NAT'L INST. OF STAND & TECH NBSiR 75-947 /Rfivi5;f?d December 1977)

PUBLICATIONS

REFERENCE

AlllOt, fltEtlE

SIOOiES OF THE NATIONAL MEASUREMENT SYSTl

1S72-75

Raymond C. Sangster

Office of the Deputy Director

Institute for Basic Standards

National Bureau of Standards

Boulder, Colorado 80302

December 1977

/cro

/?77

NBSm 75-947 (Revised December 1977)

COLLECTED EXECUTIVE SUMMARIES

STUDIES Of THE NATIONAL MEASUREMENT SYSTEM

1972-75

Raymond C. Sangster

Office of the Deputy Director

institute for Basic Standards

National Bureau of Standards

Boulder, Colorado 80302

December 1977

U.S. DEPARTMENT OF COMMERCE, Elliot L. Richardson, Secretary

Edward 0. Vetter, Under Secretary

Dr. Betsy Ancker-Johnson , Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
FOREWORD

The concept of a National Measurement System has, for many years,

provided a useful focus for the considerations important to physical

measurements in our technology intensive economy. Dr. R. D. Huntoon,

in his October 6, 1967, article in Science, emphasized the basis for a systems viewpoint in interrelated measurements activities and the idea

has continued to evolve. Today, we think of the U.S. National Measurement

System in terms of all the intellectual, functional and institutional

activities which enter into measurements throughout our society, flore- over, we seek to understand more completely the structural nature of this

system and its architectural needs.

There have been a number of approaches to the study of our national

system for physical measurements. The present series of studies was initiated in 1972 by Dr. Ernest Ambler, then Director of the Institute

for Basic Standards. It was Dr. Ambler's purpose to organize the essential information necessary for the effective management of NBS resources

and to promote the direct interaction between IBS staff members and the

communities of users they serve.

This document reflects the results of the intensive studies carried

out during the period from 1972 - 1975. It is important to recognize

that the National Measurement System is extremely complex having widely

distributed elements and impacts. The detailed analysis of this system

is well beyond the state-of-the-art of econometric modeling, and therefore, any study, no matter how intensive, is necessarily incomplete.

Nevertheless, the information which is now in hand provides an important

addition to our capability for planning and implementing the programs

of IBS. It also represents a growing foundation upon which we can continue our efforts to build a more effective structure.

A. 0. McCoubrey

Director, Institute for Basic Standards

National Bureau of Standards

August 1976

ii
PREFACE

The 1972-75 Study of the National Measurement System by the iJBS Institute for Basic

Standards has been a massive effort involving many people in all divisions of the

Institute. The information compiled in this document is one of the results of this

effort, and could never have been developed without the contributions of a large number

of knowledgeable individuals.

The Study was organized around a central coordinator and a group of "National Measurement System Study representatives" from the technical divisions of the Institute. The

initial central coordinator was Dr. James R. Seed, a Presidential Interchange Executive

from the Dow Chemical Company, on temporary assignment to the National Bureau of Standards.

Dr. Seed was responsible for the initial formulation of the tactical plans for this Study,

and carried the project through to the generation of a complete set of comprehensive

reports on the structure and operation of the various portions of the System, in December

1973. In August 1974, I took over the central coordinator position, and worked with the

Study representatives from the divisions of the Institute, to round out the pattern of

the Study and to develop the final reports which have been issued by NBS for the different

areas of measurement interest. Dr. David T. Goldman, deputy director of the NBS Institute

for Basic Standards, provided direct management guidance to this study, and he made many

contributions, both broad and specific, to all aspects of this study.

The "Executive Summaries" presented in this document were taken from the final

drafts of these reports. Because this document is being published before all of the

individual reports have received final editorial clearance, there may be slight discrepancies between the summaries contained herein and those ultimately published with the

individual reports; none of these discrepancies is expected to involve any matter of

substance.

We trust that the availability of this document will be useful to many readers who

need only an overview of the results of our Study of the National Measurement System.

For those who want more detailed information about any part of this study, we have

provided a "Report Request Card" at the back of this document, which can be used to request the specific reports wanted.

At this point, it would be customary to acknowledge by name the efforts of the

secretaries and other supporting personnel without whose unstinting efforts no document

of this type could be created. However, inasmuch as these summaries were generated as parts of a large number of reports, it seems most appropriate not to attempt to acknowledge these contributors by name, but simply to salute the devoted efforts of the secretaries and supporting staff members of the fiational Bureau of Standards, without which

the work of the Bureau would be im.possible.

Raymond C. Sangster

December 1977

i i i
CONTENTS

COLLECTED EXECUTIVE SUMMARIES

STUDIES OF THE NATIONAL MEASUREMENT SYSTEM

1972-1975

FOREWORD ii PREFACE lii FINAL SUMMARY REPORT, STUDY OF THE NATIONAL MEASUREMENT SYSTEM 1 TRANSACTIONS MATRIX DESCRIPTION OF THE NATIONAL SYSTEM OF PHYSICAL MEASUREMENTS 5 ECONOMIC ANALYSIS OF THE NATIONAL MEASUREMENT SYSTEM 6 STRUCTURE AND FUNCTIONS OF THE NATIONAL MEASUREMENT SYSTEM 7 THE NATIONAL MEASUREMENT SYSTEM FOR TIME AND FREQUENCY 9 THE NATIONAL MEASUREMENT SYSTEM FOR LENGTH AND RELATED DIMENSIONAL MEASUREMENTS:

PART 1 n

THE NATIONAL MEASUREMENT SYSTEM FOR SURFACE FINISH 13 THE NATIONAL MASS, VOLUME, AND DENSITY MEASUREMENT SYSTEM 14 THE NATIONAL FORCE MEASUREMENT SYSTEM 16

THE NATIONAL MEASUREMENT SYSTEM FOR FLUID FLOW 18

THE NATIONAL MEASUREMENT SYSTEM FOR PRESSURE

.

20

THE NATIONAL TEMPERATURE MEASUREMENT SYSTEM 21 THE NATIONAL HUMIDITY AND MOISTURE MEASUREMENT SYSTEM 22 THE NATIONAL MEASUREMENT SYSTEM FOR THERMODYNAMIC PROPERTIES OF FLUIDS 24

THE NATIONAL MEASUREMENT SYSTEM FOR CRYOGENICS 25 THE NATIONAL MEASUREMENT SYSTEM FOR ELECTRICITY 28 THE NATIONAL ELECTROMAGNETICS MEASUREMENT SYSTEM 30 THE NATIONAL MEASUREMENT SYSTEM FOR MEDICAL ULTRASONICS. . . .

.- 32 THE NATIONAL MEASUREMENT SYSTEM FOR ACOUSTICS 33

THE NATIONAL MEASUREMENT SYSTEM FOR RADIOMETRY AND PHOTOMETRY 35 THE NATIONAL MEASUREMENT SYSTEM FOR SPECTROPHOTOMETRY 37

THE NATIONAL MEASUREMENT SYSTEM FOR FAR ULTRAVIOLET RADIOMETRY 38 THE NATIONAL MEASUREMENT SYSTEM FOR OPTICS 40 THE NATIONAL MEASUREMENT SYSTEM FOR THE PHYSICAL PROPERTIES OF ATOMS AND MOLECULES ... 41 THE NATIONAL MEASUREMENT SYSTEM FOR SURFACE PROPERTIES 42

THE NATIONAL MEASUREMENT SYSTEM FOR IONIZING RADIATION 44

LIST OF TABLES

Table 1. Direct measurements transactions matrix for IBS Study of

National Measurement System 3 Table 2. Direct measurements transactions matrix for outputs of NBS 4

iv
FINAL SUMMARY REPORT

STUDY OF THE NATIONAL MEASUREMENT SYSTEM

Raymond C. Sangster

Institute for Basic Standards

National Bureau of Standards

December 1976

EXECUTIVE SUMMARY

The National Measurement System consists

of all of the activities and mechanisms that

provide physical measurement data to allov/

creation of the objective, quantitative knowV

edge required by our society.

In 1972, the Assistant Secretary of Com- merce for Administration directed the preparation of a study of "the NBS standards of

measurement to determine if their accuracy

is sufficient for the needs of U.S. industry.

This request led to initiation of a threeyear study of the National Measurement System for the purpose of developing answers

in depth to the questions posed. The internal motivation for the activity was to:

1. Provide management with enough information to aZZoccze Z'i'rr^zsa. veso^xfoes to most timely, significant programs.

2. Assist in c'otaininc our resources by

demonstrating clear concept of responsibi 1 iti es . .

.

3. Motivate our own people to improve vhe

manager<.er.t of public funds spent on techno logica I progrcs^.s

.

Implementation involved a macroeconomi

c

study of the cost of measurements in our economy and a series of microstudies in the

following technical areas: Time & frequency Electromagnetics

Length & related dimen- Medical ultrasonics

sional measurements Acoustics

Vibration and shock Radiometry & Surface finish photometry

Mass, volume & density Spectrophotometry

Force Far ultraviolet

Fluid flow radiometry

Pressure Optics

Temperature Lasers

Humidity & moisture Physical properties

Thermodynamic properties of atoms & moleCryogenics cules

Electricity Ionizing radiation

The structure of the system has been

depicted by a model with five levels:

I. The conceptual system , the intellectual foundation that defines the measurement

quantities and units.

II . The basic technical infrastructure

that provides the tools and techniques and

agreements that allow the conceptual system

to be reduced to practice.

III. Realized measurement capabilities , i.e., abilities to measure specific quantities to known accuracies under defined condi ti ons

.

IV. The institutional dissemination and

enforcement network ; components include NBS,

state and local weights and measures agencies, standards laboratories, and some regulatory agencies.

V. End-use measurements , which all other

levels of the system exist tn <:unnort. Supporting all of these levels is a central pillar of measurement science, know-how,

and trained people.

Interactions among different institutional

sectors of the system have been described by

a direct measurements transactions matrix.

Measurements cost an estimated 6% of GNP. About 85" is for labor. All 78 major industrial sectors, all levels of government, and consumers buy measurement equipment or labor.

Federal, state and local governments are the largest user sector, about 35% of the

total. Other service industries, principally

trade, utilities, transportation and communication, account for about 25%. "High technology" manufacturing industries spend a larger share of their value-added but relatively few actual dollars. Preliminary cor- relations of measurement intensity with

economic growth and productivity data for

major industrial sectors reveal a significant positive coi^relation

.

The technical microstudies reveal a number of serious deficiencies, especially

in areas associated with governmental regulation for health, safety , and environmental

protection. They provide information used

by NBS to define new program directions.

Even in such basic areas as measurement

of time, length, and mass, there are needs

for improvements, for example, in mass mea- surements for inventory control of fissionable nuclear materials. Economics is a prime
motivator for a number of dramatic technological changes: satellite time and frequency

broadcasts, electronic distance-measuring sur- veying equipment, and automated digital grocery store scales. The major problems are those of scaling to large or small magnitudes,

e.g., very precise navigational positioning,

measuring the volume of oil in a supertanker

or the breadth of a line in an integrated circuit.

On the other hand, there are deficiency

areas where it is hard to say that a national

measurement system even exists: Surface properties (of importance in such diverse areas

as catalytic petroleum refining and microelectronics) and medical ultrasonics (used

for detecting cancer and monitoring the un- born), fields which have blossomed dramatically very recently. Far ultraviolet radiometry (used in phototherapy of newborn infants

and for monitoring the earth's shielding ozone

layer), a field in which measurement standards

have existed only recently. Spectrophotometry

(of importance in all fields of color and

appearance and lighting), because of a lack

of national leadership until recently. Electromagnetic interference phenomena (of importance in virtually all uses of electronics),

because of the subtlety and complexity of the

measurement problems.

The most critically important deficiency

area identified is in the measurement system

needed for the safeguards program for special

(fissionable) nuclear materials, and NBS has

initiated a major program here in collaboration with ERDA and NRC.

Other areas in which improvements in the

system are needed include the following:

1. A firm base for measurement under

dynamic, time-varying conditions, of force,

fluid flow, pressure, temperature, humidity,

electrical quantities, and tohers.

2. Standards support to high speed,

dynamic, automated measurement systems, in

electronics and electromagnetics.

3. Measurements made under hostile environmental conditions, such as the measurement

of temperature, pressure, neutron flux, and

fission rates inside- nuclear reactors.

4. Precision characterization of many

kinds of measurement transducers, especially

for temperature and pressure.

5. Non-contacting, on-line, manufacturing

instrumentation for measurement of surface

finish parameters.

6. Flow measurements in the field, such

as low air velocities for mine ventilation,

water supply and waste water flows for pollution control, metering of natural gas, and

mul ti -component flow.

7. Measurement assurance for auto tire

pressures and aircraft altimeters.

8. Electronic medical thermometry.

9. Measurement of moisture in grain (in

conjunction with the Dept. of Agriculture).

10. Gathering and predicting measurement

data on the thermodynamics of fluids, especially complex mixtures in support of such

fields as the chemical and petroleum refining

i ndustries

.

11. A measurement system and data for

liquified natural gas, and for superconductivity in the electrical power industry.

12. Measurement techniques for monitoring

noise to support its regulation and control.

13. Widely available 1% end-use measurements in radiometry and photometry, where 20%

is common today, in support of many new areas

of lighting and optical technology.

14. Improvement of measurement of ionizing

radiations used in medicine, to which workers

are exposed, or present in the environment.

The major trends of the System are these:

Inoreased complexity, resulting from the

ever-increasing scooe of science and technology, from the development of the information

economy, and from the challenge of mastering

the ever-growing complexity of our society.

Improved quality control.

Improved information resources

.

Automation.

Metrication, to bring the U.S. into line

with the rest of the world.

Consolidation of the scientific revolution

in the basis of the system-- the shift from

dependence on artifacts to natural phenomena

as our basic standards.

The most significant deficiency lies in

the lack of adequate mechanisms for quality assurance throughout the measurement system.

Closely related is the wide-spread need for more "how-to" information at the working

level. Inversely, NBS and other infrastructural institutions need more knowledge of

real needs of the system.

As the central measurements standards

institution in this country, NBS contributes

to every aspect of the National Measurement

System. Its two primary unique functions are custody of the national standards of physical

measurement and promotion of the health of

the entire National Measurement System.

NBS is currently responding to most of the

measurement systems needs identified by this

study. Most especially, NBS is moving to meet the needs of a new major sector of the

system: measurements for establishment of,

enforcement of, and compliance with, governmental regulations. The major challenge

facing the Bureau is that of wise deployment

of our resources, as other demanJs are put on NBS expertise, to support the needs of a con- stantly expanding National Measurement System.

2
Table 1. Direct measurements transactions matrix for IBS Study of National Measurement System.

DIRECT nWNSACTIWS

MAiaiJl FOR

•iATIOHAC SYSTEM

Of PrirSiCAL

,>«ASUR£f1ENTS

l.Marcn 1375)

U

E

R

S

o ^ —

J <

1 § §

3

^

^

4

lig

•1 i i

3 3S =

21

7

O

ill

8

o ^ <=

9

-

- -r:

Sil

10

— c ^

11

ill

2 o 3

1/1 <J o

12

S < ill

13

i

14

5.| o iyi

15

§ — SoC3 ^ 2%

S ^ C

5 ^ 3." S E ^

18

d ,3

^ - _ o — o _ " .5 o ^'

19~1 20

2 o Hi

21

1 -5 II--

22 23

o vi a: o a. — o

24

1

25 SUPPLIERS \

S5 6 le 17

1 CtOaL£3'l£ :3."»JNIT» (Science. Education.

Prof. Soc. i '-jtil

.

6 i__

3

1

3

)

4

2

1

; 2

1 2

2

T—

T

3

1

T—

r

3 2

1

1

r ^ I

2

1 I

'

1

1 TT21 1

2 1 2

I

3 2 3 1

3

1

Z 1 7

2

"

3 1

1

I

2 1

1

1

2 2

I

1

-ETSCLZGIC^L

:RaA'ii';T::'iS

; ;

)

1 1

3 1

:

"

2 2

1

1

3 1 3

2

1 1 1 1 1 1

3 MC'jNENTAR* STANDARDISATION ORMfillATlONS

3 2 3

2 :2

3

3

1

3 1 2

2

3 1

1

1

3 1 23 2

2

2

3 1 2 2 1 i'

1

3 1 2

2

2 2

2 1 : 2 2

1

2 i 2

1

2 1 2

1

2 1 2

1

3 1 2

2

1 2 1

4 INSTSUHcNTATION

INDUSTRY

(SIC "aior t-c 33)

2 I 2

1

2 I

1

1

Z 1

7

5

3 1 3 I 1

3 I 33 1 2

7

3 1 53 1 4

1

3

2 I 2

1

3 4

3 I 3

2

3 1 3 t 3 4

1 I

3 I 5

I

3 1 5 J3 1 5

1

3 1 5

J

3 1 5

1

3 2 4

3 1 4

5 NBS 3

1

3 ) 3

2

3 1 3 3 2J 1 4

1

1

4 i 2

7

3

,

' 3

1

3 I

3 3 2

2 1

1

2 1 2 2

4 i 2 1

2 2

1

1

2 2

2

2

4 2

2 2

2 1

1

'

3 1 2

1

4 I 2

1

4 2 2

2

4 3

1 2

4 3 2

2 1

1

1 6 OTHER U.S. •WTIONAL STANDARDS 1 ' 1

3 i

1 J 1

I 1 1 7 1 I 1 1 1 1 1 7trlT;T:j;;.

OFflCES OF WEIGHTS

& "EASORES (Cffl's)

1 1

1 S

T"

;

2

1 "

R

1 1

1

1 1

3 1 2 2

1 —

^ 2

1

1 2

4

3

1 4~r

1

1 8 STi.NDARDS S TESTING LABORATORIES

S.ND SERVICES

2 1

1

1

2 1 2 ) 3

1 R

3 1 2 : R

3 1 2 1 2

3 1 3

3 1 2

1

2

1

1 1 1

2 1 2

1

2

3

1

1

3 1 2

1

3 1 3

1

3 2 2

7

3 1

1

1

2

,

2 2

2

9 SEGULATCRY

AGE.1CIES (excl. O'W^'s!

3 )

I 2

3 1 23 1 2

? P

3 2

2

2 R 2

"

P

3 2

3

1

2 1

1

1 R

2

2 R

1 R

2 1 2

2 R

4 2

2

1 R \'

2 R

4 J

2

1 R

3 1 2

1 R

3 1 2

1 R

4 1 2

1 R

3 2 2

1 R

3 1 2

2 R

3 1 2

2 R

3 1 2

2 R

4 2 2

3 R

3 r

2 2 R

'lb SrFiSSThE.iT 5r DEFENSE

(eicl. SMS. L3bs)

3 2

2 22

1

3 2 R

3

1 R

1

3 1 3

1 R

1

J

7 2

1

2 t

1

2 113 1

' 2

1 r! 1 R

3 1 2 R3 1 4

2 R

3 1 4

2 R

2 1

2 R \

1 R

11 CIVILIAN "^E^ERAL GOVT AGENCIES (excl.

Stds. cats 1 '»<3. Aq. >

3 1 2

1

Z 1 2

2

2 1 2

2

3 1 3

1

1

t 2

2

1

2 1 2

2

2 i

1

1

3 1 7 i2 1 2

1

2 1

2

2 , 1 1

2 2!3 3 1

1

3 1 2

2

3 1 2

1

4 I 4

1

1 2 2

12 STAYE i LOCAL

GOV£aN.>€NT AGENCIES

f exc . O'WM' s 5 ".M . Aq.

'

1 1 1 P

2 I

1

1 R

1 1 R Q

1 1 1

^

7

6 1

' 2 1

'

1

' 1 1 1 1

13 INCU5T3IAL TRADE ASSOCIATIONS

2 2 2 1 2

J .

I 1

1 7

2 1

1

1 2

1 71

2 1

1

1

1

-

, )^

.-

2 )

1 I 1 1

14 AGSlCuLIJRi.rOKta;!*' FISHING; MINING

(SIC Dlv. A 1 3)

1

2 i

1 1 R

I 2

1 R1

' 1 S' R

1 1 2 1 5 1 2 1 2

'' 1

CONSTRUCTION

(SIC Div. C]

1 1 I R1 R1 1 R R1 1 1 1 6 1 R1 1 1 1

16 f000/T03/TEXTILE/

APPAREL/LBR/ FURN/PAPER/

LEATHER (SIC 20-26. 31)

1 3 13 2

I 1

1 2 R

3 2

1 2 R

2 2 1 R R3 1

1 21 1 1

3 1 2

2

1

2 1 6

1

1 R R R

1 R1

17 CHjM/Pr:(S0L/5lj63;P,/ PLAST ICS/STONE/CLAY/

GLASS (SIC 28-30, 32)

1

2 12 1 2 2

2 1

3 2 2

2

1

2

1

2 2 2

2

2 1

1

1

2 2

2

2

I

2 1

1

1

1 1

1

'

2 ) 6

1

1 1 1 1 1

18 PRIMARY S FAB. HETAL PRODUCTS

(SIC 33-34. 391)

2 1

1

3

2

3 1

1 " R

3 2

1 2 RI

3

R

2

3 1 2 2

1

I 2 1 1 1 1—

r

6

2 1 3

2 2 1 1 1

19 «CHINERY.

