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Standards and Code Information Q laboratory Accreditation Q Industrial Partnerships
NIST Calibration Services Users Guide 1998

J. L. Marshall, Editor

Calibration Program

Office of Measurement Services

Technology Services

National Institute of Standards and Technology

Gaithersburg, MD 20899-0001

U.S. Department of Commerce

William M. Daley, Secretary

Technology Administration

Gary R. Bachula, Acting Undersecretary for Technology

National Institute of Standards and Technology

Raymond G. Kammer, Director

FOR INFORMATION, PHONE (301) 975-2002

NIST Special Publication

Revised January 1998

(Supersedes 1991 Edition)
National Institute of Standards and Technology

Special Publication 250, 1998 Edition

Natl. Inst. Stand. Techno!., Spec. Publ. 250, 1998 Ed.,

228 pages (Revised Jan. 1998)

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON: 1998

For sale by the Superintendent of Documents,

U.S. Government Printing Office, Washington, DC 20402

U.S. Government Printing Office

Washington: 1998
Foreword

The NIST Calibration Services Users Guide provides detailed descriptions of the NIST calibration services, special-test services, and measurement assurance programs currently available as of the fourth quarter of 1997. This revised edition of NIST Special Publication (SP) 250

reflects important changes in services since the last edition was published. A detailed description is given of each measurement service, and a large number of NIST technical experts are

cited (who may be contacted for further information concerning services or measurement

problems). The current edition will be published in hard copy and maintained on the Internet. See the Calibration Program's Web Site at: http://ts.nist.gov/calibrations

A Fee Schedule listing current prices for the services described in the Users Guide is published aimually as NIST SP 250 Appendix. NIST will notify users of changes in services or proposed changes in services by means of announcements in the Fee Schedule and on the

Internet. In addition, information about upcoming NIST Measurement Seminars will be

announced in both locations. It is important that you refer to the current issue of the Fee

Schedule or the Web site in order to have up-to-date information with respect to NIST contacts. A companion document to this guide is NIST Special Publication 260, NIST Standard

Reference Materials Catalog. This document describes 1 ,200 Standard Reference Materials

(SRM's) certified by NIST for use in industrial quality control, materials testing, environmental testing, and clinical testing applications. A copy of SP 260 may be obtained by calling

(301) 975-6776, or by faxing (301) 948-3730.

The Calibration Program welcomes suggestions on how this publication can be made

more useful to those who rely on NIST calibration services. Suggestions are also welcome

concerning needs for new calibration services, measurement assurance programs, or other measurement services.

Sharrill Dittmann

Calibration Program

iii
Abstract

The National Institute of Standards and Technology (NIST) Calibration Services Users Guide

provides detailed descriptions of NIST calibration services, measurement assurance programs, and special-test services currently available. The following measurement areas are covered:

(1) dimensional; (2) mechanical, including flow, acoustic, and ultrasonic; (3) thermodynamic;

(4) optical radiation; (5) ionizing radiation; (6) electromagnetic, including dc, ac, rf, and

microwave; and (7) time and frequency. A separate Fee Schedule (NIST Special Publication

250 Appendix) is issued annually, providing current prices for the services offered, updates on

points-of-contact, and information on NIST measurement seminars. See also the most current information at the Internet Web Site: http://ts.nist.gov/calibrations

Key words: calibration; measurement assurance; measurement services; standards;

traceability.

iv
Acknowledgments

Many NIST staff members contributed to the development and preparation of this guide. Over

50 members of the NIST technical staff contributed data and information that have been incor- porated into the guide. Special thanks go to John Mayo-Wells, Barry Taylor, and Simone Yaniv

for their efforts. Joanne Marshall served as production manager and coordinated preparation

of the Users Guide. Editorial and production assistance was provided by Carroll Brickenkamp

and Dawn Geraci. General support was provided by Tracy Arnold, Paula Hewitt, Denise

Lockard, and Ernest Garner of the Calibration Program Staff. The NIST Publication Production

staff made many valuable suggestions and typeset the final draft.

Sharrill Dittman

Chief, Calibration Program

('

V
List of Tables

Table Page

5.1 Uncertainty of the NIST Low Velocity Airflow Measurement Facility 33

5.2 Uncertainty of the NIST Airflow Measurement Capabilities in the Dual

Test-Section Wind Tunnels 33

5.3 Typical Expanded Uncertainties for Pressure Calibrations of Type-L

Microphones 43

6. 1 Relative Expanded Uncertainties of Piston Gage Standards in Gage Mode 50

6.2 Calibration Uncertainties for Total Immersion Thermometers 58

6.3 Maximum Expanded Uncertainties of SPRTs at NIST 63

6.4 NIST Expanded Uncertainties for Comparison Measurements of RIRTs 63

6.5 NIST Two-Pressure Humidity Generator, Mark 2, Range and Uncertainty 69

7.1 Calibration Uncertainties for Spectroradiometric Source Measurements 78

7.2 Detector Measurement Services Uncertainties 83

7.3 NIST Spectroradiometric Detector Measurement Services 83

7.4 Laser Power and Energy Measurement Capabilities 91

7.5 Measurement Capabilities of Automated Calibration System for Optical Fiber

Power Meters 92

7.6 Low-Level MAP Transfer Standards 93

8. 1 Specifications for Calibration of Solutions of Gamma-Ray Emitting

Radionuclides Having Half Lives Greater Than 15 Days 97

8.2 Specifications for Calibration of Gamma-Ray Emitting Radionuclides

Having Half Lives Less Than 15 Days 98

8.3 Specifications for Calibrations Using the 2 na Proportional Counter and

the 0.8 7Ta Defined Solid Angle Counter 98

8.4 Specifications for Special Tests of Beta-Particle-Emitting Solution Sources 99

8.5 Irradiation Parameters for Fission Spectra and Maxwellian Thermal

Neutron Fields 100

8.6 Tungsten-Anode X-ray and Gamma-Ray Beam-Quality Parameters 105

8.7 Tungsten-Anode ISO X-Ray Beam-Quality Parameters 106

8.8 Mammography X-Ray Beam-Quality Parameters 107

8.9 Uncertainties for Gamma-Ray Source Calibrations, 4701 OC and 4701 IC 108

vi
Table Page

8.10 Uncertainties for Beta-Particle Source and Instrument Calibrations 108

9.1 Temperature and Current Levels for Customer's Resistors 114

9.2 Calibration Uncertainties for DC Resistance Standards 115

9.3 Calibration Uncertainties for Capacitance Standards with Coaxial Connectors 123

9.4 Calibration Uncertainties for Capacitance Standards with Terminal

(Banana) Plugs 124

9.5 Expanded Uncertainties of NIST DC Voltage Measurement 1 30

9.6 25-Point Standard DMM Test 135

9.7 AC-DC Difference Calibration Service 137

9.8 Measurement Ranges and Uncertainties for Low-Frequency TVC

Services 140

9.9 Measurement Ranges and Uncertainties for High-Frequency TVC

Services 1 40

9.10 Measurement Ranges and Uncertainties for Peak-to-Peak Detector

Services 140

9. 1 1 Measurement Ranges and Uncertainties for RF Micropotentiometer

Calibrations 141

9.12 Available Values of the Parameters for Routine Wattmeter, Watthour, Varmeter and Varhour Testing 155

9. 1 3 Measurement Ranges and Uncertainties for Coaxial Thermistor Mounts 159

9.14 Measurement Ranges and Uncertainties for Waveguide Thermistor Mounts 160

9.15 Measurement Ranges and Uncertainties for Coaxial Two-Port Devices 164

9.16 Measurement Ranges and Uncertainties for Waveguide Two-Port Devices 165

9.17 Measurement Ranges and Uncertainties for Coaxial One-Port Devices 165

9. 1 8 Measurement Ranges and Uncertainties for Waveguide One-Port Devices 166

9. 1 9 Summary of NIST Standard Field Strength Facilities 178

9.20 NIST Impulse Generator Spectrum Amplitude Measurement Service

Capabilities 180

9.21 Uncertainty for Calibration of Fast Repetitive Pulse Transition Parameters 180

9.22 Uncertainty for Measurement of Repetitive Pulse Settling Parameters 181

vii
List of Figures

Figure Page

5.1 Traceability to the SI Unit of Mass 35

5.2 NIST's Relative Expanded Uncertainties for Normal Calibrations of

Mass Standards 35

5.3 Relationship of Force to SI Units 39

6.1 Uncertainties of the NIST Low-Pressure and Vacuum Standards 55

6.2 Uncertainties of the NIST Leak and Low-Gas-Flow Standards 55

7.1 Measurement Uncertainty for NIST Spectral Radiance Calibrations 79

7.2 Measurement Uncertainty for NIST Spectral Irradiance Calibrations 79

9.1 Expanded Uncertainty in Tjc 160

9.2 Reflected and Transmitted Voltage Waves for a Typical Two-port Device 163

viii
Contents

Chapter 1—

Policies

A. Introduction 1 B. Types of Services 1 C. Other NIST Measurement Transfer Standards 1 D. Criteria for Quality Assurance 3

E. Fees 3

F. Reports of Calibration/Test Results 3 G. Traceability 3 H. NIST Policy on Reporting Measurement Uncertainty 4

I. NIST Policy Regarding Use of Metric (SI) Units 5

J. References to NIST in Advertisements 5 K. Disclaimer 5

L. Questions and Inquiries 5

Chapter 2—

Ordering Instructions for Domestic Customers

A. Customer Inquiries 7

B. Prearrangements >^nd Scheduling 7

C. Purchase Orders 7 D. Shipping, Insurance, and Risk of Loss 8

E. Turnaround Time 8

F. Customer Checklist 9

Chapter 3—

Special Instructions for Foreign Customers

A. Foreign Inquiries 1

1

B. Criteria for Providing Service 11 C. Special Instructions 1

1

D. Shipping Charges 12

Chapter 4

Dimensional Measurements

A. Length Measurements 15 A.} Gage Blocks

lOOlOC Gage Blocks

A.2 Line Standards 16 10020C Line Standards

A.3 Surveying Tapes 17 10030C Surveying and Oil Gaging Tapes

10040S Special Tests of Surveying Leveling Rods

ix
A.4 Other Length Standards 18 100508 Special Tests of Length Standards

A.5 Sieves 19

1 0060S Special Tests of Sieves

A.6 Algorithms Testing and Evaluation Program for Coordinate 20

Measuring Systems

10070S-10071S Special Test of CMS Software:

NIST-Generated Data Sets 10080S-10081S Special Test of CMS Software:

Customer-Generated Data Sets

B. Diameter Measurements 22

1 101 OS Special Tests of Cylindrical Diameter

Standards (i.e.. Plug and Pin Gages)

1 1020C Measuring Wires for Threads and Gears

1 1030S Special Tests of Spherical Diameter

Standards: Balls

1 1040S Special Tests of Internal Diameter

Standards: Ring Gages

1 1050S Special Tests of Length and Diameter

1 1060S Special Tests of Step Gages

C. Complex Dimensional Standards 24

12010C API Threaded Plug and Ring Gages

12020S Special Tests of Threaded Plug and Ring Gages

12030S Special Tests of Two Dimensional Gages

12040S Special Complex Dimensional Tests

D. Optical Reference Planes and Roundness Standards 26

13010S Special Tests of Optical Reference

Planes (Flats) I3020S Special Tests of Roundness

13030S Special Tests of Roundness Calibration

Specimens

E. Angular Measurements 27

14010C Angle Gage Blocks

14O20S Special Tests of Optical Polygons

14030S Special Tests of Rotary and Indexing Tables 14040S Special Tests of Optical Wedges

14050S Special Angular Measurements

F. Laser Measurements

1451 OS Laser Frequency/Wavelength

29
Surface Texture 30

150 IOC Roughness Calibration Specimens

15020C Surface Roughness Comparison Specimens

15030C Step Height Calibration Specimens

1 504OS Special Roughness Tests

H. Hydrometers 31

16010C , Reference Standard Hydrometers

I. Volume and Density 32

17010C . Volume Standards

17020S . Special Tests of Volume Standards

17040S . Special Tests of Density: Liquids

Chapter 5

Mechanical Measurements

A. Flow Measurements 35

18010C . Gas Flow Meters 18020C . Water Flow Meters 18030C , Hydrocarbon Flow Meters 18040C . Transfer Standards

18050S . Special Tests Using Gas or Liquid Flows

B. Flow Measurements at Cryogenic Temperatures 37

18800S . Special Tests of Cryogenic Liquid Flow

Airspeed Instruments 38

190 IOC Pitot-Static Tubes

I9020C Low Airspeed Instruments I9030S Meteorological Airspeed Instrumentation

19040S Special Tests of Airspeed Instruments

D. Mass Standards 39

22010C-22030C .... Weight Sets (1 mg to 30 kg)

22040C Single Weights (1 mg to 1 kg)

22060C-22100C .... Single Weights (2 kg to 30,000 kg)

221 IOC Single Weights (> 30 kg to 1200 kg, Calibrated in a Weighing Design)

22130C-22150C .... Single Weights for Deadweight Pressure Testers 221 70S Special Mass Measurement Services

22180M Measurement Assurance Program for Mass

xi
E. Force Measurements

23010C-23250C Force Transducers

23260S Special Tests of Force Transducers

43

F. Vibration Measurements 46

24010C-24030C Pickup Sensitivity

24040S Special Shock Measurements

24050S Special Tests of Pickup Sensitivity

24060S Special Vibration Tests

G. Acoustic Measurements 48

25010C-25050C Pressure and Free-Field Responses of Microphones

25060S Special Tests of Acoustic Devices

25070S Special Tests of Audiometers/Earphones

H. Ultrasonic Reference Block Measurements 51

26030S Special Tests of Area Amplitude Aluminum

Reference Blocks

26040S Special Tests of Area Amplitude Titanium or

Steel Ultrasonic Reference Blocks

26050S Special Tests of Distance Amplitude Aluminum

Reference Blocks

26060S Special Tests of Distante Amplitude Titanium or

Steel Ultrasonic Reference Blocks

26070S Special Tests of Distance and Area Amplitude

Aluminum Titanium or Steel Ultrasonic

Reference Blocks

I. Ultrasonic Transducer Measurements 53

26100C Ultrasonic Power Output

J. Acoustic Emission Transducer Measurements 54

26200C Acoustic Emission Transducer Sensitivity

Chapter 6—

Thermodynamic Quantities

A. Pressure Measurements 57

2901 OC Deadweight Piston Gages

29020C Controlled Clearance Piston Gages

29030C Pressure Gages and Transducers

29035C Non-Mercurial Barometers 29040S Special Tests of Pressure Gages

xii
B. Low Pressure, Vacuum, and Leak Measurements 59

30010C-30011C Low-Pressure Transducer

30020C-30021C Differential Low-Pressure Transducer

30025C Ball-Type Deadweight Tester 30029C-30031C Spinning Rotor Gages

30032S Special Tests of Spinning Rotor Gages

3O034C-3O038C Ionization Gages

30040S Special Tests of Low-Pressure Gages

30050S Special Tests of Vacuum Gages

30060S Special Tests of Leak Artifacts 30061C-30062C Helium Leaks

30063S Special Tests of Low-Gas-Flow Instruments

C. Laboratory and Industrial-Grade Thermometers 64

31010C-31050C Laboratory Thermometers

31 lOOC Quantity Tests of Liquid-in-Glass Thermometers

311 lOS-31 150S Special Tests of Thermometers

3 11 70S Special Tests of Calorimetric Thermometers

31 180S Special Tests of Beckmann Thermometers

31260S Special Thermometry Services

D. Thermocouples, Thermocouple Materials, Thermometer Indicators 66

32010C-32061C Type S, R, B, E, J, K, N, and T, Thermocouple

Comparison Calibrations 32070C Thermocouple Materials Tested Against Pt Thermoelectric Standard

32090C Type S or R Thermocouple Calibration at Metal

Freezing Points 3209 IC Type S or T, Thermocouple Freezing-point

Determination

32100C-32101C Digital Thermometer Indicator or Potentiometer

321 10C-32147C Thermocouples or Thermocouple Materials

Tested Against Pt Thermoelectric Standard,

Temperature Measured with SPRT

321 SOS Special Tests of Thermocouples and Thermocouple

Materials

E. Resistance Thermometry 69

33010C-33130C Capsule SPRT

33140C-33141C Rhodium-Iron or Germanium Resistance Thermometers

33150C-33310C Long Stem SPRT

33350S Special Tests of Resistance Thermometers

33360S Special Tests of Thermometric Fixed-Point Devices

33370M-33380M Measurement Assurance Program for Temperature

xiii
F. Radiance Temperature Measurements 73

35010C-35040C Radiance Temperature Standard, Disappearing

Filament Optical Pyrometer

35050C-35060C Radiance Temperature Standard, Ribbon Filament

Lamp

35070S Special Tests of Radiation Thermometers

G. Humidity Measurements 76

36010C-36020C Dew-Point Hygrometers

36030C Electric Hygrometers

36040C Electrolytic Hygrometers

36050C Aspirated Hygrometers

36060C Pneumatic Bridge Hygrometers

36070S Special Tests of Humidity

Chapter 7—

Optical Radiation Measurements

A. Photometric Measurements 79

3701 OC Luminous Intensity and Color Temperature Standard

Lamps

37020S Special Tests for Luminous Intensity and Color

Temperature of Submitted Lamps

37030C-37040C Color Temperature Standard Lamps

37050S Special Tests for Color Temperature of Submitted

Lamps

37060S Special Tests for Total Luminous Flux of Submitted

Incandescent Lamps and Fluorescent Lamps

37070C Opal Glass Luminance Coefficient Standards

37080S Special Tests for Submitted Luminance Sources and Transmitting Diffusers

37090S Special Tests for Photometers, Illuminance Meters,

and Luminance Meters 37100S Special Photometric Tests 37 11 OS Special Tests for Submitted Flashing-Light

Photometers

B. Optical Properties of Materials Measurements 82

38010C-38O4OC Spectral Transmittance Filters 38050C Wavelength Standards

38060S Special Tests of Spectral Transmittance or

Spectral Reflectance

38070M-38074M Measurement Assurance Programs for Retroreflectance 38080M Measurement Assurance Program for Transmittance

xiv
C. Spectroradiometric Measurements 86

C.l Spectroradiometric Source Measurements

39010C-39030C Spectral Radiance Lamps

39040C-39050C Spectral Irradiance Lamps

39060S Special Tests of Radiometric Sources

C.l Spectroradiometric Detector Measurements 89

39071S-39072S UV Silicon Photodiodes

39073S-39074S Visible to Near IR Silicon Photodiodes

39075S Special Tests of Near IR Photodiodes

39080S Special Tests of Radiometric Detectors 3908 IS Special Tests of Photodetector Responsivity

Spatial Uniformity

39090S Special Tests of IR Detectors

D. Radiometric Standards in the Far Ultraviolet 94

D.l Standard Sources 4001 OC Spectral Irradiance Standard, Argon Mini-Arc

40020C Spectral Radiance Standard, Argon Mini-Arc

40030C Spectral Irradiance Standard, Deuterium Arc Lamp

40040S Special Tests of Radiometric Devices in the Near

and Vacuum Ultraviolet

D.l Standard Detectors in the Far Ultraviolet 96

40510C-40531C Detector Standard, Windowless Photodiode

40540C Uncalibrated Windowless Photodiode

40560C-40561C Detector Standard, Windowed Photodiode

40599S Special Tests on Detectors from the Ultraviolet to the Soft X-Ray Region

E. Lasers and Optoelectronic Components Used with Lasers 98

421 lOC-421 lie Laser Power and Energy Meter (or Detector)

Calibrations

42120M Laser Power and Energy Measurement Assurance Program

42130C-42131C Optical Fiber Power Meter (or Detector) Calibrations 42140M Optical Fiber Power Meter Measurement Assurance Program

42150M Low-Level Laser Measurement Assurance Program

421 5 IC Low-Level Laser Radiometer Calibration 421 60S Special Test for Frequency Response Measurements

of Detectors 4216 IS Special Test for Impulse Response Measurements

of Detectors 421 62S Special Test for High Accuracy Laser and Optical

Fiber Power Measurements

42163S Special Test for Linearity Measurements of Laser and Optical Fiber Power Meters (or Detectors)

42164S Special Test for Spectral Responsivity Measurements

of Laser and Optical Fiber Power Meters (or Detectors)

XV
42165S Special Test for Spatial Uniformity of Laser and

Optical Fiber Power Meters (or Detectors)

421 70S Special Test for General Laser Measurements

421 SOS Special Test for General Optical Fiber Power

Measurements

Chapter 8—

Ionizing Radiation Measurements

A. Radioactivity Sources 105

43010C-43020C Gamma-Ray-Emitting Radionuclides in Solution

43030C-43050C Alpha-Particle-Emitting Solid Sources 43060S-43070S Special Tests of Beta-Particle-Emitting Solution Sources 43090S Special Tests of Alpha-Particle-Emitting Solid Sources

B. Neutron Sources and Neutron Dosimetry 109

44010C-44020C Radioactive Neutron Sources 44060C Personnel Protection Instrumentations

44070C-44090C Activation Detector Dosimetry

441 OOS Special Tests of Neutron Sources and Dosimeters

C. Dosimetry of X-Rays, Gamma-Rays, and Electrons 112

C.l X-Ray and Gamma-Ray Measuring Instruments 113

46010C-4601 IC Radiation Detectors Calibration/Correction Factor 46020C-46021C Passive Dosimeters

46030S Special Tests of High-Gain Electrometers

Charge Sensitivity

46040S Special Tests of X-Ray Penetrameters, Ardran-Crookes

Type

46050S Special Tests of X-Ray and Gamma-Ray Measuring

Instruments

C.2 Gamma-Ray Sources, Beta-Particle Sources, and Measuring Instruments 116

47010C-47011C Gamma-Ray Sources 47030C-47035C Beta-Particle Sources 47036C Ionization Chambers Calibrated with Beta-Particle Sources for Radiation Protection 47040S Special Tests of Gamma-Ray and Beta-Particle Sources

C.3 Dosimetry of High-Energy Electron Beams 117

48010M-4801 IM Dose Interpretation of NIST-Packaged Dosimeters

Irradiated by Customer

48020S Special Tests of Electron-Beam Dosimeters

D. Dosimetry for High-Dose Applications 120

490 IOC Calibration Irradiations of Customer-Supplied

Dosimeters with ^Co Gamma Rays

XVI
49020C-49030C Dose Interpretation of NIST Transfer Dosimeters

Irradiated by Customer

49040S Special Tests of Dosimeters by Reading with

Spectrophotometer

49041 S Spectrophotometric Readings of Dosimeters,

Ultra-Violet and Visible Spectrum Scan

49050S Special Measurement Services for Dosimeter

Response and Dose Distributions

Chapter 9—

Electromagnetic Measurements

A. Resistance Measurements

A.] DC Resistance Standards and Measurements

51 lOOS Special Resistance Measurement Services

51 1 lOM Measurement Assurance Program for Resistance

5 1 1 30C-5 1 1 3 1 C Standard Resistors 1 O and 1 0 kH

5 1 1 32C-5 1 1 42C Standard Resistors 1 0 ^ O to 1 0'^ 0

51 143C-51 154C High-Value Standard Resistors: 10' fl to 10'^ H

51 160C-51 163C High-Current Standard Resistors-Shunts

123

A. 2 High-Voltage Standard Resistors 51210C High-Voltage Standard Resistors

ill

A. 3 High-Frecfuency Standard Resistors 51310S High-Frequency Standard Resistors; Two-Terminal

128

£>. iiiipcuaiicc ivicasuiciiieiua ^^jUACcpi rvesisiursj B. 1 Low-Frequency Capacitance and Inductance Measurements and Standards

521 1 OS Special LF Impedance Measurements

521 20S Special Measurement Assurance Program for Standard Capacitors

52130C-52131C Fused-Silica Dielectric Standard Capacitors

52140C-52176C Standard Capacitors

52 1 80C-52 1 8 1 C Standard Inductors

1 9Q

B.2 High-Frequency Standard Capacitors and Inductors 52210S-5221 IS Two-Terminal, Low-Loss Standard Capacitors

5222 IC Three-Terminal, Low-Loss Standard Capacitors

5231 OS Two-Terminal, High-(3 Standard Inductors

136

B.3 Power-Frequency Capacitors

52400C Power-Frequency Capacitors

138

B.4 Q-Standards

527 1 OC-527 1 1 C Inductive Q -Standards

139

xvn
C. Voltage Measurements 140

C.l DC Voltage Measurements and Standards

53 11 OS Special DC Voltage Measurements

53120M Measurement Assurance Program for DC Voltage

53130C-53131C Saturated Standard Cell 53 1 40C Platinum Resistance Thermometer Temperature

Determination for Standard Cell Calibration 53150C Unsaturated Standard Cells 53160C-53161C Solid-State Voltage Reference Standards

53180S-53190S Special Handling

C.l AC Voltage Measurements 1 44

53200S Digital Multimeters (DMMs) and Multifunction

Calibrators 53201 S Low-Voltage AC-DC Transfer Standards

53202S-53203S Special 25-Point Test of Digital Multimeters (DMMs)

C.3 AC-DC Thermal Voltage and Current Converters (to I MHz) 146

5331 OS Special Ac-dc Measurement Services

53350C-53352C Ac-dc Difference Calibration

(Voltage or Current)

C.4 RF-DC Thermal Voltage and Current Converters (100 Hz to I GHz) 149

53405S Special Tests of AC Thermal Voltage Converters 53410C-53415C Low-Frequency TVC Calibration

53420C-53421C High-Frequency TVC Calibration 53430S-53431S Peak-to-Peak Detectors 53440S-53445S RF Micropotentiometers

C.5 Data Converters 152

53500S Special Data Converter Services

D. Precision Ratio Measurements 153 D. l Inductive Dividers

541 lOS Special Ratio Measurements and Tests of Inductive Voltage Dividers

54120C-54131C Inductive Voltage Dividers

D.2 Resistive Dividers 1 55

54210C-5421 IS Resistor and Resistive Dividers

54212C-54213S Resistor and Resistive Dividers, 60 Hz Measurements

542 14S Resistor and Resistive Dividers, Pulsed High-Voltage

Conditions

xviii
D.3 Capacitive Dividers 158

5431 OS Capacitive Dividers, 60-Hz Measurements

5431 IS Capacitive Dividers, Pulsed High-Voltage

Conditions

DA Mixed Dividers 159

5441 OS Pulse Voltage Measuring Systems, Including Kerr Cells

D.5 Voltage and Current Transformers 160

54510C-54513C Voltage Transformers

54520C-54522C Current Transformers

54600S Special Tests of Dividers and Transformers

E. Phase Meters and Standards and VOR Measurements 1 63

551 1 OS Special Tests of Phase Standards and Related

Instruments 55120C-55141C Phase Meters

F. Power and Energy Measurements, Low-Frequency 1 65

561 1 OS Special Tests of AC-DC Wattmeters 56200C-56202C Watt, Watthour, Var or Varhour Meter 562 lOM Measurement Assurance Program for Watthour

Meters 56220S Fast Turn-Around Energy Measurements, Low-Frequency

G. RF, Microwave and Millimeter-Wave Measurements 168

G.l Thermistor Mounts

61 1 lOS-61 136S Commercial Coaxial Thermistor Mounts

61 137C-61138C NIST Model CN Coaxial Mounts

61 144S-61 155S Waveguide Thermistor Mounts

61 160S High Power Wattmeters

61 190S Special Microwave and RF Power Measurement

Services

G.l Scattering Parameters of Passive Multi-Port Devices 172

61210S-61221S Coaxial Fixed and Variable Attenuators 61230S-61243S Rectangular Waveguide Fixed and Variable Attenuators 61249S Special Attenuation Measurements

61250S Time Delay, Coaxial and Waveguide

61260S-61271S Coaxial One-Port Devices

61280S-61293S Waveguide One-Port Devices

61294S Special Reflection Coefficient Measurements

61295S-61296S Coaxial Fixed and Variable Phase Shifters 61297S Special Tests of Phase Shifters

xix
G.3 High Accuracy Attenuation Measurements 177

61 3 IOC Coaxial Fixed and Variable Attenuators 61320C Waveguide Below-Cutoff (Piston) Attenuators 61330S Attenuation Measurements of Three-Port and

Two-Port Devices

61350C Coaxial Fixed and Variable Phase Shifters

G.4 Thermal Noise Measurements 179

61410S-61465S Noise Temperature Measurements

61495S Special Noise Temperature Measurements

G.5 Dimensional Verification of Coaxial Air Line Standards 1 8

1

615 lOS Dimensional Measurement of Air Lines

and Verification of Characteristic Impedance

from Dimensional Measurements

G.6 Dielectric and Magnetic Material Measurements 182

61620S Special Tests for Dielectric and Magnetic Materials

61640S Special Consulting and Advisory Services

for Dielectric and Magnetic Materials

H. Electromagnetic Field Strength and Antenna Measurements 184

H.] Microwave Antenna Parameter Measurements

63100S Gain and Polarization Calibrations of Standard Antennas Using Extrapolation Range

63200S Measurement of Pattern, Gain, and Polarization of Arbitrary Antennas Using Near-Field

Scanning Techniques

63300S Special Test Service for Calibration of Probes

Used with Near-Field Scanning Facilities 63400S Special Consulting, Advisory, and Other Services

H.2 Field Strength Parameter Measurements 187

64100S Special-Test Service for Antennas/Field Strength

Measurements, Utilizing the Transverse Electromagnetic (TEM) Cell Method

64200S Special-Test Service for Antennas/Field Strength

Measurements, Utilizing the Open Area Test Site and Standard Antenna Method

64300S Special-Test Service for Antennas/Field Strength/

Reflectivity Measurements, Utilizing the Anechoic Chamber and Standard Field Method

XX
I. Pulse Waveform Measurements 1 89

65100S Impulse Spectrum Amplitude

65200S Fast Repetitive Pulse Transition Parameters 65250S Fast Repetitive Pulse Settling Parameters 65300S Network Impulse Response (Transfer Function)

of Coaxial Networks

65400S Pulse Time Delay Interval

Chapter 10—

Time and Frequency Measurements

A. Broadcast and Measurement Services 195

76100S Frequency Measurement Service

7611 OS Global Time Service

B. Characterization of Oscillators 197

77100C Oscillator Frequency Calibration

771 IOC Characterization of Atomic Frequency Standards

77120C Characterization of Oscillators: Time Domain

77130C Characterization of Oscillators and Amplifiers:

Phase Noise in the Frequency Domain

77131C Characterization of Oscillators and Amplifiers:

Amplitude Noise in the Frequency Domain

77135C Tests of RF PM/AM Noise Measurement Systems:

On-Site Tests 77136C Tests of Microwave PM/AM Noise Measurement

Systems: On-Site Tests 77140S Special Time/Frequency Measurements:

Oscillators and Other Components

xxi
Chapter

A Introduction

B Types of Services C Other NIST Measurement Transfer Standards

D Criteria for Quality Assurance E Fees F Reports of Calibration/Test Results G Traceability

H NIST Policy on Reporting Measurement Uncertainty

/ NIST Policy Regarding Use of Metric (SI) Units

J References to NIST in Advertisements

K Disclaimer

L Questions and Inquiries
Policies

Introduction

The calibration services of the National

Institute of Standards and Technology

(NIST) are designed to help the makers

and users of precision instruments

achieve the highest possible levels of

measurement quality and productivity.

The services listed in this Guide constitute the highest order of calibration services available in the United States. They directly link a customer's precision

equipment or transfer standards to national and international measurement

standards. These services are offered to public and private organizations and indi- viduals alike. S Types of Calibration

Services

• Calibration Services

• Special Tests

• Measurement Assurance Programs

(MAPs)

NIST provides Calibration Services using

well-characterized, stable and predictable

measurement processes. NIST calibrates instruments and devices that are metrologically suitable as reference or transfer standards. Special Tests are either unique or seldom-performed calibrations or measurements requested by the customer. Measurement Assurance Programs are quality control programs for calibrating a customer's entire measurement system. In a typical MAP, a stable artifact or set of

artifacts, called transfer standards, are

first measured by NIST and then sent to a customer's laboratory for a series of measurements. The transfer standards are then returned to NIST for remeasurement, along with the participating laboratory's data. NIST reports its comparative

findings to the customer and, when necessary, offers guidance on achieving and

maintaining measurement quality.

Successful use of a NIST MAP requires

that the customer make periodic measurements of in-house check standards to estimate their measurement process

uncertainty and to ensure that the measurement process remains in a state of

statistical control. Unless a laboratory has

a measurement quality assurance pro- gram to monitor its own measurement

process parameters continuously, there is no value in participating in a MAP. In

fact, NIST recommends that its cus- tomers establish and use a measurement

quality assurance program to monitor

their measurement parameters, whether

or not they participate in a MAP.

C Other NIST Measurement Transfer Services

National Voluntary Laboratory

Accreditation Program (NVLAP)

NIST does not audit, or regulate metrol- ogy laboratories as part of MAP or other

calibration services. Calibration laboratories and testing facilities may be accredited by NIST under the National

Voluntary Laboratory Accreditation Pro- gram (NVLAP). The basic procedures

and general accreditation requirements of

NVLAP are described in NIST Handbook 150. A participating laboratory may

voluntarily take steps to improve or as- sess its measurement process. For further information about NVLAP, contact:

National Voluntary Laboratory

Accreditation Program (NVLAP)

National Institute of Standards and

Technology

Building 820, Room 282

Gaithersburg, MD 20899-0001

Telephone: (301)975-4016

E-Mail: NVLAP@nist.gov

Fax: (301) 926-2884

Internet: http://ts.nist.gov/nvlap

1
Standard Reference Materials

Program (SRMP)

Calibration assistance and alternative paths for traceability are provided by

NIST's Standard Reference Materials

Program. For examples:

Chemical measurement instruments

are not calibrated at NIST, but NIST pro- vides various Standard Reference

Materials (SRMs), some of which are used to calibrate chemical measuring

systems.

Dimensional Measurements—NIST

also provides several SRMs for calibrat- ing instruments for dimensional measurements. These include socketed ball bars and probe performance spheres for coordinate measuring machines; surface roughness blocks to calibrate stylus in- struments; powders and soHd^ to calibrate

particle size measuring instruments; and

magnification, linewidth measurement,

and optical fiber diameter standards for instruments such as scanning electron,

optical, and video microscopes.

Sieves—NIST provides a series of

SRMs for evaluating and calibrating vari- ous types of particle size measuring in- struments, including light and electrical zone flow-through counters, optical and

electron microscopes, sedigraphs, and

wire cloth sieving devices. Thermodynamic Property Measure- ments—NIST offers SRMs for calibrat- ing instruments used to determine

thermodynamic properties, such as enthalpy and heat capacity, heat of combustion, heat of solution, vapor pressure of metals, and thermal expansion and

resistance. Also available are defining

fixed points of the International Temperature Scale, ITS(90), melting points, triple

points, secondary temperature reference

points, thermocouples and thermometers.

Liquid Densitities—NIST offers SRMs

of certified density for the determination

of liquid densities. Photometric Measurements—In addition to calibrations and special tests, NIST also offers SRMs for spectrophotometry, including diffuse transmittance

(photographic step tablets).

For further information about SRMs,

contact:

Standard Reference Materials Program

(SRMP)

National Institute of Standards and

Technology

Building 202, Room 204

Gaithersburg, MD 20899-0001

Telephone: (301) 975-6776

E-Mail: SRMINFO@nist.gov

Fax: (301) 948-3730

Internet: http://ts.nist.gov/srm

Standard Reference Data

Program (SRDP)

Very few calibrations can be conducted

without quantitative information related

to measurements of physical or chemical

properties. NIST develops and publishes evaluated data for technical and scientific applications called Standard Reference Data (SRD). For further information

about SRD, contact:

Standard Reference Data Program

(SRDP)

National Institute of Standards and

Technology

Building 820, Room 113

Gaithersburg, MD 20899-0001

Telephone: (301) 975-2208

E-Mail: SRDATA@nist.gov

Fax: (301) 926-0416

Internet: http://www.nist.gov/srd

Weights and Measures Program (OWM)

The NIST Office of Weights and Measures (OWM) provides measurement

services to State and local governments

responsible for marketplace transactions involving measurements. State weights

and measures laboratories provide alter- native sources for calibration services in mass, length, volume, and certain other measurement areas. For further information about OWM, contact: Office of Weights and Measures (OWM)

National Institute of Standards and

Technology

Building 820, Room 232

Gaithersburg, MD 20899-0001

Telephone: (301) 975-4004

E-Mail: jkoenig@nist.gov

Fax: (301) 926-0647

Internet: http://www.nist.gov/owm
D Criteria for Quality

Assurance

All the measurement services listed in

this document meet rigorous criteria for quality assurance. Calibration Services

and MAPs satisfy the most demanding

and explicit requirements in that they are

carried out regularly under pre-established and well-defined conditions; the measurement processes are well- characterized, stable, and statistically controlled; and quality-control proce- dures are well-defined and strictly followed. Furthermore, each Calibration Service or MAP is planned and documented to provide continuity of service over time. A Special Test is so designated for one

or more of the following reasons: (1) the specific type of calibration is seldom

requested, thus precluding the mainte- nance of a large statistical base for characterizing the measurement process;

(2) the requested test is unique; or

(3) the service is still under development—meaning the measurement or cali- bration methods are still being perfected, or the quality-control documentation has

not all been completed.

Fees

NIST recovers the costs of calibration services by charging a fee for each cali- bration performed. These fees range from

a low of several hundred dollars to cali- brate a laboratory thermometer to $75,000 or more for special tests of large

microwave antenna systems.

The costs of services are published in the Fee Schedule (NIST SP250 Appendix), which is updated and published

annually to reflect changes in prices and

services. Even so, the cost of many ser- vices may vary according to your exact

calibration specifications; you must therefore provide the technical contact with an

exact description of work before receiv- ing a price quote. Please refer to Section

L of this Chapter for information on obtaining a copy of the current Fee Schedule or Users Guide.

NOTE: Fees for NIST services do not

include shipping costs or insurance.

Reports of Calibration/

Test Results

Reports on calibrations or other services

are the property of the customer. Copies

are supplied to other parties only as re- quired by Federal law or requested in writing by the customer. The results of

calibrations and tests performed by NIST

apply only to the specific instrument or standard at the time of test unless other- wise clearly stated.

Traceability

The International Vocabulary of Basic

and General Terms in Metrology (VIM;

1993) defines traceability as:

The property of the result of a measurement or the value of a standard whereby it can be related

to stated references, usually national or international standards, through an unbroken chain of comparisons

all having stated uncertainties.

Many government regulations and

commercial contracts require regulated

organizations or contractors to verify that the measurements they make are "traceable" and to support the claim of

traceability by keeping records that their own measuring equipment has been cali- brated by laboratories or testing facilities whose measurements are part of this "unbroken chain." The purpose of requiring traceability is to ensure that measure- ments are accurate representations of the

specific quantity subject to measurement,

within the uncertainty of the measurement. NIST reports calibration results, with

the measurement values accompanied by

the uncertainties associated with the methods, operators, and environment at NIST. Users of these calibration services make their own measurements with the calibrated instruments or artifacts. In addition to the uncertainty indicated by

3
NIST, other uncertainties are inherent in the instrument, associated with the method or protocol in using the instru- ment, with the operator of the instrument,

and with the physical environment (pressure, temperature, humidity, etc.) in which the measurements are made. Thus,

the measurements made with the cali- brated instruments or artifacts by organizations outside NIST have associated

total uncertainty budgets, only one component of which is the uncertainty

reported by NIST.

NIST often receives calls to verify the

authenticity of a NIST Report of Test number appearing on another organization's report. Although NIST can verify the authenticity of its report numbers, the number itself does not provide complete

assurance or evidence thr t tne measure- ment value provided by another organization is traceable. Not only should there be

an unbroken chain of comparisons, each

provided measurement should be accompanied by a statement of uncertainty as- sociated with the farthest link in the chain from NIST, that is, from the facility providing the most recent measure- ment value. NIST does not have that information; only the facilities that provided the measurement values to the customer can provide the associated

uncertainties and describe the traceability chain.

In summary, to adequately establish an

audit trail for traceability, a proper

calibration result must include: the assigned value, a stated uncertainty,

identification of the standards used in the

calibration, and the specification of any

environmental conditions of the calibration where correction factors should be

applied, if the standard or equipment

were to be used under different environmental conditions. NIST does not define nor enforce

traceability except in its NVLAP laboratory accreditation program. Moreover,

NIST is not legally required to comply

with traceability requirements of other Federal agencies, nor do we determine

what must be done to comply with

another party's contract or regulation

calling for such traceability. However,

NIST can and does provide technical

advice on making measurements consistent with national standards. Although NIST supports making the user aware of traceability and provides

the user with details as to how traceability is established, NIST does not allow

the prominent display of its name on

proprietary products or in the advertising

of them. (See Section J). HNIST Policy on Reporty ing Measurement

Uncertainty

To ensure that NIST uncertainty state- ments are consistent across the organization and with international practice,

NIST policy requires that all NIST

measurements be accompanied by state- ments of uncertainty as discussed in NIST Technical Note 1297.' This publi- cation is based on the approach to expressing uncertainty in measurements recommended by the International Committee on Weights and Measures

(CIPM).^ That committee established general rules for evaluating and expressing uncertainty in measurements that are intended to be applicable to a broad

spectrum of measurements. Copies of

NIST TN 1 297 are available upon request

(see Section L) or on the web site at:

http://physics.nist.gov/Pubs/guidelines/ contents.html

Throughout this publication, uncerntainties are expressed as standard uncertainties or expanded uncertainties. Standard uncertainties have a coverage

factor, ^, of 1, and denote a level of confidence of approximately 68 %. Unless

noted otherwise, a coverage factor, k, of

2 (95 % confidence level) applies to any

expanded uncertainty provided in this guide. The expanded uncertainties are exactly twice as large as the standard

uncertainties.

' Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results, NIST

Technical Note 1297, 1994 Edition.

^ Guide to the Expression of Uncertainty in Measurement, International Standards Organization

(ISO), 1993 Edition.

4
The uncertainty of a measurement

consists of two categories of components:

"Type A" are those uncertainties evalu- ated by statistical methods, and "Type B"

uncertainties are evaluated by other means, usually scientific judgment using

all relevant information such as previous

data, or experience with materials or instrument behaviors. Some sections of

diis Guide discuss and list the components of uncertainty associated with the measurements. /NIST Policy Regarding

Use of Metric (SI) Units

In accordance with the Metric Conversion Act of 1975 as amended by Section

5164 of the Omnibus Trade and Competitiveness Act of 1988 and as required by

related provisions of the Code of Federal

Regulations, the National Institute of

Standards and Technology (NIST) uses

the modern metric system of measure- ment units (International System of

Units—SI) in all publications. When the

field of application or the special needs

of users of NIST publications require the use of non-SI units, the values of quantities are first stated in the SI units and the corresponding values expressed in non-SI

units follow in parentheses. Copies of

NIST SP 81 1^ are available upon request

(see Section L) or on the web site at:

http://physics.nist.gov/Pubs/SP8 1 1/ sp811.html

J References to NIST in

Advertisements

The NIST measurement or test results or

reports shall not be used to indicate or imply that NIST approves, recommends,

or endorses the manufacturer, supplier, or user of any instruments or standards or

that NIST in any way guarantees or predicts the future performance of items after calibration or test. No reference shall be made to NIST or to reports or results furnished by NIST in any advertising or

sales promotions which might indicate or imply that NIST approves, recommends.

' Guide for the Use of the International System of

Units (SI), NIST Special Publication 81 1, 1995

Edition.

or endorses any proprietary product or

proprietary material.

Disclaimer

Commercial products, materials, and in- struments, are identified in NIST communications and documents for the sole purpose of adequately describing experimental or test procedures. In no event does such identification imply recommendation or endorsement by NIST of a

particular product; nor does it imply that a named material or instrument is necessarily the best available for the purpose it serves. Questions and Inquiries

This Users Guide and the Fee Schedule

(SP250 Appendix) are intended to make

the task of selecting and ordering an appropriate calibration service as quick and

easy as possible. Nevertheless, when

questions arise you should contact NIST

for immediate clarification. General inquiries about the NIST cali- bration services, assistance in determining the availability of services, and

requests for complimentary copies of the Calibration Services Users Guide, the Fee Schedule, Guide for the International System of Units (SP 811), and Guidelines

for Evaluating and Expressing the Uncertainty of NIST Measurement Results (TN 1 297) may be addressed to:

Calibration Program

National Institute of Standards and

Technology

Building 820, Room 236

Gaithersburg, MD 20899-0001

Telephone: (301) 975-2002

Fax: (301) 869-3548

E-Mail: calibrations@nist.gov

Visit the NIST Calibration Program

Web Site on the Internet:

http://ts.nist.gov/calibrations

For technical questions concerning a

specific service, contact the NIST staff member responsible for that calibration

area. Consult the section of the Users Guide or Fee Schedule that lists the service in question for names, addresses,

e-mail and telephone numbers.

5
Chapter

A Customer Inquiries

B Prearrangements and Scheduling

C Purchase Orders

D Shipping, Insurance, and Risk of Loss E Turnaround Time

F Customer Checklist
Ordering Instructions—Domestic Customers

J^j^

Customer Inquiries

General customer inquiries for information or clarifications about the NIST cali- bration services may be directed as indicated in Section L of Chapter 1

.

SPrearrangements and

m Scheduling

Services should be arranged in advance,

beginning with direct contact with a NIST technical staff member responsible

for the desired service. Use the appropriate technical section of the Users Guide

or Fee Schedule to determine whom to contact. This advance communication

may answer your questions, clarify the

policies and procedures briefly described

here, and will permit you to schedule a

tentative calibration date. Following the

initial communication, you must complete and submit a purchase order and

prepare to ship the item according to the procedures described below or agreed

upon with the technical contact. If a cali- bration is scheduled far in advance, the item should not be shipped until shortly before the scheduled date; you must sub- mit the purchase order (complete with

the name and number of the desired ser- vice) before a firm calibration date can

be assigned. When NIST receives your purchase order and assigns a firm service

date, your order will be confirmed by the technical contact. C Purchase Orders

Before you ship an item for calibration,

send a purchase order to the address

listed in the appropriate technical section of the Users Guide or Fee Schedule. The

purchase order must:

1 ) State both the name and number

of the NIST service (listed in this Guide as the "Service ID

Number") being requested.

FAILURE TO INCLUDE THE

ORDER NUMBER WILL

SERIOUSLY IMPEDE

SCHEDULING AND SERVICE.

2) Clearly identify the item(s) being

sent for calibration, including any

serial number(s) or model number(s). 3) Give the name, address, and tele- phone number of your company's

procurement officer, purchasing

agent or other administrative/ financial authority.

4) Give the name, address, and tele- phone number of your company's

technical contact, if different from

above.

5) List separately the instructions and

address for return shipment, in- surance, mailing address for the

calibration/test report, and billing address. (Federal or State agency

requests for calibration services should be accompanied by a document authorizing that the cost of

the service be billed to the agency.)

6) Clearly state any special or neces- sary conditions of test—such as operating frequency or temperature. 7) Clearly state your customer identi- fication number; i.e., social security number (EIN) for indi- viduals; tax identification number

(TIN) for organizations; or agency

location code (ALC) for govern- ment customers.

8) If the calibration or test report is to be handled in a special manner,

give instructions on the purchase

order.

NOTE: Receipt of orders by NIST does

not imply acceptance of any provisions

set forth in the order that are contrary to the policy, practice, or regulations of

NIST or of the U.S. Government. In

general, NIST will not sign any affi- davits, acknowledgment forms, or other documents required by company policy

governing the procurement of goods and

services.

7
D Shipping, Insurance,

and Risk of Loss

Ship the instrument or standard to the maiUng address of the technical group

providing the service. Please note that the mailing address is not the same for

all technical groups. Please adhere rigorously to the follow- ing procedures:

1) Ship only items in good repair.

Apparatus in disrepair will not be

calibrated. If defects are found

after calibration has begun, the procedure will be terminated, a report issued, and a charge levied

for work completed.

2) Use strong, reusable packing

materials and containers marked

clearly and indelibly on the outside with the requestor's name,

address, and the following notation: REUSABLE CONTAINER,

DO NOT DESTROY.

3) Follow any special shipping pro- cedures given in the technical sections of this Guide, particularly those sections covering radiation and dosimetry measurements.

4) Insure the shipments to and from

NIST and clearly state the method

of return shipment. NIST will not assume liability for loss or damage, unless such loss and

damage result solely from the negligence of NIST personnel. If return shipment by parcel post is requested or is suitable, NIST will prepay the return shipment but

will not insure it. When no

shipping or insurance instructions are ftirnished, NIST will return

the shipment by common carrier, collect and uninsured.

5) Shipments to NIST must be at FOB destinations. (Customer pays

for shipping.)

6) Return shipments are sent FOB

origin. (Customer pays for shipping.)

NOTE: Fees for NIST services do not

include shipping costs.

