11.1/1958 245 T Wanach, B 6.7/1926 171

15 Warers, D. V 10.2.2/1922 230

••- Warlich, G. V 2.3.2/1942 60 • : Warman, W. A 10.2.5/1902 234 • Warner, R. M. Jr 11.3/1962 254

Warren, G. W 2.4.2/1928 73 • Warrington, D. H 11.3/1962 254

211 Washburn, E. W 1.5/1925 32 • ' Washer, F. E 6.2/1946 157

6.2/1947 157

••• Wasserman, M 2.5/1964 90

••• Watanabe, N 2.3.2/1928 59

2.4.5/1929 84 Waterman, A. T 1.1/1961 4 Waters, D. V 10.2.2/1922 230 • -'Waters, W. C 10.1.4/1961 227 • Watkin, E. L 2.4.2/1905 73 v.Watkins, A 3.6.1/1919 109

•.-Watson, A 5.2.4/1950 140

v. Watson, G. S 1.3.3/1953 23 • : Watson, J. H. L 11.3/1948 250

•;;AWattebot, L 5.2.5/1937 141

:l'.E. R. Watts & Son 3.1/1945 93

6.2/1947 157-8

6.7/1925 171

^atts, G. W 6.4/1923 165 reaver, C 2.2.5/1964 56

11.1/1956 243

11.1/1958 245

1.3.2/1950 20

I. 3.2/1954 20 : : Webber, G 2.1/1953 43 ' Webber Optical Polygons 6.3/1959 163

:" Weber, A. H 11.3/1952 251 -Weber, A. P 2.3.3/1928 61 Weber, K. H 10.1.4/1956 226

10.2.1/1964 230 • Weber, L 6.1/1908 153 — Weber, P. W 2.3.7/1964 68 • Weber, R. R 12.3/1963 264 : Webster, R. A 5.2.2/1931 133

:. Weicholdt, W

3.6.2/1902

110

3.6.4/1902 114

::! Weidenhammer, F 5.3/1963 143 ' Weill, R 12.2/1963 261

•- Weiner, B. L 1.2.2/1961 12 -jWeinhold, H 10.1.4/1960 227

Weinstein, W . . 3.3/1957 99

4.4/1957 126

Weir, J. B 5.2.3/1962 139 ^ Weisman, D 12.1/1964 258

,!|;Weis3, A

2.4.2/1954

75

'.Weiss, H 1.3.3/1962 25

:, Welford, W. T 4.4/1960 126 ' . Wells, F. O 12.6.4/1919 273 : ;JJ Wendeln, D. E

1.2.1/1963

10

jWerner, A 9.1/1932 199 vritz Werner 3.5/1932 106

jWernicke, W 2.2.5/1894 53

II. 1/1878 241

11.1/1894 241

Wescott, B. B 9.1/1937 200

Vest and Dodge Co 9.2/1918 202

>iWest, J 2.4.2/1959 76

^Westfall, F. O 2.3.4/1950 63

'0-Westinghouse Machine Co 3.2/1904 94

'"'Westmeyer, H 11.1/1960 245 mm

||jWeaver, F. D.

Subsection/Year Page Weston, S 6.7/1926 171 Wetzel, K. E 12.2/1963 261 Weyerer, H 2.2.2/1954 49 Weyl, R 11.3/1961 253

Wheeler, B 10.2.6/1927 235

Whibley, R. J 3.1/1920 92

3.5/1920 105

8.2/1920 193 Whiddington, R 5.2.2/1920 151 Whipple, R. S 5.1/1920 129 Whitaker, H 3.6.4/1931 115 White, C. E 1.6/1959 34

White Co 10.3/1913 238

White, F. L 12.5/1951 267

White, P. H 5.5/1931 146 Whitmarsh, W. L 3.6.1/1924 109 Whitney, C. A 7.4/1958 185-6 Whittemore, H. L 9.2/1911 202