EXCEPT ELECTRICAL

(SIC ^faior 50 35)

2 1

' 1

3 2

3 1 2

1 R

2

R

1 1

3 i

1

1

3 1

1 1 2

2

1 1 1 2

3 i 6

2 3

2 2 1 2

20 aECTRIC AflO ELECTRONIC EQPMT

(SIC Major Go 36)

3 1 2 23 1 2

2

3 I 3

5

3 1 2

3 1 2

2

3 1

1 2

3 1

1

3 1 2

7

1

3 1 2

1

1 1 1 1 2

3 1

i

3 i

2

7 2 1 2

2 2

2 2

21 "SANSPQRTATION

EQUIPMENT

(SIC ^jor Go 37)

2 1 2

1

2 13 1 2 2

1 1 P

2 I 2

2 1 2

1 " R

2 1 2

2

2 12 1 2 2 2 12 1

1

1

3

I 1 1 2 1)

1

2 1

1

1

2 1 3 2

2

3 6

I

2

1

. 1

22 fRA.NSPoSTATIJN i PUBLIC UTILITIES

(SIC Div. E)

2 1 2

1

2 : 2 2

J ! 2

I R

2 :

2 R

1 2

2 1

1 " R

3 2 2

2

2 1 2 2 ! 2 1 1 1 ^ 11 2

1

3 T

6

1

2 1

3 1 4

1 23 TRADE/ INS/fIn/SEAl EST/PERS SVCS/PRINT-P'JB

(SIC F-H, 3a!. I, 27;

1 1 2 R

3 1

1

1 R

2

R

1 R

2 1 1 1 2 2 2 2 7 6

^* HEALTH SERVICES

(SIC Major Gp 30)

1 1 2

'

R

1 1 1 1 1 1 1 1 I I 1 1 5 2

25 GENERAL PUBLIC

2 1

1

2 I

1 2 R

1 R

2

5

1 R1 R pI R1 R

1 R1 R R R

1 R 2

R

2 R

1 R

J—

r

7

1

KEY TO MATRIX ENTRIES

C - IMPORTANCE OF TRANSA CTIONS

1 = Purely convenience

2 = Strongly ciesirable

3 = No real alternatives

4 = Essential

B - RATE OF CHANGE

N = Declining

0 = Stable

2 = Growing

4 = Growing explosively

R = Flow of requi rements info'dominates

(IN)ADEQUACY OF SERVICES

= No improvements nee(je<j = Could be improved

= Marginal

= Serious deficiencies

= Out of control

- MAGNITUDE OF TRANSACTIONS

= Trivial

= Minor

= Moderate

= Important

•7 = Major

3
Table 2. Direct measurements transactions matrix for outputs of NBS.

DIRECT ftASUREKNTS

TRANSACTIONS

HAIR IX FOR OUTPUTS OF NBS

U

S

ER

S

KNOWLEDGE

COMMUNITY

-

(Science,

Education,

PrnfSnc-

«

Publ

.

INTERNATIONAL

~

HETROLOGICAL

ORGANIZATIONS

DOCUMENTARY

"

STANDARDS

ORGAN

I

ZPT

IONS

INSTRUMENTATION

*

INDUSTRY (SIC

Maior

Go

38)

B

S5

OTHER

U.S.

NATIONAL

STANDARDS

AUTHORITIES

STATE

S

LOCAL

OFFICES

OF

WEIGHTS

t.

MEASURES

(OHM'S

)

STANDARDS

S

TESTING

o>

LABORATORIES

AND

SERVICES

REGULATORY

>o

AGENCIES

(excl.

OHM'S)

DEPARTMENT

OF

S

DEFENSE (excl.

Stds.

Labs)

CIVILIAN

FEDERAL

GOV'T

AGENCIES

(exc.

Stds

Labs

S

Req.AqJ

STATE

»

LOCAL

~

GOV'T

AGENCIES

(exc.

nWH's

»

RpQ.

Ad.)

INDUSTRIAL

n

TRADE

ASSOCIATIONS

o z

"

35°

14

CONSTRUCTION

(SIC

Div.

C) ^ !^J o

O uj i_) O c .— £ £

16

pr o

^ z o ^

17

PRIMARY

«

FAB.

S

METAL

PRODUCTS

(SIC

33-34.

391)

MACHINERY

S

EXCEPT

ELECTRICAL

(SIC

Major

Gp

35)

ELECTRIC

AND

B

ELECTRONIC

EQPtlT

(SIC

Maior

Gp

36)

TRANSPORTATION

~

EQUIPMENT

(SIC

Major

Go

37)

TRANSPORTATION

J

K

PUBLIC

UTILITIES

(SIC

DIv.

E)

D ^ (J

23

HEALTH

SERVICES

"

(SIC

Major

Gp

80)

CS

GENERAL

PUBLIC

MEASUREMENT SECTOR

1 line b rRcyutnti

2 3 1

2

3 1 33 4

3 ^3

3 1 2

2

3 1 33

3

3 ? 4[3 3 1 I--

4 ]

3 ^

1 3

2

3

2 LENGTH & KLLAItU UlMbNblUNAL MEASUREMENTS

1 1 3 1 2 1 2

2

3 1 3

2 1 33 1

1 N

3 1 4 1 1 3

4 1 4

2

1

3 1 3J 1 4

3 1 4

3 1 3

2

3 1 3 N

3 1

1 N

1 1

3 VIBRATION S SHOCK

3 2

2

?

2 3

2

2 2

2

2

2 2

2

2 2

1 2

2 1 2 13 1

1 N

2 1

1 2

2 3

1 2 3

1

3 2 2

1

2 2

1

2 3

4 iUKrAOt rXnlbn

3 1

2

3 2

2 2

3 1 3

2

2 1 2

2

3 1 2

3 1 2

3 1 2

2 1

I

3 1 2 2

3 2

1 2

2 2

1

2 1 2

2 1 23 2 2

2

2 1

1 2

2 2 2

5 MASS. VOLUME 4 DENSITY

4 1 4 1

3

2 1 2 1 2

1

4 2

3

4 1 4

2

2 2

3 1 3

1 2

N

2

1

2

1

1

2 2

1

2

1

2 2

1

1

2 1 2

1

1 2

N 6 FORCE

2

?

2 2

3

2

3 2 4

1

1

3

3

3

3

2

1 4

N

2

4

2

2 31 2

1

1

1

1

1 21 2

1 2

1 31 21 21 2

1 2

1

7 FLUID FLOW

2 1 3 2 3

3 1 3

2

3

3

3

3

2

3

3

3

3

2 1 2 22

2

2 1 22 2

J 1 2

2 1 3

2 1

8

rKLi>iUKL

3 2

1

3 2

1

1

3 2

2

3 4

4

4

3 1

3 1 2

3 2

3

3

4 3

2

1

2 1 2

1

1 1

2 1 2

1

2 1 3

1

1

2

2

3 4

1 4 1 4

1

4 1 4

1

1 1

3

1 9

TCMDrOfiTl IDT 1 tPIKLKM 1 UKt

3 3 4 2

3

?

2 1 3 2

2 3

3 2

2 3

3

2

2 1

1 ?

2 3 ?'2 3

2

2

2 3

3

2 3 32 1 2

2

2 1 2

2

2 1 2 2

2 1 3

2

2 1 3

2

2 1 3

2

2 1 3

2

2 1 3

2

2 1 2 2

2 1

1 2

3

1 1

'^HUMIDITY i MOISTURE

2 1 2

2 3

2

3 1 3

2 1 23 3

2

2

3 1 3

3 1 32 2 3 1

3 3

3

2

3 3

3

2

2 2

1

2 1 22 2

1

3 1 2 11

11 THERMODYNAMIC

rKU"tK 1 I OF FLUIDS

4 2

3

1

4 1 3

7

4 2 3

1

3 1 3

2

4 1 3

1

3 1 2

2

2 2 2

3

3 1 4

1

3 2 4

3

3 1 2

?

2 2

3

3

2 3

1 2

X

2 3

3

3

1 1

1 2

2 1

1 2

i 1

1 2

J J

2

2 12

LK 1 UbtH 1 L i

4 1 4

4 1 2

2

4 1 3

2

3 1 3

2

4 1 4

2

3 2

1

3 1 2 2

2 1

1 3 4

2

2 1 42 1 22 1 4

2

2 1 3

2

2 1 3

2

J 1 3 2

1

1 2

1 Z

13 ELECTRICITY

3 2

3

3

3 1 3

2

2 1 3 3

4 1 4

3

4 1 4

3 2

3 3

2 2

2 f-T3

2

2

2

1 1 2

2

3 1

1 2 T 1

1 2

1 3 1 3

2

3 1 3

2

3 1 4

1

2 1 2 2 14 ELECTROMAGNETICS

3 2 4

?

3 2

3

1

2 2

2

1

3 2 4

1

3 1 4

1

3 2

4

1

3 2 2

1 f-n

3

3 2

3

1

2 2

1

1

1

3 2

3

1

3 2

3

1

4 3

3

3

1

''^MEDICAL ULTRASONICS

3 2

2

3

2

2 4 %

2

2 3

2

3

2 1

1

3 1 3

2

1

2 1 2

1

3 2

1 2 16 ACOUSTICS

2 2

3

N

2 1 3

2 1 32 1 2

1

3 3

4

2

1 2

2

3 2

3 2

3 2 1 2

2 1 3

2

2 3

1 2

2

'^RAOIOMETRY 6 PHOTOMETRY

3 1 4

2

3 1 3

2

3

2

4 2 ^-T

3

2

4 1 4 2

2

2 1 2

N

3 1 3

2

4

2

1

i

3 1 4

2

5

1 2 16 SPECTROPHOTOMETRY 2 X \'

?

1 3

2

2

1 1 2

2 2

2

2

2 1 2 21 112 3

1 2

!2

1 1

1 2

2 2

4

2 3

2

2

2 3|

2

2

2 3

2

2 2

2 3

1 2

2 3

2

2

2 1 2

2 1'fAR ULTRAVIOLET

RADIOMETRY

2 2

3

1

2 3 3 2

2 2

2

2

4 2 2

2 2

2 3

3

2

2 2

1

2 3 32 2

1 2

2 2 ] 4^ 1

2 3

1 4

2 2

1 4 20 OPTICS

2 1 2

2

2

1

3 1 3

3 1 2

1

1 N

4

3

3 1

1

4

3

4 1 21

1

2 1 2 1

4 4

4

2 4

4

2 1 3

2 1

1

1

1

21 LASERS4

3

4

2

4

3

4 2 4 4 --24

4

4

4

4 4

1 3

1 1

4 2

4

4 2

3 3 3

22PHYSICAL PROPERTIES

OF ATOMS S MOLECULES

3 4

2

2

2

3 4

4

3

4

2

3

4

2

3 3

3 4

2 23 SURFACE PROPERTIES

4 1 3 ?|3 1

! 2

;2

3 2

2

2

3 2

3

•>

2 2 3 2

3

2

3 ^ 2^3 I

3

2

i 2

3

3 2

3

3 2

3 2 24 IONIZING RADIATION

2 1 3

3 2 4

2

3 3 4

,1 /' 4

3 3 3 23 3 4

3 2 3

4 3 4

2

4 3

3

4

2 2

3

2

2 2

2

1

2 J 4

2

^ 3

2

4

i 2

4

3

^—

4

4

nj—

3

3

7—3"

4

2

1

1

25 AVERAGE3 1 3

1

3 1 3 m23 1 3

2 . . .

3 1 3 I.3 1 4

J . ..

3 1

1

4 1 2

3 1 3

1

3 2 2

,1

3 33 1 3

Z

2 1

1

1

2 1 2

>

4 1 2

1

1

2 2

1

1

2 2

2

2

4 2 2 : ...

2 1 2 I.3 1 2

1

4 1 2

1

4 2

2

2

4 3

1 2

4 3 2

2

2 1

1

1 KEY TO MATRIX ENTRIES

C - IMPORTANCE OF TRANSACT IONS

1 = Purely convenience

2 = Strongly (jesirable

3 = No real alternatives

4 = Essential

B - RATE OF CHANGE

N = Declining

0 = Stable

2 = Growing

4 = Growing explosively

R = Flow of requi rements infcf' dominates

D - (IN)ADEQUACY OF SERVICES

0 = No improvements needed

1 = Could be improved

2 = Marginal

3 = Serious deficiencies

4 = Out of control

A - MAGNITUDE OF TRANSACTIONS

Trivial

Minor

Moderate

Important

Major

? = Unknown. X = Not studied. Blank = 0

4
NBSIR 75-943

TRANSACTIONS f-IATRIX DESCRIPTION

OF THE

NATIONAL SYSTEM OF PHYSICAL MEASUREMENTS

Raymond C. Sangster

NBS Institute for Basic Standards

August 1976

EXECUTIVE SUMMARY

Direct measurements transactions matrices

have been developed to describe the U.S. national system of physical measurements.

Three primary axes have been used: A. Suvplierc

of measurement information, goods, or services.

3. Users. C. !''ecLSurs"-.er.v Sectors (kinds of

measurement quantity) being described. These

three axes define three different kinds of

matrices: I. The matrix for a piven -reasure- nen: ssczor, showing the exchanges of measurement information, goods, and services between

suppliers and users in that sector. II. The

matrix for the invv.ts to a given user sector

from all of the different supplier sectors, for

all of the measurement sectors. III. The

matrix for the outputs of a giver, suvplier seator, to all of the user sectors, for all of the

measurement sectors. A summary supplier-user

matrix has been generated by summing over all

of the physical measurement areas studied,

plus use of independent economic data.

Semi-quantitative estimates are entered in

the intersection boxes in the matrices for the

following quantities: (a) Magnitude of transactions involved, (b) Rate of change of that

magnitude, (c) Relative importance or critical ity of transactions, independent of magnitude, (d) Adequacy of transactions. Basically, a five point (0-4) logarithmic scale has

been used; a change by one unit correlates

approximately to a change in magnitude, for instance, by a factor of three. Most estimates

of these code entries have been made on the

basis of intuitive, informed judgment. Approximately speaking, there is one chance out of

three that any given estimate is improper -- either too high or too low. Zeros have been

suppressed in these tables, so that a blank

box means an estimate of a negligible transactions magnitude.

The measurement sectors studied are these:

Time and frequency

Length and related dim.ensional measurements

Vibration and shock

Surface finish

Mass, volume and density

Force

Fluid flow

Pressure

Temperature

Humidity and moisture

Thermodynamic properties of fluids

Cryogenics

Electricity

El ectromagneti cs Medical ultrasonics

Acousti cs Radiometry and photometry

Spectrophotometry

Far ultraviolet radiometry

Opti cs Lasers

Physical properties of atoms and molecules

Surface properties

Ionizing radiation

The supplier and use'^ sector lists have

been defined to be identical. As a result,

all of the intra-sector transactions are explicitly accounted for, in the diagonal

elements of the supplier-user m.atrices, and

all of the user needs information feed-back

transactions between the users and suppliers

of goods and services are entered. Standard

Industrial Classification (SIC) categories

have been used whenever possible. The

supplier-user categcies employed are the

fol lowing:

Knowledge community

International metrological organizations

Documentary standardization organizations

Instrumentation industry

NBS

Other U.S. national standards authorities

State & local office of weights & measures

Standards & testing laboratories & services

Regulatory agencies

Department of Defense

Civilian federal government agencies

State and local government agencies

Industrial trade associations

Agriculture, forestry, fishing; mining

Constructi on Food, tobacco, textiles, apparel, lumber,

furniture, paper, leather

Chemicals, petroleum, ruDber, plastics,

stone, clay, glass

Primary & fabricated metal products

Machinery, except electrical

Electric and electronic equipment

Transportation equipment

Transportation and public utilities

Trade, retail & wholesale; insurance,

finance, real estate; other services;

printing & publishing

Health services

General public
ECONOMIC ANALYSIS OF THE NATIONAL MEASUREMENT SYSTEM

Barry W. Poulson

Department of Economics

University of Colorado

September 1977

EXECUTIVE SUMMARY

The first part of this study deals with the

concept of measurement for economic analysis,

the quantitative dimensions of measurement in

the economy, and the relationship between

measurement and economic change. Measurement

goods and services yield benefits to users by

extending the physical, human senses in providing information about the properties and

characteristics of physical objects and phenomena. Measurement information is ubiquitous

in the economy; it is used by producers and consumers and as an input at the interface

between buyers and sellers. The making of

measurements is resource using, the instruments, labor, and other resources needed to make measurements each have their costs and

these costs represent the total cost of the

national measurement system. The National

Bureau of Standards has begun to study the macro economic dimensions of the national

measurement system, and one approach in this

study is a measure of the cost of labor and

equipment used for making measurements. The

cost of these resources used in making mea- surements was estimated at $36 billion or 6%

of GNP in 1963. Each of the 78 major industrial sectors incurred substantial expenditures for measurement equipment and labor in

1963. Industries that have experienced the

most rapid rates of growth and productivity

advance also tend to be measurement intensive,

i.e., measurement expenditures are high relative to value added by these industries. The

Metric Study by the National Bureau of Standards also provided insight into the macro economic dimensions of the transition to the

metric system. The cost of conversion to the

metric system over the period 1970 to 1980 was estimated to equal 10" of the total cost of

measurement in the economy in those years.

The second part of the study examines the

measurement system from the standpoint of the

private sector, including the economic rationale for r,easurement by producers, consumers,

and in exchange between producers and consumers; and case studies of the costs and benefits of measurement in the private sector.

While it is impossible to analyze the benefits

of the total national measurement system, it

is possible to examine benefits and costs of

marginal changes in the measurement system.

The third part of the study deals with the

role of government in the measurement system,

incorporating an economic rationale for mea- surement activities by the public sector, and case studies of costs and benefits of activities by the National Bureau of Standards.

Information provided by measurement is a public or collective good to the extent that

the information provided by a single measurement can be given to any number of people

with no one suffering a loss of the information. The production of measurement information is sometimes characterized by increasing

returns; producers of measurement information

often use specialized equipment and personnel

who make relatively few measurements. The

marginal cost of taking an additional measurement likely is less than the average cost, and

the cost of disseminating the measurement information from one person to another is probably trivially small compared to the cost of

making the initial measurement. Finally,

measurement is accompanied by external economies in such areas as consumer protection,

health and safety, international trade, and

research and development. Under the above

conditions the private market system may not allocate resources to the measurement system

efficiently and government intervention in

the national measurement system may increase

the general welfare.

The role of the National Bureau of Standards in the national measurement system is

based on provisions in the Constitution and

on enabling legislation designed to implement

those provisions. This study discusses the

costs and benefits of National Bureau of Standards activities in maintaining basic standards, in conducting measurement research and

development, and in providing calibration,

dissemination, and publication services. The

costs and benefits of selected National Bureau

of Standards projects are quantified, including large force calibration, time and frequency service, coaxial connectors, standard ref- erence materials for iron and steel, standard

reference materials for metals in oil, semiconductor resistivity, and LPG meter calibration. While none of these studies satisfies

the conditions of ri gorous cost benefit or

cost effectiveness analysis, they do provide

insight into the economic role of the National

Bureau of Standards in the national measurement system.

6
STRUCTURE AND FUNCTIONS OF THE NATIONAL MEASUREMENT SYSTEM

Raymond C. Sangster

Institute for Basic Standards

national Bureau of Standards

July 1977

EXECUTIVE SUMMARY

The National Measurement System consists

of all of the activities and mechanisms--

intellectual and operational, technical and

institutional--used to provide physical mea- surement data to allow the creation of the

objective, quantitative knowledge required

by our society. This report describes the

structural and functional aspects of the

System.

Measurement is necessary in conduct of

the life of the individual, pursuit of science,

operations of society, and employment of

technology. Measurements allow human beings

to describe, predict, communicate, decide,

control, and react in dealing with the physical universe. The process of measurement

requires intellectual comprehension of the

phenomenon, quantity, or property to be measured; definition of a reference unit in terms of which the measurement will be made;

existence of a means of comparing the unknown

to be measured with the reference unit; establishment of a physical reference standard

which embodies the measurement unit; agreeTTent within the human community on all

aspects of the measurement process; and

mechanisms to enforce honesty and clarity

in measurements.