Turnaround Time

The normal turnaround time for NIST

calibration services varies greatly

usually from several weeks to several months depending on the type of service requested and the service schedule. Some

services are scheduled only once or twice

a year, with appointments made months

in advance of the service date. To avoid unnecessary scheduling or administrative delays in the calibration process, always

make arrangements with the technical contact for the service you wish to utilize prior to shipping your instrument or arti- fact to us.

Customer Checklist

Please refer to the next page in this chapter for a Customer Checklist which

is intended to assist you in developing the basic information required to process an

order for calibration services at NIST.

8
Customer Checklist for Ordering NIST Calibration Services

"'1-0^ i . Isformation Ohtsvmp<1 fw»»n VI«!T

Tecbiiiral Coi '^^^^ Comments

NIST Contact (name/telephone) Provide this information on your purchase order (po)

Is the service available? Please make sure customer's technical contact discusses service with NIST technical contact before proceeding.

NIST Service Identification Number Provide this information on your po

IJMllllalCU CUM Ul ^CIVILC5> liuviuc iiila iiiiui iiiaiiuii uii your po

Estimated turnaround time Many calibration services are batched. Find out when to send

the instrument.

Special instructions

Packaging instructions

Shipping instructions

Other precautions

Tnfonnalioii

Purchase order number

Purchase order date

Customer's tax identification number

Customer's mailing address

Customer's billing address

i^aJllC, IClCLfllUllC IIUIIIUCI, 1<1A llUlllUd, e-mail address of administrative or procurement contact point at customer's

location

Name, telephone number, fax number,

e-mail address of technical contact point

at nistompr's loration

Ship-to address (including NIST technical conidci ndme^

Return address (for shipment back

to customer)

NIST Service Identification Number

Estimated cost

Shipping terms (no FOB destination on

return shipment)

Special instructions from customer's

technical contact

9
Chapter

A Foreign Inquiries

B Criteria for Providing Service O Special Instructions D Shipping Charges
Special Instructions—Foreign Customers

Foreign Inquiries

Foreign customers should address all inquiries to:

Calibration Program

National Institute of Standards and

Technology

Building 820, Room 236

Gaithersburg, MD 20899-0001

United States of America

Telephone: (301)975-2002

Fax: (301) 869-3548

E-mail: calibrations@nist.gov

Visit the NIST Calibration Program

Web Site on the Internet:

http://ts.nist.gov/calibrations

NOTE: Please clearly indicate your city

and country on all correspondence so

that we may promptly respond to your

request.

e Criteria for Providing

P

Service

NIST is authorized to provide measure- ment services, including calibration services, for organizations or individuals located outside the United States. The

Calibration Program must review each

request for calibration services to deter- mine if services are available in the requestor's country. Foreign customers may be asked to provide a written justifi- cation stating why NIST should perform

this service if an official standards laboratory in the requestor's country can

provide the requested service(s). Foreign customers must provide the following

information, in writing, to the Calibration Program (see address above):

1 . Identification of the item(s) to be

calibrated, including serial and

model numbers.

2. A detailed description of the measurements that are needed, or

indicate the service identification number as given in this Guide

(NIST SP250) or the Fee Schedule

(NIST SP250 Appendix).

3. A description of any special

requirement/circumstance that might affect the decision to provide the service. For example,

will adjustments have to be made

to the instrument, or will the time

period be restricted in which the device is available for calibration?

Special Instructions

If the request for calibration service is accepted by NIST, the requesting

organization will be notified of the cost of service and will be given the NIST

technical staff contact that will perform

the measurements. The requesting

organization must then complete the following steps:

1 . Contact the NIST technical staff that will perform the service to determine the time schedule.

2. Send a purchase order to the Calibration Program. Provide

complete addresses, including

country, for returning the in- strument and for mailing the calibration or test report.

3. NIST policy requires prepayment

for all NIST calibration services requested by non-U.S. organizations. Before proceeding with any

service(s) we will need a check,

money order or a bank wire

transfer. The prepayment must be

for the full amount and be drawn

on a U.S. bank. The prepayment

methods are as follows:

11
Money Orders & Prepayment Checks

Checks made payable to the National

Institute of Standards and Technology

(NIST) should be mailed to:

National Institute of Standards and

Technology

Calibration Program

Building 820, Room 236

Gaithersburg, MD 20899-0001

Bank Wire Transfers

Federal Reserve Bank of New York

33 Liberty Street New York, NY 10045

Phone: (212)720-5330

ABA#021030004

Account # 13060001

Account Name: Treas NYC/CTR/

BNF=/NIST/AC- 1 306000

1

Reference "Calibrations" so it will enable us to identify your payment. In

addition, please be sure to pay any fees assessed for your bank wire transfers; otherwise, they will deduct it from your prepayment wire. PLEASE NOTE: Our account number and name are of critical importance

and must be referenced in order for NIST

to be properly credited with your pay- ment. It must appear in the precise manner shown to allow for the automated

processing and classification of the funds

transfer message. Questions on bank

wiring can be directed to Randy

Angleberger at (301) 975-2694, or E-Mail: randy.angleberger@nist.gov

4. Before shipping the instrument or

standard to the appropriate NIST

technical unit, you must arrange

with a customs broker for entry of

the instrument into the U.S. with

transportation from the port of entry to NIST prepaid. Air freight is most satisfactory. Entry bond is required for instruments not manufactured in the U.S. If arrange- ments are made with a broker in the country of origin, that broker

should, in turn, have a U.S. customs broker in or near the port

of entry to arrange for the entry of

the instrument and its transportation to NIST. Direct arrangements can be made with customs brokers

located in die Washington, DC/

Baltimore, Maryland, metropolitan area or in the Denver,

Colorado, area, as appropriate.

These brokers must arrange for transportation to the port of exit after testing/calibration has been

completed.

Shipping Charges

The calibration fees quoted do not in- clude shipping, insurance, or the services of a customs broker. You must arrange and pay for these services separately. For

your information, NIST currently uses the following customs brokers:

Gaithersburg, Maryland

Laing International P.O. Box 16144

Washington, DC 20041

Phone: (703) 471-9279

Fax: (703) 471-8436

Boulder, Colorado

G. L. Gumbert

4725 Paris Street, Suite 200

Denver, CO 80239

Phone: (303) 371-9550

Fax: (303) 373-0850

You are not required to use these customs

brokers, but may select a broker of your

choice.

12
I

I

I

I

i
Chapter

A Length Measurements B Diameter Measurements C Complex Dimensional Standards

D Optical Reference Planes and Roundness Standards

E Angular Measurements F Laser Measurements G Surface Te Uure H Hydrometers

1 Volume and Density
Dimensional Measurements

A

Length Measurements*

A.I Gage Blocks

Technical Contacts:

Eric S. Stanrield TO: 301/975-3471

email: eric.stanrield@nlsLgov

Howard H. Harary

TO: 3017975-3485

email: hharay@nist.gov

Mailing Address: Building 220, Room B113,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service roNo. Items

100 IOC Gage Blocks

Gage Blocks (lOOlOC)

This calibration service provides for measurement of the length of gage blocks by

either mechanical comparison to NIST

master gage blocks or by direct interfer- ometry. Generally, the length is trans- ferred from known master blocks by a

systematic intercomparison procedure

using mechanical comparators.

All gage blocks submitted for test should be in substantially new block condition, and each block should be marked

with an identification number. In shipping gage blocks, extreme care should be

taken against both corrosion and damage

by contact with other gage blocks. All defining steel surfaces should be greased

and padded with waxed paper or volatile rust inhibitor treated paper. A greased

steel surface coming in contact with newspaper, wrapping paper (unwaxed),

or excelsior is likely to corrode. Sets of gage blocks should have packing inside the case and the case should be bound

shut, since the clasps on cases frequently

open or break during shipment.

* See Chapter 1 , Section C for information on

dimensional measurement artifacts available through the Standard Reference Materials Program.

Square or rectangular blocks up to 500 mm (20 in) long are routinely cali- brated and the lengths reported in English or metric units. For blocks

longer than 500 mm (20 in), the NIST

technical contact should be consulted

in advance to discuss alternative measurement techniques, approximate costs, and scheduling.

The reported measurement uncertainty** depends on the length of the blocks. For blocks near 2 mm (0.1 in), the expanded uncertainty** is approximately 25 nm. The uncertainty is larger

for blocks significantly longer or shorter than 2 mm. A report describing the NIST

gage block laboratory measurement

assurance process is sent to all new

customers or on request to past cus- tomers.

References—Gage Blocks

The Gage Block Handbook, T. Doiron

and J. S. Beers, NIST Monogr. 180

(1995).

Drift Eliminating Designs for NonSimultaneous Comparison Calibrations, T. Doiron, J. Res. Natl. Inst. Stand. Technol. 98 (2), 217-224

(1993).

A Gage Block Measurement Process Using Single Wavelength Interferometry, J. S. Beers, Natl. Bur. Stand.

(U.S.), Monogr. 152 (1975).

** See Chapter 1, Section H for more information about uncertainty.

15
10020C

A

Length Measurements

A.2 Line Standards

Technical Contact:

William Penzes

Tfel: 301/975-3477

email: wpenzes@nist.gov

Mailing Address: Building 220, Room Al 17, National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service roNo. Items 10020C Line Standards

Line Standards (10020C)

Line scales are calibrated on an instru- ment called a Line Scale Interferometer

(LSI). The NIST LSI consists of a scan- ning electro-optical line detector, a high

precision one-axis motion system, and a high accuracy heterodyne interferometer

for determining the displacement of the

test artifact beneath the line detector. The

wavelength of a stabilized helium-neon

laser corrected for temperature, humidity,

and atmospheric pressure is used as the length standard. The instrument is housed

in a temperature controlled chamber in which all environmental properties are carefully monitored.

The minimum line spacing on a line standard is 1 (xm and the maximum line spacing of 1 m can be measured on this instrument. The line width can be varied from 1 [xm to 100 jxm, 2 (xm to 10 \xm

being optimum. The maximum overall length of a line standard should not exceed 1020 mm, and the maximum

width of any part of the standard should

not exceed 150 mm.

The accuracy of the calibration of a

line standard depends significantly on the shape and optical properties of the graduation lines, the background, and the flatness of the graduated surface. The ac- curacy of the calibration will be optimum

if the lines are uniform, have straight

parallel edges, uniform reflectivity, are

2 fxm to 10 |xm wide and are between

20 |xm to 100 (xm long, if there is good

contrast between the line and the background, and if the graduated surface of

the artifact is flat within 10 |xm.

Expanded uncertainties* of Inm can be

achieved for intervals of 1 mm or less. For intervals of about 1 m, standard

uncertainties* of 50 nm can be achieved.

References—Line Standards

NIST Length Scale Interferometer Measurement Assurance, J. S. Beers and W. B. Penzes, Natl. Inst. Stand. Technol., NISTIR 4998 (Dec. 1992).

Length Scale Measurement Procedures at the National Bureau of Standards,

J. S. Beers, NBSIR 87-3625 (1987).

* See Chapter 1 , Section H for more information about uncertainty.

16
10030C-10040S

A

Length Measurements

A.3 Surveying Tapes

Technical Contact:

Ronald G. Hartsock

Tel: 301/975-3465

email: rhartsock@ni$t.gov

Mailing Address: Building 220, Room BUS,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 10030C Surveying and Oil Gaging Tapes

10040S Special Tests of Surveying; Leveling Rods

Surveying and Oil Gaging Tapes

(10030C)

The calibration of surveying tapes and oil gaging tapes is caiTied out in a laboratory

that houses two permanent working stan- dards, a laser interferometer, and a 50 m

(200 ft) stainless steel bench. For the most part, measurements are performed

using a laser system that is referenced

against a cube-corner retroreflector at- tached to a microscope, which is used

manually for line location. The laboratory is maintained at 20 °C, but a control system can vary the chamber temperature

from 15 °C to 40 °C for special tests. Calibration of tapes will normally be

made with the tape under tension and

supported on a horizontal flat surface. Unless otherwise requested, the total length and each 15 m or 50 ft subinterval

will be measured and reported. Each in- terval calibrated on a surveying tape will have computed lengths for two (single

catenary), three, four, and five equidistant

points of support.

The laser standard is capable of cali- brating tapes with scribed graduations

with a relative expanded uncertainty*

of 2 X 10"*. Calibrations made with

respect to the stainless steel tape bench

are normally reported with a relative expanded uncertainty of 10 X 10"*. A

NIST serial number will be engraved on

each calibrated tape for identification.

Special Tests of Surveying Leveling

Rods (10040S)

Leveling rods are currently calibrated us- ing either of two methods. One method

involves the comparison of the rod to a

3 m standard at the intervals of 1 m, 2 m,

and 3 m (Other intervals can be accommodated.). A second system provides au- tomated measurement at multiple

intervals and automatic report generation.

Both systems incorporate a 7 m one- dimensional measuring machine with a helium-neon laser interferometer inter- faced to a minicomputer. The automated

system uses a motorized carriage and a photoelectric microscope for automatic

edge detection of the graduations. Measurements can be made on virtually any

type of linear scale or leveling rods with

scribed, engraved, or painted graduations.

The expanded uncertainty* for high-quality new Invar leveling rods is 50 |xm and

100 [Lm for used rods. Current studies suggest that these may be lowered in the future to near 20 |xm and 50 jjim, respectively. The length of intervals will be

reported as measured at 25 °C unless otherwise requested. The report can be

supplied in either written or digital form.

* See Chapter 1 , Section H for more information about uncertainty.

17
10050S

I A

Length Measurements

A.4 Other Length Standards

Technical Contacts:

Eric S. Stanfield TO: 301/975-3471

email: eric.$tanfield@nisLgov

Howard H. Harary

Ttl: 301/975-3485

email: hharary@nistgov

Mailing Address: Building 220, Room Bl 13,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 10050S Special Tests of Length Standards

Special Tests of Length Standards

(10050S)

Measurements on end standards with

spherical ends, gage blocks of unusual

shape or exotic materials, or measure- ment of standards between* 24 in and

240 in can sometimes be done, but agreement with the technical contact should be made before sending material.

* This is a special test when customer requests

characterization in inches rather than SI units.

18
KX)60S

^1 Length Measurements

m A.5 Sieves*

Technical Contacts:

Eric S. Stanfield Howard H. Harary

Tfel: 301/J75-3471 Ttl: 301/975-3485

email: eric.stanfleld@nisLgov email: hhararyf^nistgov

Mailing Address: Building 220, Room B113,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 10060S Special Tests of Sieves

Special Tests of Sieves (10060S)

Sieves are tested using a high accuracy

optical projector. The average wire di- ameter of both the warp and shoot wires

are determined by measuring 20 or more

wires at five different positions along

the diameter of the sieve. The average opening is found by measuring the aver- age pitch of the wires and subtracting the average wire diameter. These results are compared with the tolerances in the ASTM E-11 specifications. The frame

dimensions are also checked.

*See Chapter 1, Section C for information on

calibration materials available from the Standard Reference Materials Program.

19
10070S-10081S

^1 Length Measurements

A.6 Algorithms Testing and Evaluation

Program for Coordinate Measuring

Systems

Technical Contacts:

Cathleen Diaz Pluguez Craig M. Shakarji

Tfel: 301/975-2889 Tel: 301/975-3545

email: cdpIuguez@ni$tgov email: shakarji@nistgov

Mailing Address: Building 220, Room A 127,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 10070S Special Test of CMS Software: NIST-Generated Data Sets (Basic Service) 1007 1 S Special Test of CMS Software: NIST-Generated Data Sets (Per Geometry Evaluated)

10080S Special Test of CMS Software: Customer-Generated Data

Sets (Basic Service) 1008 IS Special Test of CMS Software: Customer-Generated Data

Sets (Per Geometry Evaluated)

General Information (10070S-10081S)

The Algorithm Testing and Evaluation

Program for Coordinate Measuring

Systems (ATEP-CMS) evaluates the per- formance of data analysis software used

in coordinate measuring systems (CMSs).

Tested software is treated as a filter that transforms point coordinate data into feature parameters according to a defined

transfer function. NIST evaluates the accuracy of the filter under conditions

typical of those found in industrial

practice. NIST independently compares

the output of the software under test to predetermined corresponding reference

values. NIST uses orthogonal-distance

least squares algorithms and supports

the following geometry types: circle,

line, plane, sphere, cylinder, cone and

torus. In the Special Tests, the reported

measurement uncertainty is determined

by the effects of computational roundoff

and convergence settings used to generate the reference fits, the propagation of

these effects through the comparison

algorithms, and sampling uncertainty

due to the number of data sets used to perform the test.

Special Test of CMS Software: NISTGenerated Data Sets (10070S-10071S)

The customer and NIST will agree on

general guidelines for determining the ranges of parameters (geometry types,

form errors, measurement errors, sampling plans) to be used in defining

the customer's test experiments.

NIST then provides the customer with

NIST-generated data sets based on these

guidelines. The customer produces fit results from their data analysis software

using the NIST-generated data sets. NIST generates fit results from the same

data sets using the ATEP-CMS reference

algorithms. The two sets of fit results are then compared by NIST. NIST then

provides the customer with a Report of

Special Test containing results of the test and the combined standard uncertainty.

Special Test of CMS Software:

Customer-Generated Data Sets (10080S-10081S)

NIST receives customer-generated data

sets and corresponding fit results from

the data analysis software to be tested. NIST then generates fit results from the same data sets using the ATEP-CMS

reference algorithms. The two sets of

fits are then compared by NIST. NIST

then provides the customer with a Report of Special Test containing

results of the test and the combined

standard uncertainty.

20
10070S;-ioo8is

References—Algorithm Testing and

Evaluation Program for Coordinate

Measuring Systems

Methods for Performance Evaluation of

Coordinate Measuring System Soft- ware, ASME B89.4.10-199X, ASME,

New York, NY (1997).

Algorithm Testing and Evaluation

Program for Coordinate Measuring

Systems: Testing Methods, C. Diaz,

Natl. Inst. Stand. Technol., NISTIR

5686 (1995).

Evaluation of Software for Coordinate

Measuring Systems, C. Diaz and

T. Hopp, Proc. Of the 1995 SME

Clinic, CMMs Week, June 5-8, Soc.

of Manuf. Eng., Dearborn, MI; also

in Proc. Of the 1995 Interface Symp.,

June 21-24, Interface Foundation of

North America, Carnegie Mellon

Univ., Pittsburgh, PA (June 1995).

Testing Coordinate Measuring Systems

Software, C. Diaz and T. H. Hopp,

Proc. 1994 Natl. Conf. Stand. Lab.

Ann. Workshop and Symp. (Aug.

1994).

Concept for an Algorithm Testing and

Evaluation Program at NIST, C. Diaz,

Natl. Inst. Stand. Technol., NISTIR

5366 (Jan. 1994).

Computational Metrology, T. H. Hopp,

Manufacturing Review 6 (4), 295-304, ASME, NY (1993).

21
11010S-11060S

Diameter Measurements

Technical Contacts:

Eric S. Stanneld Howard H. Harary

Tfel: 301/975-3471 Tel: 301/975-3485

email: eric.stanfield@nisLgov email: hharary@ni$t.gov

Mailing Address: Building 220, Room Bl 13,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items

1 lOlOS Special Tests of Cylindrical Diameter Standards

(i.e., Plug and Pin Gages)

1 1020C Measuring Wires for Threads and Gears

1 1030S Special Tests of Spherical Diameter Standards: Balls

1 1040S Special Tests of Internal Diameter Standards: Ring Gages

1 1050S Special Tests of Length and Diameter

1 1060S Special Tests of Step Gages

Special Tests of Cylindrical Diameter

Standards (i.e., Plug and Pin Gages)

(IIOIOS)

Plain plug gages (not threaded) are cali- brated using a laser-interferometer-based

micrometer. The uncertainty of the diameter is dependent on the geometry

of the artifact, particularly the roundness.

Please consult the technical contacts

listed above about auxiliary measure- ments needed to assure a satisfactory

level of accuracy.

Measuring Wires for Threads and

Gears (11020C)

This service provides for measurement

of the diameter of thread and gear measuring wires by either comparison to NIST master wires or absolute calibration with a laser-interferometer-based micrometer. Both types of calibrations are carried out under a measurement

assurance program based on the measurement of control wires. All measuring wires submitted for test should be in substantially new condition,

each wire should be appropriately bottled, and the bottle should be labeled with an identification number. In shipping

wires, extreme care should be taken to prevent corrosion; all wires should be

properly greased and their bottles rigidly

contained inside an appropriate packing

case. Thread measuring wires for 60° and

29° threads are tested for compliance

with the latest specifications in commercial use. These wires are calibrated, and

the deformed diameter under standard

conditions (as called out in the H28

Screw Thread Standard) are reported.

The primary elements of uncertainty

are based on the reproducibility of the check standards and estimates of the uncertainty in the deformation corrections. For wires in good condition the expanded

uncertainty* is 0.10 |xm (4 jxin).

Special Tests of Spherical Diameter

Standards: Balls (11030S)

Ball diameters are determined from

multiple comparisons in random orientations with either NIST master balls or

calibrated gage block stacks. The ball diameter reported is the undeformed size as calculated with the Hertz relations. For calibrations at a specific orientation or with roundness traces to reduce the geometric components of uncertainty, the technical contact listed should be contacted before the calibration is submitted.

Special Tests of Internal Diameter

Standards: Ring Gages (11040S)

Ring gages are calibrated by mechanical

comparison to a calibrated gage block

stack. The gage block stack is calibrated by multicolor interferometry to minimize

the uncertainty due to wringing and

geometry variations in the stack. The

diameter is measured at one marked

orientation. The technical contact listed should be consulted about calibrations needed in different orientations or roundness traces needed for a fuller determination of the ring geometry, if needed.

* See Chapter 1 , Section H for more information about uncertainty.

22
11010S-11060S

Special Tests of Length and Diameter

(llOSOS)

NIST has a wide variety of state-of-theart metrology equipment and can provide

services associated with dimensional

quality control as special tests. A three- dimensional measuring machine is avail- able for calibration of two- and

three-dimensional ball plates, two-dimensional grid plates, and other artifacts of

complex shape. Please consult with the technical contacts listed.

Special Tests of Step Gages (11060S)

Step gages having flat parallel faces can

be measured in lengths up to 1 .2 m

(60 in). These tests are performed at the NIST Gaithersburg site or at the DOE

Y-12 plant in Oak Ridge, TN. All of

these calibrations are made under the metrological control of the Dimensional

Metrology Group and use NIST cali- brated check standards in a Measurement

Assurance Program.

References—Diameter Measurements

Federal Standard H-28, Screw Thread

Standards for Federal Services,

English and metric versions. These

handbooks are available from the General Services Administration

(GSA).

American National Standard B 1 .2, ANSI, New York.

On the Measurement of Thread Measuring Wires, B. N. Norden, Natl. Bur.

Stand. (U.S.) Report 10987 (Jan. 1973).

Measurements of Cylindrical Standards,

R. C. Veale, Natl. Bur. Stand. (U.S.),

NBSIR 73-136 (1973).

On the Compression of Cylinders in Contact with a Plane Surface,

B. Norden, Nad. Bur. Stand. (U.S.),

NBSIR 73-243 (1973).

23
12010C-12040S

c.

Complex Dimensional Standards

Technical Contacts:

Edgar G. Erber 12010C-12020S

TO: 301/975-3473

email: edgar.erber@

nistgov

Dennis Everett 10210C-12040S

Tel: 301A>75-3472

email: dennis.everett@

nisLgov

Howard Harary

TO.: 301/975-3485

email: hharary@ni$t.gov

Mailing Address: Building 220, Room Bl 13, National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items

120 IOC API Threaded Plug and Ring Gages

12020S Special Tests of Threaded Plug and Ring Gages

12030S Special Tests of Two Dimensional Gages

12040S Special Complex Dimensional Tests, by Prearrangement

API Threaded Plug and Ring Gages

(12010C)

NIST provides calibration and certification services for API threaded plug and

ring gages, casing, tubing and line pipe

plug and ring gages, and sucker rod

gages. NIST is the custodian of the American Petroleum Institute (API)

Grand Master rotary thread gages. These

Grand Master gages are maintained and

have been recalibrated at NIST for more

than 60 years. They can be considered an

international standard since all API

Regional Master Gages throughout the world are referenced to NIST. Foreign

product manufacturers can have their Reference Master Gages calibrated by

NIST or by one of the other national standard laboratories listed below:

National Physical Laboratory,

Teddington, England

National Research Laboratory of

Metrology, Ibaraki, Japan

National Measurement Laboratory,

Lindfield, N.S.W., Australia

Laboratory National d'Essais, Paris, France

Instituto Nacional de Technologia

Industrial, Buenos Aires, Argentina

National Institute of Metrology, Beijing,

People's Republic of China

As required, the API laboratory is temperature controlled at 20 °C. Parameters measured for plug gages are length of

plug, taper, pitch diameter, major diameter, thread lead, lead and following thread

half-angles, depth of thread, pitch line width, and radius of curvature. Parameters measured for ring gages

are length of ring, taper, thread lead,

minor diameter, lead and following

thread half-angles, counter bore, depth of

thread, pitch line width, radius of

curvature, and standoff. Elements of rotary gages, buttress gages, extreme line casings, and large

casing and tubular gages are measured on

a coordinate measuring machine with an expanded uncertainty* of 2.5 |jLm

(0.0001 in) for diameters under 254 mm,

increasing to 5.0 jxm (0.0002 in) as the gage diameter increases to 500 mm.

Profile measurements are made on a contour tracing machine with an expanded uncertainty of 12.5 \xm

(0.0005 in). All gages received must be marked

with the API monogram and the API

registration number. If not so marked, the gages will be returned to the customer

uncalibrated. Gages which meet the specifications will be marked as specified in the API Standards. All thread gages must be submitted in sets of plug

and ring. The name of the gage owner

should be given for inclusion in the Report of Calibration.

* See Chapter 1 , Section H for more information about uncertainty.

24
12010C:-12040S

Special Tests of Threaded Plug and

Ring Gages (12020S)

NIST will provide special tests of

threaded plug and ring gages in the areas

listed for API gages (12010C). The accuracy of these calibrations is determined

substantially by the quality of the

artifact, but high quality artifacts yield uncertainties approximately the same

as API gages.

Special Tests of Two-Dimensional

Gages (12030S)

NIST can provide special tests of twodimensional gages, ball plates or grid

plates, with dimensions up to 600 mm X 600 mm (24 in x 24 in). The accuracy of the calibration depends

substantially on the quality of the gage,

but expanded uncertainties* of 1 [im or

less are obtainable for high quality arti- facts.

Special Complex Dimensional Tests,

by Prearrangement (12040S)

For requirements not covered by the services described above, special

arrangements may be made by

contacting Howard Harary

(301) 975-3485.

References—Complex Dimensional

Standards

On Characterizing Measuring Machine

Geometry, R. J. Hocken and

B. Borchardt, Natl. Bur. Stand. (U.S.),

NBSIR 79-1752 (1979).

Three Dimensional Metrology,

R. J. Hocken, et al.. Annals of the CIRP, 26/1 (1977).

* See Chapter 1 , Section H for more information about uncertainty.

25
13010S-13030S

D.

Optical Reference Planes & Roundness

Standards

Technical Contacts:

Eric S. Stanfield

Tel: 30iy97S-3471

email: eric.stanfield® nistgov

Howard Harary

Tfel: 301A>75-3485

email: hharary@nist.gov

Mailing Address: Building 220, Room Bl 13, National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

References—Optical Reference Planes

The Calibration of an Optical Flat by

Interferometric Comparison to a Master Optical Flat, C. P. Reeve, Natl. Bur. Stand. (U.S.), NBSIR 75-975

(Dec. 1975).

Service ID No. Items 13010S Special Tests of Optical Reference Planes (Flats) 13020S Special Tests of Roundness

13030S Special Tests of Roundness Calibration Specimens

Special Tests of Optical Reference

Planes (Flats) (13010S)

Optical reference planes are tested inter- ferometrically, with the test surface horizontally supported on three equally

spaced pads located at 0.7 of the radius from the center. The measurement is per- formed along two marked orthogonal di- ameters. The technical contact listed should be consulted for these

calibrations.

Roundness Calibration Specimens and

Measurements, Special Tests of Roundness (13020S and 13030S)

The deviation from roundness at eight or more positions around nominally

round standards is determined. The size of the calibration step or deviation from

roundness is determined. The departure

from roundness of components and gages

is measured, and the results are reported

in graphical form.

NIST will provide special tests of

roundness calibration specimens by

request. Please consult with the technical contacts listed.

26
14010C-1

Angular Measurements

Technical Contacts:

Eric S. Stanfleld Howard Harary

Tel: 301/975-3471 1^1:301/975-3485

email: ericstanfield© email: hharary@ni$t.gov

nistgov

Mailing Address: Building 220, Room Bl 13 National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service roNo. Items 14010C Angle Gage Blocks 14020S Special Tests of Optical Polygons

14030S Special Tests of Rotary and Indexing Tables 14040S Special Tests of Wedges

14050S Special Angular Measurements, by Prearrangement

Angle Gage Blocks (140 IOC)

Angle blocks are measured in an angle

comparator system consisting of a

special chamber and two autocollimators. The blocks are placed in the chamber to minimize air currents and

stray light effects. The test blocks are compared to NIST master angle blocks

following an intercomparison method

to eliminate thermal drift. Measurements

are made in both top up and bottom

up positions. Check standard blocks are measured during the procedure and

used for process control. Standard size block sets include (1, 3, 5, 20, and

30)' sizes; (1, 3, 5, 20, and 30)" sizes; as well as 1°, 3°, 5°, 15°, 30°, and 45°

sizes. The expanded uncertainty* for this calibration is approximately 0.18" for

ideal blocks, however, this value

varies with the condition and geometry

of the test block gaging surfaces. Customer angle blocks with poor gaging

surfaces blocks can have uncertainties as high as 0.3" to 0.4". Angle blocks

with dimensions other than standard

(1 in by 2 (2.54 cm by 5.08 cm) in

measuring faces) require different measurement methods and generally re- sult in higher uncertainties. All angle blocks submitted for cali- bration should be in substantially new

block condition and each marked with an identification number. In shipping

angle blocks, the same care exercised in gage block shipment should be used.

Special Tests of Optical Polygons

(14020S)

Optical polygons are calibrated using an

indexing table stack, an autocollimator and circle closure measurement tech- niques. Currently only polygons with

nominally equal integer angles between

faces can be measured. For example,

a 12 sided polygon with nominally 30°

angles between faces can be measured, but a 13 sided polygon with nominally 27.69° between faces cannot be

measured. Check standard optical

polygons are used for process control. The expanded uncertainty for this cal- ibration is approximately 0.14"; however, this value varies with the condition

and geometry of the polygon faces.

Special Tests of Rotary and

Indexing Tables (14030S)

Indexing tables (limited, fixed-incre- ment, high repeatability) and rotary

tables (continuous increment, low re- peatability) are calibrated using an au- tocoUimator and reflecting target, an

indexing table stack, and circle clo- sure techniques. The standard set of an- gular increments is every 30°. Additionally, every 5° of the first 30° in- terval, and every 1° of the first 5° in- terval can be measured. Check standard indexing tables are used for process

control during the measurement procedure. The expanded uncertainty* for this calibration is approximately 0.14"; however, this value varies with the locking mechanism repeatability and

the scheme of angles chosen to be

measured.

* See Chapter 1. Section H for more information about uncertainty.

27
14010C-14050C

Special Tests of Optical Wedges

(14040S)

Optical wedges are calibrated using an

autocollimator, a reflecting target, the

test wedge and a repeated reversal measurement series. Fixed angle and

adjustable wedges can be calibrated. The wedge is inserted between the auto- collimator and reflecting target and

measured. The wedge is removed, rotated 180° about the same base, re-inserted and measured. In this reversal technique

the difference in the two measure- ments is equal to twice the actual angle.

Check standard wedges are measured

for process control. The expanded uncertainty* for this calibration is approximately 0.12"; however, this value varies with condition and geometry of me wedge surfaces.

Special Angular Measurements, by

Prearrangement (14050S) For angular measurement requirements

not covered by the services described

above, special arrangements may be

made by contacting Engineering Metrology Staff (301) 975-3471. Requests for service will be discussed and honored

if current equipment and means are

available. Artifacts such as optical squares

(pentaprisms), apex angle measurements

of prisms, true squares, and polygons not

already described, typically fall into this category.

References— Angular Measurements

Uncertainty and Dimensional Calibrations, Ted Doiron, John R. Stoup,

NIST Journal of Research (In Press).

The Calibration of Angle Blocks by In- tercomparison, C. P. Reeve, Natl. Bur.

Stand. (U.S.), NBSIR 801967 (1980).

The Calibration of Indexing Tables by

Subdivision, C. P. Reeve, Natl. Bur.

Stand. (U.S.), NBSIR 75-750 (1975).

* See Chapter 1, Section H for inore information about uncertainty.

28
Laser Measurements

Technical Contacts:

Jack Stone Howard H. Harary

Tfel: 301/975-5638 Tel: 301/975-3485

email: jack.$tone@nisLgov email: hhrary@nist.gov

Mailing Address: Building 220, Room Bl 13 National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items

14510S Laser Frequency/Wavelength

Laser FrequencyAVavelength

(14510S)

The frequency (or, equivalently, the vacuum wavelength) of a red He-Ne

laser is determined by comparison to an iodine-stabilized He-Ne laser. The

attainable accuracy of this technique is ultimately limited by the uncertainty in the wavelength of the iodine stabilized

laser. The relative standard uncertainty*

of the laser vacuum wavelength at NIST

is 5 X 10"". The relative expanded

uncertainty is 1 X 10"'° . The relative expanded uncertainty can be reduced

to 5 X 10"" on special requests. As a

practical matter, however, the uncertainty

of a comparison is usually determined

by the limited reproducibility of the

laser under test.

* See Chapter 1, Section H for more information about uncertainty.
15010C-15040S

G.

Surface Texture

Technical Contact:

Charles D. Foreman

Tel: 301A»7S-5836 Email: €harles.foreman@nistgov

Mailing Address: Building 220, Room A11 7, National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 15010C Roughness Calibration Specimens

15020C Surface Roughness Comparison Specimens

1 5030C Step Height Measurements

1 5040S Special Roughness Tests

Roughness (15010C-15040S)*

NIST provides measurement services for roughness calibration specimens, other types of roughness specimens, and step

height calibration specimens (see stan- dards ASME B46.1-1995 and ISO 5436).

Surface roughnesses up to 10 |j,m Ra

and step heights up to 50 jjim are measured by means of a computerized stylus

instrument system. Using an interfero- metrically measured step, the system is calibrated at each value of magnification

employed during a measurement. Certain

horizontal parameters are calibrated us- ing a laser interferometer. A number of

other statistical parameters and functions may also be calculated, including the rms

roughness, average slope, average wavelength, skewness, amplitude density

function, autocorrelation function, and

power spectral density. In measurements of roughness, surface

profiles are taken according to American

National Standard, ASME B46.1-1995,

using a 0.8 mm cutoff length and a

traversing length of 4 mm. In step height

measurements, straight lines are fitted by

* Also see Chapter 1 , Section C for Standard Reference Materials to calibrate stylus instruments

that measure surface roughness.

the method of least squares to the top and

bottom of the profile of the step, and the step height is calculated from the vertical difference of the lines at the middle of

the step transition. The uncertainty in the NIST calibration for step height or Ra

depends on a number of factors, the most

important being the step or Ra value

itself. The expanded uncertainties** range approximately from 0.4 [jim at a

step height of 50 ixm to 0.5 nm at a step

height of about 8 nm. Comparable

uncertainties are achieved for measure- ments of Ra.

References—Surface Texture

Stylus-laser surface calibration system,

T. V. Vorburger, J. F. Song, C.H.W.

Giauque, T. B. Renegar, E. R

Whitenton, and M. C. Croarkin,

Precision Engineering 19, 157 (1996).

Methods of Characterizing Surface

Topography, T. V. Vorburger, Tutorials

in Optics, D. T. Moore, ed. (Optical

Society of America, Washington, DC,

1992).

Standard Reference Specimens in Quality

Control of Engineering Surfaces,

J. F. Song and T. V. Vorburger, J. Res.

Natl. Inst. Stand. Technol. 96, 271

(1991).

Surface Finish Metrology Tutorial,

T. V. Vorburger and J. Raja, NISTIR

89-4088 (National Institute of Stan- dards and Technology, Gaithersburg,

MD, June 1990).

Surface Texture, J.F. Song and T. V. Vorburger, ASM Handbook 18, 334.

** See Chapter 1, Section H for more information about uncertainty.

30
16010C

H.

Hydrometers

Technical Contacts:

John F. Houser

Tel: 301/97S-S9S6

Email: john.houser@

nistgov

Vern E. Bean

Tel: 301/975-4830 Email: vern.bean@

nistgov

George E. Mattingly

Ttl: 301/975-5939

Email: gmaUingly@

nistgov

Mailing Address: Building 230, Room 105,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 160 IOC Reference Standard Hydrometers

Reference Standard Hydrometers

(16010C)

NIST provides measurement services for reference hydrometers. These reference

standard hydrometers are generally used

as laboratory standards to calibrate other hydrometers. Reference hydrometers

should be made of smooth, transparent

glass, free of bubbles or other imperfections. The hydrometer should bear an in- scription which indicates the purpose of

the instrument. This inscription should

denote the reference temperature at which it is to be used. The maker's name

or trade mark and an identification number should be inscribed on the hydrometer scale. Hydrometers accepted for calibration must conform to specified

requirements. The technical contacts

listed above can give guidance on these requirements.

Reference hydrometers accepted for calibration include specific gravity, proof

spirit for alcohol solutions, API degrees

for petroleum measurements, degrees

Baume heavy and degrees Baume light,

and other arbitrary scales, all subject to discussion with the technical contacts. Specific gravity hydrometers cover the

specific gravity range of 0.65 to 2. The

hydrometer scale should be divided into 0.001, 0.0005, 0.0002, or 0.0001 units of

specific gravity. Proof spirit hydrometers

cover the range of 0 to 200 proof. The al- cohol hydrometer scale should be divided

in whole, half, fifth or tenth percents.

Visual inspection should be made by

the customer before shipping to NIST for calibration. The hydrometer should be

packed in a safe reusable shipping container. NIST will provide a three-point cali- bration on these reference hydrometers.

Additional points can be provided at an

additional charge if requested. The cali- bration at NIST consists of comparing

NIST master hydrometers directly with

the customer's hydrometers in a liquid of

low surface tension. Hydrometer Facilities Uncertainty:

The expanded uncertainty* for NIST

master hydrometers depends on stem

scale. Components of the expanded uncertainty* include the Type A Standard

Uncertainty, composed of the imprecisions of such process components as

scale readings, thermal gradient of the

calibration fluid, etc., and Type B

Standard Uncertainty, based on direct comparisons to solid density standards (plummets), density of water, and

precision mass standards.

References—Hydrometer

Measurements

Testing of Hydrometers, J. C. Hughes,

Natl. Bur. Stand. (U.S.), NBS Circular 555. ASTM Standard El 00-81 Standards

Specifications for ASTM Hydrometers,

Annual Book of ASTM Standards

14.01. An Improved High-Precision Calibration Procedure for Reference Standard

Hydrometers, H. A. Bowman and

W. H. Gallagher, J. Res. Natl. Bur.

Stand. (U.S.) 73C (June 1969).

* See Chapter 1 , Section H for more information about uncertainty.

31
17010C-17040S

/.

Volume and Density

Technical Contacts:

John F. Houser

301/975-5956

Email: john.houser@

nisLgov

Vern E. Bean

Tfel: 301/975-4830

Email: \crn.bean@

nistgov

George E. Mattingly

Tfel: 301/975-5939 Email: george.mattingly@

nisLgov

Mailing Address: Building 230, Room 105

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service roNo. Items

170 IOC Volume Standards

1 7020S Special Tests of Volume Standards 17040S Special Tests of Density: Liquids

Volume Standards (17010C)

The procedure used for testing glass

volumetric apparatus is to weigh the amount of distilled water contained or delivered with reference to the graduations marked on the instrument, the volume being computed from the density of the water. The quality of the markings and the care exercised in reading or setting the liquid level are major factors in test calibration and

usage. NIST does not provide routine

calibration services for glassware;

however, NIST will accept factory standards and replacement glassware for the State Weights and Measures Offices

or Departments, in the range of 10"^ L to 5 L, which conform to specified

requirements. The technical contacts given above can give guidance on

these requirements.

NIST provides a calibration service

for metal volumetric test measures. The

volumetric test measures which are accepted for calibration should be free

from dents, rust, etc. Special care should be taken by the customer to insure the cleanliness of the inside of the test measures. Should the test measure be

equipped with a bottom drain valve, it is the customer's responsibility to insure

that the valve be in proper working condition. These test measures should bear an inscription which indicates the nominal value of its volume, the thermal coefficient of expansion, an identification number, and its reference temperature.

The scale plate should be legible in that the scale division can be estimated to one-tenth of a single division. A scale calibration is provided; however NIST

does not adjust scales. The zero index or

the scale should, therefore, be adjusted

prior to the calibration. The slicker- plate-type volume standards should be

adjusted by the manufacturer.

Normally NIST will accept for calibration, test measures with sizes in the range

of 5 L to 7600 L or 1 gal to 2000 gal. The calibration procedure for these test measures consists of determining the contained volume or delivered volume by

either gravimetric determinations, which

is the result of direct comparisons with mass standards, or by the use of transfer standards, for which volumes have been

predetermined. The reported result for the calibrated volume is the arithmetic mean of two independent observations. The reported volume is corrected to a requested reference temperature.

Volume Facilities Uncertainty: The

uncertainty for NIST volume standards

will vary with the instrument size and

design. Relative expanded uncertainties* range from 0.003 % to 0.065 %.

Special Tests of Volume Standards

(17020S)

Special tests may be made on volume

standards other than those mentioned

above. The technical contacts cited above

should be contacted regarding testing.

* See Chapter 1 , Section H for more information about uncertainty.

32
17010C-17040S

Special Tests of Density Liquids*

(17040S)

Currently NIST is involved in a research

project to improve its capabilities to measure liquid density. Contact the technical contacts cited above.

References—Volume and Density

Measurements

ASTM Standard 694-83 Standard Specifi- cations for Volumetric Ware, Annual

Book of ASTM Standards 14.02. The Equivalence of Gravimetric and

Volumetric Test Measure Calibration, R. Schoonover, Natl. Bur. Stand.

(U.S.), NBSIR 74-454 (Feb. 1987).

* See Chapter 1 , Section C for information about

the Standard Reference Materials Program. NIST

offers Standard Reference Materials of certified density.

Calibration of Small Volumetric Laboratory Glassware, J. Lembeck, Natl. Bur. Stand. (U.S.), NBSIR 74-461

(Oct. 1974).

Procedures for the Calibration of

Volumetric Test Measures, J. F. Houser, Natl. Bur. Stand. (U.S.),

NBSIR 73-287 (Aug. 1973).

Testing of Volumetric Standards,

J. C. Hughes and B.C. Keysar,

Natl. Bur. Stand. (U.S.), NBS

Monograph 62 (Apr. 1963).

Testing of Glass Volumetric Apparatus,

J. C. Hughes, Natl. Bur. Stand. (U.S.),

NBS Circular 602 (Apr. 1959).

33
Chapter

A Flow Measurements B Flow Measurements at Cryogenic Temperatures

C Airspeed Instruments D Mass Standards

E Force Measurements

F Vibration Measurements

G Acoustic Measurements

H Ultrasonic Reference Block Measurements

I Ultrasonic Transducer Measurements

J Acoustic Emission Transducer Measurements
Mechanical Measurements 18O1OC-18O50S

Flow Measurements

Technical Contacts:

John D. Wright George E. Mattingly

Tfel: 301/975-5937 Tel: 301/975-5939 Email: john.wright@nisLgov Email: george.mattingly@nistgov

Mailing Address: Building 230, Room 105

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items

180 IOC Gas Flow Meters 18020C Water Flow Meters 18030C Hydrocarbon How Meters I8040C Transfer Standards

1 8050S Special Tests Using Gas or Liquid Flows

Gas Flow Meters (18010C)

NIST provides calibration services for gas flow meters using piston provers,

bell provers, and a Pressure-VolumeTemperature-time (PVTt) system.

Throughout this section, flow rates are quoted at standard conditions of

P = 101 325 Pa and T = 20 °C. The

piston and bell provers cover flow

ranges from 3.7 X 10^^ m^/min to 1.4 m-Vmin (1.3 X 10 ftVmin to 51 ftVmin). Gases available for cali- bration work in the piston and bell provers are: dry air, nitrogen, carbon

dioxide, and argon. The piston and bell provers have connections for meters with

Swagelok"^*^, A/N, or National Pipe

Thread fittings from 0.64 cm to 5 cm

(1/4 in to 2 in) in diameter.

The PVTt system permits calibrations with dry air for flows from 0.86 m'/min

to 78 mVmin (30 ftVmin to 2740 ft^/min). Calibrations are normally

performed using a set of critical flow

nozzles as working standards.

Pipe diameters from 5 cm to 20 cm

(2 in to 8 in) with ASA 150 lb flanges*

are available and arrangements for other connections can be made upon request. Straight runs of piping of up to 18 m

are available. Meters can be tested if the flow range,

gas, and piping connections are suitable,

and if the system to be tested has preci- sion appropriate for calibration with the NIST flow measurement uncertainty.

The relative expanded uncertainty* for the NIST gas flow systems is 0.22 % or

better. A normal flow calibration in- cludes five different flows, with five aver- ages of the meter readings and the standard flow made at each flow, with

this entire test sequence repeated on a second day. It is helpful if the customer

specifies the flow set points and the in- strumentation requirements of the meter

(pressure, temperature, full scales re- quired, etc.).

Water Flow Meters (18020C)

The water flow facility consists of a

reservoir, pumps, meter runs, and weigh

tanks. The system operates as a constant flow facility and uses timed collections of water to compute the average flow

through the meter being calibrated. The relative expanded uncertainty** for these facilities is 0.12 %. Flows up to 38 mVmin (10,000 gal/min) can be pro- vided in pipes up to 40.6 cm (16 in) in diameter. Pipe connections should be

ASA 1 50 lb steel flanges, Victaulic^^ couplings, or adapters thereto. The

normal testing sequence is the same as

that described for gas flow meters.

Hydrocarbon Flow Meters (18030C)

Calibrations of hydrocarbon flow meters can be performed using a surrogate

liquid for JP-4 and JP-5 jet fuels. Both

volumetric and gravimetric systems can

be used over the flow range from

* ASA 150 lb flanges is a commercial designation

for these connectors. ** See Chapter 1, Section H for more information about uncertainty.

35
3.5 X 10"' mVmin to 1.5 mVmin

(0.01 gal/min to 400 gal/min). The relative expanded uncertainty* for the hydrocarbon flow system is 0.12 %. Preferred piping connections are AJN fittings, ASA

150 lb flanges, and National Pipe

Threads up to 7.6 cm (3 in) in diameter.

Transfer Standards (18040C)

Transfer standards are available for in situ calibrations of flow meters or flow

standards at the customer site. Details about this calibration service can be

obtained from the technical contacts

listed at the beginning of this section.

Special Tests Using Gas or Liquid

Flows (18050S)

Special tests for liquid and gas flows are

available. Examples include interlabora- tory comparisons, round robin tests, and

proving other fluid measurement

systems. Tests to establish or maintain

realistic flow measurement traceability for flow facilities can be designed and

performed for specific situations. Details about this calibration service can be

obtained from the technical contacts

listed at the beginning of this section. Special tests can be done using gas mixtures that simulate auto exhaust. These tests can range from 0.06 m'/min

to 6.2 mVmin (2 ftVmin to 220 ftVmin)

where temperatures can range from

20 °C to 400 °C; relative expanded

uncertainties are 1 % or better. Special tests are also available through

Service ID No. 30063S. These tests which use nitrogen can be done in the range from 10"** mol/s to 10"^ mol/s

(2 X 10"^ cmVs to 20 cm'/s) with

relative expanded uncertainties*

that range from 0.1 % to 0.05 % (low to high range, respectively.) The range of

flow rates are quoted at standard conditions of P = 101 325 Pa and T = 20 °C. Specific details should be discussed with

the technical contacts listed above or with

Stuart Tison at (301) 975-2857.

References—Flow Measurements

Flowmeter Calibration Facility for Heated Gas Mixtures, J. D. Wright

and P. I. Espina, NCSL Proc, Atlanta

(1997).

Flow Metrology: Standards, Calibrations, and Traceabilities, G. E. Mattingly, Flow Measurement: Practical Guides for Measurement and

Control, D. W. Spitzer, ed., ISA,

Research Triangle Park, 1991. Gas Flow Metrology, G. E. Mattingly,

NCSL Newsletter 29 (1), 9-16

(Jan. 1989).

NBS Primary Calibration Facilities for Air Flow Rate, Air Speed, and Slurry

Flow, K. R. Benson, N. E. Mease,

G. Kulin, and G. E. Mattingly, Proc.

Intl. Flow Meas. Symp., Washington,

DC, 1986, Amer. Gas Assoc., Arlington, VA.