Whitten, L. G 6.2/1964 162

7.4/1963 187 Whitworth, J 1.2.1/1858 6

1.2.1/1946 7 1.2.2/1857 10 7.1/1858 175

12.1/1840 257

Wick, C. H 1.2.3/1962 15

2.4.1/1962 72 Wickman 1.2.3/1920 13 3.5/1923 105

10.1.4/1924 223

10.2.6/1920 235

Wieckowski, J

1.6/1962

34 Wiegand, H 1.7/1958 38 Wiemer, A

1.7/1957

38

Wiener, O 11.1/1887 241

Wiens, J. H .2.3.4/1946 63 Wigan, E. R 10.2.1/1955 230

Wiggins, T. A 2.3.1/1957 58

Wight, K. C 2.3.1/1951 57

Wilcox, R. H

3.6.1/1952

110

Wilde, H 9.2/1926 203

Wildhaber, E 7.3/1955 182

10.1.3.5/1923 222

10.2.6/1923 235

_10.3/1945 239

10.3/1946 239

12.6.3/1924 272

Wildhack, W. A

1.1/1961 4

5.2.5/1950 141 Wilharm, L. F

6.6/1949

169

Wilhelm, J 9.3/1933 208

Wilhelm, J. H _8.1/1918 189

Willey, E. J. B 1.1/1948 2 Williams, C. W 5.2.2/1952 136

Williams, D. C

1.5/1962

33

2.2.2/1962 50

3.1/1962 94

3.2/1962 97

Williams, F. R 9.1/1917 197

Williams, H. B 6.2/1946 157

Williams, M. H _3.2/1924 95

Williams, W. E 2.1/1930 41 2.1/1948 42

2.3.2/1938 60

Williamson, D. E 9.3/1946 210

Williamson, J. L 10.1.3.6/1949 222

10.1.3.6/1957 222

10.1.4/1925 223

10.1.4/1926 223

10.2.2/1957 231 Willoughby, A. B 2.4.2/1948 74

Wills, H. J 12.4/1944 266

Wilson, B. L 2.4.2/1944 74

Wilson, B. W 2.4.1/1950 70

Wilson, D. C 2.3.7/1963 68

2.3.7/1964 68

5.4/1957 145 307
SubsectionI Year Page Wilson, J. H 7.1/1961 180

Wilson, L 7.1/1962 180

Wilson, M. D 10.2.4/1921 232

Wilson, R. N 8.1/1956 192

8.2/1956 196

Wilson, W. K

1.7/1945

36

Wilson, W. M 10.1.4/1905 222

Winchester Repeating Arms Co 6.8/1928 172 Winder, G. E 6.5/1950 167

Winkler, O 1.4/1953 28

Winter, P. K 1.1/1962 5 Winterbottom, A. B 11.2/1946 247

11.2/1948 247

Wirrer, G 10.2.1/1920 228

Wise, J. F 2.3.2/1956 60

Wise, W. F 12.2/1935 259

Wittke, H 2.1/1948 42

Wittrick, W. H 5.7/1948 148

10.1.4/1947 225

Witzke, F. W 1.7/1961 38

3.6.2/(1959) 113

5.2.2/1960 137 7.4/1958 185-6

7.4/1962 186 Wizenz, L 1.3.1/1959 18 3.3/1959 99

3.3/1960 100

3.4/1960 103 Wobschall, D 5.2.2/1961 137 Wojtowicz, W. J 11.3/1948 250

Wolf, F 9.3/1952 210

Wolfe, K. J. B 1.7/1953 37

Wolfer, A 1.2.3/1907 13 Wolper, M 10.1.4/1948 225

Wolter, H 2.4.1/1956 70

11.3/1952 251

11.3/1957 252 Womack, J. D 6.2/1958 159 Wong, G. S. K 2.5/1964 90 Wood, B 10.1.4/1959 227 Wood, Mrs. J. G 8.2/1951 195

9.3/1958 211 Wood, J. K 3.5/1925 106 Woodman, L. E 1.3.3/1942 22 Woods, R. C 9.1/1941 200 Woods, R. W 1.4/1955 29 Woodson, R. A 6.5/1960 168 Woodward, R 6.4/1876 164 Woodward, R. S 4.1/1893 128 Woodward, R. W 6.1/1933 153 Woodworth, W. D 12.6.4/1918 273 Wootan, G. G 1.3.3/1963 26 Woran, H. P 2.2.5/1922 54 Work, R. N 2.4.2/1950 74

2.4.2/1951 74 Worthen, J 7.4/1958 185 Worthen, J. H 3.5/1962 108 Worthy, R. J 6.8/1923 172 Wouterlood, H. J 5.2.2/1960 137