Our model of tne National Measurement System involves five structural levels.

I. Conceptual System of measurement

phenom.ena, quantities, units, and definitions.

II. Basic Technical Infrastructure to provide tools, techniques, and agreements

that allow the conceptual system to be

reduced to practice.

III. Realized Measurement Capabilities,

abilities to measure specific quantities to known accuracies under defined conditions.

IV. Dissemination and Enforcement fJet- work, institutions that disseminate realized

measurement capabilities to users and enforce

their use.

V. End-use Measurements.

The base phenomena or quantities to be

measured include length, m.ass, time, electric

current, temperature, amount of substance.

and luminous intensity. Many subsidiary units

are derived from the basic units. The United

States uses both the customary "English" system of units and the modernized m.etric system, SI.

The technical means required to make mea- surements include both physical hardware and

intellectual software. Software aspects include documentary specifications and standards, descriptions of measurement techniques,

educational materials, reference data, predictive methods, and the basic recorded knowledge of science. Hardware aspects include

basic artifact standards, transfer and working

standards, reference materials, and measurement instruments.

Documentary standards and specifications

in the broad sense include international

treaties and conventions; Federal and state

constitutions; Feaeral , state and local laws

and ordinances; engineering standards; and

procurement specifications.

Suitable instrumentation is an indispensable element in any measurement process.

Both physical apparatus and the techniques

by which it can produce the desired results

must be available.

When a given aspect of matter, material,

or fabricated product is sufficiently stable,

well defined, and of wide enough interest,

measurement data that characterize it can become useful as reference data. Existence

of reference data takes a substantial load

off the operational measurement system,

since it eliminates much repetitive measurement. Measurements of unknown systems are often performed by comparison with known

systems, using reference data. Such data

may also be used to calibrate measurement

equipment. Further, properties of materials

may be used to define the measurement process

itself, as in use of properties of water to define the temperature scale.

Reference materials complement and supplement reference data in the Measurement

System. Their function is very similar to that of reference standards, and for some

7
phenomena, such as density, the reference

standards are reference materials.

In some measurement circumstances, the

volume of data needed may be so large, or

the experimental circumstances so inaccessible, that it is not physically or econom- ically feasible to measure all of the desired data. Predictive methods--model s of the

phenomena being measured--then become an essential element of the Measurement System.

The central core of the Measurement System consists of knowledge or science and of

the people who employ it. In some newer measurement fields, there is no further

institutional infrastructure.

The institutional elements of the system

include the documentary specifications and

standardization organizations, the instrumentation industry, central measurement standards authorities, state and local offices of

weights and measures, standards and testing

laboratories and services, and technical

regulatory agencies.

Institutions that produce documentary

standards operate at levels from the international to the individual company or local

governmental unit. Major relevant bodies are

the International Organization for Standardization, International Electrotechnical Commission, American National Standards Institute, American Society for Testing and Materials, Department of Defense, and General

Services Administration.

Over 5000 U.S. companies are known to produce m.easurement instrumentation. The instrumentation industry was at an $8 billion level

in 1974 and has been predicted to grow to $15 billion in 1980.

Legal responsibilities for enforcement of

justice in the use of weights and measures in our domestic commercial marketplaces lie with

the state and local offices of weights and

m.easures; the National Conference of Weights

and Measures is the central coordinating unit.

Its paid staff and executive secretariat are employees of the NBS Office of Weights and

Measures.

Standards and testing laboratories and

services provide physical standardization

services to specific portions of the National Measurement System. The most highly developed institutional structures are in the

military services. The National Conference

of Standards Laboratories provides a central

forum for this portion of the measurement

system. NBS provides its central secretariat.

Promulgation, enforcement, compliance, and

adjudication with respect to the regulatory

actions of technical regulatory agencies re- quire a substantial measurement base and com- prise a significant portion of the System,

making the regulatory agencies the newest re- cognizable institutional structural element

of the System.

The National Bureau of Standards is the

principal authoritative central measurement

standards institution in the United States.

Its calibration and related measurement ser- vices provide access to the national standards

of physical measurement; it operates the

National Standard Reference Data System and

provides Standard Reference Materials; it

provides coordination services to the System

through the Offices of Weights and Measures

and Measurement Services, and through the

Standards and Applications Division, the Office of International Standards, and the Office of International Relations; and it provides a variety of information services.

The U.S. National Measurement System is

embedded in and is part of an international

measurement system, for which the International Bureau of Weights and Measures (BIPM)

is the central institution.

The major trends of our National Measurement System are toward increased complexity,

increased integration, improved quality control, improved information resources, automation, metrication, and an expanded scientific

base. The increasing complexity of our society is reflected in the Measurement System.

Increased integration of the System is required

to improve its ability to provide most econ- omically and effectively the needed measurement data. Improved quality control of the

measurement process, through such mechanisms

as the NBS Measurement Assurance Programs, is

needed to control complexity and effect integration. Automation is vastly expanding the

technical power of the System. Passage of

the Metric Conversion Act of 1975 recognizes

a major trend in the System, which will have

a permanent impact on this country. The scientific developments of the past quarter

century have nearly put us in a position to realize the goals of the founders of the

metric system, namely a universal system

for physical measurements founded on natural

law and a single constant of nature.

8
NBS SP 445-1

THE NATIONAL MEASUREMENT SYSTEM FOR TIME AND FREQUENCY

Allan S. Risley

NBS Time and Frequency Division

June 1976

EXECUTIVE SUMMARY

The major purpose in studying the National

Measurement System for Time and Frequency was

to determine who uses time and frequency, how

they use them, and what their use means to society.

The system is viewed from three vantage

points:

1. The instwjnentation that provides

sources of time and frequency (T&F).

2. The suppliers and users of T&F.

3. The calibration hi erojcshies for T&F

sources.

Most of the work of this study went into

determining the present status of the system.

Historical information was, however, helpful

in forecasts of the future and in putting

NBS T&F activities into perspective.

Instrumentation . The major types of instrumentation which have served as sources of

time and/or frequency over the last 75 years

are pendulums, tuning forks, quartz oscillators, and atomic oscillators. Quartz and

atomic oscillators are the sources of primary

importance today.

The characteristics of precision quartz

oscillators, superconducting cavity oscillators, and the major atomic oscillators are

given, and some of their areas of application

are described. For example, atomic oscillators are shown to be an increasingly important part of the telephone industry and basic

science. The National Bureau of Standards

has been a central element in the research

and development of atomic T&F standards

throughout the some 25-year history of these

standards. The Bureau has also made some basic contributions to the development of

precision quartz oscillators.

Suppliers and Users . A compact description

of fourteen basic supplier-user categories is given in matrix form. The relationship between a given supplier and user is specified

by two descriptors. One descriptor gives the

volume of use of a specified time or frequency output. The other gives the importance (to an organization's internal operations) of that output.

The majority of the effort devoted to this

study of the National Measurement System for

Time and Frequency went into extensive

studies of eight major areas. They are:

- Standards Laboratories

- Users of NBS Radio Broadcasts

- Telephone Industry and Specialized

Carriers

- Military

- Position Location

- Aviation Industry

- Electric Power Industry

- Shipping and Boating Industries

Information gathered in these studies was

vital in completing major portions of the

T&F flow matrix. The communication and position location industries emerge as two of the

most important and sophisticated users of

T&F. The matrix indicates the great importance of the NBS standard T&F broadcasts. A current study is increasing our understanding

of the users of stations WWV and WWVH. The

study confirms that the applications of

communications, navigation, and standards

laboratories are very important. The three

most heavily used aspects of our broadcast

services are voice announcements of time-ofday, one-second "ticks", and standard frequencies . Calibration Hierarchies . The various

sources of time and frequency must be compatible with one another to within some specified tolerance. The stringency of this re- quirement depends on the sources involved and

the uses to which they are to be put. The

necessary compatibility is often achieved by means of a calibration hierarchy.

There is no legal, technical, or economic

force to create a unified calibration hierarchy, and none exists. This is one reason

why it is difficult to comprehend the

National Measurement System for Time and Frequency. Multiple hierarchies do exist, how- ever, and they are basic to the system. Some

of these hierarchies have the force of law

and apply across organizational boundaries.

Others are voluntary or are only binding

within one organization. Those net having

the force of law usually have the greatest

requirements for quality of T&F. To understand why these several hierarchies exist, it

is essential to consider cost and ease-of-use

as well as quality.

9
Four major calibration hierarchies are

those of the standards laboratories (industrial, governmental, etc.), telephone timeof-day, the military, and the telephone

industry. The National Bureau of Standards

has been a part of these four hierarchies.

It is presently a fundamental part of the

standards laboratory hierarchy and telephone

time-of-day. It is also an important part

of the military T&F calibration system.

The National Bureau of Standards' importance

to the telephone industry is much less than

it was in the past (since the telephone

industry is now basing its synchronization

on atomic oscillators), but is potentially

still important.

The Future . The system appears to be

changing in three major ways:

1. ) By 1980-85 there will probably be a widespread, low-cost network of

clocks that are synchronized in the

range of 1 to 10 ys, Today, widespread synchronization, at a cost of

a few hundred dollars per site, can only be done to about 1 ms.

2. ) By 1980-85 the market for frequency

equal izati99 in the range 1 x 10"^

to 1 X 10" will probably be quite

important. The cost per site will

need to be less than about $2000 (in

1975 dollars), and the equipment must

be easy to use.

3. ) The use of quartz watches and clocks,

with digital readouts and the capability of being set to the precise

second, will probably be extensive.

This may necessitate a widespread

calibration network for time-of-day

that is accurate to about 0.1 seconds.

The Time and Frequency Division of NBS

currently has two programs - T&F dissemination via satellite, and frequency calibration

via TV - that address the first two areas

of probable change. A third program directed

to these frequency equalization requirements,

a low-cost, medium-accuracy oscillator, will

likely begin soon.

The third area of probable change, if it

occurs, will be more of an economic than a technical problem. As such, it would not

likely increase the demand for NBS resources with regard to time-of-day.

Conclusions . This study of the National

Measurement System for Time and Frequency

clearly demonstrates that NBS has an important and unique role in the system. The

Question is not whether there are desirable

alternative sources for the services presently rendered, or whether these services are in

fact needed. It is instead whether NBS can perform its function more economically and

effectively. Experimental broadcasts, of

standard T&F via satellite and other developments indicate that it can do both.

The NBS T&F services heive been, and are,

and should be, in the nature of what econo- mists call a "collective good". This is a "good" (product) which is clearly of social

value but one for which a fair market price

is difficult to determine. It is interesting

to note however, that there is now a minimum

of one million dollars worth of specialpurpose receiving equipment in the field.

This equipment was specifically designed to receive the broadcasts of WWV and WWVH or WWVB. Also, if $0.05 per call were received

for the ^BS telephone time-of-day service

this would generate a revenue of $50,000 per

year.

One of the most general things that

emerges from the entire study is that time - and its ever-present companion, frequency - are the great coordinators, the great organizers. Almost any activity today that

requires precision control and organization

rests on time and frequency technology.

(A diligent effort has been made to make

this report comprehensive and accurate as of

March, 1975. Since that time no important

changes or additions have been made. There

have, however, been a few significant changes

in the National Measurement System for Time

and Frequency. The interested reader may

wish to contact the author for his opinions

on these changes.

10
NBSIR 75-926

THE NATIONAL MEASUREMENT SYSTEM FOR LENGTH AND RELATED

DIMENSIONAL MEASUREMENTS: PART 1

J. W. Lazar and R. L. Bach

NBS Mechanics Division

March 1976

EXECUTIVE SUMMARY

The determination of length and related

dimensional measurements constitute the

largest group of measurements made in science, manufacturing, and technology. It has

been estimated that 80% of all measurements

made in industry are of length and displacement. Figures developed from our recent

study of the National Measurement System

shows that an average of $9.4 billion is ex- pended annually by the manufacturing sector

alone to perform dimensional measurements in our economy.

Length and related dimensional measurements have impact upon many areas of the

economy. The largest area is in manufacturing and within manufacturing the firstorder impact areas are air frames and aircraft equipment, ball and roller bearings,

car accessories, domestic appliances, electronic equipment, gears, general engineering,

geodetic investigations, integrated circuit

industry, photogrammetry , research and development, screwthread industry, scientific

instruments, and watches. In many of these

areas dimensional measurements are made to satisfy functionality requirements and little

else. For example, the parts of an automobile engine would not fit properly if they were measured with different micrometers

which were not accurately calibrated.

In the course of our National Measurement

System study in Length and Related Dimensional Measurements, we have established

over one hundred and fifty contacts with

individuals within governmental agencies;

industry; professional societies and organizations; scientific and trade journals; and

universities and colleges around the nation.

Many of these people contacted were sur- prised that we were willing to listen to their problems in dimensional measurements.

In almost all cases, the organizations con- tacted expressed a keen desire to continue

the dialogue established between the Bureau

and thei r oersonnel

.

The primary industrial contact was within

Standard Industrial Classification 3548, Machine Tool Accessories and Measuring Devices.

This industry was expanded into further oro- uct codes such as 35452, Precision Measuring

Tools; 3545211, Comparators; 354221, Gage

Blocks; etc. In many cases the contacts expressed no pressing need for any greater

accuracy in standards for dimensional mea- surements. For example, the accuracy inherent

in various dimensional artifacts (gage blocks,

etc.) and instrumentation (laser interferometers, etc.) far outpaces the ability of many

to transfer displacements obtained from these

devices to other objects. (This is verified

by viewing the results of some recent surveys

contained in our report illustrating inconsistencies of 0. 00177mm to 0.00254mm-70 to 100 microinches-in the measurement of internal diameters of finely finished ring gages.

The primary users of the National Bureau of

Standards' most accurate dimensional measurements are the Department of Defense Primary

Standard Laboratories, the various gage and

measurement instrument manufacturers, and the

private standards laboratories including those

who only service the parent organization.

Another major user category of NBS ser- vices is the machine tool industry. In the

recent U.S. Industrial Outlook 2973, the machine tool industry ranked first in percentage

increase in value of shipments from 1972 to 1973 (27 percent increase from $0,825 billion

to $1,050 billion). An increasing percentage

of manufacturing is being done under numerical control (NC). NC machine tool shipments

are growing three times as fast as conventional machines and it is estimated that 15-

20% of U.S. metalworking machine tool shipments are currently NC. There are pressing

needs to develoo standards and algorithms to characterize the accuracy of these machines.

The reason for accurate calibration of NC

machines is that the accuracy of parts produced is 100% dependent on the inherent positioning accuracy and geometry of the machine

tool

.

The areas of surveying and geodetic investigations are frequent users of NBS calibration facilities (tapes). In recent years

calibrations have been steadily declining and

the 1974 NBS calibrations in this area were

only approximately 20% of the same services

in 1971. I'Je have found that with the recent

advent of relatively inexpensive electronic

distance measuring devices, many comoanies

and individuals are now able to afford these

devices

.

We had initiated steps to interact with

the machine tool industry to a greater ex- tent even to the point of obtaining complin
mentary exhibit space in the International

Machine Tool Show (IMTS) in September 1974 in

Chicago. The specific purpose of our exhibit

was to listen to and view first-hand some of

the measurement problems within this important area. Four hundred and sixty-one people

requested 1300 copies of the various dimensional technology and optics and micrometrology reports. The majority of these reports

are the "how we do it" type.

Space has already been reserved for ano- ther NBS exhibit at the next IMTS in September.

One fact has been repeatedly borne out from all contacts--the need for more awareness of the work being done at NBS and the

need for more publications at multi levels

discussing how to make accurate and precise

measurements.

The results of the recent NCSL audit package measurements show the need for dimensional artifacts to verify the accuracy and

precision of industry's gages and measurement system other than the standard set of

gage blocks, angle blocks, plug and ring

gages, spheres, etc. NBS should develop

these standards and make them available to the various laboratories for their use to

determine the accuracy and precision of their

measurement system. In addition NBS should

develop, in conjunction with industry, a three dimensional artifact to be used to

determine the accuracy of their three dimensional measuring machines as well as their

complex NC machining centers.

12
NBSIR 75-927

THE NATIONAL MEASUREMENT SYSTEM FOR SURFACE FINISH

Russell D NBS Optical Phy:

March

EXECUTIVE SUMMARY

Surface finish measurements involve the

outside surfaces of products, the part which

is most evident to the user and which is frequently responsible for the quality of its

performance. The average consumer can visually detect less than one millionth of an inch

of surface roughness in a highly finished

chrome plated surface. The reliability of

clock motors, the performance of switches,

the effectiveness of razor blades, the safety

of a wheel bearing, all of these depend on careful measurements of manufactured surfaces.

The National Measurement System for surface finish consists of the standards, the

measurement techniques and procedures, the

personnel, and the equipment through which

surface finish measurements are conducted in

the United States. The purpose of this study

was to determine as quantitatively as possible

the structure, vitality, integrity and future

requirements of this measurement system. The

study was initiated by a literature search,

followed by visits to instrument manufacturers,

industrial laboratories and academic institutions.

Each of the hundreds of metalworking industries has a special surface finish requirement.

The highly polished pipes and tanks of' the

dairy, food and hospital supply industries

permit rapid sanitation inspection. Quality

of magazine illustrations depends upon the

surface finish of gravure plates and cylinders.

Automotive safety and reliability is related

to the surface finish of hundreds of bearing,

seals, brake drums, valves, cylinders, etc. The lifetime of surgical implants is directly

related to their surface finish. Military

applications abound. The list is endless.

Yet, each application requires different sur- face micro-features. The most important con- clusion of this study was that NBS should

develop measuring procedures and methods for

analyzing surface profiles so that each metalworking industry can properly inspect its

surfaces according to its needs.

The second most important measurement need

is for instrumentation capable of measuring

new, high technology surfaces such as integrated circuits, computer discs and drums, surgical implants and precision bearings. New

molecular electronic devices require surfaces

which are smooth on the atomic scale. A third

important need is for on-line surface finish

measurement in manufacturing processes.

Young

ics Division

NBS calibrates precision reference specimens of surface roughness (carefully manufactured rough surfaces) according to the voluntary American National Standard B46.1. These

specimens provide calibration users with a readily available physical standard to check

their instruments. The integrity of the mea- surement system is maintained by national and

international intercomparisons and by direct

calibration of users' standards. There are

no regulatory agencies in surface finish.

NBS also calibrates thin film steps for the

microcircuit industry. Since both thin film

steps and surface finish measurements are basically length measurements, NBS bases

these calibrations on the defined unit of

length through interferometry

.

The information gathered in this study

has already provided a solid basis for management decisions within NBS with regard to the

distribution of the very limited resources in

the surface program (2 1/3 man years; $84K

of NBS funds). For example, first priority

has been given to a new calibration facility

which includes computer analysis of surface

profiles. Second priority is assigned to the development of new, high resolution instrumentation. Work with standards committees

also has a high priority.

The study revealed a broadly based need

for research leading to an understanding of

the relationship between the surface finish

and the function of a part. Such a study

cannot be underwritten by instrument manufacturers since the 25,000 instruments now in use are very long lived. Yearly sales of the

largest U.S. instrument manufacturer amount

to only $1 million per year. The metal

working industry spends $54 million yearly

in making surface finish measurements on products whose market value exceeds $40

billion. Yet this effort is thinly spread over hundreds of industries, so that little

reported research is done. These circumstances have resulted in stagnation in U.S.

surface programs relative to governmentsupported foreign research. NBS is now

able to provide measurements and instrumentation to those who wish to pursue such

programs in the U.S. Several small cooperative efforts with industry and a university are now underway.

13
NBSIR 75-928

THE NATIONAL MASS, VOLUME, AND DENSITY MEASUREMENT SYSTEM

P. E. Pontius, J. A. Simpson, and J. R. Whetstone

NBS Mechanics Division

December 1977

EXECUTIVE SUMMARY

Mass, a property of all matter, is

unique in the sense that the concept is

generally deduced from the motion of a body under the influence of an applied

force. It is for this reason the mass

unit for measurements over the range of

objects which can be physically handled

is now, and for some time to come will

continue to be, embodied in an artifact

standard. The mass of one object with

respect to another is deduced from a comparison of the gravitational forces

acting on the two objects. The additive

nature of mass makes it possible to con- struct appropriate subdivisions and

multiples of a single defining artifact.

The present mass unit, the International

Prototype Kilogram, is one of the Base

Units of the International System of

units. Access to the unit is provided by

Bureau International des Poids and Mesures

(Sevres, France) through prototype kilogram

replicas of the unit. Prototype Kilograms

No. 20 and No. 4 provide such access for

the United States, and are in turn the

basis for the U.S. practical mass scale as established by the nichrome kilograms Nl and N2.