The National Measurement System for Fluid Flow, W. C. Haight, P. S. Klebanoff, F. W. Ruegg, and G. Kulin,

Natl. Bur. Stand. (U. S.), NBSIR

75-930 (Aug. 1976).

* See Chapter 1 , Section H for more information about uncertainty.

36
18800S

B.

Flow Measurements at Cryogenic

Temperatures

Jennifer L. Scott

Tfel: 303/497-3684 Email: jennifer^ott@

nistgov

Fax: 303/497-5224

Technical Contacts:

Paula M. Hewitt Administration and Logistics

Ttl: 303/497-3753 Email: paula.hewitt@nist.gov Fax: 303/497-3970

Mailing Address: M.C. 838.07,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service roNo. Items 18800S Special Tests of Cryogenic Liquid Flow

Special Tests of Cryogenic Liquid

Flow (18800S)

Measurement services are provided for cryogenic liquid flow. A dynamic

weighing system is used to measure

totalized mass flow and, with liquid

density provided by the NIST Standard

Reference Database 1 2: Thermophysical

Properties of Pure Fluids, volumetric

flow. Mass flow measurements are performed using liquid nitrogen at flow

rates of I kg/s to 10 kg/s, over a pressure range of 0.4 MPa to 0.76 MPa,

and a temperature range of 80 K to 90 K. The relative expanded uncertainty*

within this flow range, is 0.17 %. For

volumetric flow rate measurement, the uncertainty in fluid density must also be included. The relative expanded uncertainty for volumetric flow rate is 0.53 %. Lower flow rates may be possible, but the uncertainty at these flows is undetermined.

References—Flow Measurements at Cryogenic Temperatures

Uncertainty Analysis of the NIST Nitro- gen Flow Facility, J. L. Scott and

M. A. Lewis, Natl. Inst. Stand. Technol. Tech. Note 1364 (Apr. 1994).

Progress Report on Cryogenic Flowmetering at the National Bureau of

Standards, J. A. Brennan, J. F. LaBreque, and C. H. Kneebone, Proc.

1st Biennial Symp. Instrumentation in the Cryogenic Industry, Houston, TX,

Oct. 11-14, 1976, 1, 621, Instr. Soc. of America, Pittsburgh, PA (1976).

NBS-CGA Cryogenic Flow Measurement

Program, J. A. Brennan, R. W. Stokes, C. H. Kneebone, and D. B. Mann

(Proc. ISA Intl. Instrument. Automation Conf. and Exhibit, New York, NY,

Oct. 28-31, 1974), Paper in Adv. in Instrument. 29, 612.1 (Instr. Soc. of

America, Pittsburgh, PA, 1974).

Cryogenic Flow Research Facility Provisional Accuracy Statement, J. W.

Dean, J. A. Brennan, D. B. Mann, and

C. H. Kneebone, Natl. Bur. Stand.

(U.S.), Tech. Note 606 (July 1971).

* See Chapter 1 , Section H for more information about uncertainty.

37
19010C-19040S

a

Airspeed Instruments

Technical Contacts:

James Michael Hall

Tfel: 3017975-5947 Email: j.hall@ nistgov

Vern E. Bean

Tel: 301/975-4830

Email: vern.bean@

nistgov

George E. Mattingly

Tel: 301/975-5939

Email: george.mattingly@

nistgov

Mailing Address: Building 230, Room 105,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items

190 IOC Pitot-Static Tubes 1.3 m/s to 67 m/s (3 mph to 150 mph)

19020C Low Airspeed Instruments 0.76 m/s to 10.2 m/s (15 fpm to 2,000 fpm)

19030S Meteorological Airspeed Instrumenta'ion

1.3 m/s to 67 m/s (3 mph to 150 mph)

1904OS Special Tests of Airspeed Instruments

Airspeed Instruments

(19010C-19040S)

Calibration of airspeed measuring

devices is performed in one of two

special wind tunnels, as described in the Proceedings of the 1 992 Measurement

Science Conference. The differential pressure measured from ellipsoidal-nosed

Pitot-Static tubes provides the basis of

airspeed measurement in these facilities. Pitot-Static tubes and meteorological

instruments are calibrated in the NIST

Dual Test Section Wind Tunnel. Low

velocity airspeed measurements are made

using Laser Doppler Velocimetry (LDV)

in the NIST Low Velocity Airflow Facility, described in NBS Technical Note

989. Calibration of the LDV is done

using the Pitot-static tube at velocities which produce a sufficiently large differ- ential pressure in the tube that the uncertainty in the pressure does not propagate

unacceptable levels of error into the velocity determination. Use of the LDV

capability in the low velocity range, where the Pitot-static tube has large

measurement uncertainties due to the

inability to measure accurately the asso- ciated small differential pressures, allows considerably improved measurement

uncertainty. Air density values in the tunnels are computed from pressure.

temperature, and humidity measurements

in the settling chambers of the tunnels. Details on the range and expanded

uncertainty of the currently offered NIST airspeed calibrations are shown

in Tables 5.1 and 5.2. Special tests of airspeed instruments can be arranged. Examples include

in-situ calibrations of airspeed instrumentation, proving other airspeed measure- ment systems, and tests where appropriate scaling will allow the results to be

applicable to fluids other than air. Details can be obtained and arrangements made

through the technical contacts cited above.

Table 5.1. Uncertainty* of the NIST Low Velocity

Airflow Measurement Facility

Relative Expanded Uncertainty

(m/s) (mi/h) (%)

Velocity

0.15

0.25

0.5

1 to 10

0.33 0.56

1.1 2.2 to 22

4.0 2.4

1.2 0.6

See Chapter 1, Section H for more information about uncertainty.

Table 5.2. Uncertainty* of the NIST Airflow Measurement Capabilities in the Dual Test-Section Wind

Tunnels

Velocity Relative Expanded Uncertainty

(m/s) (mi/h) (%)

0.4 1 8.0

1 2 3.8 2 5 1.3 3 6 0.6 5 11 0.45 10 22 0.31

15 to 67 34 to 150 0.28

See Chapter 1, Section H for more information about uncertainty.

References— Airspeed Measurements

Air Speed Calibrations at the National

Institute of Standards and Technology, N. E. Mease, W. G. Cleveland,

Jr., G. E. Mattingly, and J. M. Hall, Proc. 1992 Meas. Sci. Conf.,

Anaheim, CA (1992).

A Low Velocity Airflow Calibration and

Research Facility, L. P. Purtell and

P. S. Klebanoff, Natl. Bur. Stand.

(U.S.), Tech. Note 989 (May 1979).

38
22010C-22180M

D.

Mass Standards

Technical Contact:

Jerry G. Keller

Tfel: 301/975-4218 Email: jerry.keller@ nisLgov

William E. Crupe

Ttl: 301/975-4215 Email: wcrupe@

nistgov

Zeina J. Jabbour

Tel: 301/975-4468

Email: zeina.jabbour@

nistgov

Mailing Address: Building 233, Room A 147,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address: National Institute of Standards

and Technology,

1-270 at Quince Orchard Road,

Building 233, Room A 147,

Gaithersburg, MD 20899-0001

Note: For weights larger than 30 kg (50 lb), contact J. G.

Keller prior to shipment.

Service ID No. Items 220 IOC Weight Set (1 mg to 100 g) 22020C Weight Set (1 mg to 1 kg)

22030C Weight Set (2 kg to 30 kg)

22040C Single Weights (1 mg to 1 kg)

22060C Single Weights (2 kg to 30 kg)

22080C Single Weights (> 30 kg to 1200 kg, 2 double

substitution weighings)

22100C Single Weights (> 1200 kg to 30,000 kg) 221 IOC Single Weights (> 30 kg to 1200 kg, calibrated in a weighing design)

22130C Single Weights for Deadweight Pressure Testers 5.9 kg to 22.7 kg (13 lb to 50 lb) 22140C Single Weights for Deadweight Pressure Testers > 22.7 kg (> 50 lb) 22150C Single Weights for Deadweight Pressure Testers < 5.9 kg (<13 lb) 22170S Special Mass Measurement Services 22 1 80M Measurement Assurance Program for Mass

Mass (22010C-22110C)

NIST maintains the national standard for mass in the form of the prototype kilo- gram (K20) and provides services to support the parts of the national measurement system that rely directly or

indirectly on mass measurements.

These services include the calibration of

suitable weight sets. Figure 5.1 shows the

traceability to the SI unit of mass for the

unit of mass as disseminated by NIST. A calibration consists of establishing a mass value and the appropriate uncertainty for that value for each weight that has been designated to be a reference

standard. It is desirable, but not necessary, that a weight meet the adjustment

tolerances established for NBS Classes A, B, M, S, S-1, or equivalent prior to submission. Weights are available from

manufacturers, many of whom can

directly furnish documentation suitable

for meeting quality assurance contracts and requirements.

NIST calibrates individual weights or

sets in the range of 1 mg to 30 kg or 0.45 kg to 22.7 kg (1 lb to 50 lb) in decimal subdivisions. If the weights are designated as reference standards, they

must be of design, material, and surface

finish comparable to NBS Classes A, B,

M, S, or S-1. These include ASTM Type

I and II, classes 1, 2, 3, 4, and OIML El,

E2, Fl and F2. NIST also calibrates large mass standards 27.3 kg to 27 300 kg

(60 lb to 60 000 lb) if the design, material, and surface finish are compatible

with the intended usage. For these large mass standards, an adjustment with refer- ence to a nominal or desired value can be

included as a part of the calibration procedure.

In the absence of instructions from the customer, weights will be cleaned prior

to calibration. If weights are to be cali- brated "as found" (without cleaning), and

returned without cleaning, customers

should note this in their instructions to NIST. If weights are to calibrated "as found" and calibrated again after cleaning, double the fee will apply. The values of true mass (and an apparent mass

correction) included in the report will be

determined by using computed volumes

based on the manufacturer's statement of

density of the material, or on the density

computed from measured volumes, or, in the absence of this information, on esti- mated density values.

39
'I'

22010C-22180M

BIPM

Iiternitionil Prototype Kilogm

(Pt-Ir)

US Priati7 NitK

(Pt

ionil Stiidtrd

21

-Ir)

US Sccoid

(StllDl EI,E2, RLJ/

try SUidirdi M Stetl) D2, Ckyo

, RL///

NIST WorkiigStiidirdi

(StaiilcM Steel) B1,B2

MIST WorUai Slandirdi

(SUiilefi Steel) C1,C2

Special CtUbritioni

Ctlibritioii

1 k{-27M»k{

Calibritloni 1kg -lug

Figure 5. 1 Traceability to the SI Unit of Mass.

However. 1 kg mass standards fabricated from stainless steel and of one-piece construction will have their density deter- mined as part of a "first-time" calibration

at NIST. The apparent mass corrections

are computed for 20 "C with reference to Normal Brass (density 8 400 kg m' at 0 and volume coefficient of expansion

0.000054 "C^ and to stainless steel (densit) S 000 kg m' at 20 "C) in a conventional air density of 1.2 kg/m'.

Apparent mass corrections to any other

basis can be furnished if requested.

Typical relatiNe st:indard uncertainties* ranse from 50 X lO""" at 1 kg. up to 330" X 10"^ at 1 mg, and 0.2 X KT* at 10 kg. Figure 5.2 shows the NIST

uncertainties for normal calibrations of mass standards over the range 10"^^ kg to UVks.

* See Chapter 1. Section H for more information about uncertainiv.

10 •1

Figure 5.2. NIST's Relative Expanded Uncertainties

for Normal Calibrations of Mass Standards.

Single Weights for Deadweight

Pressure Testers i22130C-22150C)

Weights are compared to discrete standards by the method of double

substitution weishins.

40
22010C-22180M

Special Mass Measurement Services

(22170S)

For tests not covered by the previous

descriptions, the NIST technical contact

cited at the beginning of this section should be consulted to determine whether a test can be performed and to obtain an estimate of the price of the test.

Measurement Assurance Program for Mass (22180M)

This service is most appropriate for primary

calibration laboratories. Total relative uncertainties ranging from a few parts in 10^

to a few parts in 1 0' for 1 kg can be obtained. Unlike most other NIST MAP ser- vices, the Mass MAP service does not

involve the use of a NIST-owned transport standard that is shipped to participants for measurement. The transfer standards in the Mass MAP are a set of mass standards owned by the participant and sent to NIST

for calibration. These standards are referred

to as the starting standards. In addition to the starting standards, the mass MAP participant must also furnish a set of much

smaller weights called "sensitivity weights."

The choice of both the starting standards and the sensitivity weights will depend on

the particular mass range of interest to the

participant; NIST staff can provide advice regarding suitable starting standards and

sensitivity weights for a particular range of mass weighings. In addition to the starting standards and the sensitivity weights, the participating facility should have a working

set of weights known as the "test set" and a

set of weights to be used as check stan- dards. This set usually consists of weights

in the range of 1 g to 1000 g. This service,

like other NIST MAP services, samples the participant's measurement process and

establishes its uncertainty. Once the participant has become well-established in the Mass MAP, two options are possible:

( 1 ) NIST personnel do all of the data

analysis and record keeping for the participant and provide periodic reports on the uncertainty of the participant's mass

measurements.

(2) The participant keeps all records and calculates the uncertainties of his measurements using NIST methods and computer codes.

The implementation of the Mass MAP in

its most complete form typically proceeds

in four distinct phases, which may be

abbreviated somewhat if the participant

already has a suitable mass measurement

quality control system.

Phase I: Each new participant completes a

questionnaire on equipment and facihties and receives a written description of the NIST process, methods and procedure to be

used, an introduction to the interpretation of

results, and information on the use of these

results in measurement decisions. At the participating laboratory, the suitability of

the weighing equipment is verified, the

starting standards selected or procured, and

operators are trained, if the procedures are

entirely new. The starting standards and

sensitivity weights are sent to NIST for calibration. If the starting standards have a NIST calibration history, those data

are reviewed and, if satisfactory, are considered, along with the data from the more recent determinations to arrive at as- signed values for the starting standards. NIST will recommend a weighing design to be used for calibrating the test weight.

This weighing design prescribes the set of

observations for intercomparing the test weights with known weights. NIST will also supply data sheets to be used throughout the first three phases of the program for recording data taken using the design. The

objective of the first phase is to ensure that the new participant is familiar with good

laboratory practices for high precision

weighing. If the participating laboratory has an established mass measurement

capability and an existing quality control procedure for mass measurements. Phase I

is abbreviated considerably.

Phase II: The starting standards and sensitivity weights are returned to the participant and, following the prescribed

procedures, measurements are made by the participant over a period of time to verify

that a state of statistical control exists. The

data sheets are sent to NIST for review,

comments, and processing after each measurement. If there are unanticipated problems, or if the procedure has not been

followed exactly, more measurements may

be required. After three or more successful

calibrations in the user's facility, NIST

analyzes the data to determine the values of the check standards.

41
22010C-22180M

Phase III: A comprehensive report is issued by NIST containing a review of the

actions and decisions in each of the phases,

control charts for the check: standards to be

used in the participant's facihty, and a comparison of the values assigned to the

starting standards by NIST and by the

participant. It is assumed at this point that the participating facility is now ready to extend the operation of the MAP to its regular workload. Phase IV: Having thus established measurement comparability, the MAP user can

then, in principle, operate independently of NIST. As long as there is no indication of a

loss of statistical control of the process, no

further checking with NIST should be necessary. Most participants request a recheck

of the starting standards every few years to ensure that no undetected Inng-term drift has taken place. For work that differs from the items nor- mally calibrated by the participant, NIST

can provide consulting help and assistance necessary to accommodate a greater range

of weights, calibrate pound standards, and

extend pound standards to large weights

normally associated with force measurement. Although the usual Mass MAP

service uses two one kilogram masses as

the starting standards, the program is suffi- ciently flexible that the same methods can

be used with other mass values.

References— Mass Standards

New Assignment of Mass Values and

Uncertainties to NIST Working Standards, R. S. Davis, J. Res. Natl. Inst. Stand. Technol. 95 (1), 79 (Jan.-Feb. 1990).

NIST Measurement Services: Mass Calibrations, R. S. Davis, Natl. Inst. Stand. Technol. Spec. Publ. 250-31 (Jan. 1989).

A Primer for Mass Metrology, K. B. Jaeger

and R. S. Davis, Nad. Bur. Stand. (U.S.), Spec. Publ. 700-1 (Nov. 1984). Air Buoyancy Correction in High-Accuracy

Weighing on Analytical Balances, R. M.

Schoonover and F. E. Jones, Anal. Chem.

53 (6), 900 (May 1981). National Bureau of Standards Mass Calibration Computer Software, R. N. Varner and R. C. Raybold, Natl. Bur. Stand.

(U.S.), Tech. Note 1 127 (July 1980).

Quick and Accurate Density Determination

of Laboratory Weights, R. M.

Schoonover and R. S. Davis, Proc. 8th Conf. IMEKO, Krakow, Poland (1980).

Precision Laboratory Standards of Mass

and Laboratory Weights. A reprint of

NBS Circular 547, Section 1, T. W.

Lashof and L. B. Macurdy, August 1954,

Natl. Bur. Stand. (U.S.), NBSIR 78-1476

(Oct. 1978).

The National Measurement System for Mass, Volume, and Density, P. E. Pontius, J. R. Whetstone, and J. A. Simpson, Natl. Bur. Stand. (U.S.), NBSIR 75-928 (May 1978). Direct Determination of Air Density in a Balance through Artifacts Characterized in an Evacuated Weighing Chamber,

W. F. Koch, R. S. Davis, and V. E. Bower, J. Res. Natl. Bur. Stand. (U.S.), 83 (5), 407 (Sept.-Oct. 1978).

The Air Density Equation and the Transfer of the Mass Unit, F. E. Jones, J. Res. Nad. Bur. Stand. (U.S.) 83 (5), 419

(Sept.-Oct. 1978).

Designs for the Calibration of Standards of Mass, J. M. Cameron, M. C. Croarkin,

and R. C. Raybold, Natl. Bur. Stand.

(U.S.), Tech. Note 952 (June 1977).

The Air Density Equation and the Transfer of the Mass Unit, F. E. Jones, Natl. Bur.

Stand. (U.S.), NBSIR 77-1278 (July

1977). Measurement Assurance, J. M. Cameron,

Natl. Bur. Stand. (U.S.), NBSIR 77-1240

(1977).

Mass and Mass Values, P. E. Pontius, Natl. Bur. Stand. (U.S.), Monogr. 133 (Jan. 1974).

Weight Cleaning Procedures, H. E. Aimer,

Nad. Bur. Stand. (U.S.), NBSIR 74-443

(Nov. 1973).

On Uncertainty in Mass Measurement, J. R. Donaldson, Nad. Bur. Stand. (U.S.), NBSIR 73-151 (Mar. 1973).

Method of Calibrating Weights for Piston Gages, H. E. Aimer, Nad. Bur. Stand.

(U.S.), Tech. Note 577 (May 1971).

Realistic Uncertainties and the Mass Measurement Process, P. E. Pontius and J. M.

Cameron, Nad. Bur. Stand. (U.S.), Monogr. 103 (Aug. 1967). Introduction to Intercomparison Methods in Mass Measurement, H. E. Aimer, Natl. Bur. Stand. (U.S.), Report 9487 (Feb.

1967). Measurement Philosophy of the Pilot Pro- gram for Mass Calibration, P. E. Pontius,

Nad. Bur. Stand. (U.S.), Tech. Note 288

(May 1966).

42
23010C-23260S

Force Measurements

Technical Contacts:

Rick L. Seifarth Thomas W. Bartel Simone L. Yaniv

Tfel: 301/975-6652 Tel: 301/975-6461 Ttl: 301/975-6655 Email: ricky^ifarth@ Email: tbartel@ Email: $imone.yaniv@

nistgov nistgov nist.gov

Mailing Address: Building 202, Room 221,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

1-270 at Quince Orchard Road,

Building 202, Room 123,

Gaithersburg, MD 20899-0001

Service ID No. Items

230 IOC Force Transducers to 1 12 540 N (25 300 Ibf),

1 mode

23020C Extra observation 23030C Additional bridges 23040C Force Transducers to 1 12 540 N (25 300 Ibf), 2 modes 23050C Extra observation 23060C Additional bridges 23070C Force Transducers, 1 12 544 N to 498 201 N

(25 301 Ibf to 1 12 000 Ibf), 1 mode

23080C Extra observation 23090C Additional bridges 23100C Force Transducers, 1 12 544 N to 498 201 N

(25 301 Ibf to 1 12 000 IbO. 2 modes

23110C Extra observation 23120C Additional bridges 23130C Force Transducers. 498 205 N to 1 334 467 N

(1 12 001 Ibf to 300 000 Ibf), 1 mode

23140C Extra observation 23150C Additional bridges 23160C Force Transducers, 498 205 N to 1 334 467 N

( 1 1 2 00 1 Ibf to 300 000 Ibf), 2 modes 23170C Extra observation 23180C Additional bridges 23190C Force Transducers. 1 334 471 N to 4 448 222 N

(300 001 ibf to 1 000 000 Ibf). 1 mode

23200C Extra observation 232 IOC Additional bridges 23220C Force Transducers, 1 334 471 N to 4 448 222 N

(300 001 Ibf to 1 000 000 Ibf), 2 modes

23230C Extra observation 23240C Additional bridges 23250C Force Transducers over 4 448 222 N ( 1 000 000 Ibf) compression only 23260S Special Tests of Force Transducers

Force Transducers (23010C-23250C)

NIST provides calibration services for force-measuring devices by applying

known forces, either tension or compression, to the elastic device and recording

the sensed deformation. Most calibrated devices are either proving rings or load

cells. The deformation of proving rings is usually measured by means of a micrometer screw and vibrating reed, which are an integral part of the device. Load cells, which utilize strain gauge bridges, pro- duce an electrical output that is related to the applied force. The calibration report describes the relationship between the applied force and the measured deformation, either in

electrical or mechanical units. A load

cell can be calibrated using (1) a readout

device furnished by the customer, in which case the load cell and the readout

device are calibrated as a system, and

the calibration is valid only when the load cell and the readout device are used

together; or (2) instrumentation furnished

by NIST, in which case data are reported

in terms of the ratio of the output voltage

to the DC excitation voltage (mV/V).

In the latter case, the customer must

possess the necessary electrical instru- mentation and expertise to utilize the

calibration results. The relative standard uncertainty* of the calibration of the

voltage-ratio measurement instrumentation used at NIST is 0.0005 %.

Tension or compression calibrations in the range of 0.445 kN to 4.448 222 MN

(100 Ibf to 1 000 000 Ibf) are performed

using deadweight machines. NIST has six deadweight machines with maximum

capacities of 2 226 N (505 Ibf), 27 134 N

(6 100 Ibf), 1 12 540 N (25 300 Ibf), 498 201 N (1 12 000 Ibf), 1 334 467 N

(300 000 Ibf), and 4 448 222 N

(1 000 000 Ibf). The standard uncertainty

of the applied forces incorporates the

uncertainties associated with the determination of the mass of the deadweight,

the acceleration due to gravity and the air density. The relative standard uncertainty* of applied force is 0.0005 %.

* See Chapter 1 , Section H for more information about uncertainty.

43
23010C-23260S

CoVnparison calibrations in the range of 4 448 226 N to 53 378 659 N

(1 000 001 Ibf to 12 000 000 Ibf) in compression only are performed in a

universal testing machine. In this case, the system to be calibrated is loaded in series with load cells that have been

previously calibrated in a deadweight

machine. See Figure 5.3 for the

relationship of force to S.I. units.

Special Tests of Force Transducers

(23260S)

Temperature sensitivity, pressure sensitivity, and creep tests of force transducers

are measured. The ranges of test parameters and environmental conditions may be

limited by the characteristics of the force transducer and the availability of special

test fixtures. These special tests should be discussed with the designated NIST

technical contact before the work is scheduled.

References—Force Measurements

Force Measurment Services at NIST: Equipment, Procedures and

Uncertainties, T. W. Bartel, S. L. Yaniv

and R. L. Seifarth, Proc. Natl. Conf.

Stand. Lab. and Symp. (1997).

Creep and Creep Recovery Response of

Load Cells Tested According to U.S. and International Evaluation Procedures, T. W. Bartel and S. L. Yaniv

J. Res. Natl. Inst. Stand. Technol. 102,

349-362 (May 1997).

Standard Practices for Force Verification of Testing Machines, ASTM Designation E4-96, Annual Book of ASTM

Standards 3.01 (1997).

Automation of Strain-Gauge Load-Cell Force Calibrations, K. W. Yee, Natl.

Inst. Stand. Technol. NISTIR 4823

(Apr. 1992).

Standard Practice of Calibration of

Force-Measuring Instruments for Verifying the Force Indication of

Testing Machines, ASTM Designation

E74-95, Annual Book of ASTM

Standards 3.01 (1994).

Summary of the Intercomparison of the Force Standard Machines of the National Institute of Standards and

Technology, USA, and the Physikal isch -Technische Bundesanstalt,

Germany, S. L. Yaniv, A. Sawla, and

M. Peters, J. Res. Natl. Inst. Stand. Technol. 96, 529 (1991).

Temperature NIST

>

Air D< Nlsnslty ST

Pressure NIST HumklKy NIST

NIST Large Mass

Starvjards: 10,000 *> 20.000 b S 30.000 b

Gravity

Verified 1966.1»79,iee4.l991

Densities

Verltied 1971. 1968

Equations Refined CIPM

1981/1991

NIST Deadweight Masses Adjusted to Produce Desired Nominal Forces

Selected Weights Re-calibrated in 1971, 1989 and 1996

Figure 5.3. Relationship of Force to SI Units.

44
23010C-23260S

Metrological Regulations for Load Cells,

OIML Recommendation No. 60, Intl. Org. for Legal Metrol., Paris 1991 (E). A New Statistical Model for the Calibration of Force Sensors, C. R Reeve,

Natl. Bur. Stand. (U.S.) Tech. Note

1246 (June 1988). Force Calibration at the National Bureau

of Standards, R. A. Mitchell, Natl. Bur. Stand. (U.S.) Tech. Note 1227

(Aug. 1986).

Interlaboratory Comparison of Force

Calibrations Using ASTM Method

E74-74, R. W. Peterson, L. Jenkins,

and R. A. Mitchell, Natl. Bur. Stand.

(U.S.), Tech. Note 1211 (Apr. 1985).

Progress in Force Measurement at NBS,

R. A. Mitchell, Proc. lOdi Conf.

IMEXO TC-3 on Measurement of Force and Mass, Kobe, Japan (Sept.

1984). Inherent Problems in Force Measurements, P. E. Pontius and R. A.

Mitchell, Exper. Mech. 22 (3) (Mar.

1982). Force Sensor-Machine Interaction, R. A.

Mitchell and P E. Pontius, Proc. 27th

Intl. Instrum. Symp. (ISA), Indianapolis, IN, Instrumentation in the Aerospace Industry 27, 225 (1981).

Characterizing the Creep Response of

Load Cells, R. A. Mitchell and S. M.

Baker, VDI-Berichte 312, 43 (1978).

Interlaboratory Comparison of Force

Calibrations Using ASTM Method

E74-74, Phase I, R. W. Peterson and

R. L. Bloss, Natl. Bur. Stand. (U.S.),

NBSIR 76-1145 (Aug. 1976).

A Study of the National Force Measure- ment System, D. E. Marlowe, Natl. Bur. Stand. (U.S.), NBSIR 75-929

(June 1975).

Universal Testing Machine of 12-MillionIbf Capacity at the National Bureau of

Standards, A. F. Kirstein, Natl. Bur.

Stand. (U.S.), Spec. Publ. 355 (Sept.

1971).

Studies of Calibration Procedures for Load Cells and Proving Rings as Weighing Devices, G. B. Anderson and

R. C. Raybold, Natl. Bur. Stand.

(U.S.), Tech. Note 436 (Jan. 1969).

Gravity Measurements and the Standards

Laboratory, D. R. Tate, Natl. Bur.

Stand. (U.S.), Tech. Note 491 (Aug.

1969).

Uncertainties Associated with Proving

Ring Calibration, T. E. Hockersmith

and H. H. Ku, Preprint No. 12.3-2-64 ISA Conference, Instr. Soc. of

America, Res. Triangle Park, NC

(Oct. 1964).

45
24010C-24060S

Vibration Measurements

Technical Contacts:

Beverly F. Payne Charles O. Schoemaker David J. Evans

Tel: 301/975-6639 Tel: 301/975-6694 (24040S) Email: beverly.payne@ Email: cshoemaker@ Tfel: 301/975-6637

nistgov nistgov Email: david.evans@

nistgov

Mailing Address: Building 233, Room A147,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service Peak Accel. Rel. Exp. ID No. Items Freq. Range Uncer*. in %

24010C Pickup

Sensitivity

2 Hz to 160 Hz 0.2 to 2 1 to 2

24020C Pickup

Sensitivity

10 Hz to 3500 Hz 2 to '0 1 to 2

24030C Pickup 10 Hz to 10 kHz 2 to 10 1 to 2 24040S Shock

Measurement

250 Hz to 10 kHz 20 to 10000 3 to 5

24O50S Pickup

Sensitivity

3 kHz to 20 kHz 4 to 200 1 to 3

24O60S Special Vibration Tests, by Prearrangement

*See Chapter 1 , Section H for more information about uncertainty.

Pickup Sensitivity (24010C-24030C)

NIST calibrations of vibration exciters and pickups are performed by comparison with the response characteristics of

NIST standards or by absolute measurements. A calibration consists of measuring the transfer function of the instrument, usually referred to as the sensitivity. For a pickup, it is the ratio of the

electrical output to a mechanical input.

The magnitude of the latter is set in accordance with the calibration method,

the type of vibration exciter, and the frequency of vibration. The magnitude of

the output depends, of course, on the nature of the test device. In the case of an accelerometer with signal conditioner,

the practice has been to express the out- put in millivolts, and the input in units of

g„, the standard acceleration of free fall:

g„ = 9.80665 ms"^ .

The acceleration sensitivity is then

given in TnV/g„. For charge-output

devices without signal conditioners, the acceleration sensitivity is stated in picocoulombs per g„ (pC/gn). All measurements are performed at 23 ± 3 °C. The calibration of an accelerometer is reported in tabular form as the sensitivity

magnitude at a set of discrete frequencies; the phase component can be

furnished at additional cost on request. The NIST vibration standards are periodically calibrated by reciprocity

and/or interferometric techniques, two

independent and absolute methods. The

use of these standards in the calibration of stable transducers furnishes calibration data with a typical relative expanded

uncertainty* of 1 % to 2 % depending on

the frequency range.

Special Shock Measurement Services

(24040S)

The shock facility provides a comparison

calibration of accelerometers by subjecting them to half-sinewave pulses with

peak amplitudes of 20 g„ to 10 000 g„ and pulse widths from 0.1 ms to 40 ms. Both time and frequency domain measurements can be performed.

Special Tests of Pickup Sensitivity

(24050S)

This test measures the pickup sensitivity

by the fringe-disappearance method, us- ing an automated Michelson interferometer. As presently configured, the system

operates between 3 kHz and 20 kHz. The

method requires precise setting of vibration amplimde to 121.10 nm; consequently, the acceleration amplitude in the

stated frequency range increases from

about 4 g„ to 200 g„.

Special Vibration Tests (24060S)

Calibration of vibration and shockmeasuring instruments to specifications other than those above, as well as other

specified measurements, can be

performed by prearrangement.

* See Chapter 1 , Section H for more information about uncertainty.

46
24010C-24060S

For example, an interferometer calibration for frequencies less than 2 Hz or

greater than 10 kHz can be performed on request. Consult with the technical contacts cited at the beginning of this section.

References—Vibration Measurements

An Application of Parameter Estimation

Theory in Low Frequency Accelerometers, B. F. Payne and M. R. Serbyn,

14th Transducer Workshop, Telemetry

Group, Range Commanders Council,

Colorado Springs, CO (June 1987).

A Description of NBS Calibration Ser- vices in Mechanical Vibration and

Shock, D. C. Robinson, M. R. Serbyn,

and B. F. Payne, Natl. Bur. Stand.

(U.S.), Tech. Note 1232 (Feb. 1987).

An Automated Fringe Counting Laser In- terferometer for Low Frequency Vibration Measurements, B. F. Payne, Proc. ISA Symp., Seattle, WA (May 1986).

Automation of Vibration Testing at the National Bureau of Standards, B. F. Payne, Proc. 30th Tech. Meeting, Inst, of Environ. Sciences (May 1984).

An Automated System for the Measure- ment of Pickup Sensitivity, B. F. Payne

and M. R. Serbyn, Proc. Natl. Conf.

Stand. Lab. Ann. Workshop and Symp.

Il-ll.l-n- 11.22 (July 1983).

The Application of Back-to-Back

Accelerometers to Precision Vibration

Measurements, B. F. Payne, J. Res.

Natl. Bur. Stand. (U.S.) 88 (3), 171 (May-June 1983).

A Real-Time Active Vibration Controller,

M. R. Serbyn and W. B. Penzes, ISA

Transactions 21 (3), 55 (1982).

Development of a Low-Frequency-Vibration Calibration System, R. S. Koyanagi, Exp. Mech. 15, 443 (Nov.

1975).

Shock Calibration of Accelerometers,

C. Federman, W. Walston, and

J. Ramboz, Minutes of the 8th Trans- ducer Workshop: Telemetry Group,

Inter-Range Instrumentation Group,

Range Commanders Council, WrightPatterson AFB, OH (Apr. 1975).

Piezoelectric Shakers for Wide Fre- quency Calibration of Vibration Pickups, E. Jones, B. YeIon, and

S. Edelman, J. Acoust. Soc. Am. 46

(6), 1556 (June 1969).

Improved Transfer Standard for Vibration

Pickups, E. Jones, D. Lee, and

S. Edelman, J. Acoust. Soc. Am. 41

(2), 354 (Feb. 1967).

Electrodynamic Vibration Standard with

a Ceramic Moving Element, T. Dimoff, J. Acoust. Soc. Am. 40 (3), 671

(Sept. 1966). Calibration of Vibration Pickups at Large

Amplitudes, E. Jones, S. Edelman, and

K. S. Sizemore, J. Acoust. Soc. Am.

33 (11), 1462 (Nov. 1961). Calibration of Vibration Pickups by the Reciprocity Method, S. Levy and R. R. Bouche, J. Res. Natl. Bur. Stand.

(U.S.) 57 (4), 227 (Oct. 1956).

47
25010C-25070S

G, Acoustic Measurements

Technical Contacts:

Victor Nedzelnitsky

Tel: 301/975-6638 Email: vnedzelnit5ky@

nistgov

David J. Evans

Tel: 301/975-6637

Email: david.evans@nistgov

Mailing Address: Building 233, Room A147,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. 250 IOC

25020C

25030C

25040C

25050C

25060S

25070S

Items

Pressure Response: WE Type 640AA microphones or

equivalent (e.g., Tokyo Riko Type ECL MR103, Bruel &

Kjaer Type 4160, Bruel & Kjaer Types 41 44 or 4132 with DBOl 1 1 adapter). 50 Hz to 10 000 Hz

Pressure Response: WE Type 640AA microphones or

equivalent (e.g., Tokyo Riko Type ECL MR 103; Bruel &

Kjaer Type 4160; Bruel & Kjaer Types 4144 or 4132 with DBOl 1 1 adapter). 50 Hz to 20 000 Hz

Pressure Response: Tokyo Riko Type ECL MR 1 1 2, Bruel & Kjaer Type 4134, or equivalent half-inch microphones,

50 Hz to 10 000 Hz

Pressure Response: Tokyo Riko Type ECL MRl 12, Bruel & Kjaer Type 4134, or equivalent half-inch microphones, 50 Hz to 20 000 Hz

Free-Field Response: Tokyo Riko Type ECL MRl 12, Bruel & Kjaer Types 4133, 4134, 4165, 4166, 4180, or

equivalent half-inch microphones, 2 500 Hz to 20 000 Hz

Special Tests of Acoustic Devices

Special Tests of Audiometers/Earphones

Pressure and Free-Field Responses of

Microphones (25010C-25050C)

Pressure calibrations (Service ID Nos. 2501 OC and 25020C) are performed on Type-L one-inch microphones* satisfying the requirements of American

National Standard SI. 12- 1967 (R1977),

Specifications for Laboratory Standard

Microphones and its impending revision. The microphones submitted for pressure

calibration must be suitable for use with

the calibrating couplers shown in Figures

6 and 10 of the applicable American

National Standard SI. 10- 1966 (R1986).

*Type-L one-inch is a commercial designation for these microphones.

Table 5.3. Typical Expanded Uncertainties** for Pressure Calibrations of Type-L

Microphones

Expanded

Uncertainty**

(dB)

Frequency Range

0.09 50 Hz to 7 kHz

0.26 7 kHz to 10 kHz

0.17 10 kHz to 17 kHz

0.32 17 kHz to 20 kHz

**See Chapter 1, Section H for more information about uncertainty.

Further information is contained in the references for acoustic measurements.

Since American National Standards

Institute publications SI. 10- 1966

(R1986) and SI. 12- 1967 (R1977) were

issued, certain types of half-inch diameter precision microphones have attained widespread use. Therefore, NIST has

developed procedures (Service ID

Numbers 25030C and 25040C) for de- termining the pressure response levels of half-inch microphones by comparison

with NIST-owned Type-L standard microphones, which in mm are calibrated periodically by the reciprocity

technique. The technique used, precautions to be observed, and uncertainties of measurement are essentially the same as those given above for one-inch

microphones. Significantly different aspects of the procedures for half-inch microphones, such as ground shield configuration, are described in the test report. Since several half-inch laboratory standard microphones have been avail- able for only a relatively short time,

their long-term stability has yet to be

determined.

The free-field response levels of

certain Type-L microphones (e.g., Western Electric Type 640AA

condenser microphones) can be

computed from pressure response

levels reported by NIST. However,

certain precautions must be taken, and

there is some degradation in accuracy.

48
25010C-25070S

Therefore, for the most demanding freefield measurement requirements, NIST

offers a calibration service (Service ID

No. 25050C) for determining the freefield response levels for half-inch microphones. The calibrations are made

over the frequency range of 2.5 kHz to 20 kHz at normal incidence. Response

levels (sensitivity levels) are reported in terms of open-circuit voltage per unit sound pressure (in the absence of the microphone) of a plane progressive wave whose direction of propagation is normal to the plane of the diaphragm.

The calibrations are performed in a

well-characterized anechoic chamber. A

typical expanded uncertainty* in this calibration is approximately 0.21 dB or

less at each frequency within the range

of 2.5 kHz to 6.3 kHz and 0.15 dB or

less at each frequency within the range

of 6.3 kHz to 20 kHz. Calibrations can be performed with or without protective

grids on the microphone. For the most

precise free-field measurements, the cus- tomer should contact the NIST staff per- son cited at the beginning of this section

for recommendations prior to submitting

the microphone to NIST for calibration.

Special Tests of Acoustic Devices

(25060S)

Acoustical measurement services are available by special arrangement. These

services include extended frequency

ranges of calibration, additional data

points, measurements at very low sound

pressure levels, and calibration of certain pistonphones and acoustic calibrators. NIST has a large general-purpose

anechoic chamber available for special calibrations requiring such a facility.

The frequency-dependent and positiondependent acoustical performance of this chamber, including extremely low

background noise, was carefully controlled during design and construction

and is documented in archival journal

publications.

* See Chapter 1 , Section H for more information about uncertainty.

Special Tests of Audiometers/

Earphones (25070S)

Earphones are tested on the NIST 9-A

Coupler from 125 Hz to 8000 Hz. Measurements of audiometer/earphone

response and linearity can be made at very low sound pressure levels.

References—Acoustic Measurements

Calibration of Pressure and Gradient

Microphones, V. Nedzelnitsky, Encyclopedia of Acoustics, Ed. in Chief

M. J. Crocker, John Wiley & Sons,

Inc., New York, 1869-1879 (1997).

Primary Method for Free-Field Calibration, V. Nedzelnitsky, AIP Handbook

of Condenser Microphones, Eds., G. S. K. Wong and T. F. W.

Embleton, Am. Inst, of Physics Press, Woodbury, NY, 103-109 (1995).

Laboratory Microphone Calibration

Methods at the National Institute of

Standards and Technology, U.S.A., V. Nedzelnitsky, AIP Handbook of

Condenser Microphones, Eds., G. S. K. Wong and T. F. W. Embleton, Am.

Inst, of Physics Press, Woodbury, NY,

145-161 (1995).

Method for Calibration of Microphones,

Amer. Natl. Stand. Inst. SI. 10- 1966

(R1986), New York, NY.

Specifications for Laboratory Standard

Microphones, Amer. Natl. Stand. Inst. SI. 12- 1967 (R1977), New York, NY.

Free-Field Reciprocity Calibration of

Microphones, E. D. Burnett and

V. Nedzelnitsky, J. Res. Natl. Bur. Stand. (U.S.) 92 (2), 129 (Mar.-April

1987).

Traceability of Acoustical Instrument

Calibration to the National Bureau of

Standards, V. Nedzelnitsky, Proc. INTER-NOISE 80, II, Dec. 8-10,

1980, Miami, FL, G. C. Maling, Jr., Ed., Poughkeepsie, NY: Noise Control

Foundation, 1043 (1980).

Calibration of Laboratory Condenser

Microphones, V. Nedzelnitsky, E. D.

Burnett, and W. B. Penzes, Proc. 10th Transducer Workshop, Transducer

Committee, Telemetry Group, Range

Commanders Council, Colorado

Springs, CO (June 1979).

49
Acoustical Properties of the National Bureau of Standards Anechoic Chamber, W. Koidan and G. R. Hruska,

J. Acoust. Soc. Am. 64 (2), 501 (Aug.

1978).

edge Design for the National Bureau of

Standards Anechoic Chamber,

W. Koidan, G.R. Hruska, and M. A.

Pickett, J. Acoust. Soc. Am. 52 (4) (Part 1), 1071 (1972).

Calibration of Standard Condenser

Microphones: Coupler Versus Electrostatic Actuator, W. Koidan, J. Acoust.

Soc. Am. 44 (5), 1451 (Nov. 1968).

Calibrations of Microphones, Vibration

Pickups, and Earphones, R.K. Cook,

S. Edelman, and W. Koidan, J. Audio

Eng. Soc. 13 ( 4) (Oct. 1965).

Free-Field Correction for Condenser

Microphones, W. Koidan and

D. S. Siegel, J. Acoust. Soc. Am. 36

(11), 2233 (Nov. 1964).

Hydrogen Retention System for Pressure

Calibration of Microphones in Small

Couplers, W. Koidan, J. Acoust. Soc. Am. 35 (4), 614 (Apr. 1963).

Method of Measurement of E'/I' in the Reciprocity Calibration of Condenser

Microphones, W. Koidan, J. Acoust.

Soc. Am. 32 (5), 61 1 (May 1960).

50
26030S-26070S

Ultrasonic Reference Block Measurements

Technical Contacts:

John A. Slotwinski Gerald V. Blessing

TbI: 301/975-2171 Tel: 301/975-6627 Email: jslotwinski@ni$tgov Email: gble$sing@ni$t.gov

Mailing Address: Building 233, Room A 147,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 26030S Special Tests of Area Amplitude Aluminum Reference Blocks—Set of Eight Blocks 2604OS Special Tests of Area Amplitude Titanium or Steel Ultra- sonic Reference Blocks—Set of Eight Blocks 26050S Special Tests of Distance Amplitude Aluminum Reference

Blocks-Set of Fifteen Blocks 26060S Special Tests of Distance Amplitude Titanium or Steel Ultrasonic Reference Blocks—Set of Fifteen Blocks 26070S Special Tests of Distance and Area Amplitude Aluminum,

Titanium or Steel Ultrasonic Reference Blocks

Miscellaneous Sets

Special Tests of Aluminum Reference

Blocks (26030S, 26050S, and

26070S)

The ultrasonic response of 7075

aluminum alloy ASTM E127-type flat- bottom-hole (FBH) reference blocks of

12.7 mm (and greater) metal path dis- tances is determined relative to a NIST

reference block. The immersion, pulseecho, longitudinal wave, 5 MHz quartz transducer testing system specified in ASTM El 27-95 is used according to NIST-modified procedures (see publication NISTIR 5430) for improved

measurement precision. Instrument gain

settings are established using a

selected 5-0050 block rather than the

steel spheres stipulated in ASTM

El 27-95, and relative gain settings for different FBH sizes are determined

from ratios of the respective FBH areas, rather than from the results of tests of

various steel spheres. A specific set of

NIST FBH check-standard blocks is tested along with the customer's block. The long-term precision and stabiUty of

the NIST testing system are monitored

using a database reflecting the results of

repeated tests of a set of check standard

blocks. Standard deviation data representing the uncertainties associated with a

particular test are reported for each block

and hole size. Relative expanded uncertainties* range from 3 % to 12 %. Upon request, block response can be determined using the procedures specified in the ASTM

Recommended Practice El 27-95. Turnaround is expedited by prearrange- ment with the technical contacts.

Special Tests of Titanium or Steel Reference Blocks (26040S, 26060S, and

26070S)

Steel and titanium ultrasonic reference blocks can be calibrated using procedures

similar to those described in ASTM

E428.

References—Ultrasonic Reference

Block Measurements

Standard Practice for Fabricating and

Checking Aluminum Alloy Ultrasonic

Standard Reference Blocks, E- 127-95,

in Annual Book of ASTM Standards

03.03, Philadelphia, PA, Amer. Soc.

for Testing and Materials (1995).

NIST Calibration of ASTM E127-Type

Ultrasonic Reference Blocks, J. A.

Slotwinski, and G. V. Blessing, Natl.

Inst. Stand. Technol., NISTIR 5430

(May 1994).

An Assessment of Ultrasonic Reference

Block Calibration Methodology, G. V.

Blessing, Natl. Bur. Stand. (U.S.),

NBSIR 83-2710 (June 1983). Recent Improvements to the ASTMType Ultrasonic Reference Block

System, D. J. Chwirut, Natl. Bur.

Stand. (U.S.), NBSIR 79-1742 (Feb.

1979).

* See Chapter 1 , Section H for more information about uncertainty.

51
The Evaluation of Search Units Used for Ultrasonic Reference Block Calibrations, D. J. Chwirut and G. D. Boswell, Natl. Bur. Stand. (U.S.), NBSIR 78-1454

(Feb. 1978).

Improved Ultrasonic Standard Reference

Blocks, G. F. Sushinsky, D. G. Eitzen, D. J. Chwirut, C. J. Bechtoldt, and

A. W. Ruff, Natl. Bur. Stand. (U.S.),

NBSIR 76-984 (Nov. 1976).

52
26100C

/.

Ultrasonic Transducer Measurements

Technical Contacts:

Steven E. Pick TO: 301/975-6629 Email: sfick@nisLgov

Gerald V. Blessing

Ttl: 301/975-6627 Email: gblessing@nistgov

Mailing Address: Building 233, Room A147,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service roNo. Items 26 1 OOC Ultrasonic Power Output

Ultrasonic Power Output (26100C)

Measurements of total ultrasonic for- ward power radiated into a reflectionless water load are offered for the purpose of

characterizing ultrasonic systems and

transducers. Ultrasonic systems are char- acterized by measurement of output

power under operating conditions specified by the customer. Transducers for which continuous-wave electrical input

voltage can accurately and reproducibly

be measured are characterized by a radi- ation conductance determined from measurements of input voltage and output

power. A typical calibration report for an ultrasonic system provides the results of at least three measurements of output

power for each operating condition

specified. Calibration reports for trans- ducers typically present a single value of

radiation conductance derived from at least 15 measurements spanning an ap- propriate range of output power. Resonance frequencies of transducers are determined from the results of iterative spot-frequency relative measurements of

radiation conductance.

Continuous-wave ultrasonic power is measured using a radiation force balance

which allows power to be determined

from the force required to arrest the motion of a conical target that diverts the output beam of the transducer under test

into a bank of absorbers. Absolute power

can be measured at spot frequencies

between 0.5 MHz and 30 MHz. The

relative expanded uncertainty* is dominated by frequency dependent effects and

ambient vibration levels at the time of

measurement, and ranges from 0.4 % to 7 % for power levels above a few mW.

The best-case minimum detectable power

is about 100 |xW; high-power measure- ments are limited by the onset of cavitation in the water load itself. Transducers

of diameter no greater than 45 mm can be tested in this apparatus.

Pulsed ultrasonic power is measured

for the purpose of characterizing ultra- sonic systems comprising a transducer and an electrical driver. Transducers by

themselves cannot be independently

characterized with nonsinusoidal drive waveforms since the electrical input

signals cannot at present be adequately

measured. Systems to be tested must be

capable of generation of a sequence of at least 15 pulses in a 500 ms interval under

external triggering.

References—Ultrasonic Transducer

Measurements

Ultrasonic Power Output Measurement

by Pulsed Radiation Pressure, S. E. Pick and F.R. Breckenridge, J. Res.

Inst. Stand. Technol. 101, 659 (1996).

An Ultrasonic Absolute Power Transfer Standard, S. E. Pick, F. R. Breckenridge, C. E. Tschiegg, and D. G.