Wright,, G D 6.6/1946 169 Wright, C. W 12.6.5/1903 274

Wright, F. E 6.2/1924 157 Wright, H. H 9.3/1918 206

Wright, H. T 9.2/1923 203

Wright, J. P 3.3/1954 99

10.2.5/1958 234

Wright, K. H. R 7.1/1961 179 Wright, P 11.3/1963 255

Wulff, J 1.7/1941 36 Wunsch, H. L 5.6/1962 147

5.7/1951 149 Wurzinger, M 2.4.5/1930 84

Wylie, K. F 11.3/1965 255 Wynn, N. R 5.2.5/1955 142 Y Subsection/Year Yakonovskii, S. V 9.2/1963 Yamada, Y 12.6.2/1959 Yamaguchi, J 5.2.2/1951 Yamamoto, A . 9.2/1963 9.2/1964 Yamamoto, H ..2.4.5/1963 Yamamoto, K 3.6.4/1962 6.1/1960

10.2.1/1959 Yamoto, S 9.2/1963 Yanus, R. I 1.3.3/1957 Yeh, L 1.6/1962 Yoder, P. R. Jr 2.4.4/1957 Yokoyama, Y 9.1/1960 Yoneyama, Y 11.2/1953 Yorgensen, P. L. L 3.6.2/1908 York, H. F 1.1/1961 Yoshida, T 2.4.2/1959 11.3/1959 Yoshitsugu, M 3.4/1963 Youden, W. J 1.1/1962

1.3.1/1961 1.3.1/1962

1.3.2/1954

1.3.3/1953 1.3.3/1962

1.3.3/1962

I. 3.4/1962 Young, A. W 1.2.1/1963 4.1/1963 6.1/1962

6.1/1963

6.2/1963 Young, C. A 10.2.6/1942 Young, I. R 1.2.3/1960 5.7/1956

6.1/1959

6.5/1959 Young, J. G 12.2/1930 Young, L 11.1/1958 Young, N. O 2.4.4/1956 Young, Thomas 2.2.1/1960 Young, T. R 1.2.1/1963 2.1/1957

2.2.1/1963

2.4.4/1957 3.1/1960

3.1/1961

II. 2/1963

11.2/1964

Yribarren, R 5.2.5/1948 Z

Zablonskii, K. I 5.2.2/1963 Zahorski, A 9.3/1939

10.2.4/1937

Zaininger, K. H 11.2/1964 Zamis, A. F 10.1.4/1947 Zarubin, A 1.2.3/1961

Zaslavskii, Y. S 11.3/1963

Zeise, G 12.6.3/1961

Zeitz, K. H 5.1/1962

Zelbstein, U 5.1/1960

Zeiss, Jena 3.3/1924

3.3/1928

3.3/1930

3.4/1926

3.5/1949

3.5/1956

3.6.1/1925 4.4/1925 4.4/1927

4.4/1930

4.4/1931 4.4/1938

5.1/1931 308
leiss, Jena—Continued

2711 m\mm

m

lie 1

1

ill] I

AV>Carl Zeiss, Oberkochen.

Ill li aI

Subsection/Year Page 6.2/1934

6.4/1946

7.1/1925

7.3/1934 8.2/1926

9.1/1925 9.1/1929

9.2/1926

10.1.4/1932

10.2.1/1927

10.2.5/1926 10.2.6/1923 10.3/1932

...2.4.5/1961

10.1.3.2/1957

157

166 176

181 194

199

199 203

223

229

234

235 239

85 219

Subsection/Year Page Zemany, P. D 11.3/1956 251

Zernike, F 2.1/1957 44

Zhuravlev, N. M 9.2/1960 204

Ziegenhals, E 1 2.2/1 933 259

Zieher, G 3.4/1937 101

10.1.4/1937 224

10.1.4/1959 227

10.2.2/1952 231

Zissis, G. J 2.4.3/1953 79

Zobel, T 2.1/1937 42

Zollner, H 9.3/1939 209

10.2.4/1939 233

Zorll, U 11.1/1952 243

Zuehlke, A. A 1.3.2/1962 21

Zwerling, C 2.5/1964 90

309
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