Volume is a quantity derived from the

length unit. It is inseparably coupled

with mass. The intent of the founders of

the Metric System was that one cubic decimeter of water at maximum density have a mass of one kilogram. The realization was

proven to be imperfect, thus introducing

for a period of time the liter as a volume

unit. (The current unit for volume is the

cubic meter). Precise mass measurement

requires a knowledge of the displacement

volume of the objects being compared.

Hydrostatic weighings are used to (a)

determine the displacement volume ratio

relative to an object with displacement

volume established by direct measurement

and (b) displacement volume relative to

a known density of the fluid.

Density is defined as mass per unit

volume. Density is a property of

interest for a variety of fluid mixtures.

The density of a fluid in conjunction

with mass measurement is a means to determine the containment volume of a variety of volumetric standards. Mass and

volume are both used to determine quantity

of material. Density is usually considered

14

to be a property of a material, however,

such extension requires an assumption on

the homogenity of the sample measured.

Considering that most of the measurement

processes within the mass, volume and

density measurement systems are based on economic compromise rather than technological capabilities, it is presumptuous to assume that NBS has any substantial impact

on the total system. On the other hand,

NBS, by providing a means for access to the unit, is generally considered to be

a partner in all measurement activity.

Consistency of results commensurate with

requirements is a fundamental to all of

the activities the system supports. Resolution of inconsistencies, by referal mea- surements, by suggested process modification, or by basic changes in measurement

concept is the essential support to the

system provided by NBS.

In spite of the size of the system, it

appears to be in almost complete control

and operating to the general satisfaction

of all concerned. There are several reasons for this: (1) mass standards are intrinsically stable so that the unit once injected into a subsystem remains reasonably consistent; (2) the instruments used

are reliable; and (3) the size of large

subsystems concerned with voluntary standards, weights and measures activities,

government requirements, etc., result in

inertia with respect to change. Through

the mechanism of Measurement Assurance

Programs, NBS or any other interested

party, can test the effectiveness of a given subsystem relative to the intended

use of the measurement results. The

same medium provides a means for a running

audit of the subsystem to insure that

stability is not lost.

With the advent of the NBS-2 kilogram

comparator the precision of measurement

has reached the point where factors

affecting the short term stability of the

defining artifact can be studied. These

factors include cleaning procedures, moisture films and environmental contamination.

Problems associated with the air density

algorithm, e.g., oversimplification and

non-uniformity, introduce small offsets

in the practical mass scales of the various countries. These offsets, too small

to be of concern in most weighing
operations, do not affect the consistency of

practical measurements in a given country.

Resolution of the problem, however, is important in support of work on fundamental

physical constants.

There are certain identifiable

constituencies within the system which rely

exclusively on NBS services. Support to the State Weights and Measures activities,

coordinated by the NBS Office of Weights

and Measures, extends to about 84,000,000

weighings in supermarket chains alone,

which in part supports a 5145,000,000 a year industry which provides the needed

weighing devices. The petroleum industry

has a worldwide investment of $1,800,000,000

in volume measurement facilities at 650,000

sites, manned by 50,000 full time personnel. Each "barrel" is measured on the

average of 12 times between the well head

and the consumer, with either custody

transfer or accountability between each

pair of measurements. All measurements on

local or imported crude and products are based on NBS calibration of metal volumetric provers. In the beverage industry,

approximately $2,500,000 is expended

annually for density measurements in the

production of 515,400,000,000 of products.

NBS is providing support in the development of procedures for both custody transfer and accountability of nuclear material.

The Mass Measurement Assurance Program provides direct support to the Department of

Defense measurement systems, measurement

systems within the nuclear and aerospace

industries, and to manufacturers of

precise weighing equipment.

Problems in the interface between the

Mass and Volume Section and the rest of

the measurement system are, in general,

matters of judgment. The section, recognizing the service roll of measurement, has

worked diligently to establish and maintain

a line of communication with the individual

users (a non-coherent constituency). Such

an approach requires not only an understanding of measurement process limitations

but also a clear definition of what is to be expected from the measurement effort.

The latter requirement is the most difficult, and where it has been possible to define acceptable limits relative to a particular undertaking there has been

visible evidence of success, e.g., savings

to the Food and Drug Administration relative to the calibration of glassware, the

adoption of measurement assurance procedures within the nuclear weapons complex,

and the efforts supporting accountability

and safeguarding of nuclear materials.

Assistance provided to large numbers of users through consultation generally

15

relates to specific problems, the

resolution of which has no visibility.

Generally, most of these problems relate to specifying what the measurement is supposed

to accomplish and there are those who

expect NBS to address his particular

problem, however ill defined.

On the other hand, there are pressures

to work through an interface (identifiable

constituency) both from within NBS and

from other sources. Working through an interface tends to isolate NBS from practical measurement problems. Interfacing

through a system of facilities which are primarily regulatory raises the question

as to whether such a system can provide

advice and guidance with regard to methods

and procedures without compromising its

regulatory function. The legalization of

all measurements, as proposed by the International Organization for Legal Metrology,

diverts attention from the measurement

result to traceability of the unit. In some instances, the consumer of measure- ment data is relieved from the burden of

proving that the results are adequate for

the intended purpose. In other instances,

there is an added burden of not only proving that the measurements are not only

adequate but also legal.

The above listed problems not withstanding; the discharge of NBS responsibilities in the area of mass, volume and

density, is judged to be satisfactory.

Except for the maintenance of certain staff

skills, the level of effort now displayed

results in slow but steady progress. The

nature of the services provided and the

role of the section will change as its

aging staff moves into retirement. The course of activities for the future

includes support to the system as it exists

at the time, and a continuing effort to improve the efficiency of measurement.
NBSIR 75-929

THE NATIONAL FORCE MEASUREMENT SYSTEM

Donald E. Marlowe

NBS Mechanics Division

June 1975

EXECUTIVE SUMMARY

This study outlines the detailed structure

of the National Measurement System as it

pertains to force, and assesses the economic,

social, and technological impacts of force

measurements in the United States.

Force, as a unit of measurement defined by

Newton's Second Law of Motion, is derived

from the basic units of mass, length, and

time. The most precise standards of force

are realized in deadweight calibration

machines such as those maintained by the

National Bureau of Standards, a few government laboratories, one commercial calibration

laboratory and a few industrial metrology

organizations. The deadweight facilities at NBS are widely accepted as the national

standards of force.

In practice, deadweight machines are used

to provide a few precisely known forces for

the calibration of high quality force transducers such as load cells and proving rings.

These secondary standards are used to calibrate the multiplicity of devices for field

measurements. Accuracy requirements in the

measurement system range from the 0.002

percent accuracy of primary standards to

about 10 percent for rough measurements such

as crane overload indicators.

T!ie principal impact of force measurements

can be classified as both social and economic.

The determination of of the strength of a material or its weight is often made to guarantee the equity in trade in a commercial transaction. However, the safety implications of

accurate measurements are obvious . The mea- surement is made to guarantee two parties

that the product is delivered in accordance

with a contractual agreement. Very often

these agreements refer to one or more voluntary consensus standard methods of test. These standards are the result of the economic needs of the manufacturing community to agree upon a common method for making a mea- surement. If the standards of force measurement had not existed, the cost of doing

business would have increased to cover the

cumulative uncertainties resulting from

inaccurate measurements. In addition, with

the current and anticipated growth in mandatory safety regulations, many of which

15

require that products be stronger than every

before, the traditional regulatory requirements of product purity are being amended or even supplanted by force measurement. Clearly, however, these regulations are resulting

in increased product cost to the consumer and

the government must weigh the social benefits

against the economic penalties paid.

The history of NBS and of force measurement in this country are closely linked,

beginning in the 1830's with the distribution of mass standards by the Office cf

Weights and Measures, and continuing today,

with the development of proving rings,

deadweight machines, and load cells and

test methods. In addition NBS has participated in the formulation of many of the

measurement test methods now in use. The

role of NBS at the primary standards level

in the measurement system is to provide

adequacy, stability and consistency to the

system. No other organization is so uniquely placed to provide that function.

Our best assessment of the National Force

Measurement System is that, while some aspects of it are stable and adequately

maintained, other needed parts of the system scarcely exist. The historical areas of

effort in static force measurement, over the

range from 0.5 newtons (0.1 Ibf) to 5 x

10"^ newtons (1 x

10'^ Ibf), are fully adequate

with the level of accuracy now provided and

will remain so for the foreseeable future.

They require only continued routine support

and maintenance. In the areas of dynamic

force, very small static forces, information

transfer and metrication, however, the mea- surement system shows serious weaknesses.

The measurement system for dynamic force

does not exist. The standards and test

methods that are needed to assure the

accuracy of dynamic measurements and the

reliability, efficiency and safety of load

carrying systems under dynamic conditions

such as impact and fatigue are not available,

A similar condition exists for the measurement of very small forces down to 10"'' newtons (10"^ Ibf). Measurements in this

range are needed in such areas as biomedical

research and ultrasonic, nondestructive

testing of manufactured parts.
The information transfer sector of the

system is quite cumbersome. This is a result of the diversity of groups performing

force measurements. In conjunction with the

adoption of a new method for the calibration

of force measurement devices, the system is now beginning to establish the lines of

information return from the end user to the source of primary calibration. NBS is

actively promoting this exchange through

round robin calibration of devices and by

measurement workshops.

The anticipated metrication of force mea- surements has become an area of increasing

concern. In the field of force measurements,

the foreseeable problems of education of

professionals and large, long-lived capital

equipment, have been compounded by the con- fusion about the unit of force which will

evolve in comnon usage. The SI unit of

force is the newton. However, European

common usage is the kilogram-force. This

usage has evolved in much the same way as the pound-force unit did in the U.S. This

confusion will delay the acceptance of the

SI unit and, as a result, the newton may be one of the last SI units which is accepted

in cornion usage.

This study has served to verify many of

the current concepts of the condition of the

force measurement system. Several strengths

and weaknesses have been discovered and

studied. NBS, through its standards and

calibration activities will continue to have

a stabilizing and unifying effect on the

system. NBS should increase its efforts in areas of the system where weaknesses have

been found.

17
NBSIR 75-930

THE NATIONAL MEASUREMENT SYSTEM FOR FLUID FLOW

William C. Haight (coordinator), P. S. Klebanoff, Fillmer W. Ruegg, Gershon Kulin

NBS Mechanics Division

December 1975

EXECUTIVE SUMMARY

Fluid flow is a diverse field concerned

with the motion of a wide variety of fluids

encountered both in daily life and in scientific applications. It encompasses movement

of weather systems by atmospheric winds,

travel and dispersion of air pollutants,

flow around aircraft and spacecraft bodies,

oil and gas pipeline flow, irrigation and

waste water flow, and many others. The types

of fluid motions encountered in descriptions

of these phenomena include closed-conduit,

open channel, supersonic, subsonic, steady,

unsteady, laminar, and turbulent flow.

Measurements of the properties of these flows

are instrumental in the functioning of the

nation's industries and the advancement of

scientific technology, and impact the lives

of every consumer.

This report presents the concept of the

National Fluid Flow Measurement System as it

exists today and the activities and mechanisms it employs to generate and implement

measurement data. The system structure is

presented, and data and information gathered

on the interrelationships between the identifiable parts are reported. To further the

study, more than 200 contacts were made with

trade associations, government agencies,

private companies and universities.

The basic structural element of this

measurement system is the combination of the

fundamental units of mass, length, and time

to describe fluid response to external forces.

Such responses are generally velocity (m/s), mass flow rate (kg/s), or volume flow rate

(m^/s), but can include specialized quantities like Mach number and frequency of flow

fluctuations. Also affecting this response

are the inherent fluid properties, such as viscosity, density, thermal and electrical

conductivity, and bulk modulus of elasticity.

Documentary standards for fluid flow meas- urement represent international, national,

and commercial viewpoints, and are used voluntarily by all parties. International organizations such as ISO and lEC are active in

fluid flow preparing measurement standards,

meter performance standards, and recommended

practices for making measurements and analyzing errors. Nationally, ANSI, ASTM, ASME,

API, and AGA prepare similar standards for

flow measurements commonly encountered in

their application areas.

Measurements are made with a variety of

tools, some of which have been in use for a great many years, and others which are innovatively new. These instruments operate on a variety of principles including differential

pressure, force, convective cooling, sound

transmission, electromagnetic effects, vortex

shedding, and more recently light scattering.

In particular, vane and cup anemometers, water

current meters, and orifice flowmeters are among the most commonly used meters in meteorology, stream flow measurements, and pipeline

flow measurements respectively. A rapidly

growing area of new instrumentation includes

sonic anemometers, laser velocimeters , and

electromagnetic meters, the latter being used

in conducting fluids such as liquid metals,

wastewater and water under certain conditions.

Current capabilities, facilities and ranges

of services of numerous calibration and standards laboratories engaged in gas and liquid

flow measurement are identified. These include

(1 ) Air flow

•80,000 scfm, 2800 psig at the Colorado

Engineering Experiment Station

•3,000 scfm, 125 psig at NBS

•2 to 150 mph at NBS

(2) Water flow

•40,000 gpm, 21 psig at Alden Research

Laboratory

•10,000 gpm, 75 psig at NBS

(3) Liquid hydrocarbon flow

•10,000 gpm, 40 psig at Brooks Instrument Division

•2,000 gpm, 50 psig at NBS

Additionally, over 60 instrument manufacturers

have been identified that are traceable to NBS

through calibrations submitted over the last seven years.

The study indicates a trend of U. S. domestic business in which total sales dollars have

increased for fluid flow measurement equipment

from $67.2 million to $123.8 million in the

period 1963 to 1973. The annual volume

continues to grow with mounting demands for

accuracy and sophistication of equipment. In testimony before the Congress, the manufacturers of scientific instruments testified

that about 25 percent of the annual value of

flow meters and instrumentation sold by the

industry is sold abroad. They believe that

these export sales exceed imports by more than

four to one, and they are the leverage for

export sales of instrumentation and control

systems valued at twice to three times the

flow measurement products.

18
state-of-the-art changes and technological

advancements in fluid flow include both

improvements in traditional instrument designs

and numerous new designs that are finding

increased application. Inflated fluid resource values and increased operating costs

in fluid transportation are forcing a general

rise in the cost to flow a unit of fluid.

Subsequently, greater investments are being

made in increased measurement reliability and

accuracy and in the managing and controlling

of fluid flow. Primary m.etering devices are becoming increasingly sophisticated. In general, the applications which impose the

most urgent requirements on flow measurements

are those which stem from the imposition of

new Federal regulations in fields that include

environmental air and water quality control,

coal mine health and safety, occupational

safety and health, and clean room and work

station requirements. Implementation of these

regulations will increase the requirements for

consistent and reliable measurements of many

flow quantities that cannot be measured

adequately today.

Specific fluid flow measurement needs are identified that include: providing new flow

standards, preparing and disseminating recommended practices, and evaluating and developing instrumentation for the measurement of

low velocities and unsteady speeds of air;

establishing a rational basis for demonstrating consistent flow measurements among laboratories, developing new instrumentation and

standards for fluid metering, and reestablishing the validity of discharge coefficients for

orifice meters; providing new flow standards,

preparing recommended practices for in-place

applications, and evaluating and developing

instrumentation for the measurement of ve- locities and flow rates of supply water and

waste water. A general trend has been discerned underlying these needs in which opportunities to implement measurement assurance and the transfer-of-measurement capability are becoming increasingly important.

NBS functions as an integral elem.ent of the

fluid flow measurement system, conducting

fluid mechanics research and development, con- tributing to flow standards, and generating

engineering data on a variety of flows. Calibrations are offered for instruments to measure

velocity and mass flow rate in air, water, and

liquid hydrocarbons. NBS services impact

government agencies concerned with health,

safety, power, fuel resources, water resources,

weather monitoring, pollution control, and

military and space programs as well as major

segments of private industry such as the oil

and gas industry, power utilities, heating and

ventilating, and transportation. These user

classes share a common concern for adequacy,

accuracy and reliability of the various

aspects of flow measurement.

Fluid flow measurement technology today

represents a constantly changing field, thus

supplying the impetus for a number of improvements within the National Fluid Flow Measurement System. In particular, a need for a national fluid flow reference system was emphasized at the 1974 NBS Flow Measurement

Conference. This need is underscored by discrepancies in flow calibration results, duplication of measurement efforts, the lack of a technical "third party" to arbitrate discrepancies in measurement, and the lack of

facility certification.

New measurement capability is also needed

in both the very small and very large rates

of flow. For example, the automotive industry is targeting for fuel flow calibrations

at approximately .08 g/s with +0.2'^

accuracy. Also, very low velocity measurements are required in air and water flows in

order to meet regulatory requirements being

established for health, safety, and environmental quality. The nuclear power industry

requires measurement of cooling water flows

on the order of 50,000 - 120,000 L/s per

minute, depending on plant power output. Such

Such plants also must be capable of measuring

150" C condensate flows of 1,200 L/s with accuracies of 0.1-".. Additionally, limited natural resources and increased competition for fresh

water between power generation utilities,

industrial users, and agricultural water

suppliers requires improved accuracies of

field measurements.

To meet these needs, the NBS fluid flow

program includes extension of measurement

capability with emphasis on flow ranges

encountered in new regulatory acts, error

analysis in field measurements, meter performance evaluation for improved accuracies, and

maintenance of contact with the user comm.u- nity through conferences and correspondence.

19
NBSIR 75-931

THE NATIONAL MEASUREMENT SYSTEM FOR PRESSURE

Peter L.M. Heydemann

NBS Heat Division

September 1976

EXECUTIVE SUMMARY

The field of this study is the measurement

of pressure and vacuum. This field has developed from humble beginnings in the laboratory

of Evangelista Torricelli in 1644 to one that

encompasses practically all manufacturing

processes, the operation of many types of

machines, important scientific endeavors and our daily life. Industrial applications cover 17 decades of pressure and science adds

another five. Within its range are billiondollar industries using pressure or vacuum

in a significant way to make or control semiconductors, radiators, beer cans, aircraft,

automobile tires, missiles, freeze dried food,

power plants and many other products or manu- facturing activities. Savings of great economic significance can be achieved through accurate measurements of pressure. The safety of

aircraft and of nuclear reactors is ensured

through, among others, pressure measurements.

A significant part of the measurements in

this system are referred to NBS primary standards mainly through the instrumentation industry. NBS calibration services now cover about

five decades of pressure and an expansion to seven decades is planned for the near future.

The calibration services are based on a number

of primary standards, whose accuracy and precision are adequate for most purposes and work

continues to update and improve these standards. The dissemination of accurate measurements into the field is not always satisfactory. Large uncertainties added in the calibration chains are due to inadequate technical

and mathematical procedures, lack of good

transfer standards and lack of training of the

personnel involved. The calibration services

are backed up by training of industrial personnel, preparation of technical manuals and

reports, data evaluation service, laboratory

evaluation service and extensive consultations.

All of these back-up services were prom.pted by

early results from this investigation.

The field of pressure measurements is

currently undergoing rapid changes through

the introduction of new types of measuring

instruments, through an expansion of the

range of pressures used in industry and

through the requirement for lower uncertainties. There is close cooperation between

NBS and the professional and engineering

societies on the development of the necessary measurement standards and test codes.

Increased awareness of possible safety

problems with gages and transducers, and

particularly with high pressure vessels was prompted by the Occupational Safety and

Health Act. Here again NBS is cooperating

with the concerned parties to provide the

necessary engineering standards. All of

these activities tend to lead to an infrastructure that is more strongly focused on the primary standards of pressure at NBS and

the related dissemination services.

A critical need, involving the safety of

people, is felt in the pressure range required

for the calibration of aircraft altimeters.

No central standards are presently available

to ensure uniform measurements throughout

this country and the rest of the world in

this important range. A new standard is,

however, under construction. Also, a measurement assurance program is under study to bring this area under control. Nuclear

reactors require numerous pressure transducers

and at least those related to safety should

be referenced to central, national standards

to ensure that necessary regulations can be

enforced.

A Delphi technology forecast was undertaken to determine the need for vacuum measurements, which are not provided by NBS.

This study is not complete, but it has provided valuable information for planning and

management decision making. Of approximately 125 randomly selected members of the

American Vacuum Society, 68% stated that thev

require vacuum calibrations in the range lO""! to 10^ Pa with an uncertainty of 0.1%, or better, now. 42% now require vacuum meas-_^

urements to better than 1% in the range 10"

to 10"4 Pa. A much larger percentage of

experts in various field? of vacuum measurements foresee these needs for the immediate

future. The most demanding requirements for vacuum measurements were found in the manu- facture of semiconductors, in the space industry and in the vacuum instrumentation industry for the calibration of standard leaks

and the measurement of pumping speeds.