Eitzen, J. Res. Natl. Bur. Stand. (U.S.)

89 (2), 209 (Mar. 1984).

Ultrasonic Transducer Power Output by

Modulated Radiation Pressure, M.

Greenspan, F. R. Breckenridge, and

C. E. Tschiegg, J. Acoust. Soc. Am. 63

(4), 1031 (Apr. 1978).

* See Chapter 1, Section H for more information about uncertainty.

53
26200C

Acoustic Emission Transducer Measurements

Technical Contacts:

Steven E. Fick Gerald V. Blessing

Tfel: 301/975-6629 Ttl: 301A»75-6627 Email: snck@nistgov Email: gblessing@nistgov

Mailing Address: Building 233, Room A147,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 26200C Acoustic Emission Transducer Sensitivity

Acoustic Emission Transducer Sensitivity (26200C)

Acoustic emission transducer sensitivity

is expressed as the voltage output of the transducer per unit of perpendicular sur- face motion (displacement or velocity)

induced by an impulsive elastic wave

traveling on the surface, or through the bulk, of a steel test block. Sensitivity is computed by comparing the output of the transducer under test (TUT) to an inde- pendently derived estimate of the surface motion that would occur if the transducer were not present. The magnitude and

phase of the computed sensitivity are reported as a function of frequency for discrete frequencies separated by

approximately 10 kHz in the interval 0.1 MHz to 1 MHz.

For surface-pulse tests, the TUT and a

capacitive displacement transducer (CDT) are placed at symmetric locations 10 cm from the center of the circular upper end face of the test block, which is a cylinder 90 cm diameter and 43 cm

long, positioned with its axis of rotation

vertical. Elastic waves are induced in the block by rapid unloading due to breakage

of a quasi-statically loaded glass capillary source located at the center of the upper surface of the block. The CDT

output, corrected for aperture effects, provides a direct measurement of surface

motion which, from independent measurements of the homogeneity of test block properties, bears a known similarity to the surface motion at the TUT

location. For through-pulse testing, the source is located on the lower end face of the block, directly opposite the TUT.

Because phenomena intrinsic to bulk wave propagation would excessively

complicate the task of correcting its output, the CDT output is not used.

Instead, an estimate of upper surface motion at the TUT location is obtained

from calculations based on the measured

unloading force due to breakage of the glass capillary.

References—Acoustic Emission

Transducer Measurements Acoustic

Emission Transducer Calibration by means of the Seismic Surface Pulse,

F. R. Breckenridge, J. Acoust. Emission 1 (2), (Apr. 1985).

Calibration and Sensor Activities, D. G.

Eitzen, F. R. Breckenridge, R. B. Clough, E. R. Fuller, N. N. Hsu, and

J. A. Simmons, Chapter 2.0 in Fundamental Developments for Quantitative

Acoustic Emission Measurements,

EPRI NP-2089, Research Project

608-1, Palo Alto, CA, Electric Power

Research Institute, 2-1-2-52 (Oct.

1981).

Surface-Wave Displacement: Absolute

Measurements Using a Capacitive

Transducer, F. R. Breckenridge and

M. Greenspan, J. Acoust. Soc. Am. 69

(4), 1177 (Apr. 1981).

Characterization and Calibration of

Acoustic Emission Sensors, N. N. Hsu

and F. R. Breckenridge, Matls. Eval. 39(1), 60 (Jan. 1981).

Acoustic Emission: Some Applications of

Lamb's Problem, F. R. Breckenridge,

C. E. Tschiegg, and M. Greenspan,

J. Acoust. Soc. Am. 57 (3), 626

(Mar. 1975).

54

Pressure Measurements

Low Pressure, Vacuum, and Leak Measurements

Laboratory and Industrial-Grade Thermometers

Thermocouples, Thermocouple Materials, and

Thermometer Indicators

Resistance Thermometry

Radiance Temperature Measurements

Humidity Measurements
Thermodynamic Quantities 2901OC-2904OS

A. Pressure Measurements

Technical Contacts:

James W. Schmidt

(all services)

Tel.: 301/975-2458

Email: jschmidt@ni$tgov

R. Gregory Driver (pneumatic gages) 290 IOC, 29030C, 29035C, 29040S

ftl: 301/975-4832

Email: rdriver@nist.gov

Donald B. Ward

(hydraulic gages) 29010C, 29020C, 29030C

Tel: 301/975-6561

Email: dbwardl^

nist.gov

Mailing Address: Building 220, Room A55,

National Institute of Standards and Technology,

Gaidiersburg, MD 20899-0001

Service ID No. Items 290 IOC Deadweight Piston Gages

29020C Controlled Clearance Piston Gages

29030C Pressure Gages and Transducers 29035C Non-Mercurial Barometers and Manometers

29040S Special Tests of Pressure Gages

Piston Gages and Pressure Transducers (29010C-29035C)

NIST provides measurement services for the calibration of piston gages (PG) and

transducers operating with gas in the range of 7 kPa to 110 MPa and with oil in the range of 1 MPa to 280 MPa. Work

is in process to extend the upper range

for oil piston gage calibration services to 500 MPa. Calibrations of customer piston gages are done in the gage mode by the cross-floating technique using NIST

working standard piston gages. NIST

pneumatic working standards have been

calibrated at the low end of the pressure range using the NIST mercury manometers and are modeled to extend their range to higher pressures. The NIST

working standards for oil service have

been calibrated using three controlled- clearance piston gages. Relative expanded

uncertainties** associated with such cali- brations are shown in Table 6. 1

.

*See Chapter 1 , Section C for information available from the Standard Reference Materials Program on

calibrating certain thermodynamic property measurement instruments. ** See Chapter 1, Section H for more information about uncertainty.

Table 6.1. Relative Expanded Uncertainties** of Piston Gage

Standards in Gage Mode

Type of Instrument

Relative Expanded

Range Uncertainty**

Gas-operated PG

Oil-operated PG

7 kPato 105 kPa 13 105 kPa to 1.4 MPa 19

1.4 kPa to 17.3 MPa 33

17.3 kPa to 103 MPa 38

1 MPa to 29 MPa 22

29 MPa to 140 MPa 37

140 MPa to 280 MPa 49

** These expanded uncertainties are based on recent evaluations of NIST

"transfer" piston gage standards. Uncertainty estimates are continually being

revised to reflect development of new primary pressure standards and improve- ments in measurement techniques.

Special Tests of Pressure Gages

(29040S)

Special tests of pressure gages and other pressure measuring devices may be per- formed on request. This includes, special

test 30040S for deadweight piston gages, an absolute mode test in the pressure range 7 kPa to 350 kPa that can provide

relative expanded uncertainties that are smaller than those given in Table 6.1. A minimum piston gage test will require data at five or more pressures for each

gas desired. Call Mr. Driver for further information about this service.

References—Pressure Measurements

Research at High Pressures (Primary

Pressure Standards), J. S. Schmidt, D. B. Ward, and S. A. Tison, Proc. 1997 Natl. Conf. Stand. Lab., Workshop and Symp. (accepted for publication). Development of High Pressure (110 MPa) Gas Calibration Service at NIST, S. W. Doty, C. D. Ehrlich, R. F. Kayser and S. A. Tison, Proc. Of the 1995 Measurement Science Conference. A Look at Uncertainties over Twenty

Decades of Pressure Measurement,

C. D. Ehrlich, Proc. of die XIII IMEKO World Congress (Sept. 1994)

57
29010C-29040S

An Intercomparison of Pressure Stan- dards in the Hydraulic Pressure Region

up to 28 MPa between NPL (India)

and NIST (USA), J. K. N. Sharma,

K. K. Jain, C. D. Ehrlich, J. Res. Natl.

Inst. Stand. Technol. (1994).

Elastic Distortion Calculations on a Special Piston Gage (PG27) up to 28 MPa

in Different Operational Modes, G. F. Molinar, P. C. Cresto, C. Ehrlich and

J. Houck, Metrologia 30 (6) (1994).

A Review of the State of the Art in GasOperated Piston Gages, C. D. Ehrlich,

Metrologia 30 (6), 585 (1994).

Operational Mode and Gas Species

Effects on Rotational Drag in Pneumatic Dead Weight Pressure Gages,

J. W. Schmidt, B. E. Welch and C. D.

Ehrlich, Meas. Sci. Technol. 4 , 26-34

(1993).

Intercomparison of the Effective Areas of

a Pneumatic Piston Gage Determined

by Different Techniques, K. Jain, C. Ehrlich, J. Houck and J. K. N. Sharma, Meas. Sci. Technol. 4, 249-

257 (1993).

Intercomparison of Hydraulic Pressure Measurements to 28 MPa using a

Single Piston Gage in the Controlled- Clearance, Reentrant and Simple

Configurations, K. Jain, C. Ehrlich and

J. Houck, Review of Scientific Instru- ments 63,3127,(1992).

The Reduction of Uncertainties for Absolute Piston Gage Pressure Measurements in the Atmospheric Pressure Range, B. E. Welch, R. E. Edsinger,

V. E. Bean and C. D. Ehrlich, J. Res.

Natl. Inst. Stand. Technol. 94, 343

(Nov .-Dec. 1989).

Practical Uncertainty Limits to the Mass

Determination of a Piston-Gage

Weight, R. S. Davis and B. E. Welch,

J. Res. Natl. Bur. Stand. (U.S.), 93 (4) (July-Aug. 1988).

International Comparison in the Pressure Range 20-100 MPa, J.C. Legras, S.L. Lewis, G. F. Molinar, Metrologia 25,

21-28 (1988).

The Pressure Balance, Theory and Practice, R. S. Dadson, S. L. Lewis, and

G. N. Peggs, Her Majesty's Stationary

Office, London, England (1982).

Piston Gages, P. L. M. Heydemann and

B. E. Welch, Chapter 4, Experimental

Thermodynamics, Vol. II, in Experimental Thermodynamics of NonReacting Fluids, B. Le Neindre and

B. Vodar, Eds., Part 3, 147, Butter- worth and Co., London, England

(1975).

58
3OO1OC-30O63S

B. Low-Pressure, Vacuum, and Leak

Calibrations

Technical Contacts:

Ren-Fang Chang

30029C-30032C,

30050S

Tfel: 301/975-2446

Email: renchang@

nistgov

Archie Miiller 30010C-3002SC,

30040S,

1tl:301A>75-5932 Email: archie.miiller@

nist.gov

Patrick J. Abbott 30034C-30038C, 30060S-30062C

Tel. 301/975-4838

Email: Patrick. abbott@nist.gov

Stuart A. Tison 30063S

Tel: 301/975-2857

Email: stison@

nistgov

Mailing Address: Building 220, Room A55,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

1-270 at Quince Orchard Rd.,

Building 220, Room A55,

Gaithersburg, MD 20899-0001

Service ID No. Items 300 IOC

30011C

30020C

3002 IC 30025C

30029C

30030C

3003 IC 30032S

30034C

30035C

30036C

30037C

30038C

30040S

30050S

30060S

3006 IC

30062C

30063S

One Low-Pressure Transducer (Absolute or Differential) Relative to Vacuum

Additional Transducers (cost per unit) One Differential Low-Pressure Transducer Relative

to Near Atmospheric Pressure Additional Transducers (cost per unit) Ball-Type Deadweight Tester Spinning Rotor Gages, below 0. 1 Pa, Nitrogen Gas With

NIST Controller Spinning Rotor Gages, below 0.1 Pa, Nitrogen Gas, Customer Controller with IEEE-488

Spinning Rotor Gages, below 0.1 Pa, Additional Gas

Special Tests of Spinning Rotor Gages, Transition Range

(above 0.1 Pa)

Ionization Gages, lO""* to 10"' Pa, Nitrogen Gas

Ionization Gages, 10"^ to 10"' Pa, Nitrogen Gas

Ionization Gages, 10"^ to 10"' Pa, Nitrogen Gas

Ionization Gages, Additional Filament or Gas for Above

Tests Ionization Gages, NIST-Supplied Gage Tube for Above Tests Special Tests of Low-Pressure Gages

Special Tests of Vacuum Gages

Special Tests of Leak Artifacts (10"" mol/s to 10"* mol/s)

Helium Leaks, Primary Calibration (10"'^ mol/s to 10"* mol/s)

Helium Leaks, Comparison Calibration (10"'^ mol/s to

10"' mol/s)

Special Tests of Low-Gas Flow Instruments

General Notes:

1 Torr= 133.322 Pa

Due to the time and effort required to prepare vacuum instrumentation for operation it is particularly important that these instruments be known to be in proper operating condition when they are submitted for calibration. Equipment will be inspected upon receipt and the cus- tomer notified of any obvious damage. If the schedule permits, we will cooperate

with the customer's efforts to repair or

replace damaged equipment so that cali- bration can proceed. However, concealed

damage or operational deficiencies most

likely will not be detected before the in- strument is operating on the vacuum sys- tem or the calibration has started; in such

cases, if the equipment cannot be cali- brated, we will charge 20 % of the regular calibration fee for capacitance

diaphragm gages and 30 % of the regular

fee for spinning rotor and ionization gages.

Low-Pressure Calibrations

(30010C-30025C and 30040S)

Low-pressure gages are calibrated by

direct comparison to NIST UIM (Ultra- sonic Interferometer Manometer) primary standards. Calibrations relative to vacuum are performed with either an oil UIM that has a range of 135 Pa (1 Torr), or one of two mercury UIMs that have

ranges of 140 kPa (1 100 Torr) and

360 kPa (2700 Torr). Calibrations relative to higher reference pressures (up to 200 kPa) are performed with either the 360 kPa UIM or a new low-differential- pressure standard based on a 1 3 kPa

(100 Torr) mercury UIM. The expanded

uncertainty* due to systematic effects of

the mercury UIM standards is 5.2 X 10"* of reading plus 1 8 mPa; the expanded

uncertainty of the oil UIM standard is 100 X 10"* of reading plus 2 mPa.

* See Qiapter 1 , Section H for more information about uncertainty.

59
30010C-30063S

Pressure measuring devices accepted for calibration generally fall into three cat- egories. The first are absolute pressure

transducers or differential pressure

transducers that are operated relative to vacuum, such as capacitance di- aphragm gages or quartz bourdon gages

(Service ID Numbers 300 IOC and

3001 IC). The second category includes

differential pressure transducers of a

similar type intended for use with

reference pressures near atmospheric

pressure (Service ID Numbers 30020C

and 30021 C). The third category

includes certain types of dead weight

testers, such as ball gages (Service ID

Number 30025C) and low range piston

gages (Service ID Number 30040S).

Calibrations of transducers relative to vacuum are performed in batches

twice a year. Please call for deadline

dates for the next calibration batch. Other calibrations are performed on

request as NIST schedules and equipment availability permit.

Spinning Rotor Gages

(30029C-30032S)

Spinning Rotor Gages (SRGs, also

called Molecular Drag Gages) are cali- brated on a new Transition Range

Standard of the orifice-flow type with an extended range from 10""* Pa to 30 Pa

and a relative expanded uncertainty*

between 0.3 % and 1.0 %. The routine

calibrations, 30029C-30031C, cover

molecular-flow pressures below

0.1 Pa, where the SRG can, for all practical purposes, be characterized by

a constant effective accommodation

coefficient without a viscosity correction. Calibrations in this range can be

performed using either the customer's

controller or a NIST controller. The vacuum flange for the thimble

assembly must be bakeable (2.75 in "Conflat" type preferred) unless

special arrangements have been made.

* See Chapter 1 , Section H for more information about uncertainty.

These calibrations are performed with

nitrogen, in batches, typically two or

three times a year. Please call for the next scheduled calibration date, or to ar- range for a gas other than nitrogen.

Viscosity effects become increas- ingly important above 0. 1 Pa. As a

special service (30032S), SRGs can be

calibrated up to 30 Pa on the Transition Range standard, and up to 100 Pa

using an ultrasonic interferometer manometer. This requires that the ball, thimble, suspension head, and controller be calibrated as unit. Please call for scheduling and costs.

Ionization Gages (30034C-30038C)

A standard of the orifice-flow type

covers the pressure range from 10"' Pa to 10 ' Pa (10 ' Torr to 10"^ Torr) for inert gases with a relative expanded uncertainty* of 0.7 % or less in the range

10"' Pa to 10 ' Pa, increasing to 2 % at 10"' Pa. To be acceptable for calibration all gages must be bakeable to 250 °C

and should be welded to "Conflat"

type flanges. Standard procedure is to calibrate the gage and its control elec- tronics as a package, although gages may

be calibrated using NIST electronics by special arrangement. Unless specifically requested by the customer, all hot-cathode gages will be calibrated with

1 mA electron emission current and the preset bias voltages supplied by

the customer's controller. Note that ionization gage controllers that do not

regulate the emission current or deliberately change it are not considered

suitable as transfer standards. After a gage has been calibrated via any of the Service ID Numbers 30034-30036C,

calibration of the gage for additional gases or additional filaments (30037C)

may be done for a reduced fee. Cold-cathode gages can be calibrated by special arrangement at the same fees. Ionization gage calibrations are generally performed twice a year; please

call for scheduled dates. For an additional fee, NIST will provide glass-envelope Bayard-Alpert

60
30010C-30063S

ionization gages with tungsten filaments

and mounted on non-rotatable 2.75 in "Conflat" type flanges* (30038C). These

will be calibrated with the user's electronics.

Special Tests of Low-Pressure Gages

(30040S)

Instruments requiring special cali- bration procedures or prolonged testing can often be accommodated as a special test. This includes, as a complement

to the 29000 Service ID Numbers, the determination of deadweight piston gage

effective area using the NIST ultra- sonic interferometer manometer as the reference standard. This test can be

done in either the gage or absolute mode

for a variety of gases. Please call for additional information.

Special Tests of Vacuum Gages

(30050S)

Instruments requiring special calibration procedures or prolonged testing can

often be accommodated as a special

test. Please call for additional information.

Leaks (30060S-30062C)

Leak artifacts are calibrated in the range 1 X 10"^ mol/s to 1 X 10 '^ mol/s

(2 X 10"^ std. cm^/s to 2 X 10"' std. cm^/s

at 0 °C). Flow rates are quoted at stan- dard conditions for leak measurements

of P = 101 325 Pa and T = 0 °C. When

referenced to the specific temperature,

std. cm^/s can be converted to mol/s by

multiplying by 4.45 X 10 I The cali- bration can be performed directly by the NIST primary leak standard (3006 IC)

which has a range-dependent relative expanded uncertainty** between 0.2 %

and 4.5 %. For a lower fee, helium leak

artifacts in the range 1 X 10"' mol/s to

1 X 10 '-^ mol/s may be calibrated

(2 X 10 ' std. cm-Vs to 2 X 10 '^ std. cmVs

at 0 °C) on a comparison system with

respect to NIST-calibrated reference

leaks (30062C). In both cases, the temperature dependence of the leak is measured and the Report of Calibration

will include tabulated leak rates at

1 °C intervals from 0 °C to 50 °C. All

leak artifacts submitted for measure- ment must be ultrahigh vacuum compatible and clean. The vacuum connection must have a standard 2.75 in "Conflat"

type flange or 1/4 in VCR type fitting

(3006 IC). An easily observable customer

identification number or code must be

engraved on the circumference of the vacuum flange or reservoir. By special

arrangement (30060S), leaks can be cali- brated with gases other than helium,

such as argon and common refrigerants.

Leaks can also be calibrated as a function of reservoir pressure. Calibrations using the NIST primary leak standard

are performed once a year, usually in January. Comparison calibrations are performed throughout the year. Please

call for further information.

Special Tests of Low-Gas-Flow

Instruments (30063S)

High precision low-gas-flow instruments

are calibrated in the range of

(10"* to 10"^) mol/s with inert gases and other gases by special arrange- ment. The calibration is performed by

direct comparison to a NIST primary

flow standard and can be accomplished

with down stream pressures ranging

from 10 Pa (vacuum) to 300 kPa. The

relative expanded uncertainties* in the measured flow are range dependent and

vary from 0.05 % at a flow of

10 ^ mol/s to 0.1 % at a flow of

10"* mol/s. Gas flows higher than

10"-^ mol/s are described under Service

ID Numbers 180 IOC and 18050S.

On-site proficiency tests may also be

accomplished by special arrangement.

* 2.75 in Conflat flange is an industrial designation

for connectors. ** See Chapter 1, Section H for more information about uncertainty.

61
30010C-3(X)63S

o

10 -9 Pressure (Torr) (log)

-7 -6 .5 -4 .3 -2-10 1

£ .3

-aoo

c« -5 a

K

Ul

Transition Range Vacuum Standard

High and Ultrahigh Vacuum Standard

Ultrasonic iDterferometer Manometer

-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 Pressure (Pa) (log)

Figure 6. 1. Uncertainties of ttie NIST Low-Pressure and

Vacuum Standards.

o

Flow (cm'/min) at standard conditions .3-2-101 2

S* -2 cnt

«

o

c3

•ac

(0a

X

lU

: 1 1 1 -1 1

1 1

- Pressure Rate of Rise Constant Pressure v

Flowmeter

-12 -11 -10 -9-8-7-6-6-4

Flow (mol/s)

Figure 6.2. Uncertainties of tfie NIST Leal< and LowGas- Flow Standards.

References—Low Pressure

Development of a Low Differential- Pressure Standard, C. R. Tilford and

A. R Miiller, Proc. Natl. Conf. Stand. Lab. Ann. Workshop and Symp.

(1997)

Measurement Performance of Capacitance Diaphragm Gages and Alternative Low-Pressure Transducers, A. P. Miiller, Proc. Natl. Conf. Stand. Lab.

Ann. Workshop and Symp. (1997). Pressure and Vacuum Measurements,

C. R. Tilford, Chapter 2 in Volume VI

of Physical Methods of Chemistry,

W. Rossiter, J. F. Hamilton, and

R. C. Baetzold, ed., John Wiley &

Sons, New York (1992).

The NBS Ultrasonic Interferometer Manometer and Studies of Gas Operated Piston Gages, C. R. Tilford and

R. W. Hyland, Metrology, Proc. 11th

Triennial World Congress of the Inter- national Measurementation Confederation (IMEKO), Houston, TX, 16-21

Oct. 1988, W. C. Rutledge, ed. (Instrum. Soc. of America), Res.

Triangle Park, NC (1988) p. 277. New Developments In Barometric Range

Pressure Standards, C. R. Tilford, Proc. 1988 Natl. Conf. Stand. Lab.

Workshop and Symp. pp. 35-1 to 35-

15 (1988).

The Speed of Sound in a Mercury Ultra- sonic Interferometer Manometer, C. R.

Tilford, Metrologia 24, 121 (1987). Zero Stability and Calibration Results for a Group of Capacitance Diaphragm

Gages, R. W. Hyland and C. R.

Tilford, J. Vac. Sci. Technol. A 3, 1731 (1985).

Ultrasonic Manometers for Low and

Medium Vacua Under Development at NBS, P L. M. Heydemann, C. R.

Tilford, and R. W. Hyland, J. Vac. Sci. Technol. 14, 597 (Jan.-Feb. 1977).

References—Vacuum

Comparison of the standards for high and

ultrahigh vacuum at NIST, NPL, and

PTB, K. Jousten, A. R. Filippelli, C. R. Tilford, and F. J. Redgrave,

J. Vac. Sci. Technol. A 15, 1 (1997)

Comments on the stability of BayardAlpert ionization gages, C. R. Tilford, A. R. Filippelli, and P J. Abbott, J. Vac. Sci. Technol. A 13, 485 (1995).

62
300 lOC-:-30063S

Long-term stability of Bayard-Alpert gage performance: Results obtained

from repeated calibrations against the NIST primary vacuum standard, A. R.

Filippelli, and R J. Abbott, J. Vac. Sci. Technol. A 13, 2582 (1995)

Influence of the filament potential wave

form on the sensitivity of glass-envelope Bayard-Alpert gages, R J. Abbott

and J. P. Looney, J. Vac. Sci. Technol. A 12,542 (1994)

PC-based spinning rotor gage controller,

J. P. Looney, F. G. Long, D. F. Browning and C.R. Tilford, Rev. Sci. Instr. 65 (9), 3012 (1994)

Behavior of commercial spinning rotor gages in the transition regime, J. Setina, and J. P. Looney, Vacuum 44,

577 (1993).

NIST Measurement Services: High

Vacuum Standard and Its Use,

S. Dittmann, Natl. Inst. Stand. Technol. Spec. Publ. 250-34 (1989).

The National Bureau of Standards Pri- mary High-Vacuum Standard, C. R.

Tilford, S. Dittmann, and K. E. McCulloh, J. Vac. Sci. Technol. A 6, 2853 (1988).

Low-Range Flowmeters for Use with

Vacuum and Leak Standards, K. E. McCulloh, C. R. Tilford, C. D.

Ehrlich, and F. G. Long, J. Vac. Sci. Technol. A 5, 376 (1987).

Long-Term Stability of Two Types of

Hot Cathode Ionization Gages, S. D. Wood and C. R. Tilford, J. Vac. Sci. Technol. A3, 542 (1985).

Sensitivity of Hot Cathode Ionization Gages, C. R. Tilford, J. Vac. Sci. Technol. A 3, 546 (1985).

References—Leaks and Low-Flow

A critical evaluation of thermal mass

flow meters, S. A. Tison, J. Vac. Sci. Technol. A 14, 2582 (1996)

Commercial helium permeation leak

standards: Their properties and reli- ability, P. J. Abbott, and S. A. Tison,

J. Vac. Sci. Technol. 14 (May-June

1996)

Using Characterized Variable Reservoir

Helium Permeation Leaks to Generate Low Flows, S. A. Tison and P. Mohan,

J. Vac. Sci. Technol. A 12, 564 (1994).

Experimental Data and Theoretical Modeling of Gas Flow Through Metal Capillary Leaks, S. A. Tison, Vacuum 44, 1171 (1993). Transfer Leak Studies and Comparisons

of Primary Leak Standards at the National Bureau of Standards and

Sandia National Laboratories, R. W.

Hyland, C. D. Ehrlich, and C. R.

Tilford, J. Vac. Sci. Technol. A 4, 334

(1986).

A Note on Flow Rate and Leak Rate

Units, C. D. Ehrlich, J. Vac. Sci. Technol. A 4, 2384(1986).

63
31010C-31260S

a

Laboratory and Industrial-Grade

Thermometers*

Technical Contact:

C. Dawn Vaughn

Tel: 301/975-4822 Email: c.vaughn@nist.gov

Mailing Address: Building 221, Room B128,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

1-270 at Quince Orchard Rd.,

Building 221, Room B241,

[Attn: C. Dawn Vaughn, ext. 4822]

Gaithersburg, MD 20899-0001

Note: The minimum number of test points per thermometer is two. Fahrenheit ranges are not direct conversions of the Celsius

ranges.

Service ID No. Items

3 1 0 1 OC Laboratory Thermometers (0 °C to 1 50 °C)

(32 °F to 300 °F) 3 1 020C Laboratory Thermometers ( 1 5 1 °C to 3 1 5 °C)

(300 °F to 600 °F) 3 1 030C Laboratory Thermometers (3 1 6 °C to 550 °C)

(600°Fto 1022°F)

3 1 040C Laboratory Thermometers (- 1 °C to - 11 0 °C)

(31 °F to-166°F)

31050C Laboratory Thermometers (Liquid N2)

(-196 °C or -321 °F) 3 1 lOOC Quantity Tests of Liquid-in-Glass Thermometers

3 1 llOS Special Tests of Industrial Platinum Resistance Thermometers, Thermistor Thermometers, Digital

Thermometers, and Other Types of Thermometers

(0 °C to 150 °C) (32 °F to 300 °F) 31 120s Special Tests of Industrial Platinum Resistance Thermometers, Thermistor Thermometers, Digital

Thermometers, and Other Types of Thermometers

(1 5 1 °C to 3 1 5 °C) (30 1 °F to 600 °F) 31 130S Special Tests of Industrial Platinum Resistance Thermometers, Thermistor Thermometers, Digital

Thermometers, and Other Types of Thermometers

(3 16 °C to 550 °C) (601 °F to 1022 °F) 31 140S Special Tests of Industrial Platinum Resistance Thermometers, Thermistor Thermometers, Digital

Thermometers, and Other Types of Thermometers

(-1 °Cto-110°C) (31 °Fto-166°F)

* See Chapter 1 , Section C for information on other thermodynamic property measurement standards available from the Standard Reference Materials Program.

Service ID No. Items

3 1 1 50S Special Tests of Industrial Platinum Resistance Thermometers, Thermistor Thermometers, Digital

Thermometers, and Other Types of Thermometers

(Liquid Nj) (-196 °C or -321 °F)

3 1 170S Special Tests of Calorimetric Thermometers

3 1 1 SOS Special Tests of Beckmann Thermometers

3 1200s Preliminary Examination of Ineligible Thermometer

3 1 250S Additional Copy of Report

31260S Special Thermometiy Services, by Prearrangement

Laboratory Thermometers

(31010C-31100C)

This service provides for the calibration of a variety of thermometers covering the range from -196 °C to +550 °C

(-321 °F to -I- 1022 °F). Thermometers belonging to the

large and varied group which may be

classified as laboratory, or "chemical,"

thermometers are regularly accepted.

These are of the liquid-in-glass type

with either solid-stem or enclosed scale. Ordinary household or meteorological

thermometers will not, in general, be ac- cepted unless the scale is graduated on

the glass stem itself and the thermometer

can be readily detached from its mounting for insertion in a liquid bath. Every thermometer submitted must be

uniquely identified by a serial number

and must pass a preliminary examination for fineness and uniformity of graduation; for cleanliness of the mercury

and the capillary bore; for freedom from

moisture, gas bubbles, and cracks in the glass; for adequacy or omission of

gas filling where needed; for insuffi- cient annealing; and, for misnumbered

graduations. When these or other seri- ous defects are found, the thermometer is returned untested. The thermometers to be calibrated

are placed in a constant temperature

bath along with a NIST-calibrated stan- dard platinum resistance thermometer

(SPRT). The SPRT maintains calibrations traceable to the International Temperature Scale of 1990 (ITS -90), with a maximum expanded uncertainty** of 0.7 mK. (See Table 6.2)

** See Chapter 1, Section H for more information about uncertainty.

64
31010C-3126OS

Ikble 6.2. Calibration Uncertainties for Total Immersion

Thermometers

Type of Thermometer Range

Expanded

Uncertainty*

(°C)

Mercury-in-glass 0 to 100

(graduations: 0.1 °C or 0.2 °C)

Mercury-in-glass 0 to 300

(graduations: l°Cor2°C) 300 to 550

Organic liquid-in-glass - 200 to 0

0.024

0.5 to 0.1 0.16 to 0.3

0.2 to 0.5

See Chapter 1 , Section H for more information about uncertainty.

Special Tests of Thermometers

(31110S-31150S)

Special tests may be conducted on

temperature-measuring devices such as

industrial grade platinum resistance thermometers, digital thermometers,

and thermistors. Laboratory personnel

should be consulted before submitting

items.

References—Laboratory and

Industrial-Grade Thermometers

ASTM Standard E 1, Standard Specifi- cation for ASTM Thermometers, Annual Book of ASTM Standards

14.03, p. 1 , Amer. Soc. for Test, and

Matls., Philadelphia, PA (1996).

ASTM Standard E 77, Standard Test Method for Inspection and Verification of Thermometers, Annual Book

of ASTM Standards 14.03, p. 61,

Amer. Soc. for Test, and Matls.,

Philadelphia, PA (1996).

A Procedure for the Effective Recalibration of Liquid-in-Glass

Thermometers, J. A. Wise, Natl. Inst. Stand. Technol. Spec. Publ. 819

(Aug. 1991). Assessment of Uncertainties of Liquidin-Glass Thermometer Calibrations

at the National Institute of Standards

and Technology, J. A. Wise, NISTIR

5341 (Jan. 1994).

The International Temperature Scale of

1990 (ITS-90), H. Preston-Thomas,

Metrologia 27, 3-10 (1990); Metrologia 27, 107 (1990).

NIST Measurement Services: Liquidin-Glass Thermometer Calibration Service, J. A. Wise, Natl. Inst. Stand. Technol. Spec. Publ. 250-23 (Sept.

1988).

Thermometer Calibration: A Model for State Calibration Laboratories, J. A. Wise, and R. J. Soulen, Natl. Bur.

Stand. (U.S.), Monogr. 174 (Jan. 1986).

65
32010C-32150S

D Thermocouples, Thermocouple Materials,

and Thermometer Indicators**

Technical Contacts:

Dean C. Ripple 32010C-321S0S

TeU 301/975-4801 Email: dripple@

nistgov

Karen Garrity 32010C-32101C, 32150S

Tel: 301/975-4818

Email: kgarrity@

nist.gov

C. Dawn Vaughn

32110C-32147C

Ttl: 301/975-4822 Email: cvaughn@

nistgov

Mailing Address: Building 221, Room B128,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

1-270 at Quince Orchard Road,

[For: 32010C-32101C, 32150S; Attn: D. C. Ripple or K. Garrity, Bldg. 221, Room B229]

[For: 321 10C-32147C; Attn: C. D. Vaughn or D. C. Ripple, Bldg. 221, Room B241]

Gaithersburg, MD 20899-0001

Comparison Calibrations, Temperature Measured with Thermocouple (TC):

Service Temp. Min. Expanded ID TC Range Points Length Temp. Uncert.* No. Type rc) (mm) (°C) (°C)

320 IOC S 0 to 1450 1 ° or 1 °F 700 0 to 1 100 0.3

Interv. Table 1450 1.6 32020C R Oto 1450 700 0 to 600 0.5 1450 1.6 32030C B 0 to 1750 1000 0 to 800 (3(jiV) 800 to 1 100 0.3 1450 1.6 1750 2.4 3203 IC B 800 to 1750 1000 800 to 1 100 0.6 1450 1.6 1750 2.4 32040C E Oto 1000 4 to 15 700 0 to 1000 0.9 32041

C

J Oto 760 4 to 15 700 0 to 760 0.7

* See Chapter 1, Section H for more information about uncertainty.

Service ID

No.

Comparison Calibrations, Temperature Measured with Thermocouple—Continued:

Temp. Min. Expanded

TC Range Points Length Temp. Uncert.* Type rO (mm) fC) (°C) 32042C K Oto 1100 4 to 15 700 Oto 1100 1 32043C N Oto 1100 4 to 15 700 Oto 1100 1 32044C T Oto 400 4 to 15 700 0 to 400 0.4 32050C Comparison calibration, 2 point minimum, per point, for all items above 32060C Each additional table of results at 1 °C or 1 °F intervals, for Type S, R, or B at later date 3206 IC Each additional table of results at 1 °C or 1 °F intervals, for Type S, R, or B at time of test 32070C Thermocouple materials tested against Pt thermoelectric

standard, 4 to 1 5 points, 700 mm minimum lengths

* See Chapter 1 , Section H for more information about uncertainty.

Calibration at Metal Freezing Points, Minimum TC Wire Diameter 0.4 mm, Freezing Point Determination at Au, Ag,

AI and Zn

Service ID

No. TCType

Temp.

Range

(°C)

Points Length

(mm)

Ex- panded

Temp. Uncert.*

(°c) ro

32090C S orR

0 to 1 450 Table, 1 °C or

1 °F interv. and

1000 at freezing 0.

1

points equations to generate table Oto 1100

1450

0.1

1.6

3209 IC Type S or T, freezing point determination, per point, 2 point minimum

* See Chapter 1 , Section H for more information about uncertainty.

Calibration ofDigital Thermometer Indicator or Portable Potentiometer

Service ID No. Items 32100C Indicator or Potentiometer, first dial or range 32101C Indicator or Potentiometer, each additional dial or range

** See Chapter I , Section C for contact information on the Standard Reference

Materials Program, which has thermocouple materials and other temperature

standards available for sale.

66

I
32010C-32150S

Comparison Calibration of Thermocouples or Thermocouple Materials Tested against Pt

Thermoelectric Standard, Temperature Measured

with Platinum Resistance Thermometer, Minimum

TC Wire Length 1.0 m, 2 Point Minimum

Service ID No. Items

321 IOC Range - 1 10 °C to +315 °C and Liquid Nj (- 196 °C) or - 166 °F to 600 °F and Liquid Nj (-321 °¥), Expanded

Uncertainty* 0.4 °C

32 1 20C 3 1 6 °C to 550 °C or 60 1 °F to 1 022 °F, Expanded

Uncertainty* 0.5 °C

Table at one degree intervals for Type T thermocouple for any of the following options:

(The cost of the table will be in addition to the calibration per point covered under fee schedule service ID numbers 321 10C-32120C.)

32141C Option 1: Table from - 190 °C to +300 °C

(-321 °F to +572 °F), calibration points at (-196, - 110, -50, +100, +200, +300) °C

32 1 42C Option 2: Table from - 1 90 °C to + 1 00 °C (-321 °F to +212 °F), calibration points at (-196,

-110, -50, +50, +100) °C

32143C Option 3: Table from - 1 10 °C to +300 °C

( - 166 °F to +572 °F), calibration points at ( - 1 10, -50, +100, +200, +300) °C

32 1 44C Option 4: Table from - 1 1 0 °C to + 1 00 °C

(- 166 °F to +212 °F), calibration points at (- 1 10, -50,

+50, +100) °C 32145C Option 5: Table from 0 °C to 300 °C (32 °F to 572 °F), calibration points at (+100, +200, +300) °C

32 1 46C Option 6: Table from - 1 1 0 °C to 0 °C ( - 1 66 °F to +32 °F), calibration points at ( - 1 10, -50) °C. 32 1 47C Option 7: Table from - 1 96 °C to 0 °C ( - 32 1 °F to +32 °F), calibration points at ( - 196, - 1 10, -50) °C

321 505 Special Tests of Thermocouples and Thermocouple

Materials Note: Due to the extra time involved in calibrating sheathed thermocouples, a surcharge of 20 % of the cost of

calibrating bare-wire thermocouples will be added

to the relevant fees listed for the above.

* See Chapter 1, Section H for more information about uncertainty.

Thermocouples, Thermocouple

Materials and Thermometer

Indicators (32010C-32147C)

Calibration services for all commonly

used types of thermocouples are pro- vided by NIST from -196 °C to 1750 °C

depending upon the wire or thermocouple type. The thermocouples are cali- brated by one or a combination of three general methods, depending on the ther- mocouple type, the temperature range, and the uncertainty required. All three methods provide traceability to the ITS-90. In the first method, thermocouples are calibrated by comparison

with a reference thermocouple maintained at NIST. In the second method,

thermocouples are calibrated by compari- son with a standard platinum resistance thermometer. In the third method, ther- mocouples are calibrated at four defining

fixed-point temperatures on the ITS-90:

the freezing points of Zn, Al, Ag, and Au. Below 0 °C, the thermocouple cali- bration is performed in a cryostat; above

0 °C, stirred liquid baths, metal freezingpoint cells, and electric tube-type fur- naces are employed for the calibrations. Vacuum or inert gas furnaces are also

available for testing thermocouples.

Only the bare wires are required to perform the thermocouple calibrations. It

is preferable not to send insulating and

protecting tubes as the rate of breakage

of these in shipment is high. If the ther- mocouple is furnished mounted (as in a protection tube assembly), a nominal

charge will be made for dismantling the mounting and the various parts will be

returned to the sender without reassembling them. Minimum thermocouple

length requirements listed in the Service

ID Number tables are exclusive of lead

wire. Lead wires (for connections) should

not be sent with thermocouples. All ther- mocouple calibration data furnished in reports will be on the basis of a reference

junction temperature of 0 °C (32 °F). The

calibration results will be given in °C or

°F, as requested by the customer. The calibration of a thermocouple will not be undertaken if it will likely not

67
yield the specified expanded uncertainty*

or if it possesses unusual characteristics that would prevent the performance

of the calibration or test at a reasonable cost. Only unused base-metal ther- mocouples and thermocouple materials

will be accepted for test. All uncertainties are expressed as expanded uncertainties* and vary with

test temperature. In cases where a range of temperatures is given, the stated expanded uncertainty is the maximum

of the expanded uncertainties over this range of temperatures.

Special Tests of Thermocouples and

Thermocouple Materials (32150S)

For requirements not covered by

calibrations described above, special

arrangements may be made by consulting one of the specified staff members.

References—Thermocouples

ASTM Standard E 220-86(96), Stan- dard Method for Calibration of Thermocouples by Comparison

Techniques, Annual Book of ASTM

Standards 14.03, 94, Amer. Soc. for

Test, and Matls., Philadelphia, PA

(1997).

ASTM Standard E 230-96, Standard

Specification and Temperature-Elec- tromotive Force (EMF) Tables for Standardized Thermocouples,

Annual Book of ASTM Standards

14.03, 106, Amer. Soc. for Test, and

Matls., Philadelphia, PA (1997).

ASTM Standard E 1751-95, Standard

Guide for Temperature Electromotive Force (EMF) Tables for Non-Letter Designated Thermocouple Combinations, Annual Book of ASTM Stan- dards 14.03, 456, Amer. Soc. For Test. And Matls., Philadelphia, PA (1996).

International Electrotechnical Commission Standard, Thermocouples, Part I: Reference Tables, lEC Publication 584-

1, Intl. Electrotech. Com., Geneva

(1994).

Assessment of Uncertainties of Thermocouple Calibrations at NIST, D. Ripple,

G. W. Burns, and M. G. Scroger,

NISTIR 5340 (1994).

Manual on the Use of Thermocouples in Temperature Measurement, ASTM

MNL 12, Amer. Soc. for Test, and

Matls., Philadelphia, PA (1993).

Temperature-Electromotive Force Refer- ence Functions and Tables for the Letter-Designated Thermocouple

Types Based on the ITS-90, G. W.

Burns, M. G. Scroger, G. F. Strouse, M. C. Croarkin, and W. F. Guthrie,

Natl. Inst. Stand. Technol. Mongr. 175

(1993).

The International Temperature Scale of

1990 (ITS-90), H. Preston-Thomas,

Metrologia 27, 3-10 (1990), Metrologia 27, 107 (1990).

NIST Measurement Services: The

Calibration of Thermocouple and

Thermocouple Materials, G. W. Burns

and M. G. Scroger, Natl. Inst. Stand. Technol. Spec. Publ. 250-35 (April

1989).

*See Chapter 1 , Section H for more information about uncertainty.

68
33010C-33380M

£ Resistance Thermometry

Weston L. Tfew 0.65 K to 84 K

1^1:301/975-4811 Email : wtew@ni$tgov

Technical Contacts:

Gregory F. St rouse 83 K to 962 °C

Tfel: 301/975-4803 Email : gstrou$e@ni$Lgov

Mailing Address: Building 221, Room B128,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

1-270 at Quince Orchard Road,

Building 221, Room B04,

[Attn: W. L. Tew or G. F. Strouse]

Gaithersburg, MD 20899-0001

Service roNo. Items 330 IOC Capsule SPRT (13.8 K to 30 °C) to Ga

33020C Capsule SPRT (13.8 K to 157 °C) H2 to In 33030C Capsule SPRT ( 1 3.8 K to 232 °C) H2 to S„ 3303 1 C Capsule SPRT (24.5 K to 30 °C) Ne to Ga

33032C Capsule SPRT (24.5 K to 157 °C) Ne to In 33033C Capsule SPRT (24.5 K to 232 °C) Ne to Sn 33040C Capsule SPRT (54 K to 30 °C) O2 to Ga

33050C Capsule SPRT (54 K to 157 °C) O2 to In 33060C Capsule SPRT (54 K to 232 °C) O2 to Sn 33065S Capsule SPRT (83 K to 0.01 °C) Ar to TPW

33070C Capsule SPRT (83 K to 30 °C) Ar to Ga

33080C Capsule SPRT (83 K to 157 °C) Ar to In 33090C Capsule SPRT (83 K to 232 °C) Ar to Sn 33100C Capsule SPRT (0 °C to 30 °C) TPW to Ga

33 1 IOC Capsule SPRT (0 °C to 1 57 °C) TPW to In 33 120c Capsule SPRT (0 °C to 232 °C) TPW to Sn

33 1 30C Capsule SPRT (234 K to 30 °C) Hg to Ga

33140C Rhodium-Iron or Germanium Resistance Thermometers (0.65 K to 24.6 K)

33141C Rhodium-Iron or Germanium Resistance Thermometers (0.65 K to 84 K)

33 1 50C Long Stem SPRT (83 K to 0.0 1 °C) Ar to TPW

33 160C Lx)ng Stem SPRT (83 K to 30 °C) Ar to Ga

33 1 70C Long Stem SPRT (83 K to 1 57 °C) Ar to In 33 180C Long Stem SPRT (83 K to 232 °C) Ar to Sn

33 190C Long Stem SPRT (83 K to 420 °C) Ar to Zn TPW = triple point of water

Test No. Items

33200C Long Stem SPRT (83 K to 661 °C) Ar to Al 332 IOC Long Stem SPRT (234 K to 30 °C) Hg to Ga

33220C Long Stem SPRT (234 K to 1 57 °C) Hg to In 33230C Long Stem SPRT (234 K to 232 °C) Hg to Sn 33240C Long Stem SPRT (234 K to 420 °C) Hg to Zn

33250C Long Stem SPRT (234 K to 66 1 °C) Hg to Al 33260C Long Stem SPRT (0 °C to 30 °C) TPW to Ga

33270C Long Stem SPRT (0 °C to 1 57 °C) TPW to In 33280C Long Stem SPRT (0 °C to 232 °C) TPW to Sn 33290C Long Stem SPRT (0 °C to 420 °C) TPW to Zn

33300C Long Stem SPRT (0 °C to 661 °C) TPW to Al 333 1 OC Long Stem SPRT (0 °C to 962 °C) TPW to Ag

33320C Additional Copy of Table from Results of 33010C-33310C at Time of Test 33330C Additional Copy of Table from Results of 33010C-33310C at a Later Date 33340C Minimum Charge for Unsuitable Thermometer

33350S Special Tests of Resistance Thermometers

33360S Special Tests of Thermometric Fixed-Point Devices 33370M Measurement Assurance Program for Temperature

83 K to 420 °C (Ar to Zn)

33380M Measurement Assurance Program for Temperature

83 K to 661 °C (Ar to Al)

Resistance Thermometers

(33010C-33310C)

NIST provides calibration services for standard platinum resistance thermometers (SPRTs) from 13.8 K to 1235 K. Both long-stem and capsule-type SPRTs

are calibrated, providing direct access to the International Temperature Scale of

1990 (ITS-90). There are eleven temperature subranges over which an SPRT may

be calibrated according to the ITS-90

definitions. From 13.8 K to 83.8 K,

SPRT calibrations are performed by

comparison with a set of NIST reference thermometers. From 83.8 K to 962 °C,

calibrations are performed using the ITS-90 defining fixed points as described

in NIST Technical Note 1265. Expanded

uncertainties*, as described in NISTIR

5319, for SPRT calibrations are given

in Table 6.3. The comparison calibration of rhodium-iron resistance thermometers

(RIRTs) in the temperature range from

*See Chapter 1, Section H for more information about uncertainty.

69
33010C-33380M

0.65 K to 26 K, using the NIST-maintained ITS-90, is based on a set of refer- ence capsule-type RIRTs. The expanded

uncertainty of those calibrations is given

in Table 6.4. Extended range RIRT

calibrations, for temperatures greater than

26 K and up to 83.8 K, are accomplished

by comparison with reference capsule

SPRTs in the range 26 K to 83.8 K.

Table 6.3. Maximum Expanded Uncertainties

of SPRTs at NIST

Maximum

Temperature Subrange Expanded Uncertainty*

(K) (mK)

13.8033 to 273.16 0.54" 24.5561 to 273.16 0.40" 54.3584 to 273.16 0.29" 83.8058 to 273.16 0.39 234.3156 to 302.9146 0.20 273.15 to 302.9146 0.04 273.15 to 429.7485 0.32 273.15 to 505.078 0.37 273.15 to 692.677 0.54 273.15 to 933.473 0.68 273.15 to 1234.93 1.1

^ The uncertainty used at the Ar, Hg, and H2O triple points

are based on the fixed-point realization. *See Chapter 1, Section H for more information about uncertainty.

Table 6.4. NIST Expanded Uncertainties for Comparison Measurements of RIRTs

Range Expanded Uncertainty*

(K) (mK)

0.65 to 2.0 0.5 2.0 to 5.0 0.08

5.0 to 8.8 0.17

8.8 to 13.8 0.21

13.8 to 17.0 0.34

17.0 to 20.3 0.18

20.3 to 24.5561 0.24

24.5561 to 54.3584 0.27 54.3584 to 83.8058 0.22

*See Chapter 1, Section H for more information about uncertainty.