20
NBSIR 75-932

THE NATIONAL MEASUREMENT SYSTEM FOR TEMPERATURE

J. F. Schooley

NBS Heat Division

January 1976

EXECUTIVE SUMMARY

Temperature is a well-defined, basic

scale quantity. It is perhaps the most

commonly-measured of all the physical units

(the possible exception being that of time).

This very ubiquity, however, nas a double

effect. We desire (in principle) that we should have access to very accurate thermometry, but, on the other hand, we tend to take the measurements for granted, so that

our practice of thermometry is often of

poorer accuracy than we suspect.

The direct temperature measurement and

control industry is a large one by any

standards, including several dozen multimillion dollar firms. The amount of

economic leverage which thermometry exercises is multiplied greatly, however, by

the fact that good thermometry is essential

to the commercial success of many industries,

such as semiconductor, steel, chemicals and

plastics manufacturing, medical testing and care, and precision instrument manufacture

and use. Temperature is acquiring a new urgency in other areas as well, with the

tremendous demand for new sources of energy;

with the more stringent pollution and

efficiency requirements under consideration

for automobiles and aircraft; with the heavy

new demands for safety and output being

placed on nuclear power reactors; and with

the desire to map and exploit the ocean's

depths

.

In briefest terms, NBS is meeting the

heaviest of today's demands. The temperature scale is known and can be transmitted

on demand with an accuracy which is satisfactory for most purposes in the range 20-

1300 K. The calibration services offered by

NBS for platinum resistance thermometers,

for liquid-in-glass thermometers, and for

thermocouples answer most of the direct

needs for accuracy in that range.

Yet many human activities suffer a lack

of adequate thermometry, even in the same 20-1300 K range. The particular reasons for

this situation are numerous, but they come

down to a few general problems:

1) Adequate thermometry exists, but it

is not applied to the problem. The

whole field of practical medicine

suffers from this difficulty.

2) The type of measurement which is

needed is not one for which a calibration rationale exists. Fastresponse, hostile environment, and

geometrical ly-constrained thermometry

requirements exist in many fields of

endeavor; many of these are noted in

the full report.

3) The calibration procedure which

exists is often expensive. The

drugstore thermometer is an example of this problem— a $10 calibration of a $1 thermometer is

simply impractical

.

Adding to these problems those which

exist where the temperature scale is not

adequate to today's needs gives one a fair

picture of the opportunities which lie before NBS in thermometry today.

Again in brief terms, NBS thermometry programs lie in several general areas:

1) Generate an adequate scale below 20 K and above 1300 K. 2) Devise calibration and temperature

standardization procedures which will

solve people's problems, rather than

simply transmitting the highest

attainable accuracy.

3) Participate in the development of

thermometry methods in areas where

glaring weaknesses exist.

The NBS temperature measurement activities

impinge on the U. S. temperature measurement

system directly in a multitude of ways. The

most obvious, of course, is through the

calibration of precise temperature sensors.

A second interaction is through NBS participation on voluntary standards committees;

that is a quite important activity, because

it serves both to communicate to others

expertise and data originating at NBS and to alert the NBS staff to problem areas. A third major interaction with the temperature

community arises through NBS staff participation in the development of measurement

methods —in general, this interaction occurs directly with one or more technical

thermometry groups in industrial or scientific

laboratories. Many such instances are detailed in the report.

The National Measurement System study has

been a valuable tool in our effort to focus our limited resources on the most pressing

and susceptible problems. We intend to con- tinue to use this approach to assess and,

as necessary, to modify the NBS temperature

program.

21
NBSIR 75-933

A STUDY OF THE NATIONAL HUMIDITY AND MOISTURE MEASUREMENT SYSTEM

Arnold Wexler

NBS Heat Division

March 1975

EXECUTIVE SUMMARY

Water in the form of vapor and liquid

(moisture) is an ubiquitous substance that

pervades our earth affecting almost every

material, process, device, instrument and

product. Life itself depends on its presence. It plays an important role in the

scientific disciplines, in many branches of

engineering, in medicine, meteorology, and

agriculture, and in such diverse industrial

fields as air conditioning, drying, refrigeration, storage, food processing, electronics and communications. Because of the

innate interaction between water and its

surroundings, and the pervasive effect water

has, it is essential to be able to determine

or adjust the amount present, that is, to be

able to measure and control its quantity in

a given environment or material.

Instruments which measure water content

in the vapor phase are classified as hygrometers; those that measure water content in

the liquid phase, that is, that measure moisture in liquids and solids, are classified as moisture meters. This study delineates the infrastructure of the humidity

and moisture measurement system and the

interrelationships that exist between the

fundamental units, the standards, the calibration procedures, the instruments, and the users. It examines the impact that this

measurement system has on economic, scientific, social and industrial aspects of our national life. Finally, it identifies and

analyzes certain deficiencies and needs in

the National Measurement System.

The primary responsibility of NBS is to provide the central basis for the National

Measurement System, to coordinate that system nationally and with those of other

nations, and to furnish the essential ser- vices leading to accurate and uniform meas- urements throughout the USA. The study

shows that the NBS base for the humidity

measurement system comprises five primary

elements: (1) measurements research, (2)

standards development, (3) development of

special instruments for specific end uses,

(4) prototype development and construction

of new instruments to meet the needs for

secondary standards, and (5) issuance of

publications, such as monographs, to provide

users with information on instruments,

methods of measurement, sources of accuracy,

NBS capabilities, etc. Coordination is

achieved through the dissemination of information, data, techniques, methods, procedures,

references and reprints to Government, industry, colleges, universities, institutes, industrial laboratories, foreign governments

and foreign organizations. One important

link in the coordination chain is the presentation of tutorial lectures before professional societies, workshops, seminars,

clinics, and training courses. Direct ser- vices are offered through (1) calibration of

plant and laboratory standards, (2) tests

for compliance with government procurement

specifications, (3) evaluation and testing

of sensors for special government programs

and (4) tests for the public when commercial,

industrial, or university laboratories cannot meet required needs.

This study categorizes and classifies the

instrumentation in current use in terms of

principles of operation, commercial sources,

and end uses. At least twenty-four distinct

types of humidity instruments and controls

are known to be made in the USA. These are available from more than 100 manufacturers.

Information gathered so far indicates

that the annual business volume of the identifiable instrumentation industry for humidity and moisture measurement and control is

of the order of 35 to 70 million dollars.

This instrumentation impacts on a great

diversity of disciplines, industries and

technologies, creating a second order effect

that is estimated to run into the billions.

In the process industries such parameters

as temperature, flow, liquid level, pressure,

chemical composition, density, viscosity,

humidity and moisture are monitored and regulated. It is estimated that of the total

number of such measurements, humidity constitutes 3.5 percent and moisture 0.7 percent.

The economic loss resulting from measurement

inaccuracies is substantial. For example,

the uncertainties in the determination of

moisture in grain, such as corn, can result

in annual dollar losses from excess moisture

or excess drying of $135 to 375 million.

The amount of water in a material is of

vital commercial concern--in buying, selling,

shipping, etc. It greatly affects the

22
properties of materials. The relative humidity of the environment and the moisture con- tent of a given material must be controlled

for many industrial processes and for the

production of a great many products. Only

through such control can such factors as product uniformity, quality, and process

economy be achieved. Such control contributes to the conservation of fuel and energy

in drying processes. In the testing of many

materials for strength, performance, life,

etc., humidity control plays a paramount

role. For example, a review of American

Society for Testing and Materials (ASTM)

standards has identified at least 45 categories of materials that must be conditioned

in cabinets or rooms prior to test and 84

categories of materials covered by procedures

for the measurement of moisture content.

Other organizations having standards, specifications or procedures involving humidity

or moisture measurement and control include

Air Conditioning and Refrigeration Institute

(ARI), American National Standards Institute

(ANSI), American Petroleum Institute (API),

American Society for Agricultural Engineers

(ASAE), American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc. (ASHRAE), American Society of Mechanical

Engineers (ASME) , Association of Official

Analytical Chemists (AOAC), Cooling Tower

Institute (CTI), U. S. Department of Agriculture (USDA), U. S. Department of Defense

(DOD), Technical Associations of the Pulp

and Paper Industry (TAPPI), Underwriters

Laboratories (UL), International Organization for Standardization (ISO), International Electrotechnical Commission (lEC),

U. S. Department of Commerce— National

Oceanographic and Atmospheric Administration

(NOAA), and the World Meteorological Organization (WMO).

This study has disclosed several shortcomings and deficiencies in the National

Measurement System. As an example, there

are no national standards for moisture measurements. Various technologies have established recommended practices or specifications through voluntary documentary organizations such as The American Society for Testing and Materials. In the agricultural

field, the U. S. Department of Agriculture

and the Association of Official Analytical

Chemists have established reference methods

for determining moisture in specific materials, yet none is directly traceable to NBS.

As a result of this study, and in re- sponse to requests from state weight and measures officials, NBS has initiated a program with the broad goal of providing

the central basis within the USA of a con- sistent measurement system for moisture in

materials and to provide essential moisture

measurement services throughout the

Nation.

23
NBSIR 75-934

THE NATIONAL MEASUREMENT SYSTEM FOR THERMODYNAMIC PROPERTIES OF FLUIDS

Max Klein

NBS Heat Division

August 1975

EXECUTIVE SUMMARY

This report describes the national mea- surement system for the generation of data

on the thermodynamic properties of fluids,

specifically the thermosphysical properties

such as vapor pressure, heat capacity, and

the equation of state. The institutional

and human elements of the system consist of

producers, evaluators, and users of such data.

Thermodynamics describes the transformation of energy and especially its interconversion as heat and work and its involvement

in chemical prodesses. Fluids are ideal

media for applied thermodynamic purposes, so that knowledge of their thermodynamic properties is of high importance. Thermodynamics is a subject of enormous generality

whose utility in science and technology is

is all-pervasive. It plays a central role

in many disciplines of physics, chemistry,

engineering, and the life sciences. Technologies impacted include the design of

engines for producing work (e.g., steam turbines), processes for purification through

phase separation (e.g., distillation and

selective freezing), the design of chemical

reaction systems (e.g., as used in petroleum

cracking and in heating), and the design of means for obtaining very low temperatures

(e.g., as used for preserving material, food

and medicine, and for obtaining special low

temperature properties like superconductivity). Industries impacted include chemicals,

petroleum, natural gas, electric power generation, aircraft production, and transportation. Societal problems affected include the

maintenance of air and water quality, the

production, distribution and consumption of

food and energy, the disposition of waste,

the design and maintenance of health care facilities, and the efficient use of mineral

and material resources. The pervasive influence of thermodynamics makes the assignment of resources to producing outputs for

this measurement system very cost effective

since a small investment can have broad

economic and social impacts.

While economic impacts can be described,

a detailed assignment of meaningful dollar

values is difficult. Scientific and technological impacts of any particular data

generation effort may be equally hard to document. Outputs of such efforts are typically freely available to all comers

(e.g., in the technical journals) and there

is no easy way to know who they are and how

they may be using the outputs. The report

contains a number of detailed examples of the

economic role played by accurate outputs

from this system. By implication, these

describe the economic role of the NBS con- tributions to this measurement system since

NBS outputs are generally of the highest

accuracy.

The total amount of data demanded from

this measurement system by its users is

truly astronomical and cannot possibly be

produced by measurement alone. Substances

of interest are normally mixtures and often

consist of several components, sometimes

distributed over several phases. Data are usually needed for a wide range of compositions, with a range of temperatures and

pressures needed for each composition.

Because of this large data need, the development of theoretical models of varying degrees

of empiricism plays an important role in the

system. Such models can be used in a wide

variety of applications, perhaps the most

important of which are for the rapid estimation of the feasibility of industrial processes, for control of industrial processes

during operation, and in the analysis of ex- perimental measurement designs. Extrapolations are often made to conditions other

than those for which data are available or

to material systems for which no measured

data exist. Such extrapolations must be

based on accurate models, which, in turn,

require in their development data of the

highest accuracy on representative substances . Because material and energy supplies have,

until recently, been abundant and cheap,

highest accuracy has not been a major concern

in the design of most industrial systems

which require the application of thermodynamics. However, because of current needs

to conserve energy and material and to predict the environmental impact of plants before their construction, demands can now be

expected for designs and analyses based on thermodynamic data of the highest accuracy.

24
Currently, the best attainable accuracies

for the thermophysical properties under con- sideration lie in the range 0.01-0.5 percent.

Because measurement of these properties is

difficult and hard to automate, the accuracy

attainable is generally much less than that

needed. By implication, this defines a strong role for NBS in the development of

improved national measurement capabilities.

Needs of the system are many and include

the development of rapid automated measurement methods (especially for pressure and

composition), the production of data on a wide selection of mixtures carefully chosen

to provide insight into the role of molecular

properties, the development of methods for

describing the entire P^/TX surface of fluid

mixtures of various kinds, the development

of accurate measurement techniques for transient equilibrium measurements and those

under extreme environmental conditions, the

development and application of new techniques

(especially optical ones), the development

of fluid theories for systems of non- spherical molecules, and the production of

data and understanding regarding nucleation

phenomena

.

The basis for an NBS role in a measurement

system whose outputs are so directly involved

in technology and fundamental science is

clearly stated in its organic act. The NBS

has, since its inception, indeed been active

in the generation of thermodynamic data,

having produced benchmark data and publications, some of which still play central

roles even after over half a century after

publication. NBS outputs have provided the

knowledge to support vast improvements in

entire industries, such as agriculture

(ammonia fertilizer), electric power generation (steam), plastics (ethylene), and

steel (oxygen). The acquisition of data of

sufficient quality to be called reference

data is still so time consuming as to be

rarely undertaken outside a laboratory like

NBS, hence the especially strong NBS role

at the highest level of data accuracy.

The NBS appears to be doing a good job of

communicating with the user community. Some

improvement is needed in developing communications with the portion of the user com- munity at the ultimate use point. Much has

already been done on this. Meetings between

users and producers of data are being

pi anned.

Satisfying the entire set of system

needs will be difficult for the producer

part of the system. A concerted effort will

first be needed to overcome the negative

effects of declines in recent years. These

declines resulted from an emphasis on short

range research (whereas the major problems

of the system are long range), a lack of

incentive among the mission-oriented government agencies for the support of research

aimed at developing new experimental and

theoretical techniques, a reduction of the

number of students available at universities

and the difficulty of predicting the future

availability of students, and a reduction of

funding for basic research over the past

several years.

These needs contain much which properly

fits the NBS mission. NBS resources are, however, insufficient to cover them even with rather extensive reprogrammi ng , and

selection is needed. The development of

measurement techniques for rapid data taking,

the taking of needed data, and the development of predictive theories of mixtures have

been taken as programs for NBS concern in

the near future, provided sufficient NBS resources are available.

NBS resources available for producing

outputs in this measurement system are small

and have other programmatic demands on them.

Approximately 50 percent of the current

financial support comes from outside sources. These resources, while supporting outputs

into the measurement system, nevertheless

do this from the point of view of the organizations supplying the funds. This reduces

considerably the ability of the NBS to design programs according to the needs of

the measurement system as a whole. With

growing demands expected, NBS resources applied to this measurement system will need

to be increased in the near future.

25
NBSIR 75-825

THE NATIONAL MEASUREMENT SYSTEM FOR CRYOGENICS

Thomas M. Flynn

NBS Cryogenics Division

October 1975

EXECUTIVE SUMMARY

The National Bureau of Standards is not

responsible for only one unit of measurement,

or even a set of measurements. Rather, the

legislative mandate calls for NBS to provide

a base for such a system, coordinate that

system, and furnish essential services. Thus

it is the responsibility of NBS to assure the

proper functioning of the Nation's system of

physical measurement, the National Measurement System. Accordingly, the present

microstudy was conducted to examine and

document the way in which the NBS Cryogenics

Division is meeting its particular responsibility to assure the proper functioning of our system of cryogenic measurement.

The Cryogenics Division of NBS provides

the measurement and data services that support a whole technology. Almost every category of measurement and data service is

offered that NBS as a whole provides: not

just an instrumentation system (including,

for example, pressure, temperature, density,

liquid level, flow rate, etc.), but also

properties of fluids (both thermodynamic and

transport properties); properties of solids

(thermal, mechanical, and electrical); an interface with the users through systems

integration, and advisory and consulting

services; and our own dissemination network

through the Cryogenic Data Center.

This study shows that there are three

specific emerging technologies within this

broad area of Cryogenics which need a com- plete and consistent system of measurements

and data.

For instance, a comprehensive measurement

system for liquefied natural gas needs to be

developed, with special emphasis on quantity

gaging in storage, flow-metering for both mass and heating value, and basic measurements of thermal and mechanical properties

of structural materials.

Basic measurements and data are required

to support the development of hydrogen as a fuel, to improve hydrogen liquefaction efficiency, to recover liquefaction energy, to document hydrogen-compatible materials of

construction, to develop improved insulation

materials, plus measurement tools and techniques for the eventual commercial exchange

of liquid hydrogen.

Si/nprconduotivity connects cryogenic

measurements and data to the electrical power

industry, for power transmission, generation,

and storage. Knowledge needed here includes

heat transfer rates, behavior of helium re- frigerant flow systems, and the degradation

of the superconductors with time and stress.

Other practical uses of superconductivity are becoming apparent, such as the application of

Superconducting QUantum Interference Devices

(SQUIDs) to problems ranging from mineral

prospecting to magnetocardiography . Accordingly, the needs to support this technology

encompass instruments and techniques for

physical measurements plus a technical data

base.

The technologies discussed above show the

importance of cryogenics in commerce in the

U.S. today, and also show its truly diverse

applications. If there were a "General

Cryogenics Corporation" like a General

Motors, it would appear in the top 10% of the

Fortune list of the 500 largest U.S. Industrial Corporations. But it is important to note that there is not a "Cryogenics Corporation", per se. Cryogenics is an infrastructure industry. Similarly, the national

system of cryogenic measurements is an infrastructure of cryogenic technology itself.

The crucial question of this report is, how

well does the measurement and data structure

support the technology as a whole?

This study shows that some parts of the

cryogenic measurement system seem to be

characterized by adequate services and quality assurance (cryogenic temperature mea- surements, for instance). It appears one should have less confidence in other parts of

the system. Pressure measurements, for

instance, which are probably the measurement

most widely made in all of cryogenics,

appear not nearly so well supported, especially pressure measurements in extreme

environments. Attention by NBS to these

issues is in order.

Especially apparent at this time is the

need for a different kind of measurement,

namely one that describes the quality or availability of the commodity. Specifically,

we refer not so much to the flow measurement

of liquefied natural gas, for example, as to the need to measure its potential heating

value.

25
It appears that one component of the problem of cryogenic measurement is that the

field is somewhat static. There has been no concerted national effort since the peak of

the space program.

A second part of the problem arises from

the way cryogenic measurements fit into the

National Measurement System. As long as only

a single agency or one sector of our economy

(National Aeronautics and Space Administration, the aerospace industry) was using es- sentially all of the results of its own meassurements, then that part of the National

Measurement System was internally consistent

and in harmony with itself. Now, however,

cryogenics is becoming more commercialized

and moving to the market place, and thus

external consistency as well as internal

consistency is required to make this part of

the National Measurement System work.

The third part of the problem is perhaps a derivative of the first. Because the field

is relatively static, a crucial question is

not being asked: are there predictable technological developments that will either

create a need for new cryogenic instruments,

or possibly provide an altogether new mea- surement means?

Certain parts of the cryogenic measurement

system at the national level seem to be disconnected, or working independently of one another at this time. For instance, our perception is that the U.S. Coast Guard has

the necessary authority to regulate certain

aspects of liquefied natural gas transportation by setting certain physical standards,

measurement codes, and practices. They may do

this without necessarily having recourse to the NBS. Other national authorities, especially in the area of public safety come to mind. Accordingly, it appears that this part

of the measurement system is disjointed.

There is no objective reason why it should

remain so. It would be in accord with the

NBS mission and tradition to pursue these

issues and resolve them.

A goal of this study was to achieve both

conceptual breadth and depth by examining our

role in the national measurement system as a whole, and illustrating this role with a specific case study, the liquid nitrogen

flowmetering program. This program was instigated by the needs of state weights and measures officials, the industry concerned,

and the public for confidence in the custody

transfer of liquid nitrogen. This effort used

nearly every competence and capability that

NBS has developed: measurement services

(tests and calibrations of meters), property

data (thermodynamic property data for cryogenic fluids), standard codes and practices

(Handbook 44), dissemination services (Office

of Weights and Measures, the National Conference of Weights and Measures), and both

voluntary and regulatory standards activities

(through the most relevant industry group

concerned - the Compressed Gas Association,

and by adoption in state codes).

The general conclusion of this study is

that the cryogenic measurement system is

doing its job adequately at reasonable cost.

There is no widespread feeling of inadequacy,

such as that which led to the creation of the

National Bureau of Standards seventy-five

years ago. On the other hand, there are both

systematic and specific deficiencies that can

and should be corrected. Further, there are

several areas in which the cryogenic measurement system will be subjected to severe

strains in the foreseeable future, unless

appropriate responsive steps are taken soon. Specific needs and responses, which are only summarized here, are documented within

the body of the report.

27
NBSIR 75-935

ELECTRICITY DIVISION STUDY OF THE NATIONAL MEASUREMENT SYSTEM

Norman B. Belecki, Bernadine L. Dunfee, and Oskars Petersons

NBS Electricity Division

June 1976

EXECUTIVE SUMMARY

Electrical measurements are of critical

importance due to the universal use of

electricity as the primary means for the

transmission amd control of energy and data.

The National Electrical Measurement System

is that set of laboratories, organizations,

documents, and people which make possible

and are responsible for all electrical

measurements made in the U.S. at all levels

of accuracy. This document summarizes the

results of a four-year study of that system.

The structure of the system may be con- ceived as having a number of components,

each serving a particular sector of society

and each having distinct characteristics

reflecting differing requirements. Two

major components exist: the industrial electronics component and the electric power

industry component. There are a number of

mi nor parts as wel 1

.

Electrical measurements in the system's

industrial electronics component are used

to insure quality and reliability of

materials and manufactured products, to provide for interchangeabi 1 i ty of components

and parts, and to control manufacturing

processes.

This component can also be further

sub-divided into two general areas: the

measurement-intensive industry segment and

the general industry segment. Measurementintensive industry and ite measurement

system are characterized by high technology

and the need for a very high degree of product reliability. Included in this

portion of the system are the instrumentation, aerospace, defense, communication,

computer, and electronic component

industries. Measurement accuracy within

this segment is insured by a hierarchical

laboratory system in each organization.

Test equipment used for quality and process

control is calibrated periodically using

precision instruments which are in turn

calibrated by comparison with primary standards in the corporate standards laboratory.

These corporate primary standards are then

periodically calibrated at the National

Bureau of Standards or i ntercompared

regularly with standards which have been so calibrated. This system, which in large

organizations can have a complex hierarchy

of laboratories, is primarily the result of

the quality control requirements of DOD,

GSA, and NASA procurement contracts and

the requirements of regulatory agencies such

as EPA and OSHA.

In the general industry segment of the

system, quality control requirements are usually less stringent than in the high

technology segment; accuracies are generally

lower; and the manufacturing processes are

less affected by absolute accuracy of

measurements. Thus, organizations in this

portion of the system are inclined to buy

calibration and repair services from

instrumentation manufacturers, large

corporate laboratories in the aerospace

industry, or companies specializing in

calibration and repair work. As previously

noted, each of these generally maintains a rigid, well-defined measurement support

system.

There appears to be a number of problems

and shortcomings in the industrial electronics component of the system. Among

the most important are a lack of standards

(written and artifact) for the support of

dynamic, high-speed electrical measuring

instruments and automated test systems;

the non-availability in certain areas of

procedures and test techniques of guaranteed

reliability; a potential future shortage of

competent measurement personnel; a failure

on the part of some people in the system

to perceive that calibration is not always

a sufficient condition for assurance of

measurement quality; and an inherent

rigidity in the government contractural

requirements which stifles innovative

approaches to measurement problems.

The electric power industry segment of

the National Electrical Measurement System

can also be divided into two parts: operational and research for improved electric

power transmission and distribution. Electrical measurements play an important role

in the day-to-day operation of the nation's

electric power systems. They are used to control the generation and transmission of

28
electricity, to provide a basis for equitable exchange (energy metering), and for

testing machinery and equipment supplied

to the power companies.

Measurement support for both of these

areas is generally provided by the measurement laboratories of power companies and

those of the electrical equipment manufacturers. In the energy metering area, many

of the state and local public utility com- missions which regulate the power companies

require acceptance testing of watthour

meters as well as retesting of older meters.

NBS calibration of physical standards and

electrical apparatus, both at NBS and in

the power companies' and manufacturer's

laboratories, insures the overall integrity

of the system.

Most of the industry - both utilities

and manufacturers - is adequately equipped

to measure traditional quantities such as current and voltage at levels up to 15 kilovolts. Fewer companies, especially in the

utility sector, have capabilities above

100 kilovolts. At extra high voltage (EHV)

and ultra high voltage (UHV), the utility

companies, with rare exceptions, have little

measurement and calibration capability.

Such capability, however, does exist with

the manufacturers of large electrical equipment. With respect to non-traditional

quantities, such as high transient voltages

and currents, measurement capability is generally available only with the large

equipment manufacturers.

The quality and consistency of electric

power system-related measurements, including

traceability to NBS-maintained standards,

follow the above pattern of measurement

capability. Whenever the calibrations are relatively simple and inexpensive, and if

there is also regulatory incentive to do

adequate work, the system is in excellent

condition. A good example is watthour

meter calibrations. But for higher voltage,

and especially for non-conventional measurements where the calibrations are difficult

to perform and reliable methods are not

always readily available, the system has

deficiencies. Included in this category are

EHV and UHV steady state measurements, and

transient measurements in general.

Electricity will become the predominant

form of energy in use before the end of the

century. Consequently, a large research and

development effort funded by the Energy

Research and Development Administration and

the Electric Power Research Institute is

being directed at ways to increase the transmission capability and efficiency of the

country's electric power systems. New high

voltage and electrical-related measurements

are required as transmission technology ad- vances. Examples of the new technologies

include cryogenic transmission systems, UHV

overhead lines, compressed-gas insulated

substations, and high-voltage direct-current

transmission. Each is a relatively measure- ment-intensive, emerging technology area. While some older types of measurement

methodologies can be adapted for these new

areas, generally they cannot and some significant deficiencies now exist including

accelerated aging tests of electrical insulation, and traceability to national

standards for impulse measurements.

Two important additional components of

the National Electrical Measurement System

are associated with the scientific community

and consumer electronics. Measurements made

in laboratories not under DOD or NASA con- tract are generally supported by local

instrumentation shops. In contrast with

the usual practice in the industrial electronics component, periodic recal ibration is

unusual - calibration is generally performed only before and after a crucial

experiment, or as part of a special

maintenance effort. Measurements in support of consumer electronics, such as TV,

stereo systems, citizen band and amateur

radio, auto electronics, and general electrical work are usually of low accuracy. Consequently, manufacturers' claims of test

equipment accuracy are accepted until malfunction occurs. This portion of the system

has few, if any, serious technical problems.

In summary, the Electricity Division of

NBS provides the basis for that uniform

system of electrical measurement in the

U.S. which permits equity in trade, interchangeability of components, the transmission and distribution of electric power, a means of maintenance for electronic equipment, the ability to control the quality of

production, and the general advance of

science and technology. This is achieved by

developing improved means for realizing,

maintaining, and disseminating the basic

electrical units; by calibrating electrical

standards, instruments, and systems for

industry, government, and the academic com- munity; by developing new instrumentation

and measurement methods; by obtaining basic

data and determining fundamental constants

related to the electrical units; by ensuring

that electrical m asurements carried out in

the U.S. are consistent with those made in

other countries; and by providing advisory

and consultative services.

29
NBSIR 75-936

THE NATIONAL ELECTROMAGNETIC MEASUREMENT SYSTEM

Robert A. Kamper

NBS Electromagnetics Division

June, 1977

EXECUTIVE SUMMARY

Electromagnetic technology is the practical exploitation of electromagnetic waves,

propagating either in transmission lines or freely through the atmosphere, and occupying

a very wide spectrum of frequencies. It has

grown up within the limitations set by

nature.

In the range of frequencies below a few

hundred MHz components are cheap, most

antennas are not very directional, and the

background is noisy. This part of the

spectrum is very heavily used by telecommunication systems, both for business and for

pleasure. High performance brings no significant advantages to these systems, so accurate measurements of the characteristics of

components are rarely called for. The FCC

keeps order among the various users of the

spectrum by assigning frequencies, which are checked routinely, and power levels, which

are rarely enforced. Many electronic systems,

such as computer and servo control systems,

are unintentional transmitters and receivers

of electromagnetic radiation in this part of

the spectrum. Interference is therefore a severe problem, that calls for repeatable

measurements of complex, fluctuating quantities, to be used as the basis for the

assignment of responsibility for its resolution . An extreme case of electromagnetic

interference occurs when fields are strong

enough to injure people. This is a real

danger with radio and TV transmitters and

leaking microwave ovens. Exposure to hazardous fields is regulated by OSHA, supported

by measurements of the field levels in

question

.

Another aspect of electromagnetic waves

in this part of the spectrum that is not yet

fully exploited is their ability to penetrate

to useful distances in rock, soil, concrete,

water, etc., to probe structures of these

materials to supply information for civil

engineering, mining, or agriculture. This

will require extensions in the formulation

of electromagnetic theory and the acquisition

of a base of data on the properties of

materials, which are the subjects of research

that is in progress now.

At frequencies in the range from about

300 MHz to 30 GHz we find a higher preponderance of more sophisticated systems. Here

wavelengths are short enough that highly

directional antennas are quite common. The

background noise is low enough to enable

systems to operate with very weak signals.

This range of frequency is used by most of

the radar systems on which modern navigation

depends, both for ships and for airplanes.

Improved systems such as discrete address

microwave beacons are under development for

air navigation. Microwave systems are under

development for landing in conditions of

poor visibility. The armed services use radar for the automatic guidance of terrainfollowing aircraft and of weapons, as well

as for searching for the enemy. On the

highways, the police use radar for speed

control

.

In addition to radar, this region of the

spectrum is used for telecommunications.

Most long-distance telephone traffic is carried by microwave beams between repeater

stations in direct line of sight with each

other. Satellite communications are a rapidly growing business. The driving force

in the expansion of the telecommunications

industry is the trend towards having distant

computers communicate directly with one another. In addition to demanding large

channel capacity, computers and the asso- ciated digital technology encourage a trend

towards digital communication, and separating

different messages in time rather than

frequency. This also has advantages for

transmitting the voice, in the efficiency of

use of channel capacity and the quality of

the transmission. This is generating a new

demand for time-domain measurements. The

electromagnetic systems that use this part

of the spectrum tend to be expensive, but do

repay their expense with very high performance if they are carefully designed and

maintained. For this they require the

support of accurate measurements.

The region of the spectrum from 30 GHz to 300 GHz is presently regarded mainly as an overflow for users of the crowded channels

at lower frequency. Components become much

more expensive and less efficient in this

region, and the atmosphere has strong absorption bands. The most significant commercial

system, under development in several countries,

is for telecommunication at 90 GHz through

oversize circular waveguides.

There is not much commercial activity at frequencies between 300 GHz and 100 THz.

30
There is much scientific activity in the development of lasers, and the world's most

accurate spectroscopy is done in this region.

Surely conmiercial or military exploitation

will follow, especially of the CO2 laser,

which can already be made to be cheap, efficient, and powerful. There is some activity

with military funding to develop it into a weapon, and the most significant measurements

to be made are of its beam profile and

energy output.

The near infrared and visible parts of

the spectrum are used for all the activities

that the possession of eyesight has suggested

to us, in addition to some that had to await

the development of instruments. These

include the remote sensing of temperature by

radiometry, and all the possible applications

of visible lasers, such as alignment and

measurement of linear displacement, micromachining and surgery, holography, information processing (especially Fourier transformation), video disc recording, and automatic checking of groceries at the supermarket. Obviously, a very diverse collection of measurements must be made to support

these activities, not the least important of

which is the measurement of power and energy

to regulate safety.

One newly developing optical technology

that has much in common with the corre- sponding microwave techniques is telecommunication through optical fibers and the

integrated electro-optical systems that will

be used for transmitters and receivers.

These will call for all the types of mea- surement that have been made on microwave

systems, translated to a different region of

the spectrum with different difficulties and

conveniences

.

In general, electromagnetic measurements

do not attempt to attain the degree of accuracy that is possible for dc electrical mea- surements. Practical systems must be designed to tolerate variations of a few percent

in circuit parameters due to instability of

components and variations in operating con- ditions. Therefore measurements with uncer- tainty less than 0,1% are rarely called for.

Another striking feature of the electromagnetic scene is the high demand for mea- surements of dimensionless quantities, such

as attenuation, phase angle, reflection

coefficient, and antenna gain. There are national standards and calibration services

for many of these, but the trend is to replace them with self-calibration techniques.

Reference to the SI base units is tempered by the modest requirement for accuracy. The ohm can readily be independently

realized in the form of a length of transmission line whose characteristic impedance

can be calculated from its geometry. The

amplitude of waves is determined by mea- suring power, voltage, current, electric, or magnetic field. The essential step in all

these measurements is the conversion of the

quantity to be measured to an equivalent dc

quantity. Reference of the latter to the

basic SI units is a trivial step at the

level of accuracy required.

The foreseeable future challenges to the

National Electromagnetic Measurement System

will come from: heavier use of the "underdeveloped" parts of the spectrum, such as millimeter waves, and the infrared and visible, for communication; wider use of multimode transmission lines; the quest for opti- mum use of time division multiplexing and

the consequent need for the precise characterization of the time-domain response of

devices, systems, and materials; and the new

forms of interference that all this activity

will generate.

31
NBSIR 75-937

THE NATIONAL MEASUREMENT SYSTEM FOR MEDICAL ULTRASONICS

I

P. A. Hudson

NBS Electromagnetics Division

February 1976

EXECUTIVE SUMMARY

The medical applications of ultrasonics

have increased at a rapid rate during the

past five years. Ultrasonics is used for

diagnostics, therapy (diathermy) and surgery.

The most important of these is the diagnostic

applications. Recent advancements in signal

processing techniques and hardware have made

possible the conversion of ultrasonic images

to real-time optical images of good quality.

Systems employing complex phased arrays of

transducers are now in the laboratory stage

and will find their way to the practitioner

within the next two years. A large amount

of activity is going on in these developments

in university laboratories, manufacturers,

and non-profit organizations. The size of

the field of medical ultrasonics is estimated to be between $50M and $100M. These

figures include doctor's fees, research and

equipment production. Projections by knowledgeable people indicate that by 1985 sales

of ultrasonic diagnostic instruments will

equal or exceed sales of X-ray equipment.

Reviews of the literature have uncovered

a considerable concern with regard to the

toxicity of ultrasonic waves on certain parts

of the body. Since ultrasonics is widely

used in fetal studies, a large amount of the concern was in this area. Certain consumer

groups (e.g., Ralph Nader) have testified

before congressional committees detailing

their concern over this new medical tool.

Research into the toxic effects and damage thresholds of ultrasonic radiation are

in progress. However, it is expected to require several years before definitive,

quantitative results are obtained. In the

meantime, measurements are hampered by a lack of standards and measurement consistency between various researchers.

The National Measurement System as it

applies to medical ultrasonics is fragmented,

uncoordinated and inadequate. Measurement

capability for the more important parameters,

power, intensity, and beam pattern, is mostly

centered in development laboratories, certain

manufacturers, and government laboratories.

The Bureau of Radiological Health (DHEW/FDA)

maintains measurement capability designed to aid in their role as the regulatory agency

under provisions of the Radiation Health and

Safety Act of 1968. The Electromagnetics

Division of NBS began standards development

three years ago and now offer a limited

calibration service at 1 , 2, 3, and 5 MHz for

total beam power. Also offered is a measurement service for efficiency of high-Q quartz

transducers in the band 0.5 to 10 MHz. Ac- curacies at NBS are 5% or better as compared

to 10% to 30% in the field. A serious hindrance to more widespread standards dissemination is the lack of a suitable transfer standard device. It is believed that a low-cost,

rugged and reliable device can be developed

for use by both technical and non-technical

(medical) personnel.

National laboratories in foreign countries,

notably West Germany and Australia, have

developed standards for important ultrasonic

quantities and offer a more complete measurement service than does NBS at this time. At

the PTB in West Germany, for example, the

ultrasonics group consists of 15 people and

they have been working in the field for more

than 12 years.

As a result of announcement of NBS services

(August, 1974), numerous inquiries have been

received, calibrations have been performed,

and negotiations are in progress for intercomparisons with two leading university

laboratories. Intercomparisons with BRH have been carried out. This was important

to that agency in that they v;ere able to

proceed with the preparation of regulatory

documents. Information received at NBS

indicates that these documents will prescribe that all ultrasonic medical equipment be metered for power output and that

the accuracy of the metering be within cer- tain limits. This is expected to create a demand for NBS measurement services from

manufacturers who wish to insure that their

equipment m.eets BRH requirements.

Close cooperation and exchange of information is maintained between NBS and BRH. For example, information gained by BRH in

their field surveys and contacts with manu- facturers is passed on to NBS. The BRH program in ultrasonics standards is aimed at development of working standards for use in

their regulatory role. They look to NBS for

development and maintenance of basic standards.

For the future, the Electromagnetics

Division has under development a precision

scanning system (computer controlled) to yield accurate measurements of field and

beam patterns of ultrasonic transducers

and arrays. This system is expected to become a major factor in solving measurement problems which now exist. A new calorimeter which is to serve as a basic

standard for power measurement, is nearing

completion. Thus, the potential impact of

NBS on the important field of medical ultrasonics appears to be substantial.

32
NBSIR 75-937

THE NATIONAL MEASUREMENT SYSTEM FOR ACOUSTICS

David S. Pallett and Marilyn A. Cadoff

NBS Institute for Basic Standards

March, 1977

EXECUTIVE SUMMARY

This report describes acoustical

measurement processes that are motivated by

societal concern over noise and which are continuations or extensions of traditional

acoustical measurements. In addition,

material is presented to describe an important relatively new application of

acoustical technology, the field of

ultrasonic non-destructive testing.

Acoustics, the branch of science dealing

with sound, has become a field that is an important element in many aspects of our contemporary technological society.

Acoustical measurements are performed in

order to quantitatively characterize noise

levels, to specify noise emissions, to specify the acoustical properties of

architectural materials, and to quantify and

interpret human response to sound, to name

but a few examples. Applications of

acoustical principles to be found in other

aspects of our technology include the use of

ultrasonic acoustic energy to identify and

characterize flaws. These ultrasonic

measurements are performed in order to meet

the increasingly severe requirements for

mechanical integrity and reliability as well

as in response to pressure for material

conservation and increased productivity.

Although the report describes a diverse

range of acoustical measurement tools and

methods, there remain numerous acoustical

measurements not covered in this report.

These deliberate exclusions were made for

two major reasons. First, resources -- in

terms of available time, manpower, and

funding -- were too limited to carry out the

comprehensive literature study which would

have been required to survey adequately such

a broad topic as acoustics. Secondly, it was decided to direct attention to those

areas in acoustics in which the necessity of

obtaining increased objective quantitative

knowledge has recently become apparent, and

that is primarily in the area of noise

abatement and control

.

The principal user groups for noise

measurements include various departments,

agencies, and laboratories of Federal and

State governments; manufacturers of

measurement instrumentation, products for

which noise emissions are of immediate or potential concern, or architectural

materials; acoustical consultants,

architects, and urban planners; and

university faculty and staff members

affiliated with research laboratories or speech and hearing clinics. Users of

ultrasonic non-destructive evaluation

equipment include the aerospace, power

generating, construction, metals production,

auto manufacturing, metals fabrication, and

railroad industries.

There are numerous identifiable social,

technological, and economic impacts for

these measurements. Measurement of noise is now an important element in the protection

of hearing. Conduct of some ten to twenty

million annual audiometric examinations will soon demonstrate an increased level of awareness of the effects of noise and of the

importance of hearing preservation in our

society. Acoustical measurement processes

are explicitly involved in noise control and

hearing preservation. Economic impact is more difficult to assess quantitatively, and

a well-defined picture of the economic

impact of acoustical measurements is not yet

available.

The work of the National Bureau of

Standards in acoustics and its role within

the infrastructure of the National

Measurement System is based primarily upon a number of interactive processes. The

substance of the interactive process

consists of such elements as provision and

interchange of test and calibration data and

technical reports, as well as the

development of calibration and test

procedures and measurement methodologies.

Participants in this interactive process

include standards organizations, various

industrial representatives (including trade

associations and individual manufacturers),

professional societies and universities, and even representatives of foreign

laboratories. Because of the increased

legislative attention given to noise and its

control, and the consequent promulgation of

regulations that require measurements for

enforcement, the adequacy of required

measurement methods is now the subject of

intensive study, both within NBS and within

other Federal, State and local agencies.

The study indicates that there is a continuing demand for improved accuracy and
precision in both the development and

calibration of acoustical measurement

instrumentation and in the evolution of

improved measurement methods. Research in

these areas has traditionally been a strength of the NBS program in acoustics.