To qualify for testing, either long-stem

or capsule SPRTs must meet two conditions. They must meet the ITS-90

criteria** of W(Hg) < 0.844 235 or W(Ga) > 1.1 18 07, and for use above

660 °C the criterion of W(Ag) > 4.284 4. Second, they must be compatible with

the NIST calibration equipment. It is important that, insofar as possible, resis- tance thermometers be protected from

any mechanical shock that could alter their calibration. For shipment, the ther- mometer should be softly supported

within a case but not be free to rattle. This necessitates the use of packing

material that does not become compacted. The thermometer case should be

softly packed inside a shipping container. The shipping container must be suffi- ciently rigid and strong that it will not appreciably deform under the treatment

usually given by common carriers. Styrofoam is not sufficiently rigid to be used

as an outside container. Similarly, mailing tubes are unacceptable. Thermometers will not be returned in containers

that are obviously unsuitable, such as those closed by nailing. Suitable containers will be provided when a thermometer

shipping container is not satisfactory for

re-use.

Special Tests of Resistance Thermometers and Special Tests of Thermometric Fixed-Point Devices (3.3350S and

333608)

Special tests (e.g., certification, prototype

testing) of various resistance thermometers and thermometric fixed-point

devices may be made by prior arrange- ment with the specified technical contacts. Fixed-point cells may be sent to NIST for certification by the method of

direct comparison with the applicable

NIST laboratory standard fixed-point

cell.

**See 1990 publication "The International Temperature Scale of 1990 (ITS-90)" reference at end of

the section.

70
33010C-33380M

Measurement Assurance Program for Temperature (33370M and 33380M)

The purpose of this Measurement

Assurance Program (MAP) is to assure

the accuracy of the calibration of temperature standards (83 K to either 420 °C

or 661 °C) conducted by participating

laboratories when using platinum resis- tance thermometry. Other temperature

ranges are available upon request.

The MAP transport standard consists of sets of three commercial SPRTs

packaged in a special shock-proof

shipping container (mechanical shock

may shift calibration values). These

SPRTs are used to assess both the reproducibility and the uncertainty of cali- brations performed by the participating

laboratory.

MAP participants should use the techniques described in NIST Technical Note 1265 and ITS-90 fixed-point

cells, or use an SPRT previously

calibrated by NIST. In order to achieve

high accuracy, SPRTs used as standards should be either metal sheathed

or of the matte-finish glass-sheathed

type to avoid systematic errors arising

from light-pipe effects in the glass

sheath. The participant must have a triple

point of water cell and an appropriate

resistance bridge.

NIST provides worksheets on which

the participant records data. The participant calculates the thermometer constants from experimental data, records them, and prepares tables of either

resistance ratio or resistance versus temperature. These completed worksheets

and the participant's calibration reports

are sent to NIST with the return of the MAP SPRTs.

The SPRTs are recalibrated upon

return to NIST and the participant's data

are compared with NIST's calibration

results. NIST provides a plot of the

participating laboratory's temperature

deviation from NIST values and a written

analysis of the data, including any

pertinent observations. In a typical MAP

transfer, the participant makes measurements over a period of 1 to 2 months.

A typical turnaround time from the

date NIST receives the participant's data

until a test report is sent to the participant is 4 to 6 weeks. Former participants

in the MAP have had expanded uncertainties* that ranged from about 1 mK

to several tens of millikelvins. No rigid recommendations can be

given concerning how often a participant

should utilize the temperature MAP

service. Experience has indicated that when temperature measurements are in a

state of statistical control, as evidenced

by in-house check standards and control charts used to monitor the measurement

process, the participant should be able to go at least 3 years between transfers from

NIST without significantly degrading the confidence in the correctness of the measurements. Among other NIST Services for Temperature Calibration Laboratories,

NIST provides Standard Reference

Materials for use as defining fixed points

of the ITS-90 and as secondary reference

points.**

References—Resistance Thermometry

Assessment of Uncertainties of Calibration of Resistance Thermometers at the National Institute of Standards and

Technology, G. F. Strouse and W. L. Tew, Natl. Inst. Stand. Technol. NISTIR 5319, 16 (1994).

NIST Measurement Assurance of SPRT

Calibrations on the ITS-90: A Quantitative Approach, Session 1-D, G. F. Strouse and B. W. Mangum, Proc. Meas. Sci. Conf., Anaheim, CA (Jan. 1993).

NIST Implementation and Realization of

the ITS-90 Over the Range 83 K to 1235 K. Reproducibility, Stability, and

Uncertainties, G. F. Strouse, Temperature. Its Measurement and Control in Science and Industry, J. F. Schooley,

Ed., 6, 169-174, Amer. Inst. Phys.,

New York, NY (1992).

*See Chapter 1. Section H for more information about uncertainty. ** See Chapter 1, Section C for information on the Standard Reference Materials Program.

71
Realization of the ITS-90 Below 83.8 K

at the National Institute of Standards

and Technology, E. R. Pfeiffer, Temperature. Its Measurement and Control in Science and Industry, J. F. Schooley, Ed., 6, 155-160, Amer.

Inst. Phys., New York, NY (1992).

The International Temperature Scale of

1990 (ITS-90), H. Preston-Thomas,

Metrologia 27, 310 (1990); Metrologia 27, 107(1990).

NBS Measurement Services: Platinum

Resistance Thermometer Calibrations, B. W. Mangum, Natl. Bur. Stand.

(U.S.), Spec. Publ. 250-22 (1988).

Reproducibility of Some Triple Point of Water Cells, G. T. Furukawa and

W. R. Bigge, Temperature, Its Measurement and Control in Science

and Industry 5, 291, Arr er. Inst. Phys., New York, NY (1982).

Standard Reference Materials: Application of Some Metal SRM's as Thermometric Fixed Points, G. T. Furukawa, J. L. Riddle, W. R.

Bigge, and E. R. Pfeiffer, Natl. Bur.

Stand. (U.S.), Spec. Publ. 260-77

(Aug. 1982).

A Measurement Assurance Program—

Thermometer Calibration, G. T. Furukawa and W. R. Bigge, in Natl. Conference on Testing Laboratory

Performance, Evaluation, and

Accreditation, Natl. Bur. Stand. (U.S.),

Spec. Publ. 591, 137 (Aug. 1980).

Determination of the Triple-Point

Temperatures of Gallium, B. W.

Mangum and D. D. Thornton,

Metrologia 15, 201-215 (1979).

Platinum Resistance Thermometry, J. L. Riddle, G. T. Furukawa, and H. H. Plumb, Natl. Bur. Stand. (U.S.),

Monogr. 126 (Apr. 1973).

72
35010C-35070S

Radiance Temperature Measurements

Technical Contact:

Charles E. Gibson

Ttl: 301/975-2329

Fax: 301/869-5700

Email: cgibson@nist.gov

Mailing Address: Building 221, Room B208,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items

Calibration reports are issued giving the radiance temperature of the blackbody at 655.3 nm versus

the scale reading, output current, or output voltage.

350 IOC Radiance Temperature Standard, Disappearing Filament Optica! Pyrometer (800 °C to 2400 °C, 4 to 1 2 points, 1 range)

35020C Radiance Temperature Standard, Disappearing Filament Optical Pyrometer (each additional range up to 4200 °C, only available with 350 IOC)

35030C Additional Interpolated Values 35040C Radiance Temperature Standard, Disappearing Filament Optical Pyrometer (800 °C to 4200 °C, 3 or fewer points, 1 range)

Calibration reports are issued giving the radiance temperature of the lamp at 655.3 nm versus the lamp current.

35050C Radiance Temperature Standard, Ribbon Filament Lamp

(800 °C to 2300 °C, 6 to 16 points)

35060C Radiance Temperature Standard, Ribbon Filament Lamp

(800 °C to 2300 °C, 5 or fewer points)

Test reports are issued giving the radiance temperature

of the blackbody at 655.3 nm, 900 nm, or 1000 nm versus

the indicator reading, output current, or output voltage.

35070S Special Tests of Radiation Thermometers

Standard Temperature Range

(°C)

Expanded

Uncertainty*

(°C) Ribbon filament lamp 800 to 1600 0.7 1600 to 1900 1.0 1900 to 2300 1.5

Leeds & Northrup 800 to 1600 4

Model ouuu series 1 600 to 2 1 00 5 1900 to 2300 7

Disappearing filament 2400 to 2700 8

optical pyrometer 2700 to 3200 17 3200 to 4200 25

Pyrometer Instrument 800 to 1400 3

Model 95 1400 to 1800 4

Disappearing filament 1800 to 2400 5

optical pyrometer 2400 to 2700 8 2700 to 3200 12

Infrared radiation 800 to 2000 2

thermometer 2000 to 2700 3

* See Chapter 1, Section H for more information about uncertainty.

This laboratory's quality system is based on the ANSI/NCSL Z540-1-

1994 standard and the ISO/EEC Guide

25.

Disappearing Filament Optical

Pyrometers and Ribbon Filament

Lamps (35010C-35060C)

These calibration services provide

access to the International Temperature

Scale of 1990 (ITS-90) as realized by

NIST for the temperature range 800 °C to 4200 °C. NIST disseminates the radi- ance temperature scale by issuing ribbon

filament lamp standards of radiance

temperature and by calibrating customer

supplied pyrometers and radiation thermometers.

High-accuracy monochromatic dis- appearing filament optical pyrometers

are calibrated in the full temperature

range. Calibration reports are issued

giving the radiance temperature of the NIST blackbody versus the test pyrometer scale reading, output current, or output voltage.

73
Ribbon filament lamps are calibrated us- ing the NIST photoelectric pyrometer.

Calibration reports are issued giving the radiance temperature of the test lamp

at 655.3 nm versus direct current for the temperature range 800 °C to 2300 °C. The radiation thermometry portion of

ITS-90 is defined in terms of the fixed

temperature of the freezing point of gold

(1064.18 °C) and the Planck equation

for the radiation of a blackbody source.

In practice, the temperature scale is realized by constructing a gold-point

blackbody and a variable temperature

blackbody, and then measuring the

spectral radiance ratio at a red wavelength (approximately 650 nm) in terms

of the Planck equation. Gold-point

blackbodies are reproducible to 0.02 °C, but the temperature assignment of the freezing point of gold is uncertain by

about 0.23 °C. The spectral radiance

ratio measurements can be performed

with a relative expanded uncertainty*

of 0.2 % to 0.3 %. Smaller uncertainties than available in the routine services described above can be provided as

special tests subject to the ITS-90

uncertainties noted. Calibrations at wavelengths other than 655.3 nm can be provided in the wavelength range 250 nm to 2500 nm subject to an additional uncertainty due to the quality of

the variable temperature blackbody.

Special Tests of Radiation

Thermometers (35070S)

Infrared thermometers are calibrated at 655.3 nm, 900 nm, and 1000 nm as special tests. Absorbing glass filters used

for range changing in disappearing

filament optical pyrometers can also be

calibrated as special tests.

Calibration Schedule

Radiance temperature calibrations are performed in February, May, August,

and November. Requests for calibration services are scheduled after the receipt

of a purchase order.

* See Chapter 1, Section H for more information about uncertainty.

References—Radiation

Thermometry

International Comparison of Radiation

Temperature Scales Among Five

National Metrological Laboratories

Using a Transfer Standard Radiation

Thermometer, B. C. Johnson,

F. Sakuma, H. Sakate, C. Gibson, G. Machin, T. Ricolfi, M. Battuello,

J. Fischer, and H. J. Jung, Metrologia

33, 241 (1996).

Intercomparison of the ITS-90 Radiance

Temperature Scales of the National

Physical Laboratory (U.K.) and the National Institute of Standards and

Technology, B.C. Johnson, C. Gibson, G. Machin, and R. L. Rusby, J. Res.

Natl. Inst. Stand. Technol. 99, 731

(1994).

The New International Temperature Scale of 1 990 and its Effect on Radiometric, Photometric, and Colorimetric

Measurements and Standards, K. D.

Mielenz, R. D. Saunders, A. C. Parr, and J. J. Hsia, CIE Proc. 22nd Session Melbourne 1991 no. 91 (1991).

Temperature, Its Measurement and

Control in Science and Industry, J. F. Schooley, Ed., 6, Part 1, Amer. Inst. Phys., New York, NY (1992).

Temperature, Its Measurement and

Control in Science and Industry, J. F. Schooley, Ed., 6, Part 2, Amer. Inst. Phys. New York, NY (1992).

The International Temperature Scale of

1990, H. Preston-Thomas, Metrologia

27(3), (1990).

The 1990 NIST Scales of Thermal

Radiometry, K. D. Mielenz, R. D.

Saunders, A. C. Parr, and J. J. Hsia,

J. Res. Natl. Inst. Stand. Technol.

95, 621 (1990).

Spectroradiometric Determination of

the Freezing Temperature of Gold, K. D. Mielenz, R. D., Saunders, and

J. B. Shumaker, J. Res. Natl. Inst. Stand. Technol. 95, 49 (1990).

Temperature, T. J. Quinn, Academic

Press, San Diego, CA (1990).

Theory and Practice of Radiation

Thermometry, D. P. Dewitt and

G. D. Nutter, eds., John Wiley and

Sons, New York, NY (1988).

74
35010C-35070S

NBS Measurement Services: Radiance

Temperature Calibrations, W. R.

Waters, J. H. Walker, and A. T. Hattenburg, Natl. Bur. Stand. (U.S.),

Spec. Publ. 250-7 (Oct. 1987).

Applications of Radiation Thermometry, J. C. Richmond and D. R Dewitt,

eds., (American Society for Testing

and Materials, Philadelphia, 1985).

The International Practical Temperature Scale of 1968, Amended Edition

of 1975, Metrologia 12 (7) (1976).

Temperature, Its Measurement and

Control in Science and Industry, 4, Part 1, Instrument Society of America,

Pittsburgh, PA (1972).

Corrections in Optical Pyrometry and

Photometry for the Refractive Index

of Air, W. R. Blevin, Metrologia 8

(146) (1972).

Vacuum Tungsten Strip Lamps with

Improved Stability as Radiance

Temperature Standards, in Temperature: Its Measurement and Control

in Science and Industry, T. J. Quinn

and R. D. Lee, 4, Part 1, 395,

Instrument Society of America,

Pittsburgh, PA (1972).

Intercomparison of the IPTS 68 Above

1064 °C by Four National Laboratories, in Temperature: Its Measurement

and Control in Science and Industry, R. D. Lee, H. J. Kostlowski, T. J. Quinn, P. R. Chandler, T. N. Jones,

J. Tapping, and H. Kunz, 4, Part 1, 377, Instrument Society of America,

Pittsburgh, PA (1972).

High-Accuracy Spectral Radiance Calibration of Tungsten-Strip Lamps, H.

J. Kostkowski, D. E. Erminy, and A.

E. Hattenburg, Adv. Geophys. 14

(111) (1970).

The NBS Photoelectric Pyrometer and Its Use in Realizing the International

Practical Temperature Scale Above

1064 °C, R. D. Lee, Metrologia 2 (4), 150 (Oct. 1966).

Theory and Methods of Optical

Pyrometry, H. J. Kostkowski and

R. D. Lee, Natl. Bur. of Stand.

(U.S.), Monograph 41 (Mar. 1962).

Temperature, Its Measurement and

Control in Science and Industry,

3, Part 1 , Instrument Society of

America, Pittsburgh, PA (1962).

75
36010C-36070S

Humidity Measurements

Technical Contacts:

Peter H. Huang Joseph T. Hodges Gregory E. Scace

Tel: 301/975-2621, or 2626 Ttl: 301/975-2605 Ttl: 301/975-2626

Email: phuang@ni$t.gov Email: jo$eph.hodges@ Email: gregory.scace@

nisLgov nistgov

Mailing Address: Building 221, Room B128,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

1-270 at Quince Orchard Road,

B349 Physics,

Gaithersburg, MD 20899-0001

Service ID No. Items 360 IOC Dew-Point Hygrometers {+25 °C to -15°C)

36020C Dew-Point Hygrometers (-70 °C to -15°C)

36030C Electric Hygrometers

36040C Electrolytic Hygrometers

36050C Aspirated Hygrometers

36060C Pneumatic Bridge Hygrometers

36070S Special Tests of Humidity

Hygrometers (36010C-36060C)

NIST provides calibration services for a wide variety of humidity-measuring in- struments. Calibrations are performed by

subjecting the instrument under test to atmospheres of known moisture content produced by the NIST two-pressure

humidity generator. The instruments and

ranges of calibration are listed below: A. Dew-Point Hygrometers cali- brated over the dew/frost range of

-70 °C to + 60 °C. B. Electric Hygrometers classified under this category are sensors which

sorb water vapor as a function of relative humidity; associated with this sorption is a corresponding change in an electric parameter (that is, resistance, capacitance). The range of calibration is 3 % to 98 % relative humidity over the temperature range -55 °C to -i- 40 °C.

C. Psychrometers are wet-dry bulb

hygrometers (aspirated psychrometers).

The contact person should be consulted

for the special features of the psychrometer which are necessary in order that the instrument can be calibrated at NIST. D. Electrolytic Hygrometers are devices which electrolyze water into gaseous oxygen and hydrogen by the application of a voltage in excess of the thermodynamic decomposition voltage

for water, and then measure the electrolysis current. The range of calibration in volume ratio is 10"* to 3 X 10"l

E. Pneumatic Bridge Hygrometers

are instruments that measure the variation of the pressure drop across two combinations of nozzles, operating at critical flow, with a desiccant between one pair

of nozzles. The range of calibration in mixing ratio (grams of water vapor/grams

of dry air) is 0.0005 to 0.015. Table 6.5 illustrates typical NIST

uncertainties for measurement of humidity standards with atmospheric air at atmospheric pressures.

Special Tests of Humidity (36070S)

Tests for response time, hysteresis, and

stability can be provided upon request.

Table 6.5. NIST Two-Pressure Humidity Generator,

Mark 2, Range and Uncertainty

Humidity Range Expanded

Parameter Uncertainty*

Mixing ratio, rw 0.0015 < r„ < 0.005 1 .5 % of value

(g water vapor/ 0.005 < rw<0.1 1.0 % of value kg dry air) 0.1 < rw < 0.3 0.5 % of value

0.3 < rw< 515 0.3 % of value Volume ratio. 3 < V< 10 1.5 % of value V(X 10"*) 10 < V< 170 1.0 % of value 170 < V<500 0.5 % of value 500 < V < 820 000 0.3 % of value Dew point tem- -70 < Td < -35 0.1 °C

perature, Td (°C) -35 < Td< + 40 0.04°C

Relative humidity, -55 < Tc<-40 3-98 1.5 %

RH (%) at test -40 < Tc < -20 3-98 0.8 %

chamber temperature, -20 < Tc<0 3-98 0.2 %

Tc (°C) of: 0 < Tc<-h40 3-98 0.2 %

* See Chapter 1, Section H for more information about uncertainty.

76
360 IOC:-36070S

References—Humidity Measurements

Thermodynamic Properties of Moist Air

Containing 1000 to 5000 PPMv of Water Vapor, R H. Huang, NISTIR

5241,43-51 (Apr. 1993).

NIST Calibration Services for Humidity

Measurement, R H. Huang, NISTIR

4677-A (Superseding NISTIR 4677,

Oct. 1991).

National Basis of Accuracy in Humidity

Measurements, S. Hasegawa, ISA

Trans. 25 (3), 15-24, 1986. The NBS Two-Pressure Humidity Generator, Mark 2, S. Hasegawa and J. W.

Little, J. Res. Nat. Bur. Stand. (U.S.),

81A (1), 81-88 (Jan.-Feb. 1977).

Vapor Pressure Formulation for Ice, A.

Wexler, J. Res. Nat. Bur. Stand. (U.S.),

81A (1), 5-20 (Jan.-Feb. 1977).

Vapor Pressure Formulation for Water in Range 0 °C to 100 °C. A Revision, A.

Wexler, J. Res. Nat. Bur. Stand. (U.S.),

80A (5 and 6), 775-785 (Sept.-Dec.

1976).

Functional Equations for the Enhancement Factors for C02-Free Moist Air, L. Greenspan, J. Res. Nat. Bur. Stand.

(U.S.), 80A (1), 41-44 (Jan.-Feb.

1976).

The NBS Standard Hygrometer, A. Wexler and D. W. Hyland, NBS

Monograph 73, (May 1964).

77
Chapter

A Photometric Measurements

B Optical Properties of Materials Measurements

C Spectroradiometric Measurements

D Radiometric Standards in the Far Ultraviolet E Lasers and Optoelectronic Components Used with Lasers
Optical Radiation Measurements 37010C-37110S

A

Photometric Measurements*

Technical Contacts:

Yoshi Ohno

Tel: 301/975-2321 Email: ohno@nist.gov

Magdalena Navarro

Tel: 301/975-2130

Email: mnavarro@nist.gov

Fax: 301/840-8551

Mailing Address: Building 220, Room A320,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 37010C Luminous Intensity and Color Temperature Standard Lamps

37020S Special Tests for Luminous Intensity and Color Temperature of Submitted Lamps

37030C Color Temperature Standard Lamps

37040C Each Additional Color Temperature for 37030C

37050S Special Tests for Color Temperature of Submitted Lamps

37060S Special Tests for Total Luminous Flux of Submitted

Incandescent Lamps and Fluorescent Lamps

37070C Opal Glass Luminance Coefficient Standards 37080S Special Tests for Submitted Luminance Sources and

Transmitting Diffusers 37090S Special Tests for Photometers, Illuminance Meters, and Luminance Meters 37100S Special Photometric Tests 371 lOS Special Tests for Submitted Flashing-Light Photometers

General Information

Calibration services in this area provide

access to the photometric scales that are realized and maintained at NIST.

Lamp standards of luminous intensity,

luminous flux, and color temperature, as well as reference photometers and materials as described below, are issued or

calibrated on a routine basis. This laboratory's quality system is based on the ANSI/NCSL Z540-1-

1994 standard and the ISO/IEC Guide

25.

*See Chapter 1. Section C for information on spec- trophotometry standards available from the Standard Reference Materials Program.

Luminous Intensity and Color Temperature Standard Lamps (37010C)

NIST will issue to the customer 1000 W

modified PEL (free electron laser) quartz

halogen lamps calibrated for luminous in- tensity (candela) and color temperature

(kelvin). These lamps have a double coil filament and a clear bulb, and are potted on a medium bipost base. The lamps are operated at approximately 7 A/85 V dc,

at a color temperature of 2856 K. The

relative expanded uncertainty** of the luminous intensity of these lamps is 0.6 % and the expanded uncertainty of

the color temperature is 8 K at 2856 K.

Special Tests for Luminous Intensity

and Color Temperature of Submitted

Lamps (37020S)

NIST will calibrate the luminous intensity and color temperature of incandescent lamps with a medium bipost base

submitted by customers. The inside

frosted lamps, the airway beacon lamps,

and the 1000 W PEL lamps previously

issued by NIST can be submitted for

recalibration. Customers can specify

either the lamp current or the color temperature of the lamp (normally

2856 K) for calibration. The uncertainty

of calibration is described above.

Color Temperature Standard Lamps

(37030C)

NIST will issue to the customer 1000 W

modified FEL quartz halogen lamps as described in 37010C calibrated for color temperature. The lamps are usually cali- brated for a color temperature of 2856 K. The expanded uncertainty** of the color temperature of these lamps is 8 K at 2856 K.

Each Additional Color Temperature

for 37030C (37040C)

The color temperature standard lamps

issued for 37030C can be calibrated for additional color temperature points in a

**See Chapter 1, Section H for more information about uncertainty.

79
range from 2000 K to 3200 K. The ex- panded uncertainty* of this calibration

is 4 K to 1 1 K in the range from 2000 K

to 3200 K.

Special Tests for Color Temperature

of Submitted Lamps (37050S)

NIST will calibrate the color temperature of incandescent lamps with a medium bipost base submitted by

customers. The inside frosted lamps, the airway beacon lamps, and the 1000 W

FEL lamps previously issued by NIST

can be submitted for recalibration.

Special Tests for Total Luminous

Flux of Submitted Incandescent

Lamps and Fluorescent Lamps

(37060S)

NIST will calibrate the total luminous

flux (lumen) of incandescent lamps and

fluorescent lamps submitted by

customers. The standard lamps previously

issued by NIST can be submitted for

recalibration. Miniature lamps may also be accepted. Customers should contact NIST before submitting lamps. The

relative expanded uncertainty* of this calibration is typically 1 .0 % for incandescent lamps and 2.0 % for fluorescent lamps, depending upon the reproducibility of test lamps.

Opal Glass Luminance Coefficient

Standards (37070C)

NIST will issue flashed opal glass plates, 5 1 mm X 5 1 mm, calibrated for lumi- nance coefficient (ratio of luminance/

illuminance, unit: sr"') for International Commission on Illumination (CIE)

Illuminant A (2856 K source). The

glass plates, masked with a circular aperture 25 mm in diameter, are cali- brated for the luminance within a

circular area of 1 cm in diameter in the center of the aperture. The relative expanded uncertainty* of this calibration is 0.8 %.

*See Chapter 1, Section H for more information about uncertainty.

Special Tests for Submitted Luminance Sources and Transmitting

Diffusers (37080S)

NIST will calibrate luminance (cd/m^) of

submitted sources or the luminance

coefficient (sr ') of submitted transmitting diffusers, including opal glass

previously issued by NIST. Customers

should contact NIST before sending

sources or diffusers. The relative expanded uncertainty* of luminance

calibration is 0.8 %.

Special Tests for Submitted Photometers, Illuminance Meters, and

Luminance Meters (37090S)

NIST will calibrate photometers, illumi- nance meters, and luminance meters

submitted by customers. Calibration is usually made with the CIE Illuminant

A (2856 K incandescent source) in a range of 0. 1 Ix to 3000 Ix for illumi- nance and 0.1 cd/m^ to 4000 cd/m^ for luminance. The relative expanded

uncertainty* of calibration is 0.5 % for illuminance and 0.7 % for luminance

at normal levels, which will increase at low levels. As an option, NIST can measure the relative spectral responsivity

of submitted instruments and calculate

spectral mismatch correction factors

for a source of known spectral power

distribution. Illuminance calibrations

at a level up to 1(X) klx can also be

made under a special arrangement.

Special Photometric Tests (37100S)

NIST can provide special tests for sources, detectors, and photometric

instruments other than those stated above under limited conditions by special arrangements with NIST. Customers

should contact NIST for consultation.

Special Tests for Submitted Flashing-Light Photometers (371 lOS)

NIST will calibrate submitted flashinglight photometers to measure inte- grated illuminance [Ix • s] or effective

intensity [cd]. Calibration is normally

* See Chapter 1 , Section H for more information about uncertainty.

80
37010C-37110S

performed with white light (== 6500 K)

from a xenon strobe light in the range of

1 Ix • s to 100 Ix • s and with red light

using an Aviation Red filter. The relative expanded uncertainty* of calibration is ~ 1 % or larger depending on the perfor- mance of the instrument under test.

References— Photometric Measurements

NIST Measurement Services: Photometric Calibrations, Y. Ohno, Natl. Inst. Stand. Technol. Spec. Publ. 250-37

(1997).

Improved Photometric Standards and

Calibration Procedures at NIST,

Y. Ohno, J. Res. Natl. Inst. Stand. Technol. 102 (3), 323-331 (1997).

The Detector-based Candela Scale

and Related Photometric Calibration

Procedures at NIST, Y. Ohno,

C. L. Cromer, J. E. Hardis, and

G. Eppeldauer, J. lES 23 (1), 89-98 (1994).

National Institute of Standards and

Technology Detector-based Photometric Scale, C. L. Cromer,

G. Eppeldauer, J. E. Hardis, T. C.

Larason, and A. C. Parr, Applied

Optics 32 (16), 2936-2948 (1993).

* See Chapter 1 , Section H for more information

about uncertainty.

81
38010C-38080M

e Optical Properties of Materials

Measurements*

Technical Contacts:

p. Yvonne Barnes 38010C-38060S

TO: 301/975-2345 Email: yvonne.barnes@nistgov

Fax: 3017840-8551

Edward A. Early 38070M-38080M

Tel.: 301/975-2343

Email: edward.early@nist.gov

Mailing Address: Building 220, Room A320,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 38010C Spectral Transmittance Filters (Cobalt Blue Glass)

38020C Spectral Transmittance Filters (Copper Green Glass)

38030C Spectral Transmittance Filters (Carbon Yellow Glass)

3804OC Spectral Transmittance Filters (Selenium Orange

Glass)

38050C Wavelength Standards (Holmium Oxide Glass)

38060S Special Tests of Spectral Transmittance or Spectral Reflectance (Directional-Hemispherical or Bidirectional Geometry) and Appearance

38070M Measurement Assurance Program for Retroreflectance—Complete Package

3807 IM Retroreflectance MAP—Sheeting Standards or Prismatic Standard with Colored Filters 38072M Retroreflectance MAP—Sheeting Standards and

Prismatic Standard without Colored Filters 38073M Retroreflectance MAP—Sheeting Standards or

Prismatic Standard without Colored Filters 38074M Retroreflectance MAP—Colored Filters Only

38080M Measurement Assurance Program for Transmittance

This laboratory's quality system is based on the ANSI/NCSL Z540-1-

1994 standard and the ISO/IEC Guide

25.

Spectral Transmittance Filters (38010C-38040C)

NIST supplies to the customer stan- dards of spectral transmittance for checking the photometric scale of

spectrophotometers. These are either 30 mm polished glass disks or 51 mm

*See Chapter 1 , Section C for information on

spectral reflectance standard artifacts available through the Standard Reference Materials Program.

polished glass squares, 2 to 3 mm thick,

designated as cobalt blue, copper green, carbon yellow, and selenium orange. The

relative expanded uncertainty** ranges from approximately 0.2 % to 0.3 % of

the value. Information provided to the user includes values of transmittance at 25 °C at 10 nm intervals from 380 nm to 770 nm, the estimated uncertainty of

each value, and data as to the effect of

temperature change on transmittance at each wavelength.

Wavelength Standards (38050C)

NIST supplies to the customer holmium

oxide glass standards for checking the

ultraviolet and visible wavelength calibrations of recording spectrophotometers

having a bandpass less than 2 nm. These

are made of polished Corning 3130 glass, 51 mm X 51 mm, or cuvette size

[11 mm X 15 mm], approximately

2.5 mm thick. A table of wavelengths of

minimum transmittance is provided in the report to the user. The expanded uncertainty** is 0.2 nm.

Special Tests of Spectral Transmittance or Spectral Reflectance (38060S)

Measurements of spectral transmittance can be made for the wavelength region

190 nm to 2500 nm. Measurements of

absolute spectral reflectance factors (using either bidirectional or directional- hemispherical geometry) and of spectral

specular reflectance (using bidirectional geometry) can be made for the wavelength region 250 nm to 2500 nm. Color

and appearance attributes of materials

are provided using bidirectional or direc- tional-hemispherical geometry over the

visible spectral region and can be ex- tended depending on available instrumentation. However, arrangements for these measurements on submitted specimens must be made before shipment. The decision as to whether or not to perform the measurements and selection of the instru- ments to be used will rest with NIST.

Specimens not accepted for measurement

will be returned. Uncertainty estimates

** See Chapter 1, Section H for more information about uncertainty.

82
38010C-38080M

will be given and will depend on the optical characteristics of the submitted

specimens and whether a primary or

transfer instrument is used to perform the measurement.

Measurement Assurance Programs for Retroreflectance (38070M-38074M)

These Measurement Assurance Programs

(MAPs) verify, within certain limits, how

well a laboratory can measure the coefficient of luminous intensity. The verification is accomplished by means of a MAP

package. The MAP package contains two

white bead sheeting retroreflectors, one

colorless prismatic retroreflector, and

seven colored glass filters. The elements

in this package are measured by NIST,

then by the participating laboratory, and

finally by NIST. Quality control proce- dures are maintained by using NIST

master standards. The use of three retroreflectors enables

the determination of how well the participant can measure coefficient of lumi- nous intensity for white or colorless samples of three kinds of geometries.

The luminous transmittance of the seven colored glass filters can be used as a di- agnostic tool to check measurements of

coefficient of luminous intensity of col- ored retroreflectors. This is accomplished

by checking the conformance of the source-receiver combination to CIE

Illuminant A and CIE 2° standard observer respectively.

The coefficient of luminous intensity

of each of the bead sheeting standards is measured at six combinations of observation and entrance angles. The coefficient of luminous intensity of the prismatic

retroreflector is measured at 1 8 combinations of entrance and observation angles.

The luminous transmittance of the filters

is provided only for the spectral conditions of source and receiver specified above. A general testing laboratory will probably need the service that utilizes the complete MAP package. However, some

laboratories may be specialized. For this reason, we list five options that offer not only the complete package, but also some selected components. These options

are:

A. Complete MAP package;

B. Sheeting standards or prismatic standard with colored filters; C. Sheeting standards or prismatic standard without colored filters; D. Sheeting standards and prismatic standard without colored filters; and

E. Colored filters only.

Even measurement of the complete

MAP package achieves only part of the goal of a MAP service. To fully benefit from the MAP procedure, we suggest

that the participant have on hand several check standards to be measured while

also measuring the MAP package. These

check standards can then be measured

periodically to determine any gross error

in measurement procedure, and a control chart can be constructed. A control chart

is a plot of measurement result versus time, and the measurement process is normally considered to be under control

if measurements fall within ± 2 standard

deviations of the mean. For retroreflec- tance measurements where geometric

errors are large, the standard deviation obtained after changing geometrical

parameters may be large compared with

that obtained from repeated measure- ments without changing the apparatus.

Thus, the total variation for a given

instrument can be obtained only by repetition over a period of time and realignment of the experimental apparatus.

The uncertainties of retroreflectometer measurements have three sources: uncertainties associated with values assigned

by NIST to the MAP package, participant uncertainties, and uncertainties due

to environment and sample interaction. Repeated measurements without changing the apparatus show that the NIST

random error is small relative to the sys- tematic errors. A large fraction of the lat- ter arise when the retroreflector is rearranged and realigned for making

measurements with different measure- ment parameters. The NIST relative expanded uncertainty* for retroreflec- tance measurement ranges from 2.7 % to

1 0 % of the value depending on the

*See Chapter 1, Section H for more information about uncertainty.

83
geometry and the type of retroreflectors. The NIST expanded uncertainty for luminous transmittance of the colored

glass filters varies up to 0.002.

Measurement Assurance Program

for TVansmittance (38080M)

The Transmittance Measurement Assurance Program (MAP) provides a means for a laboratory to assess the uncertainty of its spectral transmittance

measurement capabilities. A laboratory

that participates in this program will be

sent a package of transmittance filters that have been measured at NIST. These

are to be measured by the laboratory on its spectrophotometer(s) and returned,

together with the measurement results, to NIST. NIST will then remeasure the

filters and send a final analysis of the

results to the participating laboratory.

The range of filter measurements pro- vided in the MAP package permits an

evaluation of the uncertainty of a laboratory's spectral transmission measure- ments and will often reveal the cause of any systematic errors that exist. The

NIST expanded uncertainty* ranges from approximately 0.03 % to 0.3 % of

the value for filters with nominal

transmittance from 0.92 to 0.001. The MAP package includes seven

neutral density filters with nominal

transmittances ranging from 0.92 to 0.001. The filters are available in three sizes. The filter holders are 51 mm X 51 mm, 51 mm X 38 mm, or

standard cuvette. In addition, the package contains one didymium glass filter or cuvette-sized holmium oxide solution that is to be used for wavelength

scale calibration. Several wavelengths

of transmittance minima and points of

inflection have been measured by

NIST for the didymium filter. These

wavelengths have been shown to be

stable over long periods of time; therefore, these didymium filters are not normally measured by NIST with every use of the MAP package. The

didymium filter is useful for triangular

*See Chapter 1 , Section H for more information about uncertainty.

bandpasses between 1.5 nm and 10.5 nm

with an expanded uncertainty* up to 0.2 nm. The holmium oxide solution has

been certified at several wavelengths for bandpasses up to 3.0 nm with an expanded uncertainty* of 0.1 nm. It

is strongly suggested that the participating laboratory acquire a set of check

standards similar to the NIST filters for maintaining a control chart and

measurement assurance.

References—Spectrophotometric

Measurements

NBS Measurement Services: Sp)ectral

Reflectance, P. Y. Barnes, E. A. Early,

and A. C. Parr, Natl. Inst. Stand. Technol. Spec. Publ. 250-8 (revised 1997).

NIST High Accuracy Reference Reflec- tometer-Spectrophotometer, J. E.

Proctor, P. Y. Barnes, J. Res. Natl.

Inst. Stand. Technol. 101 (5) 619

(1996).

45 Degrees/0 Degrees Reflectance Factors of Pressed Polytetrafluoroethylene

(PTFE) Powder, Natl. Inst. Technol.

Stand. Tech. Note 1413 (1995).

Compliance in Spectrometry: -Quality Assurance of Spectrophotometric

Measurements at NIST, J. J. Hsia,

T. C. Larason, P. Y. Barnes, Spectrophotometry, Luminescence and

Coulour; Science & Compl. (1995).

Comparison of Regular Transmittance

Scales of Four National Standardizing

Laboratories, K. L. Eckerle, J. Bastie,

J. Zwinkels, V. Saprintsky, and A.

Ulyanov, Color Res. Appl. 18 (1), 35-40 (Feb. 1993).

International Intercomparison of Regular

Transmittance Scales, K. L. Eckerle,

E. Sutter, G. H. C. Freeman,

G. Andor, and L. Fillinger, Metrologia

27, 33-38 (1990).

National Scales of Spectrometry in the U.S., J. J. Hsia, Advances in Standards

and Methodology in Spectrophotometry 1987, Elsevier Science Publishers, B. v., Amsterdam, 99-109 (1987).

NBS Measurement Services: Spectral

Reflectance, V. R. Weidner and J. J. Hsia, Natl. Bur. Stand. (U.S.), Spec.

Publ. 250-8 (July 1987).

84
38010C-38080M

NBS Measurement Services: Regular

Spectral Transmittance, K. L. Eckerle, J. J. Hsia, K. D. Mielenz,

and V. R. Weidner, Natl. Bur. Stand.

(U.S.), Spec. Publ. 250-6 (July 1987).

White Opal Glass Diffuse Spectral

Reflectance Standards for the Visible Spectrum (SRM's 2015 and 2016),

V. R. Weidner, Natl. Bur. Stand.

(U.S.), Spec. Publ. 260-82 (1983).

Extension of a Reference Spectrophoto- meter into the Near Infrared, K. L.

Eckerle, V. R. Weidner, J. J. Hsia, and

Z. W. Chao, Natl. Bur. Stand.

(U.S.), Tech. Note 1175 (Apr. 1983).

Measurement Assurance Program —

Transmittance Standards for Spectrophotometric Linearity Testing:

Preparation and Calibration, K. L.

Eckerle, V. R. Weidner, J. J. Hsia,

and K. Kafadar, J. Res. Natl. Bur.

Stand. (U.S.) 88 (1), 25 (1983).

Second-Surface Mirror Standards of

Spectral Specular Reflectance

(SRM's 2023, 2024, 2025), J. C. Richmond, J. J. Hsia, V. R. Weidner, and

D. B. Wilmering, Natl. Bur. Stand.

(U.S.), Spec. Publ. 260-79 (Oct.

1982).

Proposed Standards for the NBS

Retroreflectance MAP, K. L. Eckerle and J. J. Hsia, Color Res. and Appl.

7(3), 235 (1982).

NBS 457Normal Reflectometer for Absolute Reflectance Factors, J. J. Hsia and V. R. Weidner, Metrologia

17, 97 (1981).

NBS Specular Reflectometer

Spectro-photometer, V. R. Weidner

and J. J. Hsia, Appl. Opt. 19, 1268

(Apr. 1980).

New Reference Retroreflectometer, K. L. Eckerle, J. J. Hsia, V. R. Weidner,

and W. H. Venable, Jr., Appl. Opt. 19

(8), 1253 (1980).

Photometry and Colorimetry of Retroreflection: State-of-Measurement

Accuracy Report, K. L. Eckerle, Natl. Bur. Stand. (U.S.), Tech. Note 1 125

(July 1980). Inverse-Fourth Apparatus for Photometric Calibrations, D. A. Swyt and

J. G. LaRock, Rev. Sci. Instrum. 49

(8), 1083 (Aug. 1978).

Basic Considerations of Densitometer

Adjustment and Calibration, R. E. Swing, Natl. Bur. Stand. (U.S.),

NBSIR 75-682 (Feb. 1975).

Establishing a Scale of Directional- Hemispherical Reflectance Factor 1: The Van den Akker Method, W. H.

Venable, Jr., J. J. Hsia, and V. R. Weidner, J. Res. Natl. Bur. Stand.

(U.S.), 82 (1), 29 (July-Aug. 1977).

New Reference Spectrophotometer, K. D. Mielenz, K. L. Eckerle, R. R

Madden, and J. Reader, Appl. Opt.

12 (7), 1630 (July 1973).

The Optics of Densitometry, R. E. Swing, Opt. Eng. 12 (6), 185

(Nov.-Dec. 1973).

Basic Considerations of Densitometer

Adjustment and Calibration, R. E. Swing, Natl. Bur. Stand. (U.S.),

Report 10970 (Dec. 1972).

Permanence of Glass Standards of

Spectral Transmittance, K. S. Gibson and M. A. Belknap, J. Res.

Natl. Bur. Stand. (U.S.) 44, 463

(May 1950).

85
39010C-39060S

a Spectroradiometric Measurements

C. 1 Spectroradiometric Source

Measurements

Technical Contact:

Charles E. Gibson

Ttl: 301/975-2329

Email: cgibson@nist.gov

Fax: 301/869-5700

Mailing Address: Building 221, Room B208,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items NIST calibrates and issues a type 30AIT24I13

ribbon filament lamp with a mogul bi-post base.

390 IOC Spectral Radiance Standard, Ribbon Filament Lamp

(225 nm to 2400 nm)

39020C Spectral Radiance Standard, Ribbon Filament Lamp

(225 nm to 800 nm)

39030C Spectral Radiance Standard, Ribbon Filament Lamp

(650 nm to 2400 nm)

NIST calibrates and issues a 1000 W, quartz halogen

lamp mounted in a medium bi-post base. The

calibrations are performed at 50 cm

3904OC Spectral Irradiance Standard, 1000 W Quartz-Halogen

Lamp (250 nm to 1600 nm)

39045C Spectral Irradiance Standard, 1000 W Quartz-Halogen

Lamp (250 nm to 2400 nm)

NIST calibrates and issues a 30 W deuterium arc lamp mounted in a medium bi-post base. 39050C Spectral Irradiance Standard, 30 W Deuterium Lamp

(200 nm to 400 nm)

39060S Special Tests of Radiometric Sources

Calibration Schedule: Spectroradiometric source calibrations are performed in March, June, September, and December. Requests for calibration services are scheduled after receipt of a purchase order.

C.l. Spectroradiometric Source

Measurements (39010C-39060S)

This laboratory's quality system is based on the ANSI/NCSL Z540- 1-1994 stan- dard and the ISO/IEC Guide 25.

Spectral Radiance Lamps (39010C39030C)

Tungsten ribbon filament lamps

(30A/T24/1 3) are supplied by NIST

Table 7.1. Calibration Uncertainties for Spectroradiometer Source Measurement

Relative Standard Wave- Topical Expanded

length values Uncertainty*

(nm) (W cm-^ sr-') (%)

Ribbon 225 5.5 1.5 filament 250 36 1.3 lamp JDK) j.U X ILr l.U 655 1.3 X 10^ 0.6 900 2.2 X 10^ 0.6 1700 1.1 X 10^ 0.5 4 n V in''

Quartz 250 0.2 1.8 halogen 350 85 1.1 lamp 655 170 0.9 900 230 1.1 1600 120 1.4 2400 40 4.4

Deuterium 200 0.5 5.0

arc lamp 250 0.3 3.2 400 0.05 3.2

*See Chapter 1, Section H for more information about uncertainty.

as lamp standards of spectral radiance. The lamps are calibrated at 34 wavelengths from 225 nm to 2400 rmi, with

a target area 0.6 mm wide by 0.8 mm

high. The irradiance temperature ranges from about 2650 K at 225 nm,

and 2475 K at 654.6 nm, to 1610 K at 2400 nm. Also see related services 40010C-40040S in next section.

Spectral Irradiance Lamps

(39040C-39050C)

These spectral irradiance standards are supplied by NIST. Lamp standards of

spectral irradiance are provided in two forms. For general use, tungsten

filament, 1000 W quartz halogen type

PEL lamps are calibrated at 31 wavelengths in the range 250 nm to 2400 nm. The working distance is 50 cm. For

use in the ultraviolet region, deuterium

arc lamps are calibrated at 21 wavelengths from 200 nm to 400 nm. The deuterium lamps are intended

86
39010C-39060S

200 600 1000 1400 1800 Wavelength (nm)

2200 2600

Figure 7. 1. Measurement Uncertainty for NIST Spectral

Radiance Calibrations.

primarily for the spectral region

200 nm to 250 nm. The relative expanded

uncertainty* in relative spectral distri- bution is 3 %. It is strongly

recommended that the deuterium

standards be compared to an FEL tungsten standard over the range 250 nm to 300 nm each time the deuterium lamp is operated to take advantage of the accuracy of the relative spectral distribution.

Special Tests of Radiometric Sources

(39060S)

Spectroradiometric source calibrations are performed in the Facility for Automatic Spectral Calibrations (PASCAL).

This instrument has the capability of

performing spectral radiance measure- ments from 200 nm to 2500 nm and

measuring radiance temperatures from

1050 K to 2700 K with an adjustable

spectral bandwidth down to 0.1 nm.

Spectral irrdiance measurement capability from 200 nm to 2400 nm at flux

levels down to 0. 1 W/cm' is also

*See Chapter 1, Section H for more information about uncertainty.

available. For both spectral radiance and

irradiance measurements a wide vari- ety of sources and measurement

geometries are possible. Special tests utilizing the capabilities of FASCAL are occasionally performed depending on

the availability of the equipment and

associated personnel.

References—Radiometric

Measurements

Results of a NIST/VNIIOFI comparison

of spectral-radiance measurements,

R. D. Saunders, C. E. Gibson, K. D.

Meilenz, V. I. Sapritsky, K. A.

Sudarev, and B. B. Khlevnoy,

Metrologia 3, 449 (1995).

The New International Temperature Scale

of 1990 and its Effect on Radiometric, Photometric, and Colorimetric

Measurements and Standards, K. D.

Mielenz, R. D. Saunders, A. C. Parr, and J. J. Hsai, CIE Proc. 22nd Session Melbourne 1991, no. 91 (1991).

200 600 1000 1400 1800 Wavelength (nm)

2200 2600

Figure 7.2. Measurement Uncertainty for NIST Spectral

Irradiation Calibrations.

87
39010C-39060S

Results of a CCPR Intercomparison of

Spectral Irradiance Measurements by

National Laboratories, J. H. Walker, R. D. Saunders, J. K. Jackson, and K. D. Mielenz, J. Res. Natl. Inst. Stand. Technol. 96, 647 (1991).

The 1990 NIST Scales of Thermal

Radiometry, K. D. Mielenz, R. D.

Saunders, A. C. Parr, and J. J. Hsia,

J. Res. Natl. Inst. Stand. Technol. 95,

621 (1990).

Spectroradiometric Determination of the Freezing Temperature of Gold, K. D.

Mielenz, R. D. Saunders and J. Shumaker, J. Res. Natl. Inst. Stand. Technol. 95, 49 (Jan.-Feb. 1990).

The International Temperature Scale of

1990 (ITS-90), H. Preston-Thomas,

Metrologia 27, 2-310 (1990).

NBS Measurement Services: Spectral Irradiance Calibrations, J. H. Walker,

R. D. Saunders, J. K. Jackson, and

D. A. McSparron, Natl. Bur. Stand.

(U.S.), Spec. Publ. 250-20 (Sept.

1987).

NBS Measurement Services: Spectral

Radiance Calibrations, J. H. Walker,

R. D. Saunders, and A. T. Hattenburg,

Natl. Bur. Stand. (U.S.), Spec. Publ. 250-1 (Jan. 1987).

Spectral Irradiance Standard for the Ultraviolet: The Deuterium Lamp, R. D.

Saunders, W. R. Ott, and J. M.

Bridges, Appl. Opt. 17, 593 (1978).

The 1973 NBS Scale of Spectral Irradi- ance, R. D. Saunders and J. B. Shumaker, Natl. Bur. Stand. (U.S.), Tech. Note 594-13 (1977).