The study also illustrates that a significant increase in the number and scope

of legislative actions directed toward noise

control has taken place. State and local

governments are becoming active

participants. Inconsistencies in the

relevant measurements required for effective

implementation of these regulations

introduce ambiguities. These ambiguities

also involve the imprecisions inherent in

these measurements. Consequently,

inequities in trade can arise. A need,

therefore, is shown for acoustical research

directed toward the basic physical

phenomena, the study and evolution of

improved measurement facilities and

instruments, and the improvement of the

required measurement methodologies.
NBSIR 75-939

THE NATIONAL MEASUREMENT SYSTEM FOR RADIOMETRY AND PHOTOMETRY

Henry J. Kostkowski

NBS Optical Physics Division

November 1977

EXECUTIVE SUMMARY

This National Measurement System Study is on the measurement of light. More specifically it is concerned with the measurement

of the energy or power in ultraviolet, visible and infrared radiation.

The study was undertaken to determine the

importance of such measurements in the U.S.,

the accuracy and ease with which they could

be made, the adequacy of this capability,

and finally, the nature of the program NBS

should pursue in this measurement area.

In the last ten years, the economic and

social impact of radiometric and photometric

measurements has increased significantly.

Such measurements are required in the manufacture of cameras, color TV and copying

machines. Ultraviolet radiation is being

used extensively for the polymerization of

industrial coatings. An attempt is being

made to use radiometry in measuring atmospheric temperatures for the purpose of

forecasting weather. New solid-state lamps

(LEDs) are used in a variety of visual

displays. Phototherapy is used almost ex- clusively in the treatment of some diseases

(e.g. jaundice in the newborn). Regulatory

agencies are concerned with the hazardous

effects of UV on the eyes and skin (skin

cancer), particularly in industrial environments. Dentists are now using a com- mercially available "UV gun" for curing

various new dental materials. Applications

in the lamp industry are increasing because

of our energy problems. Twenty-five percent

of the U.S. electrical power is used for

lighting, and thus, developing lamps that

will produce the same light for less electrical power has a high priority. Improving the utilization of solar energy will

require better measurements than are now

available. All of these uses and applications of light require radiometry or photometry. Many of them will require a state-ofthe-art accuracy of a few percent in order

to achieve their objectives.

Unfortunately, the current radiometric

and photometric measurement system is inadequate for the many uses and applications

described. Radiometric measurements are among the most difficult measurements to make. The radiant power varies with position, direction, wavelength, polarization

and time, and the responsivity of most radiometers also varies with these and other

parameters, making such measurements a difficult, multi-dimensional problem. In addition,

most of the people needing radiometry

have not been trained in the field. There

are relatively few experts available. As a result of these two factors, measurement

accuracy is poor and large differences in

measurement are widespread. Much time and

money is spent trying to resolve these differences, particularly when mass produced

products require components from various

companies and these components must meet

radiometric or photometric specifications.

The cost of inadequate radiometry and

photometry is very high. The electro-optical

industry alone has annual sales approaching

15 billion dollars per year. A leading

instrument manufacturer estimates that about

$200 million is spent each year in calibrating radiometric systems or resolving

discrepancies in radiometric measurements.

If better radiometry can improve long-term

weather forecasting as predicted, the economic

impact would be tremendous. It is virtually

impossible to estimate the cost of inadequate

radiometry relative to medical and safety

applications, but public health and safety

are certainly given a high priority in this

country.

Adequate radiometry today means making mea- surements with a few percent accuracy commonplace. This will require greater expertise in

the system and more accurate, easy-to-use, and

less expensive standards and techniques.

NBS has addressed itself to solving these

problems. It helped organize the Council for

Optical Radiation Measurement (CORM), a group

largely representing industry and providing

detailed information and a consensus of the

needs in the system. It has worked with the

Illuminating Engineering Society (lES), the

Commission Internationale de L'^clairage (CIE),

and the Infrared Information Symposia (IRIS).

NBS is developing more accurate, easy-to-use,

less expensive standards and techniques and

is beginning to monitor the capability of the

system by interlaboratory comparisons. It has created specialized publications to insure that all this information is efficiently disseminated. Finally, NBS is also

starting to produce a Self-Study Manual for

Optical Radiation Measurements. This is

expected to significantly upgrade the level

of expertise in the U.S. in this area.

35
In summary, this study has shown that

radiometry and photometry are having a significant economic and social impact in the

U.S. today and this impact is expected to increase. The capability of this portion

of the measurement system is inadequate for

today's needs. An accuracy of a few percent is frequently needed; 10-50 percent is commonplace. The reason is that radiometric and

photometric measurements are very difficult

to make, and there is too little expertise

to make these difficult measurements. NBS'

program is designed to improve the situation

by (1) making the measurements easier through

simpler, inexpensive standards and techniques and (2) increasing the expertise

through a Self-Study Manual on the subject.

36
NBSIR 75-940

THE NATIONAL MEASUREMENT SYSTEM FOR SPECTROPHOTOMETRY

Wi n iam H. Venable , Jr. NBS Optical Physics Division

August, 1977

EXECUTIVE SUMMARY

This microstudy covers the field of spectrophotometry and the work in this field being

conducted in the Radiometric Physics Section

at NBS. In general, spectrophotometry provides an answer to such questions as how much

light is reflected by an object or transmitted

through it. ("Light" is used here in a very

general sense which includes the light we see

and other electromagnetic radiation in the

adjacent portions of the spectrum which behaves in a manner similar to light.) The

technological significance of spectrophotometric measurements lies in its use as a tool

for determining something about the object.

Combined with a knowledge of the way the human

eye functions, spectrophotometry can be used

to predict and control the way an object will

appear. Thus spectrophotometry can become

the "eye" for the automated production and

quality control in the manufacture of objects

and materials in which appearance is important. Taken with knowledge of the optical

properties of chemicals, spectrophotometric

data forms a basis for quantitative chemical

analysis in a huge variety of fields from

clinical testing to manufacturing. There are countless other applications in such areas as photography, remote sensing, warning devices

for safety, and non-destructive inspection of

agricultural products.

As the foregoing indicates, the user com- munity is huge. The processes in which spectrophotometric measurements are or could be

significant are estimated to account for about

one-fourth of the gross national product. It should be pointed out, that in most cases, the

spectrophotometric measurement is only a small

part of the total operation for a given user.

As a result, the spectrophotometric measurement community for the most part is made up of

a huge number of widely diverse individuals

who use spectrophotometry as a tool and who

do not have a strong knowledge of the field.

They rely on the instructions which come with

their instruments and on standard test procedures. This large, highly diverse community

is the productive level of the spectrophotometric community.

At the next level above the user community

lies practically all of the rest of this

measurement system, e.g., the instrument manufacturers, the military, government, and

commercial measurement laboratories, and the

37

many committees which develop and publish the

standard measurement techniques interact

directly or nearly directly with the user community. The standards and services

supplied by this second level are adequate

for some applications but if the full value

of spectrophotometry is to be realized, the error in these measurements must be reduced

by a factor of ten

.

In order to bring about such an improvement in the measurement system, a strong

capability for highly accurate measurement

must be built up. The instrumentation and

labor required for this effort would be too

much for any one of the instrument manu- facturers of commercial laboratories to handle, much less for any individual user. Economically, this capability should be in

a central laboratory, and, in the interest

of fairness, this laboratory, should be on "neutral ground". Quite obviously, NBS is

the laboratory for such universal standardization of these measurements to take place.

From the mid 1950's until very recently, the

spectrophotometry program at NBS was small

and geared principally to measurements as a service to the rest of NBS and to other

government agencies. However, during the

past two years, the spectrophotometry program

at NBS has been revised and our measurement

capability is being built up to the point

where we can supply the leadership required

for increasing the accuracy and extending

the range of spectrophotometric measurements.

Through this study and through our routine

contacts with the technical community, we

have clearly recognized the magnitude of the user community and the potential advantages

which can come from an order of magnitude

improvement in the measurements. We have

gained an insight into what needs to be done

by NBS in this respect and have initiated a program through which we can do our part.

The new NBS capability should be fully

developed during the next five years, at which time the full impact of our efforts

will begin to be felt. The potential benefits

which can be obtained from improving spectrophotometric measurements is estimated to be

as great as two billion dollars annually. It

is our intent to provide leadership which

will enable the scientific, technical and

industrial community to obtain those benefits

as readily as possible.
NBSIR 75-941 THE NATIONAL MEASUREMENT SYSTEM FOR FAR ULTRAVIOLET RADIGMETRY

William R. Ott

NBS Institute for Basic Standards

June 1977

EXECUTIVE SUMMARY

Radiometry is the quantitative measurement of radiant power. By restricting the

region of interest to the far ultraviolet,

the wavelength region from about 10 nm to 300 nm is specified. The corresponding

photon energy range extends from 125 eV to

4 eV, very large compared for example with

the visible range which extends only from

3 eV to about 1.8 eV. Because of this, a wide variety of phenomena and radiometric

applications can be found throughout the

far ultraviolet. This report is a description of the evolving National Measurement System in the field of Far Ultraviolet

Radiometry; at the same time a critical

evaluation of the NBS role in the System is

made in order that we might optimize our efforts toward serving the System and thus

promote progress toward the national goals

of our government.

The technological importance of the far

ultraviolet spectral region stems essen- tially from: (a) the increasing use of high

temperature devices such as the fusion

plasmas being produced in the search for new energy sources; (b) the industrial

potential of far ultraviolet and x-ray

lasers; (c) the high energy content of

short wavelength radiation with the con- sequent ability to drive and control chemical reactions; and (d) the very low diffraction limit of short wavelength radiation. The problem areas where ultraviolet

radiation measurements are important include both national research and development programs and major industrial applications in the following fields:

(1) Industrial Photochemistry

(2) Bacteriological Control

(3) Environmental Studies

(4) Medical Therapy

(5) Fusion Research

(6) Space Science

(7) Ultraviolet and X-Ray Lasers

(8) Plasma Chemistry

(9) Photobiology

In order to evaluate whether or not an ultraviolet radiation measurement capability is in the national interest and

affects our well being and the common good.

both the social and economic significance

of those activities which depend upon such

a capability are discussed. Examples of areas of impact where the ultraviolet

measurement system enjoys considerable

social and economic leverage are national

health and safety and solar simulation.

Numerous studies which are cited in this

microstudy indicate that ultraviolet radiation can be dangerous and can cause such

things as incapacitating burns (sunlamps

and arc welders are the biggest culprits),

premature wrinkling, and skin cancer. In view of the increasing use of ultraviolet

lamps in our society for illumination,

advertising, bacteriological control,

medical treatments and industrial polymerization applications, and in view of our recent concern with the disastrous con- sequences which would result from even a small increase in solar ultraviolet transmission through the atmosphere, a measurement capability is absolutely necessary.

It is used not only to monitor the light

environment and thus guarantee radiation

safety but also to enable definitive ex- periments which will accurately specify the

safety limits themselves. If the social

benefit is obvious, the economic leverage

is no less so. Our work force is weakened

considerably not only by work-related

radiation accidents involving arc welders,

high intensity sterilization lamps, etc.,

but also by the common weekend-in-thegarden sunburn. Outdoor workers are especially affected and experience in addition

a significantly high incidence of skin cancer. The statistics are available and

one can easily estimate the economic impact

of thousands of careers terminated in this

way.

Accelerated weathering machines and

solar simulators are used by the paint,

dye, plastics, and building material industries as well as for space-related

applications, for example, in determining

the lifetime of solar cell arrays. Correlations up to now have not always been

significant partly because the irradiance

is specified by time exposed and not in

terms of intensity and spectral distribution. Because of the uncertainties in the

38
lamp characteristics, not only are large

amounts of money and effort wasted annually

in the collection of misinformation and in some cases by the production and distribution of inferior products, but also the

industries are discouraged from increasing

their efforts toward developing superior

weather-resistant products. Ultraviolet

calibrations of these machines for wavelengths as low as 121.6 nm are required

accuracy, consistency, and cost effectiveness are to be achieved in testing. Manufacturers of the simulators are equally

' concerned with improved diagnostic methods

since their world market could be threatened by the imposition of radiometric

specifications on the machines by international standardizing bodies.

The NBS program on far ultraviolet

radiometric calibrations is carried out in

the Plasma Spectroscopy Section (232.07)

and in the Far UV Physics Section (232.03).

It consists of several complementary com- ponents and makes use of absolute detectors

as well as standard radiation sources. The primary consumers of our far ultraviolet services have been the space scientists who need absolute detectors and sources to determine the response of

spectrometric optical systems. At present

these users dominate by about 10:1 over

the combined number of all other consumers.

This statistic is due mainly to the chronology of how the National Measurement

System has evolved: research and scientific explorations (NASA in the 60' s)

force the development of advanced technology which, in turn, stimulates and makes

possible new applications of that technology.

There is substantial evidence that we are entering this latter productive and potentially explosive stage. Nevertheless, it is

shown in this report that there is little

systematic interaction between the standards

community and the users groups. Aware of

this evolution and the changing priorities,

NBS cannot only be open and receptive as it

has always been, but must actively develop

new contacts. The secondary standards labora

tories and the instrumentation industry are

two sectors of the measurement system with

which NBS could achieve a high leverage impact

i through an expanded standards program and improved communications. It is also recommended

that NBS initiate more mi ni -workshops similar

to the successful meetings involving several

regulatory agencies, which we organized during

1972-74. Photochemical and biomedical applications should be the first area where NBS should

generate such a new initiative.

There are several technical recommendatiors

in this report which are the result of some pre

liminary contacts of the type just discussed.

(1) NBS, although boasting two complementary programs toward the development of

primary, far ultraviolet radiometric source standards, currently supports no efforts to develop reliable transfer standards. This

situation must be rectified in view of

requirements for field uncertainties of

about 1 percent between 200 nm and 300 nm,

5 percent between 90 nm and 200 nm, and 10

percent below 90 nm.

(2) We must plan to develop ultraviolet

source standards of spectral irradiance,

the unit of principal interest to the users. Unless this is done, we must leave

it up to the individual users to generate

their own irradiance standards by way of our spectral radiance standards. Not only

is this an expensive and counter-productive

way to go, but also it makes for a very

uncertain traceability to NBS.

(3) The calibration limits for N3S ultraviolet standard detectors must be extended

toward both shorter and longer wavelengths

to fully cover the range 5 nm to 400 nm. Only then will several high priority users

be adequately served. Uncertainties must be

lowered to the 1-5 percent level, at least

for wavelengths above 115 nm.

(4) A new NBS service should be initiated

which would provide for monochromator or filter transmission calibrations in the far

ul traviol et.

(5) Internal consistency among the various

NBS radiometric standards must be systematically checked. This includes such independent

standards as photodiode detectors, synchrotron

radiation, hydrogen arc radiation, electrically calibrated radiometers, and tungsten lamps.

39
NBSIR 75-942

THE NATIONAL MEASUREMENT SYSTEM FOR OPTICS

Dennis A. Swyt

NBS Mechanics Division

March 1976

EXECUTIVE SUMMARY

Measurements in imaging optics are fundamental to manufacture of products ranging from

spectacles, microscopes, photographic goods

and microfilmed documents to aircraft, nuclear

reactors and oil pipelines; measurement quantities of interest are "diffuse visual density" which characterizes the darkness of photographic, radiographic and ink-on-paper images;

and numerous measures of optical system performance (refractive power, resolution, optical transfer functions, etc.). Diffuse visual

density is defined by ANSI documentary standards; many voluntary standards and federal

specifications relate to its application.

Measures of optical system performance are

in general undefined by documentary standards.

These measurements are most intimately re- lated to the photographic and optical industries. In figures characteristic of years in

the early 1970's, these goods included $1.3

billion worth of sensitized photographic goods,

$4 billion in photographic products and $485

million in lenses and optical instruments.

Typical sales of $5 million in densitometers

and $35 million in non-opthalmi c test equipment provided some of the means of indication.

Some of the measurements are performed by:

*1 8,000 eye examiners and 20,000 dispensers

of lenses supplying 100 million wearers of

corrective lenses with opthalmic lenses

costing $190 million in a $2 billion system of eye care. *10,000 medical radiologists, supported by

90,000 technicians, examining an estimated

325 million x-rays of 110 million patients

at an estimated cost of $4 billion.

*15,000 industrial radiographers performing

an estimated 45-90 million measurements in over 5300 plants at an estimated cost of

$350 million. Typical data for products

affected by these measurements are $7.6

billion in aircraft production, $4.6 billion in missiles and space hardware, $64

billion in nuclear reactors contracted for

in the period 1965-73, and $600 million of

pipelines constructed annually.

NBS provides diffuse visual density standards, microcopy resolution charts and an optical system and lens evaluation service.

The density standards are used by, among others, the eleven companies which accounted for

virtually 100% of photo film sales and 80% of

equipment sales in 1970; the standards are required by AEC, NASA, DOD, FAA, and DOT

specifications. The NBS Microcopy Resolution

Chart is a voluntary standard for the $450

million microfilm industry and a mandatory

standard for use in DOD microfilming operations; the NBS chart is on the verge of formal acceptance as an international standard.

The lens testing services have primarily

benefited federal agencies.

In an eighteen month period in which outputs of NBS were evaluated, a program which

in 1973 consisted of 3 1/2 man-years of effort

with a $319,000 budget (of which $118,000 was from other federal agencies) provided 15,000

microcopy charts, 200 density standards, 10

interferometers for an AEC prime contractor,

a handful of lens tests, a number of special

studies for federal agencies, a significant

amount of testing and consultation on optical

systems for security-classified federal agencies, as well as major publications on the

theory and operation of advanced optical systems . The primary effect of this study of the

measurement system has been to reveal the

nature of the users of NBS services and the

degree of their dependency on the standards

NBS supplies. Incremental analysis, the

tracing of the economic effect of NBS ser- vices through causal chains to final products

and services, has not proven feasible.

Recommendations regarding NBS programs are

to upgrade density measurement capabilities,

to maintain without further expansionary

investment the lens testing services, and to channel image analysis measurements toward

optics-related measurement problems. Discontinuation of NBS services in this field,

it is thought, would result in the provision

of the same services by one or more other

federal agencies. Continuation of the study

of the measurement system might involve

assessments of the desireability of NBS ref- erence standards of reflection density and of

the interest of optical manufacturers in a round-robin approach to measurement assurance

in lens testing.

Documentary data and informed opinion for

this study have been acquired by means of a survey questionnaire to 150 users of calibration services; canvassing letters to 30 instrument manufacturers, 25 trade and industrial

associations, and 50 optical companies; personal interviews with 30 individuals at organizations throughout the country; innumerable

telephone contacts; as well as direct use of

documentary and library source materials.

40
NBSIR 75-944

THE NATIONAL MEASUREMENT SYSTEM

FOR THE PHYSICAL PROPERTIES OF ATOMS AND MOLECULES

J» W. Cooper, A. V. Phelps and S. J. Smith

Institute for Basic Standards

September 1976

EXECUTIVE SUMMARY

The national activity in the measurement,

compilation, evaluation, and dissemination

of atomic and molecular data is represented

here as a component of the national measurement system. The significance and validity

of this representation rests largely on the

role of the National Bureau of Standards in

the development of measurement techniques,

the encouragement of standards of measurement performance and in efforts to generate

an adequate and wel 1 -documented data base

effectively constructed to meet the needs of

the user cormiuni ty

.

The level of national activity in this

field is estimated to be in the range of

20-25 million dollars annually, and the

NBS programs in atomic and molecular mea- surements and in data evaluation and dissemination are approximately 3 million dollars

of the total. The output of this activity

has a direct impact upon applied research

and development projects currently funded

at a level well in excess of a third of a billion dollars annually. The largest of

these are ERDA-supported programs aimed at energy generation and conversion (conventional controlled thermonuclear research,

laser fusion, laser isotope separation,

coal -burning magnetohydrodynami c generators,

etc4. There are large potential benefits

for a broad range of industrial research

and development activities. Atomic and

molecular measurements are also extremely

important to basic research in astrophysics,

atmospheric physics, plasma physics and

aerodynamics

.

Examples of recent and current contributions with large impact range from data on specific single processes which play a determining role in some development problems, such as the control of ion propulsion

engines for NASA, to entire data sets with

which the behavior of a laser plasma or an MHD generator may be programmed and studied

with electronic computers. The maturing

of this kind of computational capability

is of the greatest significance for the

advancement of the technology of plasma

devices. This significance is well recognized by the atomic and molecular research com- munity which sees it as the vehicle for meaningful contributions toward solution of urgent eco- nomic and social problems. It is increasingly

recognized within ERDA energy source development programs as an essential tool for orderly

progress in their projects. It is generally

less widely recognized in the industrial development community.