High-Accuracy Spectral Radiance

Calibration of Tungsten-Strip Lamps,

H. J. Kostkowski, D. E. Erminy, and

A. T. Hattenburg, Adv. Geophys. 14, 111 (1970).

88
39071S-39090S

a Spectroradiometric Measurements

C.2 Spectroradiometric Detector

Measurements

Technical Contacts:

Sally S. Bruce 39071S-39081S

Tel: 301/975-2323 Email: sally.bruce@ nistgov

Fax: 301/869-5700

Thomas C. Larason 39071S-39090S

Ttl: 301/975-2334

Email: thomas.larason@

nist.gov

George Eppeldauer 39090S

Tel: 301/975-2338

Email: george.eppeldauer@

nist.gov

Mailing Address: Building 221, Room B208,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service roNo. Items 3907 IS UV Silicon Photodiodes 39072S Retest of UV Silicon Photodiodes 39073S Visible to NIR Silicon Photodiodes 39074S Retest of Visible to NIR Silicon Photodiodes

39075S Special Tests of NIR Photodiodes 39080S Special Tests of Radiometric Detectors 3908 IS Special Tests of Photodetector Responsivity Spatial

Uniformity

39090S Special Tests of IR Detectors

This laboratory's quality system is based on the ANSI/NCSL Z540-1-1994

standard and the ISO/IEC Guide 25. UV Silicon Photodiodes (39071S)

NIST will supply the customer with a

1 cm^ UDT Sensors, Inc. model UVlOO

silicon photodiode characterized in the

ultraviolet (UV) spectral region. The UV

silicon photodiode includes the measured

spectral responsivity (in the unit A/W)

from 200 nm to 500 nm in 5 nm steps

and the relative changes in responsivity over the photosensitive area at 350 nm. The photosensitive area of the photodiodes is under filled for the measurements

with a 1 .5 mm diameter beam. The spectral responsivity is measured at radiant power levels of less than 20 |xW. The

bandpass of the measurement is 4 nm. The relative expanded uncertainty*

*See Chapter 1 , Section H for more information about uncertainty.

ranges from 0.4 % to 13 %, depending on the wavelength.

Retest of UV Silicon Photodiodes

(39072S)

Special tests of previously supplied

(3907 IS) NIST (UV) silicon photodiodes

are performed by measuring spectral

responsivitiy (in the unit A/W) from

200 nm to 500 nm.

Visible to Near Infrared (NIR) Silicon Photodiodes (39073S)

NIST will supply the customer with a

1 cm^ Hamamatsu model S2281 silicon photodiode characterized in the visible to near infrared (NIR) spectral region. The

spectral response (in the unit A/W)

photodiode is measured from 350 nm to

1 100 nm in 5 nm increments. The relative change in responsivity over the photosensitive area is also measured at 500 nm. The photosensitive area of die photodiodes is underfilled for the measurements with a 1.1 mm diameter beam.

The spectral responsivity is measured at radiant power levels of less than 1 jxW.

The bandpass of the measurement is 4 nm. The relative expanded uncertainty* ranges from 0.2 % to 6 %, depending on

the wavelength. The spectral range can

be extended to 200 nm with a relative expanded uncertainty* from 0.2 % to

1 3 % for an additional fee.

Retest of Visible to NIR Silicon Photodiodes (39074S)

Special tests of previously supplied

(39073S) NIST visible to NIR silicon photodiodes are performed by measuring

responsivity (in the unit A/W) from

350 nm to 1 10 nm. The spectral range can be extended to 200 nm for an

additional fee.

Special Tests of NIR Photodiodes

(39075S)

Special tests of customer-supplied NIR

photodiodes are performed by measuring

spectral responsivity (in the unit A/W)

from 700 nm to 1800 nm. A 1.1 mm

diameter beam is centered on and underfills the photosensitive area.

89
39071S-39090S

The spectral responsivity is measured at radiant power levels of less than 1 jxW.

The bandpass of the measurement is 4 nm. The relative expanded uncertainty* ranges from 0.7 % to 7 % or greater, depending on the wavelength and the individual item measured. Customers

should contact Thomas Larason or Sally Bruce to discuss details before submitting a formal request.

Special Tests of Radiometric Detectors (39080S)

Special tests of radiometric detectors generally used in the ultraviolet, visible,

and infrared regions of the spectrum can

be performed. Responsivity of detectors can be measured between 200 nm and

1800 nm at power levels less than

4.0 p,W. Examples of detf ctor characteristics that can be determined in a special

test include spectral responsivity

(expressed in the unit A/W) and quantum

efficiency (electrons per photon). The

relative expanded uncertainty* ranges from 0.2 % to 13 % or greater, depending on the wavelength and the individual item measured. Measurements of the

relative change in responsivity over the photosensitive area (responsivity spatial

uniformity) are conducted under Service

ID Number 3908 IS. Since special tests of this type are unique, details of the

tests should be discussed with Thomas

Larason or Sally Bruce before submitting

a formal request.

Special Tests of Photodetector

Responsivity Spatial Uniformity

(39081S)

Special tests of measuring the relative changes in responsivity across the photosensitive area (responsivity spatial uni- formity) can be performed for customer-supplied photodetectors. The

uniformity is typically measured at a

single wavelength in 0.5 mm spatial

increments with a beam diameter of

1 .5 mm in the 200 nm to 400 nm

spectral region at power levels less than

20 (xW, and a beam of diameter 1.1 mm

in the 400 nm to 1 8(X) nm spectral region

at power levels less than 1 |jlW. The relative expanded uncertainty* ranges from

0.0024 % to 0.5 % or greater, depending on the wavelength and the individual item

measured. Customers should contact Thomas Larason or Sally Bruce to dis- cuss details before submitting a formal

request.

Special Tests of IR Detectors (39090S)

Special tests of customer-supplied ambient temperature infrared detectors can be

performed in the 2 |jLm to 20 jxm wavelength range. Measurements at longer

wavelength are possible, and may be

provided to customers having special

requirements. The special tests include

spectral power responsivity and spatial response measurements. The standard

configuration uses a 1 .3 mm diameter

monochromatic beam to under fill the

active area of the detector with an f/#

between f/4 and f/8. The monochromator

output beam is chopped (« 39 Hz) and

has a radiant power ranging from 1 fxW

at a wavelength of 4 \xm to = 10 nW at

1 8 |xm. The optical bandpass of the measurement is = 1 % of the test wavelength.

The relative expanded uncertainty* is typically ~5 %. Customers should contact George Eppeldauer to discuss details before submitting a formal request or to get information on extended measure- ment capability.

*See Chapter 1 , Section H for more information about uncertainty.

90
39071S-39090S

Ikble 7.2. Detector Measurement Services Uncertainties*

Expanded Uncertainty

Relative Estimated Uncertainty* SStest/Stkst [%]

Wavelength UV 100 (UV) S1337 xjIIj [syiK.) invjraAS

[nm] (Visible)

200 13.10 250 1.42 300 2.56 350 1.88 2.96 400 1.50 1.56 450 0.38 0.24 500 0.38 0.22 550 0.20 600 0.20 650 0.20 700 0.20 2.48 2.50 750 0.22 1.98 2.02 800 0.22 1.86 1.88 850 0.24 1.54 1.58 900 0.22 1.28 1.30 950 2.62 1.88 1.90 1000 1.74 1.66 1.66 1050 3.16 1.80 1.82 1100 5.58 1.58 1.58 1150 1.94 1.94 1200 2.30 2.30 1250 2.60 2.60 1300 2.60 2.60 1350 3.46 3.46 1400 4.80 4.80 1450 4.64 4.64 1500 5.66 5.66 1550 5.06 5.08 1600 5.20 5.24 1650 6.10 6.14 1700 5.98 6.08 1750 5.98 6.10 1800 5.52 5.82

Spectroradiometric Detector Measurement References:

NIST Measurement Services: Spectroradiometric Detector Measurements:

Parts I and II—Ultraviolet and Visible

to Near Infrared Detectors, T. C. Larason, S. S. Bruce, C. L. Cromer,

and A. C. Parr, Natl. Inst. Stand. Techno!., Spec. Publ. 250-xx

(in preparation).

Table 7.3. NIST Spectroradiometric Detector Measurement Services

Relative Expanded

Service Item of Test Range Uncertainty* ID No. (nm) (%)

3907 IS UV Silicon Photodiodes (UDTUV 100)

200 to 500 0.4 to 13

39072S Retest of UV Silicon Photodiodes

200 to 500 0.4 to 13

39073S Visible to NIR Silicon Photodiodes (Hamamatsu

S228i)

400 to 1100 0.2 to 6

39074S Retest of Visible to NIR

Silicon Photodiodes (Hamamatsu SI337-1010BQ

or S2281)

400 to 1100 0.2 to 6

39075S Special Tests of NIR

Photodiodes

700 to 1800 0.7 to 7

39080S Special Tests of Radiometric

Detectors

200 to 1800 0.2 to 13

3908 IS Special Tests of Photodetector Responsivity Spatial Uniformity

200 to 1800 0.0024 to 0.5

NIST Measurement Services: Spectroradiometric Detector Measurements:

Part III—Infrared Detectors, A. L. Migdall and G. Eppeldauer, Natl. Inst. Stand. TechnoL, Spec. Publ. 250-xx

(in preparation).

National Institute of Standards and Technology High-accuracy Cryogenic

Radiometer, T. R. Gentile, J. M.

Houston, J. E. Hardis, C. L. Cromer,

and A. C. Parr, Appl. Opt. 35, 1056-

1068 (1996).

Realization of a Scale of Absolute Spectral Response Using the National Insti- tute of Standards and Technology

High-accuracy Cryogenic Radiometer,

T. R. Gentile, J. M. Houston, and

C. L. Cromer, Appl. Opt. 35, 4392-

4403 (1996).

* See Chapter I , Section H for more information about uncertainty.

91
A National Measurement System for Radiometry, Photometry, and Pyrometry Based upon Absolute Detectors, A. C. Parr, Natl. Inst. Stand. Technol., Tech. Note 1421 (1996).

Developing Quality System Documentation Based on ANSI/NCSL Z540-1-

1994—The Optical Technology

Division's Effort, S. S. Bruce and T. C. Larason, Natl. Inst. Stand. Technol.,

Internal Report 5866 (1996).

High Accuracy Measurement of Aperture

Area Relative to a Standard Known

Aperture, J. B. Fowler and G. Dezsi,

J. Res. Nad. Inst. Stand. Technol. 100,

277-283, (1995).

Building a Quality System Based on ANSI/NCSL Z540- 1-1994—An Effort by the Radiometric Physics Division at NIST, S. S. Bruce and T C. Larason,

Proc. Natl. Conf. Stand. Lab. Arm.

Workshop and Symp. 1995, Dallas,

TX (July 1^20, 1995).

A Cryogenic Silicon Resistance Bolometer for Use as an Infrared Transfer Standard Detector, G. Eppeldauer, A. L. Migdall, and C. L. Cromer,

Thermal Phenomena at Molecular and

Microscales and in Cryogenic Infrared Detectors, edited by M. Kaviany et al., ASME HTD 277, pp. 63-67, New

York, NY (1994).

The Radiometric Physics Division's

Efforts at Building a Quality System

Based on ISO/IEC Guide 25, T. C. Larason, Asociacion Mexicana De

Metrologia, A. C. 1994 Conf., Acapulco, Mexico (May 10-13, 1994).

Characterization of a High Sensitivity

Composite Silicon Bolometer, G.

Eppeldauer, A. L. Migdall, and C. L. Cromer, Metrologia 30, 317-320

(1993).

Comparison Between Cryogenic Radiometry and the Predicted Quantum

Efficiency of PN Silicon Photodiode

Light Traps, E. F. Zalewski and C. C. Hoyt, Metrologia 28, 203-206 (1991).

Fourteen-Decade Photocurrent Measure- ments with Large-Area Silicon Photodiodes at Room Temperature, G. Eppeldauer and J. E. Hardis, Appl.

Opt. 30, 3091-3099 (1991).

Photodetector Spectral Response Based on 100 % Quantum Efficient Detectors, J. M. Houston and E. F. Zalewski,

Optical Radiation Measurements II, James M. Palmer, ed., Proc. SPIE

1109, pp. 268-277 (1989). Current Status of, and Future Directions

in, Silicon Photodiode Self-Calibration, J. Geist, Optical Radiation Measurements II, James M. Palmer, ed., Proc. SPIE 1109, 246-256 (1989).

The NBS Photodetector Spectral Response Calibration Transfer Program,

E. F. Zalewski, Natl. Bur. Stand.

(U.S.), Spec. Publ. 250-17, 45 (1988).

ApparaUis Function of a Prism-Grating

Double Monochromator, R. D. Saunders and J. B. Shumaker, Appl. Opt.

25, 3710-3714(1986).

Automated Radiometric Linearity Tester, R. D. Saunders and J. B. Shumaker,

Appl. Opt. 23, 3504-3506 (1984).

Silicon Photodiode Device with 100 %

External Quanmm Efficiency, E. F. Zalewski and C. R. Duda, Appl. Opt.

22, 2867-2873 (1983).

Silicon Detector Nonlinearity and

Related Effects, A. R. Schaefer, E. F. Zalewski, and J. Geist, Applied Optics

22, 1232 (1983).

Introduction to Coherence in Radiometry,

Chapter 10 in Self-Study Manual on

Optical Radiation Measurements: Part

I—Concepts, Chapter 10, J. B. Shumaker, F. E. Nicodemus, ed., Natl. Bur. Stand. (U.S.), Tech. Note 910-6

(1983).

The Relative Spectral Responsivity and

Slit-Scattering Function of a Spectroradiometer. Chapter 7 in Self-Study

Manual on Optical Radiation Measurements: Part I—Concepts, Chapters 7,

8, and 9, H. J. Kostkowski, F. E. Nicodemus, ed., Natl. Bur. Stand.

(U.S.), Tech. Note 910-4 (1979).

An Introduction to the Measurement

Equation, Chapter 5 in Self-Study

Manual on Optical Radiation Measurements: Part I—Concepts, Chapters 4

and 5, H. J. Kostkowski and F. E. Nicodemus, F. E. Nicodemus, ed., Natl. Bur. Stand. (U.S.), Tech. Note

910-2 (1978).

92
39010S-39090S

Detector Spectral Response from 350 to 1200 nm Using a Monochromator

Based Spectral Comparator, A.

Corrons, and E. F. Zalewski, Natl. Bur.

Stand. (U.S.), Tech. Note 988 (1978).

Spectral Radiometry: A New Approach

Based on Electro-Optics, J. Geist,

M. A. Lind, A. R. Schaefer, and

E. F. Zalewski, Natl. Bur. Stand.

(U.S.), Tech. Note 954 (1977).

Comparison of the Laser Power and Total Irradiance Scales Maintained by the National Bureau of Standards, J. Geist, L. B. Schmidt, and W. E. Case, Appl.

Opt. 12, 2773-2776 (1973).

93
40010C-40040S

D Radiometric Standards in the Far Ultraviolet

D.I Standard Sources

Technical Contact:

Terrell Moore

Tel: 3017975-3229 Email: tmoore@nist.gov

Mailing Address: Building 221, Room A167,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 400 IOC Spectral Irradiance Standard, Argon Mini-Arc

(140 nm to 330 nm)

4O020C Spectral Radiance Standard, Argon Mini-Arc

(1 15 nm to 330 nm)

40030C Spectral Irradiance Standard, Deuterium Arc Lamp

(165 nm to 200 nm)

40040S Special Tests of Radiometric Devices in the Near and Vacuum Ultraviolet

This laboratory's quality system is based on the ANSI/NCSL Z540-1-1994

standard and the ISO/IEC Guide 25.

Source Calibrations in the Ultraviolet

(40010C-40040S)

NIST maintains a collection of secondary

standard sources such as argon maxiarcs, argon mini-arcs, and deuterium arc lamps in the near and vacuum ultraviolet radiometric standards program to provide

calibrations for user-supplied sources. The calibrations of these sources are traceable to a hydrogen arc whose radi- ance is calculable and which NIST maintains as a primary standard. Irradiance

calibrations are now also traceable to the NIST electron storage ring, SURF II, against which working standard irradi- ance sources are periodically calibrated. The collection also includes tungsten

strip lamps and tungsten halogen lamps

whose calibrations are based on a blackbody rather than a hydrogen arc. Customer-supplied sources are calibrated

in both radiance and irradiance by

comparing them with NIST secondary

standards. Argon arcs are used to calibrate other sources in the wavelength range 1 15 nm

to 330 nm for radiance and 140 nm to 330 nm for irradiance. The lower wavelength limit is determined in radiance by

the cutoff of the magnesium fluoride windows used in the arcs and in irradi- ance by the decrease in signal produced

by the addition of a diffuser. Deuterium

arc lamps are used in the range 165 nm

to 200 nm, with the low wavelength cut- off due to the onset of blended molecular

lines. The high wavelength limit is the

starting point of the range of another cal- ibration group at NIST. (See Service ID

Numbers 39010C-39050C, previous section.) The tungsten lamps are used at 250 nm and above, since their signals are too weak at shorter wavelengths. It should be noted that the wavelength

range of the NIST arcs partially overlaps

the range of tungsten lamps, thus providing an independent check on calibrations. An argon mini-arc lamp supplied by

the customer is calibrated for spectral irradiance at 10 nm intervals in the wavelength region 140 nm to 300 nm. Absolute values are obtained by comparison

of the radiative output with laboratory

standards of both spectral irradiance and

spectral radiance. The spectral irradiance measurement is made at a distance of

50 cm from the field stop. Relative expanded uncertainties* are 10 % in the wavelength region 140 nm to 200 nm and

5 % in the wavelength region 200 nm to 330 nm. A measurement of the spectral

transmission of the lamp window is in- cluded in order that the calibration be in- dependent of possible window

deterioration or damage. The spectral

radiance of argon mini-arc radiation sources is determined with a relative ex- panded uncertainty* of 7 %

over the wavelength range 1 40 nm to 330 nm and 20 % over the wavelength

range 115 nm to 140 nm. The calibrated area of the 4 mm diameter radiation source is the central 0.3 mm diameter

*See Chapter 1, Section H for more information about unceilainty.

94
400 IOC:-40040S

region. Typical values of the spectral

radiance are as follows: at 250 nm,

La = 30 mW cm~^ nni ' sr"'; and at 150 nm. La = 3 mW cm"^ nm ' sr"'. The transmission of the demountable

lamp window and that of an additional MgF2 window are determined individually so that the user may check periodically for possible long-term variations. The deuterium arc lamp is cali- brated at 10 wavelengths from 165 nm

to 200 nm, at a distance of 50 cm.

Typical values of spectral irradiance are 0.5 W/cm' at 165 nm, 0.3 W/cm' at 170 nm, and 0.5 W/cm' at 200 nm. The

relative expanded uncertainty* is 10 %. The lamp is normally supplied by

NIST and requires 300 mA at about

100 V.

References—^Source Calibrations in the Ultraviolet

Radiometric Calibrations of Portable Sources in the Vacuum Ultraviolet, J. Z. Klose, J. M. Bridges, and W. R. Ott, J. Res. Natl. Bur. Stand. (U.S.), 93, 21

(1988).

NBS Measurement Services: Radiometric

Standards in the Vacuum Ultraviolet,

J. Z. Klose, J. M. Bridges, and W. R.

Ott, Natl. Bur. Stand. (U.S.), Spec.

Publ. 250-3 (June 1987).

Radiance of a Pt/Cr-Ne Hollow Cathode

Spectral Line Source,

J. Z. Klose and J. M. Bridges, Appl.

Opt. 26, 5202 (1987).

VUV Spectral Irradiance Calibrations: Method and Applications, W. R.

Ott, J. M. Bridges, and J. Z. Klose,

Opt. Lett. 5, 225 (1980).

Spectral Irradiance Standard for the

Ultraviolet: The Deuterium Lamp,

R. D. Saunders, W. R. Ott, and

J. M. Bridges, Appl. Opt. 17, 593

(1978).

Spectral Radiance Calibrations between

165-300 nm: An Interlaboratory

Comparison, J. M. Bridges, W. R. Ott, E. Pitz, A. Schultz, D. Einfield, and

D. Stuck, Appl. Opt. 16, 1788 (1977).

VUV Radiometry, 3: The Argon MiniArc as a New Secondary Standard of

Spectral Radiance, J. M. Bridges and

W. R. Ott, Appl. Opt. 16, 367 (1977).

NBS UV Radiometric Standards,

W. R. Ott, Natl. Bur. Stand. (U.S.),

Spec. Publ. 456, 107 (1976).

*See Qiapter 1, Section H for more information about uncertainty.

95
40510C-40599S

D Radiometric Standards in the Far Ultraviolet « D.2 Standard Detectors in the

Far Ultraviolet

Technical Contact:

L. Randall Canfield

Tel: 301/975-3728 Email: r.canfield@ni$tgov

Mailing Address: Building 245, Room B119,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 405 IOC Detector Standard, Windowless Photodiode

(5 nm to 122 nm)

405 1 IC Recalibration of Detector Standard (5 nm to 122 nm)

40520C Detector Standard, Windowless Photodiode

(18 nm to 122 nm)

40521C Recalibration of Detector Standard (18 nm to 122 nm)

40530C Detector Standard, Windowless Photodiode

(52 nm to 122 nm)

4053 IC Recalibration of Detector Standard (52 nm to 122 nm)

40540C Uncalibrated Windowless Photodiode

40560C Detector Standard, Windowed Photodiode

(116 nm to 254 nm)

4056 IC Recalibration of Detector Standard (116 nm to 254 nm)

40599S Special Tests on Detectors from the Ultraviolet (254 nm) to the Soft X-Ray Region (5 nm)

This laboratory's quality system is based on the ANSI/NCSL Z540-1-1994

standard and the ISO/IEC Guide 25.

Detector Calibrations in tlie Ultraviolet (40510C^0599S)

Calibrated transfer standard detectors for the far ultraviolet are available from NIST

to cover the spectral region 5 nm to 254 nm. Users are furnished with the quantum efficiency as a function of

wavelength; quantum efficiency is defined as the number of photoelectrons

per incident photon. Three detector types

are available to cover this range: (1) a windowless silicon semiconductor photodiode for the wavelength region 5 nm to

254 nm (available under Service ID No.

40599S); (2) a windowless photoemissive

diode with an AI2O3 photocathode for the wavelength region 5 nm ro 122 nm; and

(3) a MgF2-windowed photodiode with a semi-transparent CsTe photocathode for the wavelength region 1 16 nm to 254 nm. The detectors have been extensively studied regarding radiometrically important

parameters such as photocathode spatial

uniformity and temporal stability of conversion efficiency. It should be noted that the silicon photodiode is not solar blind,

while the windowless photoemissive

diode is. Stray light considerations should

be evaluated before making a choice for the 5 nm to 122 nm region.

The relative expanded uncertainties* in the measured quantum efficiencies are 7 % to 22 % in the 5 nm to 122 nm

windowless photodiode region, and 9 %

to 10 % in the 1 16 nm to 254 nm

windowed photodiode region.

NIST working standard calbrations are based on the rare gas ionization chamber

in the 5 nm to 92 nm region, and on the calculable synchrotron flux from the NIST electron storage ring, SURF II, at wavelengths longer than 1 10 nm. Two

facilities at SURF II are used in these

calibrations, one in the 5 nm to 50 nm

region and a second in the 1 16 nm to 254 nm region. A separate laboratory

facility is used for the 50 nm to 92 nm

calibration of working standards. Outgoing detectors are calibrated by

direct intercomparison with precalibrated

working standards that are periodically

recalibrated. Windowless AI2O3 photodiodes are fabricated in-house; the windowless Si photodiodes and the windowed CsTe photodiodes are procured

commercially and tested for stability and

spatial homogeneity. Only those photodiodes meeting stringent NIST quality

specifications are selected as transfer standards. The calibration costs include

the cost of the detector and screening ser- vices unless a recalibration of previously

used detectors is requested.

*See Chapter 1, Section H for more information about uncertainty.

96
405 lOCSpecial detectors that do not lend themselves to convenient on-site cross-calibration may also be calibrated at NIST if the detectors merit radiometric application

and if the NIST calibration facilities are

suitable and available for the particular device.

References—Detector Calibrations in the Ultraviolet

Stable Silicon Photodiodes for Absolute

Intensity Measurements in the VUV

and Soft X-Ray Regions, E. M. Gullikson, R. Korde, L. R. Canfield, and

R. E. Vest, J. Electron Spectrosc.

Relat. Phenon. 80, 313 (1996).

NBS Measurement Services: Far Ultraviolet Detector Standards, L. R. Canfield

and N. Swanson, Natl. Bur. Stand.

(U.S.), Spec. Pub). 250-2 (June 1987).

Time Response of NBS Windowless

XUV Radiometric Transfer Standards,

E. B. Saloman, Appl. Opt. 14, 1764

(1975). Far Ultraviolet Detector Standards, L. R.

Canfield and N. Swanson,

J. Res. Natl. Bur. Stand. (U.S.), 92, 97

(1987).

97
42110C-42180S

E Lasers and Optoelectronic Components

Used with Lasers

Technical Contacts:

Thomas R. Scott

Ttl: 303/497-3651 Emai!: thomas^cott @nistgov

Christopher L. Cromer

(Laser Radiometry)

Tel: 303/497-5620

Email: Christopher. cromer@nist.gov

Paul D. Hale

(High Speed

Measurements)

Ttl: 303/497-5367

Email: paul.hale ^

nist.gov Paula M. Hewitt

Administration and Logistics

Te\: 303/497-3753

Email: paula.hewitt(^nist.gov Fax: 303/497-3970

Mailing Address: M. C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items

421 IOC Laser Power and Energy Meter (or Detectors Used

with Lasers) Calibrations (single wavelength and power)

421 lie Same as 421 IOC, Additional Wavelengths

or Powers 42120M Laser Power and Energy Measurement Assurance Program (MAP)

42 1 30C Optical Fiber Power Meter (or Detectors Used

with Lasers) Calibrations (single wavelength and

connector type)

42131C Same as 42130C, Additional Wavelengths or Connector Types

42 1 40M Optical Fiber Power Meter Measurement Assurance Program (MAP)

42 1 50M Low-Level Laser Measurement Assurance Program

(MAP)

42 1 5 1 C Low-Level Laser Radiometer Calibration 42 1 60S Special Test for Frequency Response Measurements

of Detectors Used with Lasers 4216 IS Special Test for Impulse Response Measurements

of Detectors Used with Lasers 42162S Special Tests for High Accuracy Laser and Optical Fiber Power Measurements 42163S Special Test for Linearity Measurements of Laser and Optical Fiber Power Meters (or Detectors Used with Lasers) 42164S Special Test for Spectral Responsivity Measurements

of Laser and Optical Fiber Power Meters (or Detectors Used with Lasers) 42165S Special Test for Spatial Uniformity of Laser and Optical Fiber Power Meters and Detectors Used with Lasers 42 1 70S Special Test for General Laser Measurements,

by Prearrangement 421 80S Special Test for General Optical Fiber Power

Measurements, by Prearrangement

General Information

The NIST Optoelectronics Division de- velops and maintains the U.S. national standards for the characterization of

lasers, along with detectors and other

optical and optoelectronic components

used with lasers and in laser-based sys- tems. These standards support applications of lasers in manufacturing,

electronics, medicine, communications,

and the military, among other fields, and

are generally used to provide calibrations of instruments used in these areas. For calibrating instruments used to measure the power or energy emitted by

a laser, specially designed standards consisting of several types of isoperibol

(constant temperature environment)

calorimeters have been developed and

used for many years. Low-level laboratory standards are realized using solidstate photodetectors and other thermal

detectors. Well-characterized transfer standards (calibrated against the primary

standards) are also maintained as laboratory standards for calibrations and for use

in Measurement Assurance Program

(MAP) intercomparisons. As part of a continuing process, new standards are being developed and implemented to improve accuracy and dynamic range. For example, the Division is developing

ultra-high accuracy laser power measure- ment capability using a new cryogenically cooled electrical substitution laser power meter. The laboratory standards and secondary transfer standards are used

in specially designed, beamsplitter-based

calibration systems that allow various power and energy detectors to be

compared to the standards. The Optoelectronics Division

maintains the capability of measuring

other laser parameters, for example,

beam profile and relative intensity noise. Because these measurements are generally less well defined than power and

energy measurements, they are under- taken as Special Tests, after consultation with the customer. Instruments used

in optical communications generally

accept or receive optical power through

a connectorized optical fiber.

98
42110C-42180S

Wavelength ranges of interest are generally centered on 850 nm, 1300 nm, and

1550 nm. In addition to power measure- ments in these ranges, calibrations of the frequency response (or impulse response)

of detectors and analog and digital re- ceivers used in optical communications

can be provided. NIST also provides several Standard Reference Materials* for

calibrating instruments used in optical

communications.

The Optoelectronics Division can also characterize many other optical and optoelectronic components used with

lasers. Within existing capabilities.

Special Test measurements can be provided. Those needing such measurements

are invited to contact the Division.

Laser Power and Energy Meter

(or Detectors Used with Lasers)

Calibrations (42110C^2111C)

Within the ranges listed in Table 7.4, NIST can perform calibrations at the power (or energy) and wavelength specified by the customer. These ranges are determined by the combined limits of our

standards and available laser sources. For these measurements, the instrument

to be measured is sent to NIST, where it

is then compared to the appropriate laboratory reference standard using a cali- brated beamsplitter measurement system.

Normally, the response of the detector is characterized but no physical adjust- ments are made to the test instrument. At

the completion of the calibration measurements, the instrument and a calibration report are sent to the customer. The

calibration report summarizes the results of the measurements and provides a

detailed listing of the associated measurement uncertainties. The laboratory standard isoperibol

calorimeters used as references for these measurements were designed and built at NIST and all their critical parameters

(electrical calibration coefficient, absorptivity, window transmittance, etc.) have

been evaluated for the laser wavelengths

* See Chapter 1 , Section C for information on other thermodynamic property measurement standards

available from the Standard Reference Materials Program.

Table 7.4. Laser Power and Energy Measurement

Capabilities

Typical

Relative Primary Expanded

Standard Wavelength Power Range Uncertainty**

(%)

C-series 488.0, 514.5 nm 1 nW to 500 mW 0.5 to 1 .0 632.8 nm 1 nW to 20 mW 0.5 to 1 .0 830 nm 100 (jlW to 20 mW 0.5 to 1 .0 1064 nm 1 mWto 1 W 0.5 to 1 .0 1319 nm 100 jjlW to 100 mW 0.5 to 1.0 1523 nm 100 (xW to 1 mW 0.5 to 1.0 Q-series 1.06 [im 1 mJ/pulse to 60 mJ/pulse 1.1 to 1.9 (Q-switched) 1 mWto 1 W

K-series 1 .06 |jLm 1 W to 300 W 1.6 to 2.5 10.6 Jim 35 mWto 900 W 1.6 to 2.5 QUV- 248 nm 0.4 mJ/pulse 1.0 to 3.0

series (pulsed) 150 mJ/pulse

3 nW to 7.5 W

**See Chapter I, Section H for more information about uncertainty.

and energies for which they are used. The characteristic voltage response of

the standard isoperibol calorimeters is described by first principles of thermodynamics and linear system analysis. Accurate quantitative responsivity characterization (including linearity and stability) of the calorimeters is accomplished by periodically performed,

electrical heater calibrations. The laser power and energy measure- ments are accomplished using a cali- brated beamsplitter arrangement in which both the standard and the test meter are exposed to the laser beam

simultaneously. In addition to the

isoperibol calorimeters, solid-state photodiodes and trap detectors are used

as laboratory standards, especially at powers below 1 mW. The beamsplitters

used in these systems have been characterized for all specific wavelengths for which they are used. Small angles of

incidence are used to minimize polarization and angular position uncertainties. The laser sources used for these calibration measurements with the primary

standards consist of the following types

(subject to change): (I) helium-neon

(632.8 nm and 1523 nm), (2) argon ion

(488.0 nm and 514.5 nm), (3) Nd:YAG

(1064 nm and 1319 nm CW, and

99
1064 nm Q-switched), (4) diode laser (825 nm to 833 nm), (5) carbon dioxide

(10.6 (xm) and (6) KrF excimer

(248 nm).

Laser Power and Energy Measurement

Assurance Program (MAP) (42120M)

The Measurement Assurance Program

(MAP) is available at the wavelengths and

powers listed in Table 7.4. The laser MAP intercomparisons are implemented

by means of transfer standards, which

have been evaluated and characterized

relative to the national primary standards. The measurement system and primary

standards discussed above are used to calibrate the transfer standards for the in- tercomparisons. The characteristics of

these transfer standards are well understood, and their associated accuracies do

not differ significantly from those associ- ated with direct comparisons to the primary standards. For a specified

wavelength and power or energy, the appropriate transfer standard is selected and

sent from NIST to the MAP participant.

The participant calibrates the NIST transfer standard using their measurement

system and then returns both his data and

the transfer standard to NIST. Before and

after the NIST transfer standard is shipped to the participant, NIST per- forms calibration measurements on the detector to provide continuity during the intercomparison. At the completion of

the intercomparison, NIST evaluates the

participant's measurement results relative to the NIST calibration results on this same meter. A MAP intercomparison

report summarizing the intercomparison

and listing the associated measurement

uncertainties is then submitted to the

participant. Customers who have the capability and require higher accuracy may request MAP services using appropriate high-accuracy transfer standards such as the photodiode trap detectors.

Optical Fiber Power Meter

(or Detectors Used with Lasers)

Calibrations (42130C^2131C)

Optical fiber power meters are calibrated using an automated calibration system in which the test meter and the laboratory

standard are alternately exposed to a

stable diode laser source. During the measurement process, the input power to the test meter is monitored with a fiber coupler and reference detector assembly.

Table 7.5 summarizes the current capabilities of this system. The laboratory stan- dard used for these measurements is an

electrically calibrated pyroelectric

radiometer (ECPR) which has been cali- brated against a primary standard

calorimeter. Various diode laser sources

are used to provide the available wavelengths. The calibrations can be accomplished with either a collimated beam or

a connectorized fiber configuration. We

can accommodate most commonly used

fiber connectors (such as FC/PC, ST,

biconic, SC, SMA, FC/APC, HMS-10

etc.).

Table 7.5. Measurement Capabilities of Automated

Calibration System for Optical Fiber Power Meters

Laboratory Typic

Standard Wavelength Window Power Range Uncertaint

(nm) (|iW) (%)

ECPR 670 10 to 200 0.5 tel. ECPR 780 10 to 200 0.5 to 1. ECPR 850 10 to 200 0.5 to 1. EPCR 980 10 to 200 0.5 to 1. EPCR 1300 10 to 200 0.5 to 1. EPCR 1500 10 to 200 0.5 to 1.

See Chapter 1, Section H for more information about uncertainty.

Optical Fiber Power Meter Measurement Assurance Program (MAP)

(42140M)

NIST maintains a set of calibrated transfer standards, which are available for MAP intercomparisons of optical fiber power meters. These transfer standards

are calibrated at the wavelengths listed

in Table 7.6 using the optical fiber power meter calibration system dis- cussed above. If the MAP is to be

conducted using a fiber with attached connector, then customers are asked to provide the specific fiber and connector which is used in their laboratories. As

in the laser MAP procedures listed above, measurements are made on the NIST transfer standard both before and

j, after the MAP participant's measure- ments are conducted. At the conclusion

I

I

1

100
42110C-42180S

of the MAP process, a calibration report

that summarizes the measurements and

associated uncertainties is sent to the

participant.

Low-Level Laser Radiometer Calibrations and Measurement Assurance

Program (MAP) (42150M)

NIST has designed and constructed

special silicon and germanium diode detectors to measure pulse energy and peak

power of low-level, 1064 nm laser pulses

of about 10 ns to 150 ns duration. These

diode detectors have been evaluated for

spatial uniformity, bandwidth, and linearity, and are used as transfer standards for intercomparisons. The output response of

each detector has been calibrated against a transfer standard which, in turn, has

been calibrated against the C-series

calorimeter. The system for calibrating these transfer standards uses a CW

Nd:YAG laser whose radiation is acoustooptically modulated to produce short, well defined pulses. The beam intensity

is attenuated to low-levels using a multiple reflection precision wedge beamsplitter. The transfer standards are available

for intercomparisons at the powers listed in Table 7.6.

Table 7.6. Low-Level MAP Transfer Standards

Relative Expanded

Transfer Standard Energy [Power Range] Uncertainty*

(%)

Silicon PIN 10~'''(JW)/[pulse] to 6 to 8 10"" (J/cm^VCpulse]

Germanium PIN 10"'^ (J/cm^)/[pulse] 15

Silicon APD 10"* W/cm^ [peak] to 6 to 8

[peak]

Special Test for Frequency Response

Measurements of Detectors Used with Lasers (42160S)

NIST measures the frequency response of photodetectors using the difference frequency beat note from 2 single fre- quency Nd:YAG lasers operating at 1319 nm. Measurements can be per- formed between 300 kHz and 50 GHz.

* See Chapter 1 , Section H for more information about uncertainty.

Normalized frequency response is proportional to the ratio of the generated

microwave power to the DC power supplied through the bias current. A

photodetector suitable for calibration includes a connectorized fiber pigtail and

precision coaxial microwave connector. Highest accuracy measurements are at- tained when the photodiode and power

sensor are calibrated as one unit. A transfer standard of this type can be used to determine the optical modulation index

of an arbitrary optical source with sinu- soidal modulation. Options available include measurement of frequency

response of a separate photodetector

using NIST power sensors, or normalization to optical power to give absolute response. Each of these options gives a degradation in measurement uncertainty

due to power sensor calibration and fiber connector insertion loss, respectively.

Measurements may also include correction for electrical impedance mismatch

when separate power sensors are used.

Special Test for Impulse Response

Measurements of Detectors Used with Lasers (42161S)

NIST uses a Ti: sapphire laser to generate

150 fs optical pulses in the 750 nm to 850 nm wavelength region. The electrical impulse resulting from the optical input

to the detector is measured on a cali- brated oscilloscope with 50 GHz bandwidth. The resulting waveform is Fourier-transformed, and the frequency

response of the oscilloscope is deconvolved to give the magnitude of the photodetector frequency response.

High Accuracy Laser and Optical

Fiber Power Measurements (42162S)

A cryogenically cooled electrical substi- tution radiometer (ESR) has been in- stalled in our measurement laboratory

and is now being thoroughly evaluated. Using this instrument as a reference,

uncertainties smaller than those listed in Tables 7.5 and 7.6 are available on

request for certain wavelengths and measurement conditions. These high accuracy measurements are appropriate only for certain transfer standards (such as photodiode trap detectors) capable of maintaining high accuracies.

101
Special Test for Linearity Measurements of Laser and Optical Fiber

Power Meters (or Detectors Used

with Lasers) (42163S)

Linearity of optical fiber power meters and detectors used with lasers can be

measured at the three nominal wavelength regions of 850 nm, 1300 nm and

1550 nm using automated NIST-designed

measurement systems. These systems are based on dual beam superposition, in which the radiation from two optical

paths is incident (both jointly and indi- vidually) onto the detector. The system can provide linearity characterizations covering a 60 dB to 90 dB power range. Various other wavelengths and powers are also available upon request.

Special Test for Spect'^'al Responsivity

Measurements of Laser and Optical

Fiber Power Meters (or Detectors Used with Lasers) (42164S)

Spectral responsivity measurements on

laser power meters and detectors used

with lasers can be performed over the wavelength region 450 nm to 1700 nm.

High resolution spectral responsivity

measurements can be performed over

limited wavelength regions centered on 850 nm, 1300 rmi, and 1550 nm. These

limited-range spectral response measure- ments can be performed with or without

connectorized fibers attached. Measure- ments over the wider wavelength region

are also available at lower accuracy.

Special Test for Spatial Uniformity of

Laser and Optical Fiber Power Meters

(or Detectors Used with Lasers)

(42165S)

Detector uniformity is measured using a

specially designed system which provides

a small beam of laser radiation (at nominal wavelengths of 850 nm, 1300 nm,

or 1550 nm) which is scanned across the detector surface. The resulting detector output response is displayed graphically

and analyzed statistically. This information is useful for characterizing the quality of a detector used with lasers and or

identifying interference effects caused

by, for example, windows with parallel

surfaces. Other wavelengths are available upon request.

Special Test for General Laser

Measurements (42170S)

The Optoelectronics Division conducts

research not described specifically above on a variety of problems in the characterization of optoelectronics components.

Consequendy, we are interested in dis- cussing and supporting all measurements

involving laser detectors, sources, components, and instrumentation. Examples

of measurement areas include beam profile, relative intensity noise (RIN), optical

density or attenuation, and polarization

(retardance).

Special Test for General Optical Fiber

Power Measurements (42180S)

In support of instrumentation used with

optical fiber power systems, various opti- cal fiber power related measurements are

available by request and prearrangement.

These include power measurements at customer-selected wavelengths (in the ± 20 nm regions around 850 nm,

1300 nm, and 1550 nm), optical attenuator characterization, high power measurements, and power meter measurements

involving unusual connector or fiber types.

References—Laser Power and Energy

NBS Laser Power and Energy Measurements, T. R. Scott, Proc. SPIE O-E

LASE '88, Optoelectronics and Laser

Applications in Science and Engineer-

' ing (1988).

A System for Calibrating Laser Power

Meters for the Range 5-1000 W., E. D. West and L. B. Schmidt, Natl. Bur.

Stand. (U.S.), Tech. Note 685

(May 1987).

A System for Measuring Energy and

Peak Power of Low-Level 1 .064-|xm Laser Pulses, A. A. Sanders and A. L. Rasmussen, Natl. Bur. Stand. (U.S.),

Tech. Note 1058 (Oct. 1982).

Documentation of the NBS C, K, and

Q Laser Calibration Systems, W. E. Case, Natl. Bur. Stand. (U.S.), Int. Report, NBSIR 82-1676 (Sep. 1982).

102
421 lOCA System for Measuring The Characteristics of High Peak Power Detectors of

Pulsed CO2 Radiation, P. A. Simpson,

Natl. Bur. Stand. (U.S.), Tech Note

1023 (Sept. 1980).

Quality Assurance Program for the NBS

C, K, and Q Laser Calibration Systems, W. Case, Natl. Bur. Stand.

(U.S.), Int. Report, NBSIR 79-1619

(Aug. 1979).

Absolute Reference Calorimeter for Measuring High Power Laser Pulses, D. L. Franzen and L. B. Schmidt, Appl. Opt.

15, 3115 (Dec. 1976).

A Calorimeter for High-Power CW

Lasers, R. L. Smith, T. W. Russell,

W. E. Case, and A. L. Rasmussen,

IEEE Trans. Instr. Meas. IM-21, (4) (Nov. 1972).

A Reference Calorimeter for Laser Energy Measurement, E. D. West, W. E. Case, A. L. Rasmussen, and L. B. Schmidt, J. Res. Natl. Bur. Stand.

(U.S.), 76A (1), 13 (Jan.-Feb. 1972). Data Analysis for Isoperibol Laser

Calorimetry, E. D. West, Nad. Bur.

Stand. (U.S.), Tech. Note 396 (Feb.

1971).

Theory of Isoperibol Calorimetry for Laser Power and Energy Measurement,

E. D. West and K. L. Churney, J. Appl.

Phys. 41, (6), 2705 (May 1970).

Deep-UV Excimer Laser Measurements

at NIST, R. W. Leonhardt and T. R.

Scott, Integrated Circuit Metrology,

Inspection, and Process Control IX,

Proc. SPIE 2439, 448-459.

Low-Level Pulsed 1064 nm Laser Radiometer Transfer Standard, R.W

Leonhardt, Optical Radiation Measure- ments III, Proc. SPIE 2815, 154-159.

References—Optical Fiber Power

Meter Measurements

Nonlinearity of Optical Power Meters, I. Vayshenker, S. Yang, X. Li, and T.R.

Scott, Natl. Inst. Stand. Technol. Spec.

Publ. 905, 101-104, (1996). Errors Due to Connectors in Optical

Fiber Power Meters, I. Vayshenker, X. Li, D. Keenan and T.R. Scott, Natl.

Inst. Stand. Technol. Spec. Publ. 905,

49-52, (1996).

Automated Measurement of Nonlinearity

of Optical Fiber Power Meters, I. Vayshenker, S. Yang, X. Li, and T. R.

Scott, Proc. Int. Symp. IMEKO, 2550,

San Diego, CA (July 11-12, 1995).

Optical Detector Nonlinearity: Simulation, S.Yang, I. Vayshenker, X. Li,

M. Zander and T.R. Scott, Natl. Inst. Stand. Technol., Tech. Note 1376 (May

19, 1995). Accurate Measurement of Optical Detector Nonlinearity, S. Yang, I. Vayshenker, X. Li, and T. R. Scott, Proc. Natl. Conf. Stand. Lab.

Workshop and Symp., Session 5A,

353-362, (July-Aug., 1994).

Optical Power Meter Calibration Using

Tunable Laser Diodes, I. Vayshenker, X. Li, and T. R. Scott, Proc. Natl. Conf. Stand. Lab. Workshop and

Symp., Session 5A, 362-372, (JulyAug., 1994).

Optical Detector Nonlinearity: A

Comparison of Five Methods, S. Yang,

I. Vayshenker, X. Li, and T. R. Scott, Digest, Conf. Precision Electromagnetic Measurements, 455-456

(June-July 1994).

Calibrated Optical Fiber Power Meters:

Errors Due to Variations in Connectors, Xiaoyu Li and R. L. Gallawa,

Fiber and Integrated Optics 7 (1988).

Calibration of Optical Fiber Power

Meters: The Effect of Connectors,

R. L. Gallawa and Xiaoyu Li, Appl.

Opt. 26, 1170 (Apr. 1987).

Optical Fiber Power Meters: A Round

Robin Test of Uncertainty, R. L. Gallawa and Shao Yang, Appl. Opt.

25, 1066 (Apr. 1986).

References—Optoelectronic

Frequency Response

A Transfer Standard for Measuring Photoreceiver Frequency Response, P. D.

Hale, CM. Wang, R. Park, and W. Y. Lau, IEEE J. Lightwave Technol. 14,

2457 (1996).

Comparison of Photodiode Frequency

Response Measurements to 40 GHz

between NPL and NIST, A. D. Gifford, D. A. Humphreys, and P. D. Hale,

Electron. Lett. 31, 397 (1995).

103
Chapter

A Radioactivity Sources B Neutron Sources and Neutron Dosimetry

C Dosimetry of X-Rays, Gamma-Rays, and Electrons D Dosimetry for Higli-Dose Applications
Ionizing Radiation Measurements

A Radioactivity Sources

Technical Contacts:

M. P. Unterweger

All Services Tel:30iy97S-5536 Email:munterweger@

nistgov

Jeffrey T. Cessna

43010C, 43020C,

43060C, 43070S

1tl:30 1/975-5539 Email:jcessna@

nistgov

Pamela A. Hodge

43030C-43050C

Ttl:301A>75-5544 Email:phodge@

nist.gov

Diana ChaHerton

Administration and

Logistics 1tl:30iy975-5371 Email:diana. chatterton@nistgov

Mailing Address: Building 245, Room CI 14, National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

For shipping, see below.

Service ID No. Items 43010C Gamma-Ray-Emitting Radionuclides in Solution (Half Lives Greater Than 15 Days)

43020C Gamma-Ray-Emitting Radionuclides in Solution (Half Lives Less Than 1 5 Days)

43030C Alpha-Particle-Emitting Solid Sources, NIST 2 xra Proportional Counter 43040C Alpha-Particle-Emitting Solid Sources, NIST 0.8 ira Defined-Solid-Angle Counter 43050C Alpha-Particle-Emitting Solid Sources, Using Both

Counting Systems

43060S Special Tests of Beta-Particle-Emitting Solution Sources—Liquid Scintillation Counting

43070S Special Tests of Beta-Particle-Emitting Solution

Sources, Other Techniques

43090S Special Tests of Alpha-Particle-Emitting Solid Sources

Radioactivity Sources—General

Information (43010C^3090S)

The National Institute of Standards and

Technology offers calibration services for over 50 radionuclides. Calibrations are provided to meet the requirements of

industry, research, environmental monitoring, and the life sciences. Radioactivity calibration services are available for alpha-particle solid sources, beta-particle

solutions, and gamma-ray solutions. In order to offer such a broad range of

services, NIST must place stringent

limitations on the physical and chemical

form and activity range of sources that

can be accepted. To ensure that these

specifications are understood, it is essential that there be good communication

between the technical user and the technical contact at NIST. When planning to have a source calibrated, the user should discuss the following points

with the NIST contact: A. Type of calibration: More than one type of calibration is often avail- able for a given source. A cobalt-60

source, for example, may be calibrated

in terms of total activity or gamma-rayemission rate. (Inquiries regarding the

calibration of radioactive sources for exposure rate should be directed to the Dosimetry Group. See Service ID

Numbers 47010C to 47040S.) The

required uncertainty in the calibration should also be discussed. B. General packaging and shipping

requirements: Two general require- ments apply to all sources submitted for

calibration: (1) all shipments must

conform to applicable Nuclear Regulatory Commission (NRC) and Department of Transportation (DOT) packaging

and transport; and (2) source descriptions, including approximate activity,

must be provided in advance. The

NIST Health Physics Group must approve

the receipt of radioactive material, and

sources may be refused if the necessary information is not available. C. Reports of Calibration: A Report

of Calibration is sent upon completion

of a radioactivity calibration service. If the user has particular requirements

for documentation of the calibration, these should be discussed with the technical contact at NIST before the services are performed. D. Sample Preparation, Packaging,

and Shipping: All samples submitted

for calibration must be chemically and

physically stable. The chemical form

of solutions suggested for beta-particle emitters and gamma-ray emitters are described later in this document. A special lot of borosilicate-glass ampoules

must be used for gamma-ray emitters. Empty ampoules are provided for this purpose. The volume of material in the ampoule should be (5.0 ± 0.2) mL.

105
43010C-43090S

Packaging for all sources must be in compliance with DOT and NRC

regulations. Copies of regulations may

be obtained from Operations Division,

Office of Hazardous Materials, Department of Transportation, Washington,

DC 20950. Postal regulations prohibit

the mailing of radioactive materials

that require a caution label under DOT

regulations.

Alpha-particle solid sources must be

supplied in special source holders designed so that the active area is not touched by any material. For sources

to be measured in the 2 ira counter

(Service ID No. 43030C), the diameter

of the source must be less than 10 cm

and that of the active surface less than

9 cm. For the 0.8 ira counter (Service ID

No. 43040C), the maximum diameter

is 1.6 cm.

All sources arriving at NIST are checked by the Health Physics Group

for radiation level and source integrity. Sources should be shipped to the attention of the technical contact at NIST,

addressed, for example, as follows: National Institute of Standards

and Technology

Health Physics (Radioactivity

Group)

Attn: (Name of technical contact)

Building 245, Room B131

Quince Orchard and Clopper Roads

Gaithersburg, MD 20899-0001

Gamma-Ray-Emitting Solution

Sources (43010C^3020C)

Tables 8.1 and 8.2 list 41 radionuclide

solutions that may be calibrated in the NIST "4Tr"7 ionization chamber. The

sources must be submitted flame-sealed

in the special ampoules provided by

NIST. The operation of this type of

chamber is described in NCRP Report

58, A Handbook of Radioactivity

Measurements Procedures, Section 4.4

"Ionization Chambers," and in NBS

SP 250-10, Radioactivity Calibrations

with the "4Tr" Gamma Ionization Chamber and other Radioactivity Calibration

Capabilities (see references).

Table 8.1. Specifications for Calibration of Solutions of

Gamma-Ray Emitting Radionuclides Having Half Lives Greater Than 1 5 Days

Typical

Suggested Chemical Form''

Relative Activity

Radio- Expanded Range""

nuclide Uncertainty'**"* (Mbq) Carrier Solution

1.1 0.4 to 40 NaCl 1 mol/L, HCl

^Sc 0.5 0.4 to 40 ScClj 1 mol/L, HCl

5'Cr 0.7 2 to 60 CrClj 0.5 mol/L, HCl

^''Mn 0.8 2 to 60 MnClj 1 moVL, HCl

"Co 0.5 2 to 60 C0CI2 1 mol/L, HCl

0.9 0.4 to 40 FeCla 1 mol/L, HCl

^'Co 0.5 0.4 to 40 C0CI2 1 mol/L, HCl

1.6 2 to 60 HzSeOj 1 mol/L, HNO3

Sr 1.3 2 to 60 SrCl: 1 mol/L, HCl

my 0.5 0.4 to 40 YCI3 1 mol/L, HCl

'°'Cd-''*^"'Ag* 1.1 2 to 60 CdCh 1.3 mol/L, HCl

0.6 0.4 to 40 AgN03 1 mol/L, HNO;

"^Sn-"^"'In"" 2.0 2 to 60 SnClj or 4 mol/L. HCl

SnCU

0.7 2 to 200 InCh 3 moVL, HCl

123m 0.7 2 to 100 TeCl 2 mol/L, HCl

'"Ba 1.0 2 to 60 BaCb 1 mol/L, HCl

'^^Cs 0.7 2 to 60 CsCl 1 mol/L, HCl

1.0 2 to 60 CsCl 1 mol/L, HCl

'^'Ce 0.7 2 to 60 CeClj 1 mol/L, HCl

'^'Ce 1.3 2 to 60 CeCl3 1 mol/L, HCl

'^Ce* 0.9 2 to 740 CeCl, 1 mol/L, HCl

'"Eu 1.1 0.4 to 40 EUCI3 1 mol/L, HCl

1.3 2 to 60 GdClj 1 mol/L, HCl

0.5 0.4 to 40 EuClj 4 mol/L, HCl

'"Eu 1.0 2 to 60 EUCI3 4 mol/L, HCl

l69Yb* 1.7 2 to 60 YbCl3 0.1 mol/L, HC

1.5 2 to 60 KAu(CN)4 10 g/L, KCN

lOg/L, KCl

0.9 2 to 60 Hg(N03)2 0.1 mol/L, HNC

The uncertainty will depend upon the activity level and the chemical form. The source activity should be in the indicated range when it arrives at NIST. The caHbration scheduling must be coordinated with the NIST technical contact.

TTiis information is based in large part on the NIST Standard Reference

Materials for these radionuclides. For those radionuclides marked with an

asterisk, the carrier should be discussed with the NIST technical contact. The calibration for Sn- "In are in terms of gamma-ray-emission rate rather than activity. **See Chapter I, Section H for more information about uncertainty.

106
43010C-43090S

Table 8.2. Specifications for Calibration of Gamma-RayEmitting Radionuclides Having Half Lives Less Than 15 Days

Radionuclide

Typical

Relative Expanded

Uncertainty"""

Suggested Chemical Form''

Activity

Range""

(MBq) Carrier Solution

(%)

^ Na 0.5 0.4 to 40 NaCl 1 mol/L, HCl

Ga 0.9 0.4 to 40 (jaLl3 z mol/L, HLI *Mo-^Tc 1.1 2 to 60 Na2Mo04 4 mol/L, HNO3

1.0 2 to 60 No carrier Saline added/

Na/Te04

'"In 0.9 2 to 60 InCl2 3 mol/L, HCl

123j*(c) 1.0 2 to 60 KI, NajSO., 0.01 mol/L,

LiOH

131j*(c) 0.9 2 to 60 Kl, NajSOj 0.01 mol/L,

LiOH

'^a-'*La 2.3 0.4 to 40 Ba(N03)2, 1 mol/L, HCl

La(N03)3

0.6 2 to 600 ReCl, Saline

1.6 2 to 60 Hg(N03)2 0.1 mol/L,

HNO3

0.9 2 to 60 KAu(CN)4 lOg/L, KCl,

lOg/L, KCN

201'j'j 1.3 2 to 60 T1(N03)3 0.9 mol/L,

HNO,

203pt, 1.1 2 to 60 PbCi2 0.5 mol/L, HCl

The uncertainty will depend upon the activity level and chemical form. The source activity should be in the indicated range when it arrives at NIST. The calibration scheduling must be coordinated with the NIST technical contact. '^'This information is based in large part on the NIST Standard Reference

Materials for these radionuclides. For those radionuclides marked with an

asterisk, the carrier should be discussed with the NIST technical contact. **See Chapter 1, Section H for more information about uncertainty.

AIpha-Particle-Emitting Solid Sources

(43030C-43050C)

Alpha-particle sources may be calibrated using the NIST 2 tt proportional counter, or the NIST 0.8 Tra defined-solid-angle

counter. The former calibration is in terms of alpha-particle-emission rate into 2 ira steradians, while the latter is in terms of total activity. Sources to be

measured by 2 ira proportional counting

should be on an electrically conductive

backing. A more detailed comparison of

these counting systems is given in NCRP

Report 58 (Section 3.7) and in NBS SP

250-5, Alpha-Particle Calibrations.

Backscattering corrections for a variety

of source-mount materials are dis- cussed in the references given. The

source thickness must be such that more than 99.5 % of the emitted alpha

particles have an energy greater than

400 keV. Further specifications for these calibration services are given in Table 8.3. Service ID No. 43050C

includes calibration of the same source using both counting systems.

Large area sources of plutonium238 may also be measured providing the source thickness is as above. The activity range is 10^ Bq to 10^ Bq utilizing

large-area internal and external counters.

Table 8.3. Specifications for Calibrations Using the 2 ira

Proportional Counter and the 0.8 ira Defined Solid Angle Counter

Service ID No. 43030CService ID No. 43040C

Counting System

Sources Calibrated For:

Typical Relative Expanded Uncertainty**'^'

(%)

Activity Range

1.0 %Maximum Source Diameter

NIST 2 TTtt proportional counter

Alpha-particle- emission

rate into 2 ira

steradians either above 400 KeV

or extrapolated

to zero KeV

1.0

-(0.4 to 10") Bq

10 cm (9 cm

active surface)

NIST 0.8 -rra defined-solid- angle-counter

Total activity

1.0

= (40 to 10") Bq

1 .6 cm

'"The uncertainty will depend upon the activity level and source geometry. **See Chapter 1, Section H for more information about uncertainty.

107
43010C-43090S

Table 8.4. Specifications for Special Tests of

Beta-Particle-Emitting Solution Sources

Kaoio*

nuclide

lypicai

unccriainiy

(%)

Suggested Chemical Composition""

Carrier Solution

0.7 H2O H2O

'"C 1.0 NajCOj 0.001 mol/L, NaOH

32p(c) 0.7 H3PO4 0.0034 mol/L, H3PO4

33p 0.7 H3PO4 0.0034 mol/L, H3PO4

''S 0.7 Li2S04 0.1 mol/L, HCl

''CI 1.3 NaCl H2O

0.7 SrClj I mol/L, HCl

90sr_90Y 0.7 SrCh/YClj 1 mol/L, HCl

0.7 YCI3 1 mol/L, HCl

0.7 PmClj 1 mol/L, HCl

20*-pj 1.3 T1(N03)3 1 mol/L, HNO3

'^'The uncertainty will depend upon the activity level and the chemical form. The chemical composition is critical for these calibrations and should be

discussed before sending the source. This calibration includes a half-life fit to determine the ''"'P impurity.

* See Chapter I , Section H for more information about uncertainty.

Special Tests of Beta-Particle-Emitting

Solution Sources (43060S and 43070S)

Beta-particle-emitting solutions that con- form to the physical, chemical, and activity specifications for measurement are assayed by liquid-scintillation counting.

The specifications are shown in Table

8.4. The suggested radioactivity concentration range is (20 to 2000) kBq/g.

No examination is made for beta-particle-emitting impurities, except in the case of phosphorus-32 where a half-life fit is made. The sources will be examined for gamma-ray emitting impurities.

Measurement of beta-particleemitting solutions by techniques other than liquid-scintillation may be made by

special arrangement.

Special Alpha-Particle-Emitting Solid

Sources (43090S)

Special arrangements may be made for measurements of solid alphaparticle-emitting sources with emission

rates exceeding 1 . 1 X 1 0'' Bq.

References—Radioactivity Sources

NBS Measurement Services: Radioactivity Calibrations with the "4tt" Gamma

Ionization Chamber and Other

Radioactivity Calibration Capabilities,

J. M. Calhoun, Natl. Bur. Stand.

(U.S.), Spec. Publ. 250-10 (Oct. 1987).

NBS Measurement Services: Alpha-Particle Calibrations, J. M. R. Hutchinson,

Natl. Bur. Stand. (U.S.), Spec. Publ. 250-5 (July 1987).

NCRP Report 58, A Handbook of Radioactivity Measurements Procedures,

Section 3.7—Alpha-Particle Counting,

W. B. Mann, Ed., Natl. Council Rad.

Protect, and Meas., Washington, DC

(1985).

Study of the Scattering Correction for Thick Uranium-Oxide and OtherParticle Sources, I: Theoretical, L. L. Lucas and J. M. R. Hutchinson, Int. J. Appl. Radiat. Isotopes 27, 35 (1976).

Study of the Scattering Correction for Thick Uranium-Oxide and OtherParticle Sources, II: Experimental, J. M. R. Hutchinson, L. L. Lucas, and

P. A. Mullen, Int. J. Appl. Radiat. Iso- topes 27, 43 (1976).

Backscattering of Alpha Particles from

Thick Metal Backings as a Function of

Atomic Weight, J. M. R. Hutchinson,

C. R. Naas, D. H. Walker, and W. B. Mann, Int. J. Appl. Radiat. Isotopes,

19, 517 (1968).

An Experimental Study of the Backscattering of 5.3 MeV-Alpha Particles from Platinum and Monel Metal, D. H.

Walker, Int. J. Appl. Radiat. Isotopes

16, 183 (1965).

108
44010C-44100S

5.

Neutron Sources and Neutron Dosimetry

James M. Adams

All Services Except 44060C

1tl:30 1/975-6205 Email :adams@nistgov

Technical Contacts:

Alan K. Thompson

44060C, 44100S

ftl: 301/975-4666

Email: alan.thompson@ni$t.gov

Mailing Address: Building 235, Room A 159,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address: National Institute of Standards

and Technology,

Health Physics (Neutron Interactions and Dosimetry)

[Attn: Name of Technical Contact],

Building 245, Room Bl 31,

Quince Orchard and Clopper Roads,

Gaithersburg, MD 20899-0001

Service ID No. Items 440 IOC

44020C

44060C

44070C

44080C

44090C

44100S

Radioactive Neutron Sources (emission rates

10^ S-' to 10** s ') Radioactive Neutron Sources (emission rates

10* S-' to 10'" s-') Personnel Protection Instrumentation, Californium

Source Bare and Moderated

Activation Detector Dosimetry, Thermal Neutrons

Activation Detector Dosimetry, Californium Fission Neutrons

Activation Detector Dosimetry, ^"U Cavity Fission Source

Special Tests of Neutron Sources and Dosimeters

Radioactive Neutron Sources

(44010C^4020C)

NIST provides calibration services

for radioisotope neutron sources with

emission rates from 5X10^ s~' to

1 X 10'" s"'. Neutron source emission rates are determined by the manganous sulfate bath method, in which the emission-rate

of the source to be calibrated is compared to the emission-rate of NBS-1, the national standard Ra-Be photoneutron

source. Neutron source calibrations typically have a relative expanded uncertainty* of about 3.4 %, depending on the

details of the source encapsulation.

*See Chapter 1, Section H for more information about uncertainty.

Personnel Protection Instrumentation

(44060C)

Neutron personnel instruments, both passive (e.g., dosimeters) and active (e.g., remmeters) are calibrated on the basis of

a certified free-field dose-equivalent or dose equivalent rate. Two "^Cf source- driven neutron fields are available on a routine basis for this purpose: bare source and heavy-water-moderated "^Cf

fission neutron sources. Thermal neutron beams are also available for special

requirements under Service ID No. 44100S. For both bare and moderated

^^^Cf source exposures, maximum doseequivalent rates are about 5 mSv/li. The

relative expanded uncertainty* is 10 %.

Activation Detector Dosimetry

(44070C-44090C)

Passive neutron detectors, generally acti- vation foils, can be irradiated to a certi- fied neutron fluence (or average

fluence-rate) in a fission neutron spec- trum or a Maxwellian thermal neutron

field. Typical irradiation parameters are given in Table 8.5.

Table 8.5. Irradiation Parameters for Fission Spectra

and Maxwellian Thermal Neutron Fields

Typical Typical

Maximum Maximum Relative Neutron Neutron Expanded

Fluence Fluence Rate Uncertainty* Neutron Field (cm--) (cm -s ') (%)

-"Cf Fission Source 5 X 10'- 2 X 10' 2.6«" "^U Cavity Fission 5 X 10'5 2 X 10'° 4.6*'

Source*^' Thermal Neutrons 1 X 10'^ 8 X 10' 5 Beam"^'

Isotropic >1 X 10"" 2 X 10" 5

Threshold detectors only. Maximum size of detector disks: 12.7 mm

dia.X about 3 mm thictc. The radial gradient of the fluence: is about 20 %

center-to-edge. Uncertainty includes neutron scattering corrections. Maxwellian distribution corresponding to a temperature of about 40 °C. *See Chapter 1, Section H for more information about uncertainty.

109
Special Tests of Neutron Sources and

Dosimeters (44100S)

Other tests of dosimetry instrumentation

may be undertaken by special arrange- ment with the Ionizing Radiation Division. In particular for personnel

protection instruments, a thermal beam

can provide dose equivalent rates of up to approximately 10 mSv/h across a 30 cm

diameter circle.

References—Radioactive Neutron

Sources

NBS Measurement Services: Neutron

Source Strength Calibrations at NBS

by the Manganese Sulfate Bath

Method, E. D. McGarry and E. W.

Boswell, Natl. Bur. Stand. (U.S.),

Spec. Publ. 250-18 (Mar. 1988). Neutron Source Calibrations at NBS for Calibration Checks of Neutron Radiation Instruments, V. Spiegel, Jr., Proc. of Symp. on Meas. for the Safe Use of

Radiation, Natl. Bur. Stand. (U.S.),

Spec. Publ. 456, 87 (Nov. 1976).

Calibration of Thermal Neutron

Absorption in Cylindrical and Spherical Neutron Sources, V. Spiegel, Jr., and W. M. Murphey, Metrologia 7, 34

(Jan. 1971).

The Correction Factor for Fast Neutron

Reactions on Sulphur and Oxygen in the Manganous-Sulfate-Bath Calibration of Neutron Sources, W. M.

Murphey, Nucl. Instrum. Methods 37, 13 (1965).

Absolute Calibration of the National Bureau of Standards Photoneutron

Source: III. Absorption in a Heavy Water Solution of Manganous

Sulfate, R. H. Noyce, E. R. Mosburg,

Jr., S. B. Garfinkel, and R. S. Caswell,

J. Nucl. Eng. 17 (7), 313 (1963).

Absolute Calibration of the National Bureau of Standards Photoneutron Standard: I., J. A. DeJuren, D. W. Padgett,

and L. F. Curtiss, J. Res. Natl. Bur.

Stand. (U.S.), 55, 63 (Aug. 1955).

References—Personnel Protection

Instrumentation

NBS Measurement Services: Neutron

Persormel Dosimetry, R. B. Schwartz,

Natl. Bur. Stand. (U.S.), Spec. Publ. 250-12 (July 1987).

Procedures for Calibrating Neutron

Personnel Dosimeters, R. B. Schwartz,

Natl. Bur. Stand. (U.S.), Spec. Publ. 250-12 (July 1987).

Calibration Techniques for Neutron Per- sonnel Dosimetry, C. M. Eisenhauer,

J. B. Hunt and R. B. Schwartz, Radiat.

Prot. Dosim. 10, 43-57.

The Design and Construction of a D2OModerated ^'^Cf Source for Calibrating Neutron Personnel Dosimeters Used at Nuclear Power Reactors, R. B. Schwartz and C. M. Eisenhauer, U.S.

Nucl. Reg. Com. Doc. NUREG/CR1204 (Jan. 1980).

References—Activation Detector Dosimetry

NBS Measurement Services: Activation

Foil Irradiations at NBS by Cali- fornium Fission Sources, G. P. Lamaze

and J. A. Grundl. Natl. Bur. Stand.

(U.S.), Spec. Publ. 250-13 (Mar.

1988).

NBS Measurement Services: Activation

Foil Irradiations at NBS by Reactor

Cavity Sources, G. P. Lamaze and J. A. Grundl, Natl. Bur. Stand. (U.S.),

Spec. Publ. 250-14 (Mar. 1988).

Derivation of Neutron Exposure Parameters from Threshold Detector Measurements, J. A. Grundl, Proc. Sixth

ASTM-Euratom Symp. on Reactor

Dosimeter, Jackson, WY (June 1987).

Compendium of Benchmark Neutron

Fields for Reactor Dosimetry, J. A. Grundl and C. M. Eisenhauer, Natl. Bur. Stand. (U.S.), NBSIR 85-3151

(Apr. 1985).

The U.S. ^"^^U Fission Spectrum Standard Neutron Field Revisited, E. D. McGarry, C. M. Eisenhauer, D. M.

Gilliam, J. A. Grundl, G. P. Lamaze,

and A. Fabry, Proc. Fifth ASTM-Euratom Symp. on Reactor Dosimetry,

Geesthacht, Germany (Sept. 1984).

1 10
44010C-44100S

National Standards for Neutron Measurements, J. A. Grundl, Proc. of a Meeting on Traceability for Ionizing

Radiation Measurements, Natl. Bur.

Stand. (U.S.), NBS Spec. Publ. 609

(Feb. 1982).

Utilization of Standard and Reference Neutron Fields at NBS, C. M.

Eisenhauer, D. M. Gilliam, J. A.

Grundl, and V. Spiegel, Proc. Sec- ond ASTM-Euratom Symp. on Reactor Dosimetry, Palo Alto, CA (Oct.

1977).

A Californium-252 Fission Spectrum

Irradiation Facility for Neutron

Reaction Rate Measurements, J. A.

Grundl, V. Spiegel, C. M. Eisenhauer, H. T. Heaton II, D. M. Gilliam

(NBS), and J. Bigelow (ORNL),

Nucl. Tech. 32, 315 (Mar. 1977).

Ill
46010C-48020S

C. Dosimetry of X-Rays, Gamma-Rays,

and Electrons

Technical Contacts:

Steven M. Seltzer

All Services

Tel: 301/975-5552

Einail:s.$eltzer@ nist^ov

Jileen Shobe

46010C^t6050S, 47010C^7011C

Tel:30 1/975-5595 Emaihjileen.shobe @nist.gov

Paul G. Lamperti 46010C-46050S

Tel: 301/975-5591 Emaihpaul.lamperti

@nist.gov

Christopher G.

Scares

Test 47030C^7035C

47036C, 47040S, 48010M^»8020S

Tel: 301/975-5589 Email:csoares@

nist.gov

C. Michelle O'Brien James T. 46010C^»6050S

Tel: 301/975-2014 Emaihmichelle.

obrien@nist.gov

Marc F. Desrosiers 48010M-480nM

Tel :30 1/975-5639 Emaihmarc.

desrosiers@

nist.gov

Weaver, Jr. 47010C, 4701 IC, 47040S

Tfel: 301/975-5586 Emaihjames.

weaver@nistgov

James M. Puhl 48010M^t8011M

1^1:301/975-5581 Eniail:jpuhl@

nist.gov

Mailing Address: Building 245, Room C229,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001 Fax: 301/869-7682

Shipment of Instruments:

National Institute of Standards and Technology,

Building 245, Room C229,

[For: 46010C-46050S; Attn: R J. Lamperti]

[For: 47010C-47040S; Attn: J. T. Weaver

(for Gamma-Ray Sources); Attn: C. G. Soares (for Beta-Particle Sources)]

[For: 48010M-48020S; Attn: C. G. Soares] 1-270 at Quince Orchard Road,

Gaithersburg, MD 20899-0001

Shipment of Sources:

National Instimte of Standards and Technology,

Health Physics,

Building 245, Room B131,

[For: 47010C-47040S;

Attn: J. T. Weaver (for Gamma-Ray Sources)] Attn: C. G. Soares (for Beta-Particle Sources)] 1-270 at Quince Orchard Road,

Gaithersburg, MD 20899-0001

Service roNo. Items CO Special Instructions for Using Electron and Photon

Dosimetry Services (46010C-48020S)

C.l X-Ray and Gamma-Ray Measuring Instruments 460 IOC Radiation Detectors—Calibration/Correction

Factor, One Beam Quality (See Tables 8.6, 8.7 and 8.8) 4601 IC Each Additional Beam Quality or Condition 46020C Passive Dosimeters—Irradiation of Up to Six, One

Beam Quality at One Set-Up

4602 1 C Up to Six Additional Dosimeters at Same Set-Up and Beam Quality

46030S Special Tests of High-Gain Electrometers—Charge

Sensitivity, One Set of Switch Positions, with 46010C/4601 IC, by Prearrangement

46040S Special Tests of X-Ray Penetrameters, Ardran- Crookes Type

46050S Special Tests of X-Ray and Gamma-Ray Measuring

Instruments C.2 Gamma-Ray Sources, Beta-Particle Sources,

and Measuring Instruments 470 IOC Gamma-Ray Sources Similar to NIST Standards—

^Co or '"Cs Having Air-Kerma Strengths 10 jjiGy mVh

to 1500 jjiGy mVh, and '"l or ''^Ir Sources: Same Type

Seeds Used to Calibrate Reentrant Chamber Having Air- Kerma Strengths 0. 1 fjiGy m% to 30 }j,Gy mVh

4701 IC Each Additional Gamma-Ray Source of Same

Radionuclide 47030C Beta-Particle Sources Calibrated for Surface Dose Rate 47035C Beta-Particle Sources Calibrated for Radiation

Protection 47036C Ionization Chambers Calibrated with Beta-Particle Sources for Radiation Protection 47040S Special Tests of Gamma-Ray and Beta-Particle Sources C.3 Dosimetry of High-Energy Electron Beams

480 lOM Dose Interpretation of NIST-Packaged Dosimeters

Irradiated by Customer—Two Dosimeters

4801 IM Each Additional Dosimeter

48020S Special Tests of Electron-Beam Dosimeters

CO Special Instructions for Using

Electron and Photon Dosimetry

Services (46010C^8020S)

The NIST dosimetry calibration and test services for x rays, gamma rays, beta particles, and electrons are performed in NIST's laboratories at Gaithersburg,

Maryland. Inquiries should be addressed

112
46010C-48020S

to the appropriate technical contacts Hsted at the beginning of this section. The inquirer must provide the name and

telephone number of an individual who

can answer technical questions that may

arise in any inquiry, order, or shipment.

Upon receipt of a purchase order, a re- port number is assigned. CaHbrations are generally performed in the sequence es- tablished by those numbers, except when

greater efficiency can be achieved by

combining similar caHbrations, or when

work for a calibration laboratory is given

a higher priority. Arrangements for cali- bration must be made in advance by let- ter, fax, e-mail or telephone, so that the instrument or source to be calibrated will not be shipped to NIST until the time of

its scheduled calibration approaches. In- quiry should be made as to scheduling

and turn-around time. Except in the event of negligence by

its personnel, NIST assumes no responsibility for loss of or damage to the instru- ments or sources while in its possession.

The risk should be covered by insurance. The report of calibration or test will carry a DG number (e.g., DG 9603/95).

Subsequent reference to that calibration or test should cite the DG number.

C.l X-Ray and Gamma-Ray Measuring Instruments (46010C-46050S)

X-ray measuring instruments are cali- brated in terms of air kerma or exposure by a substitution method in an x-ray beam at a point where the rate has been

determined by means of a free-air ionization chamber standard. In order to provide instrument calibrations over a wide range of x-ray beam qualities, many

combinations of generating potential and

filtration are available. Tungsten (W) an- ode, x-ray beams with U.S. established beam qualities are listed Table 8.6 as

lightly (L), moderately (M), and heavily

(H) filtered beams. Two beam qualities that do not fit into these categories are considered as special (S) qualities.

Cobalt-60 and cesium- 137 gamma-ray

beams are also available. New W-anode,

ISO x-ray beam qualities, listed in Table

8.7 are being installed; check for

availability. Molybdenum (Mo) and

rhodium (Rh) anode x-ray beam qualities, with application to mammography,

are listed in Table 8.8. Beam qualities are

identified by beam codes given in the

first column. The calibration beam

qualities requested should be appropriate

to the instrument submitted.

Gamma-ray measuring instruments are

calibrated in terms of air kerma, or absorbed dose at points in the collimated cobalt-60 and cesium- 1 37 gamma-ray

beams that have been standardized by means of graphite cavity chambers or a

graphite (or water) calorimeter. Rates at the time of calibration are computed

from the original beam standardization data and appropriate decay corrections. Ionization chambers submitted for an air kerma calibration should have sufficient wall thickness to provide electron equilibrium for the highest energy selected. Ionization chambers submitted for an ab- sorbed-dose calibration must be suitable

for calibration in a phantom.

An ionization chamber and electrometer combination, with the electrometer

scale in units of air kerma, exposure, or absorbed dose, is calibrated by providing a dimensionless correction factor for the electrometer scale. An ionization chamber and electrometer combination marked

in electrical units is calibrated as fol- lows: (1) the chamber is calibrated in terms of air kerma or absorbed dose per

unit charge using an NIST electrometer;

(2) the customer's electrometer is checked for linearity and charge measurement accuracy; and (3) the combination of chamber and electrometer is checked for consistency. An ionization chamber submitted without an electrometer is calibrated in terms of air kerma or absorbed dose per unit charge. Calibration can be based on measurements for positive or negative polarizing potential, or on the mean of measurements for both

potentials, as requested. The ratio of ionization currents for full and half polarizing potentials and the corresponding

ionization current will be stated in the

calibration certificate, based on precalibration measurements.

113
Table 8.6. Tungsten-Anode X-Ray and Gamma-Ray Beam-Quality Parameters

Beam Added Filter Half-Value Homogeneity

Code Layer Coefficient Al Cu Sn Pb Al Cu Al Cu

(mm) (mm) (mm) (mm) (mm) (mm)

Effective Air-Kerma Rate Energy Min. Max.

(keV) ((iGy/s) (mGy/s)

X-Ray Beams

TLIU1 n u

u L20 0

L30 0.265

T /in A < U.J A ATO

1 .Zo4

1 1 AA 1 .y /o MzU A T3 MjU A ^ U.J

IV14U U. /oo

A >f CA 1 AO 1 l.UZl MoU 1.51

MlOO 5 M120^

\ * 1 CA cJ A O < U.ZJ

\ yTO AA MzUO A 1 4. 1 l.lz M250 5 3.2 M300 4.

HIO 0.105 H15 0.5 H20 1.021 H30 413

H40 4.05 0.26 H50 4 H60 4 0.61 HlOO 4 5.2 H150 4 4 H200 4 0.6 H250 4 0.6 H300 41

S75 1.504 S60 4.0

6.5

0.1

1.51 4.16 0.77

1.04 2.72

3 5

Gamma-Ray Beams

'"Cs

70 1 C

1 D

7/1 J> / U.U/ 1 1«/O n nno 7Q

u.zz ou u.uuy AH- 0.49 57 0.009 4

0.75 58 0.009 4

1 JO A AAA u.uuy 4

/.o jV A AAA U.uuy 4

U. 1 j/ TO n AAQ u.uuy 4.4 o4 A AAA u.uuy J

U. / 3 DO A AAA U.uuy 4

1 AO 1 .Uz A A'20 U.Ujz DO DZ A AAA U.uuy 4

l.oo A A^O U.Ujz DO o4 1 z

c^ A O U.Z ccJJ y J

•7

10.2 0.67 87 62 9 4

14.9 1.69 95 69 9 3

^.z CAso y L

22 5.3 100 97 4 0.7

0.048 89 0.009 0.03 0.152 87 0.009 0.03 0.36 88 0.009 0.03

1.23 0.038 93 94 0.009 0.03

2.9 0.093 94 95 0.009 0.03

4.2 0.142 92 90 38 3 0.6 6 0.24 94 89 46 0.2 0.04

13.5 1.14 100 94 80 0.04 0.02

17 2.5 100 95 120 0.3 0.09

19.8 4.1 100 99 166 0.2 0.05 22 5.2 100 98 211 0.3 23 6.2 99 98 252 0.4 0.03

1.86 63 0.009 4

2.8 0.089 75 70 3 0.5

10.8 662 1.5 1.1 14.9 1250 0.11 6.2

For the x-ray beam codes, the letter indicates light (L), moderate (M), heavy (H), and special (S) filtration and the number is the constant potential in kilovolts. The inherent filtration is approximately 1.0 mm Be for beam codes LIO-LIOO, M2(>-M50, H10-H40, and S75; and

3.0 mm Be for beam codes M60-M300, H50-H300, and S60. The half-value layers for '"Cs and *'Co are calculated. The homogeneity coefficient is taken as 100 (1st HVLy2nd HVL).

' Beam parameters are nominal; actual values should be available by 1998.

114
460 lOCTbble 8.7. Tungsten-Anode ISO X-Ray Beam Quality Parameters (available 1998)

Beam Added Filter Half-Value Homogeneity

Code Layer Coefficient Al (mm)

Cu

(mm)

Sn Pb A! (mm) (mm) (mm)

Cu

(mm)

Al Cu

HKIO 0.15 0.036 0.010 88 90

HK20 0.15 0.12 0.007 75 78

HK30 0.52 0.38 0.013 63 72 HK60 3.2 z.4z u.u/y HA/4 11 HKIOO 5.9 0.15 O.JO U.jU Q 1 o4

HK200 1 1 c

1.15 14.7 l./V ncyj /

1

HK250 1.6 16.6 2.47 9o 75 HK280 3.0 18.6 5.51 no

yo 84

HK300 2.5 18.7 3.40 97 82 WK60 0.3 0.18 86 WS80 0.5 0.35 80

WSllO 2.0 0.96 86 WS150 1.0 1.86 89 WS200 2.0 3.08 93 WS250 4.0 4.22 96 WS3(X) 6.5 5.20 97 NSIO 0.1 0.047 90

NS15 0.5 0.14 88 NS20 1.0 0.32 86

NS25 2.0 0.66 90

NS30 4.0 1.15 88 NS40 0.21 0.084 92

NS60 0.6 0.24 92

NS80 2.0 0.58 94

NSlOO 5.0 1.11 95 NS120 5.0 1.0 1.71 97 NS150 2.5 2.36 96

NS2(X) 2.0 3.0 1.0 3.99 99

NS250 2.0 3.0 5.19 99

NS300 3.0 5.0 6.12 100 LKIO 0.3 0.058 99

LK20 2.0 0.42 99

LK30 4.0 0.18 1.47 99

LK35 0.25 2.20 99

LK55 1.2 0.25 99 LK70 2.5 0.49 99 LKIOO 0.5 2.0 1.24 99 LK125 1.0 4.0 2.04 99 LK170 1.0 3.0 1.5 3.47 99

LK210 0.5 2.0 3.5 4.54 100 LK240 0.5 2.0 5.5 5.26 100

In the beam codes, the letters indicate low air icenna rate (LK), high air kerma rate (HK), narrow spectrum (NS), and wide spectrum (WS); and the number is the constant potential in kilovolts. The inherent filtration is approximately 1.0 mm Be for beam codes LK10-LK30, NS10-NS30, HK10-HK30; for all other techniques the inher- ent filtration is adjusted to 4 mm Al. Values of half-value layers and homogeneity coefficients are nominal; actual values and available air-kerma rates are being determined.

Ionization chambers are tested, prior to calibration, for connection to the atmosphere. Chambers found unsuitable for calibration will be returned with a state- ment of the reason for rejection. A

charge may be made for time incurred on

the tests. Each instrument submitted to NIST for dosimetry calibration or test must be

uniquely identified, usually by the manufacturer's name, model number, and in- strument serial number. When the serial number is lacking, an alternative identifying mark should be provided. If none is found, NIST will mark the piece with an

identification number. If the apparatus

submitted has been calibrated previously

by NIST, the serial number or identifying

mark should be given on the new order so that a continuing record of stability can be maintained.

All shipments to NIST of instruments

for dosimetry calibration must be in reusable containers. Even if properly

packed, there can be no assurance that a

calibrated instrument has maintained its calibration during shipment unless a method of verifying instrument stability

has been established. Measurement

should be made of the instrument re- sponse both before and after shipment,

using a long-lived radioactive source and

a highly reproducible measurement pro- cedure. A long-term record of instrument

stability using a suitable constancy check

procedure is the most effective method

for assuring the validity of the instrument

calibration. Irradiation of passive dosimeters, for readout by the customer, is available for most of the beam qualities listed in Table

8.6. These irradiations are generally in terms of air kerma; for passive dosimeters suitable for insertion in a phantom,

irradiation in terms of absorbed dose can be provided by in-phantom irradiation us- ing cobalt-60 gamma rays. Calibrations of x-ray and gamma-ray

measuring instruments and of passive

dosimeters, described above, have a relative expanded uncertainty* of 1 %.

*See Chapter 1 , Section H for more information about uncertainty.

115
46010C-48020S

Table 8.8. Mammography X-Ray Beam-Quality

Parameters

lube Added Half-Value Homogeneity

Beam Voltage Filter Layer Coefficient Code (kVp) (mm) (mm Al) (Al)

]Vto Anode

Mo/Mo23 23 yj.yjDZ, iviu O.Z / I 70

Mo/Mo25 25 yj,yjjz, iviu 72

Mo/Mo28 28 n mo \Art yj.yjjz ivio 74

Mo/Mo30 30 AV.VjZ n79 \An IVlO U. j3 1 75 Mo/Mo35 35 U.UjZ ivio 78

Mo/Rh28 28 0.029 Rh 0.408 80 Mo/Rh32 32 0.029 Rh 0.445 82

Mo/Mo25x 25 0.030 Mo + 2.0 Al 0.566 91 Mo/Mo28x 28 0.030 Mo + 2.0 Al 0.626 96

Mo/Mo30x 30 0.030 Mo + 2.0 Al 0.660 95 Mo/Mo35x 35 0.030 Mo + 2.0 Al 0.748 90

Rh Anode

Rh/Rh25 25 0.029 Rh 0.351 76

Rh/Rh30 30 0.029 Rh 0.438 81 Rh/Rh35 35 0.029 Rh 0.512 86 Rh/Rh40 40 0.029 Rh 0.559 90

Rh/Rh30x 30 0.029 Rh + 2.0 Al 0.814 96

Rh/Rh35x 35 0.029 Rh + 2.0 Al 0.898 95

The beam codes are a combination of the chemical symbol of the anode and the filter respectively, followed by the constant potential in kilovolts. The

letter "x" ends the beam codes which denote "exit" beams. The exit beam

qualities, which are intended to represent the transmission of the x-rays through the breast, are generated by an additional filtration of 2.0 mm of aluminum. The inherent filtration is 1 mm Be for all beam qualities. The calibration distance is 1 m. The half-value layers were determined through direct measurements with the primary standard free-air ionization chamber. The air kerma rates for the entrance beams are between 0.5 mGy/s and I mGy/s, and

less than 0.2 mGy/s for the exit beams.

C.2 Gamma-Ray Sources, BetaParticle Sources, and Measuring

Instruments (47010C^7040S)

Sources submitted to NIST for dosimetry

calibration are subject to the following

conditions: A. Preparation: Sources submitted

for calibration must be sealed so that there can be no escape of any radioactive material, including any gaseous decay

products. The sources, shielding, and

packaging must be free of contamination.

Contaminated or leaking sources cannot be measured and may cause considerable

loss of time and damage to laboratory

facilities. Sources must have been sealed

for a sufficient time to be substantially in radioactive equilibrium with their decay

products when these contribute to the emitted radiation. B. Packaging for shipment: Packages

must be in compliance with the regulations of the Department of Transportation

as specified in DOT 49CFR173.401-

173.476. Radionuclides must be packaged as Limited Quantities (DOT

49CFR173.421-173.422) or in Type A

packages (DOT 49CFR 173.41 2 and

173.433). Type A packages must bear

the appropriate radioactive-hazard labels (DOT 49CFR 172.403). If the source is considered by the shipper to be in DOT

Special Form, a Special Form certificate must be furnished to NIST in strict compliance with DOT 49CFR1 73.476. Copies of the regulations cited above are

available from the Government Printing

Office, Washington, DC 20402.

All shipments to NIST of gamma-ray

and beta-particle sources should be in reusable containers. A drawing showing

the source container and a description of

the method of source removal should be

provided before the shipment is received

at NIST.

If the nature of the shipment requires a Type B container subject to an NRC

quality assurance program, documentation should be supplied to NIST certifying that the use of the container by NIST

is part of the program of the shipper. C. Possession of licensed materials: In submitting a source for calibration, it is necessary for the submitter to certify that he is duly authorized to possess the source under license by the applicable authority. In the case of indi- viduals residing in a State that has

entered into agreement with the Nuclear

Regulatory Commission, State regulations are applicable to all sources. In the case of other individuals, NRC regulations are applicable. This certification may be by letter, by a suitable statement on the purchase order covering the

calibration fee, or by a clear copy of the submitter's Possession License for the source.

116
46010C-48020S

Calibration in terms of air kerma

strength (air kerma rate in free space

times the square of the distance of the calibration point from the source center along the perpendicular bisector) is provided for gamma-ray sources of

cobalt-60, cesium- 137, iridium- 192,

and iodine- 125. Calibration in terms of

absorbed-dose rate is provided for suitable encapsulated beta-particle sources; the dose rate to a low-atomicnumber material (graphite or plastic) is determined by measurement with an

extrapolation chamber. The betaparticle sources may be either small-area sources such as ophthalmic applicators, or large-area plaques, and will be cali- brated for absorbed dose rate to water

either at the source surface or at a specified distance. Ionization chambers to be calibrated with beta-particle sources must be

parallel-plate chambers with thin walls. They can be calibrated with the radio- nuclides "^Sr 4- ^Y, or or '^'Pm. Measurement services in this series have uncertaities listed in Tables 8.9 and

8.10.

Tkble 8.9: Uncertainties for GammaRay Source Calibrations, 470 IOC and

4701 IC

Relative Expanded

Source Uncertainty*

(%)

«'Co 2 '"Cs 2

2

'^^I (no marker) 5(a)

'"I (Ag wire) 6(a)

'^I (Au wire) 7(a)

A new standard and calibration measurement is under development for seed sources. The new

calibrations are anticipated to be available in 1998, with smaller uncertainties than those listed above. *See Chapter 1 , Section H for more information about uncertainty.

Table 8.10. Uncertainties for Beta-Particle Source and

Instrument Calibrations

Service ID Item

Relative

Uncertainty*

(%)

47030C Sources calibrated for surface 12 dose rate 47035C Sources calibrated for radiation 4.5

protection, *Sr +

204-pj 4.59

47036C Transfer ionization chambers for same as 47035C

radiation protection

Extrapolation chambers for radiation same as 47035C

protection, absolute Extrapolation chambers for radiation J (a)

protection, relative to NIST standard chamber in reference field

Typical value. Actual value depends on response characteristics of submitted chamber. *See Chapter 1, Section H for more information about uncertainty.

C.3 Dosimetry of High-Energy

Electron Beams (48010M^8020S)

Dosimeters are provided twice a year

to users requesting assistance with

absorbed-dose measurements in high- energy electron beams. The dosimeters

are alanine dosimeters. The user irra- diates the two furnished dosimeters to between 50 Gy and 80 Gy (5000 and

8000 rad) to water at electron energies

between 5 MeV and 50 MeV, employing the irradiation geometry (field size, phantom, position of dosimeter in phantom) given in the "Protocol for Dosimetry of High-Energy Electrons,"

Physics in Medicine and Biology 11,

505 (1966).

After irradiation, the dosimeters are returned to NIST for evaluation in terms of absorbed dose in the phantom,

using the appropriate methods. These

dose interpretations ignore certain corrections for the effects of spectral

perturbations, and so represent a measurement quality assurance service

rather than a calibration service.

117
The measurement procedure with alanine dosimeters is undergoing refinement; for the current procedure, the corresponding

estimate of the relative expanded uncertainty* is 2.3 %.

References—Dosimetry of X Rays,

Gamma Rays, and Electrons

C.l X-Ray and Gamma-Ray

Measuring Instruments NBS Measurement Services: Calibration

of X-Ray and Gamma-Ray Measuring

Instruments, R J. Lamperti, T. R Loftus, and R. Loevinger, Natl. Bur.

Stand. (U.S.), Spec. Publ. 250-16

(Mar. 1988).

The Photon-Fluence Scaling Theorem for Compton-Scattered Radiation, J. S. Pruitt and R. Loevinger, Med. Phys. 9, 176 (1982).

The Graphite Calorimeter as a Standard

of Absorbed Dose for Cobalt-60

Gamma Radiation, J. S. Pruitt, S. R. Domen, and R. Loevinger, J. Res.

Natl. Bur. Stand. (U.S.), 86, 495

(1981).

Medical Dosimetry Standards Program of

the National Bureau of Standards, R. Loevinger, Proc. Symp. on Natl,

and Intl. Standardization in Rad.

Dosimetry, Atlanta, GA, Dec. 5-9,

1977, Intl. Atomic Energy Agency,

Vienna (1978). (This article provides

references for earlier publications on NBS exposure and absorbed-dose

standards.)

Uncertainty in the Delivery of Absorbed

Dose, R. Loevinger and T. P. Loftus,

Ionizing Radiation Metrology, International Course at Varenna, Italy, 1974,

E. Casnati, Ed., G-6, 459, Editrice

Compositori, Bologna (1977).

Exposure Spectra from the NBS Vertical- Beam ^Co Gamma-Ray Source, M.

Ehrlich and C. G. Soares, Natl. Bur.

Stand. (U.S.), NBSIR 76-1 1 17 (1976).

Spectrometry of a ^'Co Gamma-Ray

Beam Used for Instrument Calibration,

M. Ehrlich, S. M. Seltzer, M. J. Bielefeld, and J. I. Trombka, Metrologia 12,

169 (1976).

*See Chapter 1, Section H for more information about uncertainty.

C.2 Gamma-Ray Sources, Beta-Particle

Sources, and Measuring Instruments A Method for the Calibration of Concave

^SR -I- '"Y Opthalmic Applicators, C. G. Soares, Phys. Med. Biol. 37,

1005 (1992).

Calibration of Ophthalmic Applicators at NIST—A Revised Approach, C. G.

Soares, Med. Phys. 18, 787 (1991).

NBS Measurement Services: Calibration

of Gamma-Ray-Emitting Brachytherapy Sources, J. T. Weaver, T. P. Loftus,

and R. Loevinger, Natl. Bur. Stand.

(U.S.), Spec. Publ. 250-19 (1988).

NBS Measurement Services: Calibration

of Beta-Particle Radiation Instrumentation and Sources, J. S. Pruitt, C. G.

Soares, and M. Ehrlich, Natl. Bur.

Stand. (U.S.), Spec. Publ. 250-21 (Apr.

1988).

NBS Measurement Services: Calibration

of Beta-Particle-Emitting Ophthalmic

Applicators, J. S. Pruitt, Natl. Bur.

Stand. (U.S.), Spec. Publ. 250-9 (July

1987).

Calibration of Beta-Particle Ophthalmic

Applicators at the National Bureau of

Standards, J. S. Pruitt, J. Res. Natl. Bur. Stand. (U.S.), 91, 165 (1986).

The Effect of Altitude on Beta-Ray

Source Calibrations, J. S. Pruitt, Rad.

Protec. Dosim. 11, 151 (1984).

Exposure Standardization of Iodine- 125

Seeds Used for Brachytherapy, T. P. Loftus, J. Res. Natl. Bur. Stand. (U.S.),

89, 295 (1984).

Standardization of Iridium- 192 GammaRay Sources in Terms of Exposure,

T. P Loftus, J. Res. Nad. Bur. Stand.

(U.S.), 85, 19 (1980).

Medical Dosimetry Standards Program of

the National Bureau of Standards, R. Loevinger, Proc. Symp. on Natl,

and Intl. Standardization in Rad.

Dosimetry, Atlanta, GA, Dec. 5-9,

1977, Intl. Atomic Energy Agency,

Vienna (1978). (This article provides

references for earlier publications on NBS exposure and absorbed-dose

standards.)

1 18
460 IOC:-48020S

Standardization of Cesium- 1 37 GammaRay Sources in Terms of Exposure

Units (Roentgens), T. R Loftus, J. Res.

Natl. Bur. Stand. (U.S.), 74A, 1 (1970).

C.3 Dosimetry of High-Energy

Electron Beams

NBS Measurement Services: Fricke

Dosimetry in High-Energy Electron

Beams, C. G. Scares, E. L. Bright, and

M. Ehrlich, Natl. Bur. Stand. (U.S.),

Spec. Publ. 250-4(1987).

Radiation Dosimetry: Electron Beams

with Energies between 1 and 50 MeV,

Report 35, International Commission

Radiation Units and Measurements,

Bethesda, MD (1984).

Uniformity of High-Energy Electron- Beam Calibrations, M. Ehrlich and

R J. Lamperti, Phys. Med. Biol. 14,

305 (1969).

Proposed National Bureau of Standards

Program for the Calibration of Instru- ments Used in High-Energy Electron

and X-Ray Beams, M. Ehrlich, Ann.

N.Y. Acad. Sci. 161, 139 (1969).

119
49010C-49050S

D. Dosimetry for High-Dose Applications

Technical Contacts:

Stephen M. Seltzer

Ttl: 301/975-5552

Email: s.$eltzer@ nisLgov Fax: 301/869-7682

Marc F. Desrosiers

Ttl: 301/975-5639 Email: marc.

desrosiers@nistgov

James M. I^ihl

Ttl: 301/975-5581 Email: james.puhl@

nist.gov

Mailing Address: Building 245, Room C229,

Attn: J. Puhl,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 49010C Calibration Irradiations of Customer-Supplied

Dosimeters with *Co Gamma Rays

49020C Dose Interpretation of NIST Transfer Dosimeters

Irradiated by Customer, Three Dosimeters Pius Control(s) 49030C Dose Interpretation of Each NIST Transfer Dosimeter in Addition to Those Supplied under 49020C

49040S Special Tests of Dosimeters by Reading with Spectrophotometer, Optical Absorbance at One to Five Wavelengths (Each Dosimeter)

49041S Spectrophotometric Readings of Dosimeters,

Ultra-Violet and Visible Spectrum Scan

(Each Dosimeter)

49050S Special Measurement Services for Dosimeter

Response and Dose Distributions

Calibration Services and Special Tests of Dosimeters (490I0C^9050S)

The following dosimetry services are for individual users of intense radiation

fields, in particular large

gamma-ray sources and electron accelerators up to approximately 10 MeV. These

services include the administering of

known absorbed doses of photons to cus- tomer-supplied dosimeters; supplying

calibrated transfer standard dosimeters to customers for irradiation and subsequent

readout and dose interpretation; and special measurement services such as the determination of temperature dependence, dose-rate dependency or reproducibility of dosimeter response.