Certain atomic and molecular properties

are used at the limits of achievable accuracy as the basis of the accepted standards

for length, time and frequency. An atomic

standard for mass is foreseen. Precision

measurement techniques developed by workers

in the field of atomic and molecular physics

have been incorporated in the development of

standards for measurements of other quantities, for example, gas pressure and radiant

flux.

It is recommended that the National Bureau

of Standards undertake activities which involve

direct participation and interaction with the

major ERDA projects, that it use this experience to guide development of new measurement

methodology in atomic and molecular physics,

and that it undertake to ensure the reliability and adequacy of the data base needed for

these projects. Furthermore, it is recommended that the NBS expand its contacts with private industry, develop increased awareness of

the methodology for applying atomic and molecular data to technological development, and

provide such advice and guidance as will as- sure the effective utilization of this sector

of the measurement system for the benefit of

the economy.

41
NBSIR 75-945

THE NATIONAL MEASUREMENT SYSTEM FOR SURFACE PROPERTIES

C. J. Powell

NBS Optical Physics Division

December 1976

EXECUTIVE SUMMARY

The large number of solid-surface properties that can be measured have been

arbitrarily divided into two classes.

First, there are the properties which

can be used to characterize a surface:

surface composition (as a function of

position), surface atomic structure, surface

electronic structure, the nature and distribution of surface defects, surface topography, and the nature and area of exposed

facets. Second, there are derived properties of the surface characteristics as just

defined and measures of the processes that occur on surfaces: electrical properties,

optical properties, adhesion, bonding,

catalytic activity, plating, durability,

corrosion, decoration, grain-boundary segregation, lubrication, and reactivity. This

report discusses directly only those mea- surements that are used for surface characterization with particular emphasis being

given to the most common measurement, the

measurement of surface composition, and

lesser emphasis to the measurement of surface

atomic structure and surface electronic

structure. Measurement of surface topography

is discussed in a separate report of this

series by R. D. Young.

Throughout the report, the term "surface"

is defined as the "outermost" layer of atoms

of a solid. Thus, consideration is given

primarily to those properties (and measurement methods) which are specific to the

surface as defined. Some consideration is

given also to the measurement of composition

as a function of depth from a surface and at solid-solid interfaces.

A dramatic feature of this part of the

National Measurement System is the rapid

growth of surface science and surface technology and the substantial accomplishments

that have been made in the past ten years.

Surface science and surface technology are widely regarded as "frontier" areas in which

major scientific breakthroughs and major improvements in materials and processes will

be developed.

Most of the measurement methods now in use for surface characterization have become

commercially available within the past ten years. At this time there is a complete

lack of standards, standard procedures, and

standard materials to support surfacecharacterization measurements. In short,

there is no established measurement system

for the measurement of surface properties.

Most measurements of surface composition

are now performed by Auger-electron spectroscopy and, to a lesser extent, by x-ray

photoel ectron spectroscopy, ion-scattering

spectroscopy and secondary-ion mass spectroscopy. The sales of these instruments

have been estimated to be about $10M per

year with a current growth rate of 20 to 30%

per year. About 60% of these instruments

are in use in industrial laboratories, 20%

in Federal Government laboratories, and 20%

in university laboratories.

The surface-characterization measurements

made in university and some other laboratories are frequently made to develop a fundamental understanding of the properties of

relatively ideal (i.e., single-crystal)

surfaces and of processes that occur on them. Surface-characterization measurements

made in government laboratories support a variety of agency missions, ranging from

national defense, space, energy, to the

environment.

Measurements of surface composition are routinely made to solve an extremely wide

range of industrial problems (of which

examples are given). Most of these measurements are made in the semiconductor, chemical, petroleum, and metallurgical industries

for applications ranging from process and

device development, process control, process

evaluation, to failure analysis. The economic benefits are difficult to estimate but

are believed to be substantially greater

than the corresponding costs.

Continued substantial growth in surface

science and surface technology (and in

the required surface-measurement capability) is predicted for the next "^'ive years. Present national goals for solution

of the energy crisis, provision of an adequate defense capability, control of environmental pollution, increase of industrial

productivity, and the development of advanced

materials for improved individual health and

safety and for the automobile and aircraft

industries will require use of surface

technology and improved surface-characterization measurements. Other factors which

will stimulate growth in surface-measurement

capability are projected developments in

surface science, development of improved

42
instrumentation, development of quantitative

methods for surface characterization, legal

needs, and anticipated growth in the applications of surface analysis.

Present surface-characterization mea- surements make use of reference data generated by instrument manufacturers, universities, government and industrial laboratories, and by NBS. Many important measurement needs have been identified, the most

important, for surface technology, being to provide data and procedures to quantify

measurements of surface composition. It is

anticipated that the development of standards, standard procedures, reference data,

and standard materials will be coordinated

through the recently formed ASTM Committee

E42 on Surface Analysis.

Other measurement needs in surface science

and surface technology have been identified.

Many surface properties and processes depend

on the surface composition, atomic structure,

and particularly the surface electronic

structure. It is anticipated that future

developments in surface science will lead to

a more detailed understanding of the mechanisms of catalysis, corrosion, adhesion,

lubrication, and wear so that new materials

with improved properties can be designed.

Advances of this type depend on the development and application of new measurement

methods to characterize disordered surfaces,

highly dispersed catalysts, transient species

on surfaces, the kinetics of reacting species, and the properties of such surfaces in

their working environments.

NBS programs in surface physics have

had considerable impact on surface science

through the development of new instruments

and measurement methods, the observation

of new surface properties, the development of new theories and concepts, the

provision of reference data, and the

publication of data compilations and

critical reviews. NBS data are also

being used in surface technology. Additional NBS effort is required, however,

to promote surface technology.

Seven recommendations are given for NBS

action to improve and extend the measurement

services required for the support of surface

science and surface technology. Meaningful

action by NBS and other interested groups

should enable the establishment of a satisfactory National System for the Measurement of Surface Properties in the future.

43
NBSIR 75-946

THE NATIONAL MEASUREMENT SYSTEM FOR IONIZING RADIATION

Randall S. Caswell

NBS Center for Radiation Research

November 1977

EXECUTIVE SUMMARY

The structure of the National Measurement

System for Ionizing Radiation has been investigated for eight classes of radiation users: medical, nuclear power, industrial radiation processing, defense, environmental, science, chemical analysis, and

miscellaneous radiation applications, plus

two "overlay" categories, regulatory control

of radiation and personnel monitoring. Needed major actions on the part of NBS were identified for nuclear power and its related

environmental and safety impacts, medical

applications of radiation, assistance to regulatory control of radiation and measurement assurance for personnel monitoring..

The regulatory control of radiation is

divided among ERDA, the Nuclear Regulatory

Commission, the EPA, the Bureau of Radiological Health, the Occupational Safety and

Health Administration, the National Institute

of Occupational Safety and Health, and the

Department of Transportation. Forty seven states and Puerto Rico have passed radiation

control legislation. Radiation regulation is

normally administered by state health departments which vary widely in support, staff,

and technical competence. They work to- gether through the Conference of Radiation

Control Program Directors. Needs defined

are: (1) all regulators of radiation need

to be on the same measurement scale; and

(2) the great majority of state health

departments would be benefited by a program

of technical assistance in radiation

m.easurement. NBS has (1) instituted a program of measurement assurance testing to establish traceability with lead laboratories

of NRC, EPA, and other regulatory agencies,

and (2) proposed a National Radiation Measurement Calibration System for the benefit of

the states, regional calibration laboratories, and regulatory agencies.

About 800,000 persons considered radiation

workers wear personnel monitors. Most such

monitoring is supplied by fewer than 20 com- mercial suppliers, although government

laboratories and the military services

largely provide their own service. Two needs

are apparent: (1) a reliable measurement

assurance testing laboratory to test monitoring services, and (2) monoenergetic neutron

calibration fields to test and develop neu- tron personnel monitors. NBS actions in

response to (1) are under active discussion

with the states and other Federal Government

agencies. NBS is now developing a radiation

calibration facility for neutron personnel

monitoring with ERDA support.

Four medical radiation user groups have

been identified: radiation therapy, diagnostic x-rays, dental x-rays, and nuclear medicine. About 350,000 patients are treated

with radiation therapy per year, representing

50-60% of cancer cases. In 1970, 129 million

persons received 210 million diagnostic x-ray

examinations. In 1974 there were more than

132,000 diagnostic x-ray machines and 142,000

dental x-ray machines. In 1971 there were eight million applications of radiopharmaceuticals given for diagnosis. One patient

in four entering the hospital will be administered radioisotopes for diagnostic test(s).

Measurement needs apparent include: (1)

wider dissemination of NBS dosimetry calibrations; (2) development of primary absorbed

dose standards for high-energy (linac and

betatron) x-rays and for fast neutron radiotherapy; (3) extension of a system of quality

control throughout the approximately 8,000

institutions doing nuclear medicine; (4)

straightening our of problems with radionuclide dose calibrators. In each case NBS

actions are underway or being developed with

others to meet these needs.

The study of nuclear power is concerned

with nuclear fuel cycle operations, and

design data and reactor operations. A special study by John W. Bartlett, Assessment of the Nuclear Fuel Materials Measurement System , found that the need for ac- curate accountability of fissionable materials stems not from buyer-seller equity but

rather from the need to safeguard nuclear

material. It seems certain that there will

be a need for NBS participation in and technical assistance for a major measurement as- surance system for nuclear fuel materials

accountability, and discussions on this

subject are underway between NBS and the

Nuclear Regulatory Commission. At present,

NBS programs are responding to needs for new Standard Reference Materials, improvement of

the technical base for calorimetry, collaboration with the ERDA New Brunswick Laboratory

in support of the measurement assurance ac- tivities of the Safeguards Analytical Laboratory Evaluation (SALE) program, and analysis

of materials diversion paths and data requirements . In the area of design data and reactor

operations , needs are for standards for neu- tron cross section measurement in support of
LMFBR (liquid metal fast breeder reactor),

HTGR (high temperature gas-cooled reactor),

and thermal neutron power reactor programs;

and for measurement standards for in-reactor

measurements of neutron flux and spectra and

fission rates in fuel elements. For fission

reactors improved cross sections are needed

for shielding, fuels, neutronics of structural materials, integrity of reactor com- ponents, and reactor control and safety, "^or fusion reactors, nuclear cross section data

needs are less immediate; but data will be

needed for shielding, heat transfer element

design, tritium breeding design, integrity

of structural materials, and induced radioactivity problems. Standards for in-reactor

measurements of neutron flux and spectra and

fuel element fission rates are important in

testing reactor performance versus calculations, testing of fuel, temperatures of fuel,

reactor lifetimes, power level, control, and

safety. A neutron standards program in NBS

aimed at greatly improving the accuracy of

standard reference neutron cross sections,

and neutron fluxes used to measure other

cross sections, and providing standard ref- erence neutron fields for the basis of inreactor neutron measurements is now at full

strength using the NBS linac. Van de Graaff,

and reactor.

The field of industrial radiation processing continues to grow, although more slowly

than indicated by some earlier predictions.

The energy crisis may, in fact, speed development in this area since radiation processing uses less energy than do corresponding

thermal processes. NBS offers calibration

services for the megarad dosimetry range on

a limited basis. Establishing measurement

service requirements is somewhat hindered by

the proprietary nature of this field and the

high degree of industrial secrecy. Some new needed calibration services are being developed, but no needs for major new programs

have been identified.

The study of radiation measurement for

national defense has identified needs in the area of high-intensity, pulse x- and gammaradiation measurement. The NBS action in

response has been development of new ordersof-magnitude more intense calibration sources. Defense Department needs in the measurement

of radioactivity appear to have been met by

NBS programs for development of radioactivity

standards, particularly for the noble gases.

The study of environmental radiation meas- urement identified a need for environmental

radioactivity standards and for environmental

radioactivity measurement assurance testing.

NBS has recently developed a new series of

mixed radionuclide environmental radioactivity standards which are now available to the

environmental measurement community, and

many measurement assurance tests are being

carried out to help members of the community

and lead laboratories of NRC and EPA test

and improve their measurement performance.

State laboratories receive NBS-traceable

standards from and participate in measurement assurance testing with the NRC and EPA quality assurance laboratories.

In the areas of science and chemical

analysis , existing programs in support of

these fields need to be continued. For

science, a data compilation effort on charged-particle stopping powers, ranges,

straggling and delta-ray production below

about 10 MeV is needed.

Miscellaneous radiation applications ut- ilize radiographic equipment, gauges, irradiators, oil-well logging apparatus, selfluminous products, smoke detectors, static

eliminators, and heat sources. The annual

business in these devices is in excess of

70 million dollars. The most stringent re- quirements for accurate measurement appear

to be at the manufacturing level. A chief

problem is the need for adequate safety measures in the use of this equipment. This

problem is being attacked through vigorous

NBS participation in voluntary standards

committees such as American National Standards Institute (ANSI) Committee N43 which is

concerned with promulgating recommendations

for safe use of radiation equipment.

A number of cormion threads stand out quite

strikingly in the studies of the various

users of radiation: (1) There is often a need for new NBS measurement standards where

they do not exist--however, where NBS meas- urement standards do exist their accuracy

is generally sufficient for present needs.

(2) There is a great need for measurement

assurance, especially where regulatory re- quirements are involved. Usually priorities

found in this study are much higher for dissemination of standards to users and carrying

out measurement assurance testing than for

development of new measurement standards.

(3) A need exists for help to the poorlyqualified user--training, convenient laboratory standards, handbooks for guidance.

(4) A single measurement system under NBS

leadership is needed to help both regulators

and users, to avoid duplication and competition among regulators, to simplify the radiation users' problems of measurement and re- porting, and to protect the health and safety

of the public. (5) Needs for NBS to play

its traditional "independent third party"

role are often found.

45 USCOHM ' EJU.
NBS-n4A (REV. 7-73)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUF5LICAT10N OR REPORT .\0.

NBSIR 75-947 (Rev Dec 19 77)

2. Gov't Accession

No.

3« Recipient's .^cccs.sion No.

4. TITLE AKD SUBTITLE

Collected Executive Summaries

1972-75

5. Publicacion Date December 1977

6. Performing Organization Code

270.00

7. AUTHOR(S)

Raymond C. Sangster, Editor

8. Performing Organ. Report No.

9. PERFORMING ORCi AN 17 '\T tOV \'AMF AND ADDR F<>S NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Proiect/Task/W'ork Unit No. 2700916

n. Contract/Grant No.

1 2« Sponsoring Organization Name and Complete Address (Street, City, Stste, ZIP)

National Bureau of Standards, Institute for Basic Standards

Office of the Deputy Director, IBS/Boulder

325 Broadway

Boulder, Colorado 80302

13. Type of Report &: Period

Covered

14. Sponsoring .Agency Code

15. SUPPLEMENTARY NOTES

16. .ABSTRACT (A 200-word or less factual summary of most si^ificant information. If document includes a significant

bibliography or literature survey, mention it here.)

This report contains the Executive Summaries of the reports of the 1972-75 study by tf^e NBS Institute for Basic Standards of the U.S. National Measurement System, which con- sists of all of the activities and mechanisms which provide physical measurement

data required by our society. A series of microstudies focused on specific technical

measurement sectors. A macroeconomic study looked at costs of instrumentation and

labor for measurement- re la ted activity in our economy. University economists were

retained to assist the microstudy authors and to prepare an overall economics report.

A central coordinator set a basic pattern for the microstudies, prepared an overall

summary report, and generated several documents relating to the system as a whole.

Abbreviated titles of the executive summaries are: Final summary report. Direct

measurements transactions matrices. Economic analysis. Structure and functions of

measurement system. Time and frequency. Length and related dimensional measurements:

vibration and shock. Surface finish. Mass, volume and density. Force. Fluid flow

Pressure. Temperature. Humidity and moisture. Thermodynamic properties of fluids.

Cryogenics. Electricity. Electromagnetics. Medical ultrasonics. Acoustics.

Radiometry and photometry. Spectrophotometry. Far ultraviolet radiometry. Optics.

Physical properties of atoms and molecules. Surface properties. Ionizing radiation

17. KEY WORDS (six fo twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons

)

Acoustics; atomic properties; economics; electrical quantities; ionizing radiation;

mechanical quantities; national measurement system; optical quantities; surface

properties; thermal quantities; time and frequency.

18. AVAILABILITY [XX Unlimited 19. SECURITY CLASS

(THIS REPORT)

21. NO. OF PAGES

1 For Official Distribution. Do Not Release to NTIS UNCL ASSIFIED 50

1

' Order From Sup. of Doc, U.S. Government

Washington. D.C. 20402. SD Cat. No. CH

Printing Office 20. SECURITY CLASS

(THIS P.\GE)

22. Price

ly^

Order From National Technical Information

Springfield, Virginia 22151

Service (NTIS)

UNCLASSIFIED $4.50

LSCOMH ElU. USCOMM-DC 23n42-P74
REQUEST CARD FOR REPORTS OF NATIONAL MEASUREMENT SYSTEM (NMS) STUDY ( Circle No's wanted )

925 FINAL SUMMARY REPORT

943 TRANSACTIONS IN NMS

947 COLL. EXEC. SUMMARIES

948 ECONOMIC ANALYSIS NMS

949 STRUCTURE/FUNCTIONS NMS

345-1 TIME & FREQUENCY

926 LENGTH & DIMEN. MEAS.;

VIBRATION & SHOCK

927 SURFACE FINISH

928 MASS, VOLUME, DENSITY

929 FORCE

930 FLUID FLOW

931 PRESSURE

932 TEMPERATURE

933 HUMIDITY & MOISTURE

934 THERMODYNAMICS OF FLUIDS

825 CRYOGENICS

935 ELECTRICITY

936 ELECTROMAGNETICS

REQUEST CARD FOR REPORTS OF NATIONAL MEASUREMENT SYSTEM (NMS)

925 FINAL SUMMARY REPORT

943 TRANSACTIONS IN NMS

947 COLL. EXEC. SUMMARIES

948 ECONOMIC ANALYSIS NMS

949 STRUCTURE/FUNCTIONS NMS

345-1 TIME & FREQUENCY

926 LENGTH & DIMEN. MEAS.;

VIBRATION & SHOCK

927 SURFACE FINISH

928 MASS, VOLUME, DENSITY

929 FORCE

930 FLUID FLOW

931 PRESSURE

932 TEMPERATURE

933 HUMIDITY & MOISTURE

934 THERMODYNAMICS OF FLUIDS

825 CRYOGENICS

935 ELECTRICITY

936 ELECTROMAGNETICS

REQUEST CARD FOR REPORTS OF NATIONAL MEASUREMENT SYSTEM (NMS)

925 FINAL SUMMARY REPORT 929 FORCE

943 TRANSACTIONS IN NMS

947 COLL. EXEC. SUMMARIES

948 ECONOMIC ANALYSIS NMS

930 FLUID FLOW

931 PRESSURE

932 TEMPERATURE

949 STRUCTURE/FUNCTIONS NMS 933 HUMIDITY & MOISTURE

345-1 TIME & FREQUENCY

926 LENGTH & DIMEN. MEAS.;

VIBRATION & SHOCK

927 SURFACE FINISH

928 MASS, VOLUME, DENSITY

934 THERMODYNAMICS OF FLUIDS

825 CRYOGENICS

935 ELECTRICITY

936 ELECTROMAGNETICS

937 MEDICAL ULTRASONICS

938 ACOUSTICS

939 RADIOMETRY/PHOTOMETRY

940 SPECTROPHOTOMETRY

941 FAR UV RADIOMETRY

942 OPTICS

944 PHYS. PROP. ATOMS/MOL.

945 SURFACE PROPERTIES

946 IONIZING RADIATION

STUDY ( Circle No's wanted )

937 MEDICAL ULTRASONICS

938 ACOUSTICS

939 RADIOMETRY/PHOTOMETRY

940 SPECTROPHOTOMETRY

941 FAR UV RADIOMETRY

942 OPTICS

944 PHYS. PROP. ATOMS/MOL.

945 SURFACE PROPERTIES

946 IONIZING RADIATION

STUDY ( Circle No's wanted )

937 MEDICAL ULTRASONICS

938 ACOUSTICS

939 RADIOMETRY/PHOTOMETRY

940 SPECTROPHOTOMETRY

941 FAR UV RADIOMETRY

942 OPTICS

944 PHYS. PROP. ATOMS/MOL.

945 SURFACE PROPERTIES

946 IONIZING RADIATION
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TO: PROGRAM INFORMATION OFFICE

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FROM: NAME: Place

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ORGANIZATION:

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TO: PROGRAM INFORMATION OFFICE

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BOULDER, COLORADO, USA 80302
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