Calibration of Dosimeters Irradiated

with **Co Gamma Rays (49010C)

Calibration irradiations are available for customer-supplied dosimeters (such as

solid radiochromic or liquid chemical

types) or test samples that are sent to NIST, where they are packaged appropriately to provide electron equilibrium

conditions. They are irradiated in the NIST standard *Co calibration facility to specific agreed-upon absorbed

dose values in the nominal range of

(10 tolO^) Gy (10' rad to 10** rad). The

dosimeters are then sent back to the customer for analysis and evaluation. Dosimeters must fit within a cylindrical

volume 5 cm in height and 5 cm diameter. For our standard calibrated geometries (radiochromic film, alanine

pellets, 2 mL ampoules, and red perspex),

the absorbed dose (water) delivered to the dosimeter has a relative expanded

uncertainty* of 1.8 %.

Transfer Reference Standard

Dosimeters (49020C and 49030C)

NIST provides transfer standards in the form of sets of calibrated radiochromic

or alanine dosimeters packaged in polystyrene. The sealed, packaged

dosimeters are sent to the customer for

irradiation to nominal agreed-upon ab- sorbed dose levels in a prescribed geometrical arrangement. The unopened

packaged dosimeters are then returned to NIST to be read and evaluated and the

results reported, thus providing calibration of the customer's irradiator. The

absorbed dose range that is suitable for use with the transfer dosimeters is 50 Gy

to 200 KGy (5 rad to 20 Mrad) in water,

silicon, aluminum, graphite, or certain

plastics. The transfer standard calibrations (absorbed dose in water) have a

relative expanded uncertainty* of 2.2 %

for alanin dosimeters and 4.5 % for radiochromic dosimeters.

*See Chapter 1, Section H for more information about uncertainty.

1 20
49010C-49050S

Special Tests of Dosimeters:

Spectrophotometric Reading

(49040S^9041S)

Dosimeters may be read at several specific ultraviolet or visible optical

wavelengths or as a spectral scan over an

appropriate wavelength region of interest.

Special Measurement Services for Dosimeter Response and Dose

Distributions (49050S)

Tests of dosimeter response, such as temperature dependence, dose rate dependence, and dose distributions in specific

irradiation geometries, can be provided

as special measurement services. These

dose distribution measurements can in- clude dose profiles in heterogenous ab- sorbers and at interfaces of different materials.

References—High-Dose Dosimetry

Dosimetry Systems for Radiation

Processing, W. L. McLaughlin and

M. F. Desrosiers, Radial. Phys. Chem.

46, 1163 (1995).

ESR-Based Analysis in Radiation Processing, W. L. McLaughlin, M. F. Desrosiers and M. C. Saylor. Steriliza- tion of Medical Products, Vol. VI (R.

F. Morrissey, Ed.), Polyscience Publications, Inc. Marin Heights, Canada, p. 213 (1993).

ESR Dosimetry, W. L. McLaughlin,

Radial. Prot. Dosim. 47, 255 (1993).

NBS Measurement Services: Dosimetry

for High-Dose Applications,

J. C. Humphreys, D. Hocken, and

W. L. McLaughlin, Natl. Bur. Stand.

(U.S.), Spec. Publ. 250-1 1 (Mar.

1988).

Dosimetry for Industrial Radiation Processing, W. L. McLaughlin,

J. C. Humphreys, and A. Miller, Natl. Bur. Stand. (U.S.), Spec. Publ. 609

(1982).

A National Standardization Programme

for High-Dose Measurements, W. L. McLaughlin, Technical Report No.

205, 17, Intl. Atomic Energy Agency,

Vienna (1981).

Dye Film Dosimetry for Radiation Processing, J. C. Humphreys and W. L. McLaughlin, IEEE Trans. Nucl. Sci., NS-28, 2, 1797 (Apr. 1981).

The Measurement of Absorbed Dose and

Dose Gradients, W. L. McLaughlin,

Radiat. Phy. Chem. 15, 9 (1980).

Dosimetry Standards for Industrial Radiation Processing, W. L. McLaughlin,

National and International Standardization of Radiation Dosimetry, 1 , Intl. Atomic Energy Agency, Vienna

(1978).

121
Chapter

A Resistance Measurements B Impedance Measurements (Except Resistors)

0 Voltage Measurements D Precision Ratio Measurements

E Phase Meters and Standards and VOR Measurements

F Power and Energy Measurements, Low-Frequency

G RF, Microwave and Millimeter-Wave Measurements

H Electromagnetic Field Strength and Antenna Measurements

/ Pulse Waveform Measurements
Electromagnetic Measurements 51 1(XJS-51 163C

#1 Resistance Measurements

A.I DC Resistance Standards and

Measurements

Technical Contacts:

Ronald F. Dziuba

Tel: 301/975-4239

Email: rdziuba@

nistgov

Randolph E. Elmquist

Ttl: 301/975-6591 Email: relmquist@

nist.gov

Denise D. Prather

Administration and

Logistics

Ttl: 301/975-4221 Email: dprather@

nist.gov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 51100S Special Resistance Measurement Services, by

Prearrangement

511 lOM Measurement Assurance Program Services for Resistance 51130C Standard Resistor, Thomas-Type, 1 H

5 11 3 1 C Standard Resistor, Evanohm Wirewound High

Precision, 10 kO

51 132C Standard Resistor, Four-Terminal, 0.0001 H

51 133C Standard Resistor, Four-Terminal, 0.001 CI 5 1 1 34C Standard Resistor, Four-Terminal, 0.0 1 O

51 135C Standard Resistor, Four-Terminal, 0.1 Cl 51136C Standard Resistor, Four-Terminal, 1 Cl 51 137C' Standard Resistor, Four-Terminal, 10 Cl 51 BSC Standard Resistor, Four-Terminal, 100 fi 51139C Standard Resistor, 1 kO

5 1 1 40C Standard Resistor, 1 0 kfl 5 1 1 41 C Standard Resistor, 1 00 kO

51142C Standard Resistor, 1 MO

5 1 1 43C Standard Resistor, 1 0 Mfi

5 1 1 44C Additional Voltage, 1 0 MSI

5 1 1 45C Standard Resistor, 1 00 MCI

Service ID No. Items

5 1 1 46C Additional Voltage, 1 00 MCI

51 147C Standard Resistor, 1 GO,

5 1 148C Additional Voltage, 1 GCl

5 1 1 49C Standard Resistor, 1 0 GCl

5 II 50C Additional Voltage, 1 0 GCl

5 1 1 5 1 C Standard Resistor, 1 00 GO

5 1 152C Additional Voltage, 100 GCl

51 153C Standard Resistor, 1 TCI

51 154C Additional Voltage, 1 TCI

5 1 1 60C Standard Resistor for Current Measurements

(Shunts), with All Determinations at 300 A or Below,

One Range, One Current Level

5 1 1 6 1 C Standard Resistor for Current Measurements

(Shunts), with at Least One Determination Above

300 A (maximum current 2000 A) One Range,

One Current Level

5 1 1 62C Standard Resistor for Current Measurements

(Shunts), Additional Range of a Multi-Range

Resistor

5 1 163C Standard Resistor for Current Measurements

(Shunts), Additional Determination at Another

Current Level

123
Special DC Resistance Measurements,

by Prearrangement (51100S)

Testing or evaluation of prototype resis- tance standards or measuring instru- ments; unique resistance measurements;

and other calibration services not

specified below, such as the determination of the pressure coefficient of

Thomas-type or 10 kfl resistors, the determination of the temperature coefficient of standard resistors, and the

calibration of resistance standards in

oil at temperatures other than 25 °C, are

carried out under this Service ID

number. Such measurements are made at the discretion of the NIST technical

staff in a manner specifically agreed

upon by the customer and the expert

involved. Testing of component resistors will only be considered under the rare circumstance that the behavior of the

resistors has been observed to approximate that of state-of-the-art standards under the same conditions. Measurement Assurance Program

for Resistance (51110M)

Resistance MAP transfers are generally

carried out at the 1 Cl and 10 kfl levels. Four well-characterized commercial

standard resistors are used as transport

standards at each level. The suggested

measurement schedule at the client laboratory consists of measurements on

each transport resistor three times a week for a period of 4 to 6 weeks, de- pending upon the settling time of the

resistors due to transportation effects. Participation in this program is generally not advisable unless one is required

to support resistance measurements

with state-of-the-art or near state-of-theart uncertainties and is willing to adopt

a system for the continuous surveillance of standards during the intervals be- tween NIST MAP transfers. A successful

transfer requires a considerable amount

of data collection and a willingness to be- come involved in the data analysis process. Data supplied in the course of

routine NIST calibrations suffice for normal measurement requirements of

standards laboratories if proper methods are used by the laboratory to

quantify the additional uncertainties caused by transportation and the laboratory's own measurement process.

Special Standard Resistors 1 ft and

10 k^l (51130C and 51131C)

Thomas-type 1 fl resistors or their equivalent are calibrated directly against the NIST 1 fl reference group that is used to maintain the U.S. legal ohm. The values of the reference group are known in terms of the quantum Hall effect. Special

10 kfl standard resistors designed for air or oil use are calibrated directly against

the NIST 10 kfi working standards. The

special 10 kfl standard resistors (Evanohm wirewound high-precision or

equivalent) are characterized by resis- tance corrections within 10 X 10"^ of

nominal value, temperamre coefficients of 0 ± 1 X 10-^/°C at the operating

temperature, and drift rates of

< 1 X lO^/year.

The customer's resistors are acclimatized in their respective test environments

for approximately 1 week prior to their calibration. Measurement parameters of

temperature and current level are shown

in Table 9.1.

Table 9.1. Temperatures and Current

Levels for Customer's Resistors

Resistor Medium Temperature Current

(°C) (mA)

1 a oil 25 .000 ±0.003 100

10 kfl oil 25.000+0.005 1 10 kn air 23.0±1.0 1

The temperature of the customer's resis- tor at the time of the measurement is given in the report of calibration. Since some of these resistors exhibit a signifi- cant pressure coefficient, the barometric

pressure at the time of the measurement

is also reported. Uncertainties are based

upon (1) the random behavior of the measurement process as characterized by

data from a large population of individual

calibrations, and (2) an estimate of the systematic errors arising from such

sources as temperature inaccuracies, pressure inaccuracies, scaling errors, etc. Uncertainties are listed in Table 9.2.

124
51100S-51163C

l^ble 9.2. Calibration Uncertainties for DC Resistance

Standards

Nominal

Relative Nominal Maximum Expanded

lest Resistance ierminal Power Uncertainty*

Connpotion

51130C 1 (Thomas) 4 10 0.05 51131C 10" (Special) 5 10 0.15 51132C lO"" 4

' 100 11 51133C 10'^ 4 100 5 51134C 10-2 4 100 3 51135C 10"' 4 100 2

S 1 1 3fiP 1X 4 50 1 51137C 10 4 50 1 51138C 10^ 2 10 0.5 51139C 10' 2 10 0.5 51140C 10" 2 10 0.5 51141C lO' 2 10 2 51142C 10* 2 10 3 51143C 10' 3 • 14 to 140 51145C 10'* 3 • 40 to 400

51147C 10" 3 • 140 to 700

51149C 10'« 3 • 400 to 700

51151C 10" 3 • 700

51153C 10'2 3 • 1400

*See Chapter 1, Section H for more information about uncertainty. •Resistors at this level are tested at customer-specified voltages up to I kV.

Standard Resistors lO"'' to 10* O,

(51132C-51142C)

Standard resistors with nominal decade

values in the range between 10"" Cl and

10^ fl are calibrated by comparison with

NIST working standards of equivalent

value, known in terms of the Quantum

Hall effect. In general, these standards

are characterized by (1) resistance corrections within 500 X 10"^ of nominal

value, (2) temperature coefficients of

<10 X 10-^/°C at the temperature of use, and (3) drift rates of < 5 X IQ-^/year.

Normally, standard resistors are measured in an oil bath maintained at (25.0 ± 0.05) °C, and at a power level of

^OA W. Resistors in temperaturecontrolled enclosures with fixed terminations are also accepted for calibration. At

the levels of accuracy involved, four- terminal measurements are required for

resistors whose nominal values are 100 il or less. Expanded uncertainties* are based upon (1) the random behavior of

the measurement process as characterized by data from a large population of

individual calibrations, and (2) an esti- mate of the systematic errors. Uncertainties are given in Table 9.2.

High-Value Standard Resistors:

10' ft to 10" n (51143C-51154C)

High-value standard resistors in the range between 10' fi and 10'^ fi are calibrated

in an air bath maintained at a temperature of (23.0 ± 0.1) °C and at a relative humidity of (35 ± 5) %. The resistors are maintained at these conditions at least 24 hours prior to testing. Customer resis- tors are compared 1 : 1 with NIST working standards of the same nominal value up to and including the 10'° Cl level. Above 10'" a, 10:1 and 100:1 ratio tech- niques are employed. The maximum test voltage is 500 V for resistors < 10'° H

and 1000 V for resistors > 10'° Cl. Uncertainties depend upon the stability

and performance of the specific resistor involved and are given in Table 9.2. Only

resistors that are mounted in a shielded enclosure with a permanent identifying

number and have suitable terminations

are accepted for calibration. The resistance of thin-film, highvalued resistance standards is frequently

highly voltage dependent. Hence, the magnitude of the test voltage should be

specified by the customer when a resistor

is submitted for calibration. The temperature, relative humidity, and test voltage of

the resistor are given in the report of cali- bration.

High-Current Standard Resistors

Shunts (51160C-51163C)

Four-terminal standard resistors for use

in the precise measurement of high direct currents (shunts) are calibrated by NIST

only during May and November of the calendar year. Arrangements should be

made with NIST prior to submitting a

resistor for calibration. Normally only

resistors of 0.04 % relative uncertainty

* See Chapter 1 , Section H for more information about uncertainty.

125
or less are calibrated. The maximum test current available is 2000 A. The uncertainty of measurement depends largely

upon the performance of the customer's

resistor involved.

References—DC Resistance

NIST Measurement Services for DC

Standard Resistors, R. F. Dziuba, R A.

Bounton, R. E. Elquist, D. G. Jarrett, T. R Moore and J.D. Neal, Natl. Inst. Stand. Technol. Tech. Note 1298 (Nov.

1992).

Guidelines for Implementing the New

Representation of the Volt and Ohm

Effective January 1, 1990, N. B.

Belecki, R. F. Dziuba, B. F. Field, and

B. N. Taylor, Natl. Inst. Stand. Technol. Tech. Note 1263 (June 1989).

New Realization of the Ohm and Farad

Using the NBS Calculable Capacitor,

J. Q. Shields, R. F. Dziuba, and H. R

Layer, Conf. Precision Electromagnetic Meas. (CPEM '88), June 7-10,1988,

Tsukuba Science City, Japan, Special

Issue CPEM '88 IEEE Trans. Instrum. Meas. 38 (2), 249-251 (April 1989).

Determination of the Time-Dependence

of Ones Using the Quantized Hall

Resistance, M. E. Cage, R. F. Dziuba,

C. T. Van Degrift, and D. Yu, Conf.

Precision Electromagnetic Meas. (CPEM '88), June 7-10, 1988,

Tsukuba Science City, Japan, Special

Issue CPEM '88 IEEE Trans. Instrum. Meas. 38 (2), 263-269 (April 1989).

Monitoring the U.S. Legal Unit of Resis- tance via the Quantum Hall Effect,

M. E. Cage, R. F. Dziuba, B. F. Field, T. E. Kiess, and C. T. Van Degrift,

IEEE Trans. Instrum. Meas. IM-36,

222 (June 1987).

The NBS Ohm Past-Present-Fumre, R. F. Dziuba, Proc. Meas. Science Conf.,

Irvine, CA (Jan. 1987).

A Test of the Quantum Hall Effect as a Resistance Standard, M. E. Cage, R. F. Dziuba, and B. F. Field, IEEE Trans. Instrum. Meas. IM-34, 301 (1985).

Automated NBS 1 -Ohm Measurement

System, K. R. Baker and

R. F. Dziuba, IEEE Trans. Instrum. Meas. IM-32, 154(1982).

An Integrated System for the Precision

Calibration of Four-Terminal Standard

Resistors, T. E. Wells and E. F. Gard,

IEEE Trans. Instrum. Meas. IM-20,

253 (Nov. 1971). Calibration Procedures for Direct Current

Apparatus, P. Brooks, Natl. Bur. Stand.

(U.S.), Monogr. 39 (Mar. 1962).

Measurement of Multimegohm Resistors, A. H. Scott, J. Res. Natl. Bur. Stand.

(U.S.), 50, (3) (Mar. 1953).

Precision Resistors and Their Measurement, J. L. Thomas, Natl. Bur. Stand.

(U.S.), Circular 470 (Oct. 1948).

Methods, Apparatus, and Procedures for the Comparison of Precision Standard

Resistors, F. Wenner, J. Res. Nad. Bur.

Stand. (U.S.), 25, Res. Paper RP1323

(Aug. 1940).

126
4

Resistance Measurements

A.2 High-Voltage Standard Resistors

Technical Contacts:

Martin Misakian

Ttl: 301/975-2426 Email: mmisakian@

nistgov

James K. Oltlioff

Tel: 301/975-2431 Email :jolthofr@ nisLgov

Denise D. Prather

Administration and

Logistics

Tel: 301/975-4221 Email: dprather@nist.gov

Mailing Address: Building 220, Room B 1 46,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

[Attn: M. Misakian, Bldg. 220, Room B351, ext. 1-270 at Quince Orchard Road,

Gaithersburg, MD 20899-0001

2426],

References—High-Voltage Standard

Resistors

High-Voltage Divider and Resistor Calibrations, M. Misakian, Natl. Bur.

Stand. (U.S.), Tech. Note 1215 (July

1985).

Special Shielded Resistor for HighVoltage Measurements, J. H. Park, J. Res. Natl. Bur. Stand. 66C (1), 1924

(Jan.-Mar. 1962).

Service ID No. Items 51210C High-Voltage Standard Resistors

High-Voltage Standard Resistors

(51210C)

A routine calibration service is maintained for resistors designed for dc highvoltage applications. This service is for corona-free resistors designed for dc

operation between 10 kV and 150 kV.

Resistors may be hand-carried or shipped to NIST. If they are shipped,

they should be packaged in sturdy reusable containers with convenient ac- cess to the resistor. The design of many

high-voltage resistors makes them vulnerable to shear-type forces, so provisions

should be made to minimize the likeli- hood of damage due to such forces when

the device is in the shipping container. Users of this service should first dis- cuss scheduling of calibrations with a NIST technical contact. The purchase or- der should indicate the voltage test points, a mailing address for the calibration re- port, and a shipping address for the resistor.

127
51310S

A

Resistance Measurements

A.3 High-Frequency Standard Resistors

Technical Contacts:

George M. Free

Ttl: 303/497-3609

Email: gfree@nistgov

Paula M. Hewitt

Administration and

Logistics

Ttl: 303/497-3753

Email: paula.liewitt@nist.gov Fax: 303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

References—High-Frequency Standard

Resistors

The Measurement of Lumped Parameter Impedance: A Metrology Guide, R. N.

Jones, Natl. Bur. Stand. (U.S.),

Monogr. 141 (June 1974).

Impedance of Lumped Circuits, L. E. Huntley and R. N. Jones, Proc. IEEE,

55 (6), 900 (June 1967).

Service ID No. Items

513 lOS High-Frequency Standard Resistors; Two-Terminal

High-Frequency Standard Resistors

(51310S)

The overall frequency range covered is 10 kHz to 250 MHz. The range of resis- tance that can be calibrated depends

upon the measurement frequency, as

follows: Frequency Range

10 kHz to 2 MHz

2 MHz to 10 MHz

10 MHz to 250 MHz

Resistance Range

o.into 10 kn

50 a to 10 kn

20 n to 1 kn

Measurement uncertainties are given in the reference; the relative expanded

uncertainties* start at 0.1 %.

Reports of Calibration or Tests for

resistors will include the inductance or capacitance associated with the resistor. Equivalent series values are normally

given for inductive resistors and equivalent parallel values for capacitive

resistors.

*See Chapter 1 , Section H for more information about uncertainty.

128
52110S-52181C

B. Impedance Measurements (Except Resistors)

B. 1 Low-Frequency Capacitance and

Inductance Measurements and Standards

Technical Contacts:

Y. May Chang

Tfel: 301/975-4237 Email :ychang@

nisLgov

Summerfield B. Tillett Tel: 301/975-4244 Emaihsummerneld.

tillett@nistgov

Denise D. Prather

Administration and Logistics

Ttl: 301/975-4221 Email:dprather@nistgov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items

521 lOS Special LF Impedance Measurements, by

Prearrangement

52120S Special Measurement Assurance Program

for Standard Capacitors

(100 pF and 1000 pF, at a Frequency of 1000 Hz)

52130C Fixed Fused-Silica Dielectric Standard Capacitors

(1, 10, and 100) pF, at a Frequency of (100, 400,

or 1000) Hz

521 3 IC Additional Measurement at One of the Above

Frequencies

52140C Fixed Three-Terminal, High-Precision Nitrogen

Dielectric Standard Capacitors with Coaxial

Connectors, Small Uncertainty (10, 100, and

1000) pF, at a Frequency of (100, 400, or 1000) Hz

52141C Additional Measurement at One of the Above

Frequencies

52150C Physical Tests for Three-Terminal Nitrogen Dielectric Capacitors (at 1000 Hz only) as an Optional

Supplement to the Small Uncertainty Calibration (52140C)

52160C Fixed Three-Terminal Standard Capacitors with Coaxial Connectors, Large Uncertainty (0.00 1 pF to 10,000 pF), at a Frequency of (100, 400, or 1000) Hz

52161C Additional Measurement at One of the Above

Frequencies

52170C Two- or Three-Terminal Mica Dielectric Standard

Capacitors with Binding Post Connectors (0.001 /liF to 1 ixF), at a Frequency of (66, 100, 400, 1000, or 10,000) Hz

5217 IC Additional Measurement at One of the Above Frequencies

52176C Two-Terminal Standard Capacitors with Precision High Frequency (HF) Coaxial Connectors

(0.001 pF to 10,000 pF), at a Frequency of 1000 Hz

52180C Fixed Standard Inductors (0.00005 H to 10 H),

at a Frequency of (100, 400, 1000, or 10,000) Hz

5218 IC Additional Measurement at One of the Above Frequencies

Low-Frequency Capacitance and

Inductance Measurements and

Standards (52110S-52181C)

These services cover the calibration of

standard capacitors and inductors in the audio-frequency range. Three-terminal

standard capacitors having fused-silica

(1, 10, and 100) pF, nitrogen (10, 100,

and 1000) pF, and air, from 0.001 pF to 10 000 pF, dielectrics can be measured at (100, 400, and 1000) Hz. Two- or three- terminal capacitors with mica dielectrics

in the range from 0.001 ixF to 1 ^tF can be measured at (66, 100, 400, 1000, and

10 000) Hz. Two-terminal air and mica

dielectric capacitors with high frequency

(HF) coaxial connectors, from 1 pF to 10 000 pF, including GR900 terminations, are calibrated only at 1 kHz. Air- core standard inductors having nominal

values between 0.05 mH and 10 H can be

measured at (100, 400, and 1000) Hz.

Standard inductors of 100 mH or less also can be measured at 10 kHz. Calibration of impedance standards other than

those mentioned above will be considered

for Special Test Under Service ID

Number 52 11 OS (see below).

The calibration of some types of high

frequency capacitance standards at frequencies as low as 1 kHz can be

provided by the NIST Electromagnetic

Fields Division in Boulder, CO, provided

the uncertainty required exceeds 0.01 %.

In some circumstances this can eliminate

the necessity of sending a standard to both Gaithersburg and Boulder Laboratories for a complete calibration. See also Service ID Numbers 52210C-52310C for calibration of capacitors at higher fre- quencies. For additional details please

inquire at NIST/Boulder: Telephone (303)

497-3609.

Special LF Impedance Measurements,

by Prearrangement (521 lOS)

This service provides for the testing or

evaluation of prototype impedance

standards or measurement instrumentation at the state-of-the-art, and other

129
impedance measurements (such as the caHbration of decade or variable capacitance standards), at the discretion of NIST technical experts. Component

capacitors, inductors, and resistors are not considered for testing by NIST

unless their performance approximates

that of the best available standards. Even under those conditions, calibration

will only be done on a limited basis to ascertain the possible use of the components in precision measurement applications. The cost for such tests are deter- mined on a case-by-case basis, and may

be considerably higher than the posted

fee for Calibration Services because of

needed additional preparation and extra measurements required to perform an

uncertainty assessment.

Special Measurement Assurance

Program for Standard Capacitors

(52120S)

The Capacitance MAP (C-MAP)

transfers are carried out for standard

capacitors at the 1000 pF and 100 pF

levels, at a frequency of 1 kHz. A

commercial 1 kHz capacitance meter

is used as the transport standard. The

client laboratory (Lab) is responsible

for performing measurements (using

the Lab calibration system and the transport standard) on its own reference and/or check standards, and on the two pairs of dummy capacitors from

NIST of the same nominal values. Prior to the initiation of the C-MAP,

the Lab is required to complete a CAPACITANCE MAP INFORMATION

SHEET, and to provide a description

of its calibration procedures. At the time

the transport standard and the dummy

capacitors are shipped to the Lab for a C-MAP transfer, the Lab will also

receive detailed instructions for carrying

out the C-MAP and the software for enabling the transport standard (commercial capacitance meter) to make measurements automatically. The Lab is also

required to collect and reduce the data from its calibration system, and to enter

the results on to the CAPACITANCE

MAP DATA SHEET.

The transport standard and the dummy

capacitors are normally kept in the Lab

for about 4 to 6 weeks, as eight to twelve

sets of measurements are required. After

the completion of post MAP measure- ments and a data analysis at NIST, a REPORT OF CALIBRATION from

NIST is issued to the Lab. This report

provides the difference between the unit of capacitance maintained by the Lab and

the farad, and the assigned values for the Lab reference standards (and their uncertainties) to bring the difference to zero.

Fused-Silica Dielectric Standard

Capacitors (52130C-52131C)

Air-bath type, fused-silica dielectric standard capacitors are generally submitted in temperature-controlled ovens due

to their (10 X 10-*)/°C temperature

coefficient. Because of the magnitude of

the temperature coefficient, it is recom- mended that a reliable temperature sensor having a resolution of 0.001 °C, or better, be permanently mounted in the oven and

thus included as part of the calibration. For baths not so equipped, the temperature is measured in terms of the International Temperature Scale of 1 990

(ITS-90), using a standard platinum

resistance thermometer.

Some capacitance standards consist of

a fused-silica dielectric capacitor

completely sealed within a temperaturecontrolled oven and the ancillary

circuitry required for its operation, but

with no means of measuring or monitoring the oven's internal temperature. Since

the actual temperature of the capacitor cannot be measured, it is not reported.

Some such standards measure and display

the ambient temperature. For these, the mean value of the display readings taken

at the times of measurement is reported, but the significance of this value is decided by the user.

1 30
52110S-52181C

Oil-bath type, fused-silica dielectric capacitors are calibrated in an NIST oil bath maintained at (25 ± 0.01) °C, if the normal temperature of use for these

capacitors is approximately 25 °C. If the capacitors are supplied with built-in sensors, the sensors and the oil temperature are both measured. Requests for the

calibration of oil-bath type, fused-silica

dielectric capacitors are accepted as Special Tests (52 11 OS). Calibrations are carried out at (100,

400, or 1000) Hz, or any combination of

these frequencies chosen by the client. A

minimum of five measurements is made

over a 2-week or longer period, comparing the test capacitor directly with an NIST fused-silica standard at 10 pF. The

number of readings taken depends on the

stability of the temperature of the test capacitors. The averages of the measured

values of capacitance and temperature

are reported. The uncertainty of the re- ported capacitance value depends on the

stability of the temperature as well as on

the performance of the capacitance stan- dard itself. Because the temperature

coefficients of individual standards are usually not known quantitatively, the

results cannot be temperature corrected. Despite these factors, the Type A

standard uncertainty* can be as low as 2 X 10 of the capacitor's nominal

value.

Standard Capacitors

(52140C-52176C)

The following guidelines apply to the cal- ibration of standard capacitors having

dielectrics other than fused-silica. Calibrations are ordinarily performed

at a normal laboratory ambient temperature of (23 ± 1 ) °C except for measure- ments of high-stability nitrogen dielectric capacitors. These are measured more

than once in a period of several days to observe their stabilities and to ensure that the variation of the measurements is within the required limit of the standard

errors for these measurements.

Simultaneously, a digital thermometer

with a resolution of 0.001 °C is placed

near the capacitors to monitor the temperatures during calibrations. The cali- bration temperature, nominally 23 °C, is reported to within ± 0.01 °C. Relative humidity is maintained at 50 % or less in

all cases. Precision three-terminal nitrogen

dielectric capacitors, such as ESI Model

SCI 000 and GENRAD Model 1404,

have been found to be variously affected by mechanical shock and orientation. Accordingly, two types of calibrations,

featuring different levels of uncertainty

are offered. See Table 9.3. A qualification test (52150C) is available to supplement the small uncertainty calibration (52140C) in order to determine the ef- fects of various impacts (physical shocks)

and orientation on the capacitors. Results of this test should be coupled with the Type-B uncertainty* of the precision

calibration that follows to provide an expanded uncertainty for the calibration of a particular standard. Requests for the small uncertainty calibration without the physical tests are also accepted. For the large uncertainty test (52160C), a similar

calibration, but with reduced resolution,

is performed. Three-terminal air dielectric capacitors are accepted for the large

uncertainty calibration (52160C) only. In the case of direct or three-terminal capacitance standards, the connectors are assumed to be coaxial, such as the GENRAD Type 874. While the connectors available for this purpose are adequate, it should be noted that changes

or instabilities in the impedance of the

shield or guard connection of a three- terminal capacitor can change the capaci- tance significantly.

Capacitors requiring terminal plugs

(banana plugs) for parallel connection

should be sent to NIST together with the plugs that will be used with the capacitor

after calibration. If such a capacitor

arrives without plugs, NIST must attach plugs temporarily in order to calibrate

*See Chapter 1 , Section H for more information about uncertainty.

131
the capacitor. Those used by NIST are GENRAD Type 274-P plugs. If, after calibration with these plugs, the capacitor

is used with plugs of even slightly differ- ent length and base, the capacitance can

differ significantly from that reported,

and such differences will not be reflected

in the calibration uncertainties reported.

Unless otherwise requested, the measured value reported by NIST is the added capacitance when the standard is plugged directly into the binding posts of

the NIST bridge. For two-terminal

GENRAD capacitors. Type 509 and

Type 1409 (when used as a two-terminal

capacitor), a capacitance increase ranging from 0.01 pF to 0.04 pF has been

found for different plugs. No significant

change in conductance has been found in either the two-terminal or three-terminal

value. The importance of terminal connection methods becomes extremely crit- ical when capacitance values of 0.01 jiF or less are being measured. Improved

accuracy in two-terminal measurements

can be realized if standards are provided

with precision coaxial connectors. The terminal connections, either as two-terminal or three-terminal capacitors, for capacitors with mica dielectric,

should be specified in the customer's purchase order. Otherwise, they will be

calibrated as two-terminal capacitors

(with the case "Ground" connected to the "Low" terminal).

The capacitance value given is the equivalent parallel capacitance. In general, an accurate determination of the equivalent parallel conductance with high accuracy is not available. However, for mica dielectric capacitors in an approximate conductance value for each capacitor is also given.

The frequencies available for capaci- tance calibrations depend upon the type

of capacitor and its connectors. In general, capacitors with binding posts or GR 274-P plugs can be calibrated at (66, 100, 400, 1000, and 10 000) Hz.

Capacitors with high frequency coaxial connectors (GENRAD Type 900) are

calibrated only at 1000 Hz.

The expanded uncertainty* stated in the Report of Calibration is determined

by the random behavior of each type of

capacitor (determined from the analysis

of measurement data taken from a large

population of individual calibrations), as well as an estimate of the systematic er- rors of the NIST measurement process. These are calculated using the approach

of NIST Technical Note 1297, per NIST

policy. The expanded uncertainties are given in Table 9.3 and Table 9.4. The stated uncertainties are suffi- ciently broad to allow for variations in the

stray capacitance at the connectors, in temperature of a few degrees Celsius, in

relative humidity and atmospheric

pressure, and in frequency deviations of a few percent from the stated test conditions. Depending on the frequency and

the capacitance value, the relative ex- panded uncertainty* usually lies between

0.0004 % and 0.05 % (see Tables 9.3 and

9.4). The uncertainties do not include

allowances for effects of transportation; these must be determined by the owner

using pre- and post-calibration data from

the owner's facility.

Standard Inductors, Self or Mutual

(52180C-52181C)

Air-core standard inductors for use in ac bridges are tested at a room temperature

of (23 ± 1 ) °C and a relative humidity of

50 % or less. Measurements at 10 000 Hz

are limited to standard inductors of 0.1 H

or less. Most inductors used at 60 Hz can

be tested at 100 Hz since the variation of

inductance with frequency in this range is usually negligible. A metal-encased stan- dard is calibrated with the case "Ground"

connected to the "Low" terminal of the inductor unless other conditions are

specified. The reported values are the

self inductance values of the inductors.

*See Chapter 1, Section H for more information about uncertainty.

132
52110S-52181C

Table 9.3. Calibration Uncertainties for Capacitance Standards with Coaxial Connectors

Service ID Terminal Nominal Relative Expanded Uncertainties* ( x l(r*)

INO. Dielectric Connection Capacitance PrpniiPiirv

(p*) 100 Hz 400 H7 and 1 kHz

52130C Fused-Silica 3 1 10 4.1 and 10 4 2.5 52131C 100 A

52140C Nitrogen 3 10 6 4

and 100 6 4

52141C 1000 6 4

52160C Nitrogen 3 10 to 1000 25 25

and 52161C Air 3 0.001 M A

IN A ZOUU

0.01 1500 200

0.1 230 100

1 to 1000 1 f\f\ lUU 10000 NA 150

(only at 1 kHz)

52176C Air 2 1 NA 840

9 NA 420

5 NA 200

10 NA 100 20 NA 75 50 to 1000 NA 60

Mica 2 1000 NA 60

5000 to 10000 NA 65

Open-Circuit 2 0.172 NA 1000

Termination 2 2.670 NA 450

*See Chapter 1 , Section H for more information about uncertainty.

133
Table 9.4. Calibration Uncertainties for Capacitance Standards with Terminal (Banana) Plugs

Service Dielec- ID. trie No.Terminal ConnectionNominal

Capacitance

Expanded Uncertainties* Capacitance Conductance

Frequency

66 Hz to 10 kHz 66 Hz &

1 kHz 100 Hz

(%) (%) (ftS)

Frequency

400 Hz & 10 kHz

1 kHz

52170C Mica 2 0.001 0.018 and 0.002 0.016 52171C 0.005 0.016

0.01 0.018

0.02 0.018

0.05 0.018

0.1 0.018

0.2 0.018

0.5 0.018

1 0.018

Mica 3 0.001 0.012

0.002 0.010

0.005 0.010

0.01 0.010

0.02 0.010

0.05 0.010

0.1 0.010

0.2 0.010

0.5 0.010

1 0.015

0.018 0.0003 0.0006 0.001 0.016 0.0003 0.0008 0.002 0.016 0.0003 0.001 0.005 0.018 0.0006 0.002 0.01 0.018 0.0006 0.003 0.02 0.020 0.002 0.006 0.01 0.040 0.005 0.02 0.4 0.060 0.008 0.04 1 0.10 0.02 0.13 6

0.20 0.04 0.4 20

0.012 0.0003 0.0006 0.001 0.010 0.0003 0.0008 0.002 0.010 0.0003 0.001 0.005 0.010 0.0006 0.002 0.01 0.012 0.0006 0.003 0.02 0.015 0.002 0.006 0.01 0.03 0.005 0.02 0.4

0.05 0.008 0.04 1 0.10 0.02 0.13 6

0.20 0.04 0.4 20

*See Chapter 1, Section H for more information about uncertainty.

References—Low-Frequency

Capacitance and Inductance

Standards

NIST Measurement Assurance Program

for Capacitance Standards at 1 kHz,

Y. May Chang, NIST Technical Note

1417 (March 1996).

NIST Capacitance Measurement Assur- ance Program (MAP), Y. May Chang,

Measurement Science Conference,

Anaheim, CA, (January 1993).

New Realization of the Ohm and Farad

Using the NBS Calculable Capacitor,

J. Q. Shields, R. F. Dziuba, and H. R

Layer, Conf. Precision Electromagnetic Meas. (CPEM '88), June 7-10, 1988,

Tsukuba Science City, Japan, Special

Issue CPEM '88 IEEE Trans. Instrum. Meas. 38 (2), 249-251 (April 1989).

Testing to Quantify the Effects of Handling of Gas Dielectric Standard

Capacitors, C. R. Levy, Natl. Bur.

Stand. (U.S.), Tech. Note 1161

(1982).

New Measurements of the Absolute

Farad and Ohm, R. D. Cutkosky, IEEE

Trans. Instrum. Meas., IM-23 (4), 305 (Dec. 1974).

Applications of Coaxial Chokes to AC

Bridge Circuits, D. N. Homan, J. Res.

Natl. Bur. Stand. (U.S.), 72C (2) (June 1968).

Improved Ten-Picofarad Fused Silica Dielectric Capacitor, R. D. Cutkosky

and H. L. Lee, J. Res. Natl. Bur.

Stand. (U.S.), 69C (3), 173 (Sept.

1965).

1 34
52110S-52181C

Calibration of Inductance Standards in the Maxwell-Wein Bridge Circuit,!. L. Zapf, J. Res. Natl. Bur. Stand. (U.S.),

65C (3) (Sept. 1961).

Capacitance Bridge NBS Type 2, R. D.

Cutkosky, Natl. Bur. Stand. (U.S.),

Report 7103 (Mar. 1961).

NIST Calibration Service for Capacitance

Standards at Low Frequency, Y. May

Chang and Summerfield B. Tillett, NIST Technical Note (to be published). Error Analysis and Calibration Uncertainty of Capacitance Standards at NIST, Y. May Chang, NIST Technical Note (to be published).

135
52210S-52310S

S Impedance Measurements (Except Resistors)

B.2 High-Frequency Standard Capacitors

and Inductors

Technical Contacts:

George M. Free Paula M. Hewitt

Tel: 303/497-3609 Administration and Logistics Email :gfree@nist.gov Tel: 303/497-3753 Email:paula.hewitt@nistgov

Fax:303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items 522 lOS Two-Terminal, Low-Loss Standard Capacitors

10 kHz to 250 MHz; 1 pF to 20 pF

5221 IS Two-Terminal, Low-Loss Standard Capacitors

(High Accuracy)—10 kHz to 30 MHz;

(50, 100, 200, 500, and 1000) pF

5222 IC Three-Terminal, Low-Loss Standard Capacitors

(High Accuracy)—10 kHz to 30 MHz;

(10-^ 10'', 1, 10, 10^, and 10') pF

523 lOS Two-Terminal, High-Q Standard Inductors

(\0-^ jjlH to 1 H)

High-Frequency Standard Capacitors

and Inductors (52210S-523I0S)

Services provided in this category (and

also Service ID Numbers 51310S and

527 IOC) are for passive devices over the frequency range from 10 kHz to 250 MHz. Highest accuracy is obtained

only for standards equipped with preci- sion coaxial connectors. Standards sub- mitted for calibration should be in good repair and, except for very minor

cleaning of connector surfaces, should

require no pre-calibration maintenance.

NIST does not provide repair services; items received that require maintenance

will be returned to the sender and a handling fee charged.

Calibration services for some types of

capacitance standards at frequencies as low as 1 kHz can be provided by the NIST Boulder Laboratory if the accuracy requirement does not exceed 0.01 %. In some circumstances this can eliminate

the necessity of sending a standard to both the Gaithersburg and Boulder Laboratories for a complete calibration. For

additional details, please consult with the technical contact listed at the beginning

of this section. Calibration services are not provided

for measuring instruments such as bridges or meters. The uncertainty of

these instruments should be verified by

the owner through the use of stable stan- dards especially selected for particular values and frequencies appropriate to the instrument in question. All calibrations are performed under

typical ambient laboratory conditions of

23 °C, and an atmospheric pressure of

approximately ((8.4 ± 0.2) X 10") Pa at Boulder, Colorado. Services at ambient

conditions outside these limits are not provided. Also, the power applied to any

device being calibrated does not exceed

1 W. Additional information about immittance (impedance and admittance) measurement and standards are contained in the references.

Two-Terminal, Low-Loss Standard

Capacitors (52210S-52211S)

In the frequency range from 1 0 kHz to 250 MHz, capacitance calibrations are

available from 1 pF to 1000 pF depending upon frequency. The upper capaci- tance limit for calibration decreases as the frequency increases and is 50 pF

above 30 MHz.

From 100 kHz to 30 MHz, a special

high-accuracy service is available for capacitors with nominal values of (50,

100, 200, 500, and 1000) pF if equipped

with 14 mm coaxial connectors.

136
52210S-52310S

The minimum relative expanded

uncertainty* is 0.01 % for the high accuracy device and 0.1 % for the other other calibrations. Reports of CaHbration for capacitors

normally do not give conductance val- ues because the conductance values of

capacitors of standard quality, especially those with air-dielectric, are too small to be measured accurately at the present state of the art. A technique for extrapolating the

1 kHz values of capacitance standards to high frequencies is described by

R. N. Jones (see 1963 reference). That

reference describes a technique for obtaining a high-frequency value of a capacitor equipped with an unshielded

(banana plug) connector. The measure- ment technique yields effective capaci- tance values at high frequencies using the capacitance value at 1 kHz and the residual series inductance. The same

technique, with some modifications, is usable for three-terminal and four-terminal pair capacitors. It is emphasized

that these extrapolation procedures are only usable for air dielectric capacitors

or capacitors with insulating materials

whose dielectric constant does not change with frequency.

Three-Terminal, Low-Loss Standard

Capacitors (52221C)

Fixed-value reference standards are maintained by NIST for values of 10 pF,

100 pF, and 1000 pF. High-quality

three-terminal air dielectric capacitance

standards should have low residual series inductance (< 0.1 |jlH). This being

the case, it may be assumed that, to within an expanded uncertainty* of

0.10 %, the capacitances of standards of 1 pF or less with air-dielectric is the same at 1 MHz as it is at 1 kHz. Thus,

it is unnecessary to have capacitors smaller than 10 pF calibrated at

1 MHz.

Two-Terminal, High-Q Standard

Inductors (52310S)

In the frequency range from 1 0 kHz to 250 MHz, inductance calibrations to a minimum expanded uncertainty* of

0.1 % are available from 0.01 jjlH to

1 mH. The upper inductance limit for calibration decreases as the frequency

increases and is 1 |xH at 250 MHz. In the Report of Calibration, the resistance of

the inductor is also given. Service is available only for air-core inductors or inductors whose value is independent of

current.

References—High-Frequency Standard

Capacitors and Inductors

Calibration Service for Low-Loss, ThreeTerminal Capacitance Standards at 100 kHz and 1 MHz, G. M. Free and

R. N. Jones, Natl. Inst. Stand. Technol. (U.S.), Tech. Note 1348

(Feb. 1992).

Evaluation of Three-Terminal and Four- Terminal Pair Capacitors at High

Frequencies, R. N. Jones, Natl. Bur.

Stand. (U.S.), Tech. Note 1024

(Sept. 1980).

The Measurements of Lumped

Parameter Impedance: A Metrology

Guide, R. N. Jones, Natl. Bur.

Stand. (U.S.), Monogr. 141 (June

1974).

A Precision High-Frequency Calibration

Facility for Coaxial Capacitance

Standards, R. N. Jones and L. E.

Huntley, Natl. Bur. Stand. (U.S.), Tech. Note 386 (Mar. 1970).

Impedance of Lumped Circuits, L. E. Huntley and R. N. Jones, Proc. IEEE

55(6), 900 (June 1967).

A Technique for Extrapolating the

1 kc Values of Secondary Capacitance Standards to Higher Frequencies, R. N. Jones, Natl. Bur. Stand.

(U.S.), Tech. Note 201 (Nov. 1963).

*See Chapter 1, Section H for more information about uncertainty.

137
52400C

B. Impedance Measurements (Except Resistors)

B.3 Power-Frequency Capacitors

Eric D. Simmon

Tel:30 1/975-3956 Email:esimmon@nist.gov

Technical Contacts:

James K. OlthofT

Tel:301/97S-2431 Email:jolthofr@nisLgov

Denisc D. Prather

Administration and

Logistics Tel:30 1/975-4221 Email :dprather@nist.gov

Mailing Address: Building 220, Room B 1 46,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

[Attn: J. K. Olthoff, Bldg. 202, Room 167, ext. 2431]

1-270 at Quince Orchard Road,

Gaithersburg, MD 20899-0001

References—Power-Frequency

Capacitors

A Calibration Service for Voltage Trans- formers and High-Voltage Capacitors,

W. E. Anderson, Natl. Bur. Stand.

(U.S.), Spec. Publ. 250-33

(June 1988).

An International Comparison of HighVoltage Capacitor Calibrations, W. E. Anderson, R. S. Davis, O. Petersons, and W. J. M. Moore, IEEE Trans. Power Appar. Syst. 97 (4), 1217 (July

1978).

A Wide Range High-Voltage Capacitance

Bridge with One-ppm Accuracy, O. Petersons and W. E. Anderson,

IEEE Trans. Instrum. Meas. IM-24

(4), 336 (Dec. 1975).

Service ID No. Items 52400C Power-Frequency Capacitors

Power-Frequency Capacitors (52400C)

A calibration service is maintained for capacitors designed for 60-Hz operation,

especially at voltages above 100 V. Typical expanded uncertainties* for a

calibration are 100 X 10^ of the capacitance, and 1 % oT the dissipation factor plus 1 X 10"^. Routine calibrations are limited to devices with a dissi- pation factor of 0.01 1 or smaller and

which are operated at sufficient voltages

that at least 40 |xA passes through the device under test. The high-power limit for routine

tests is 10 kVA. Some capability to perform tests outside of these limits

exists, and NIST should be contacted to discuss special arrangements for such

tests.

*See Chapter 1, Section H for more information about uncertainty.

138
52710C-52711C

B

Impedance Measurements (Except Resistors)

B.4 e-Standards

Technical Contacts:

References

Q-Standards

Standards for the Calibration of

G -Meters, 50 kHz to 45 MHz,

R. N. Jones, J. Res. Natl. Bur. Stand.

(U.S.), 58C (4), 243 (Oct.-Dec. 1964).

George M. Free Paula M. Hewitt

1^1: 303/497-3609 Administrative and Logistics Email :gfree@nist.gov Tel: 303/497-3753 Email:paula.hewitt@nisLgov

Fax:303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service roNo. Items 527 IOC Inductive g-Standards; 50 kHz to 45 MHz, 0.25 |jlH to 25 mH

52711C Each Additional Frequency for 527 IOC

e-Standards (52710C-52711C)

Standards for Q -measurements are maintained at NIST. These are high-g inductors equipped with

banana plug connectors at a spacing of

1 inch on centers. These standards have inductance values of (0.25, 2.5, 25,

250, 2500, and 25,000) jjlH, and effective (2 -values from 100 to approximately

600. These serve as working standards

for calibration of (g -standards of a similar type. Calibration frequencies range from 50 kHz to 45 MHz. The calibration report includes effective resonating

capacitance and effective Q . Relative ex- panded uncertainties* are of the order of 0.2 % for capacitance and 2 % for Q

.

Provisions are made for calibrating

each g -standard at three frequencies;

however, adequate assurance of stability is usually provided by recalibrating

only at the center frequency.

*See Chapter 1 , Section H for more information about uncertainty.

139
53110S-53190S

a Voltage MeasurementsC. 1 DC Voltage Measurements

and Standards

Technical Contacts:

June E. Sims TO: 301/975-4238

Eniail:june.siins@nistgov

Yi-hua TUng

Tel: 301/975-4691 Email:ytang@nisLgov

Denise D. Prather Administration and

Logistics

Tel: 301/975-4221 Email:dprather@nistgov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service roNo. Items

531 lOS Special DC Voltage Measurements, by

Prearrangement 53 1 20M Measurement Assurance Program for DC Voltage 53 1 30C First Saturated Standard Cell in a Group

53131C Each Additional Cell 53 1 40C Platinum Resistance Thermometer Temperature

Determination for Standard Cell Calibration 53150C Unsaturated Standard Cells 53I60C Tests of Solid-State Voltage Reference Standard (One Output, 1 V to 10 V)

53 1 6 1 C Each Additional Output

531 SOS Special Handling (Equipment Pickup or Delivery) 531 90S Special Handling (Cleaning, Minor Repair, Return

Service Charge)

General Information—DC Voltage

Measurement Standards

The service described in this section provides for the calibration of stan- dards of direct voltage, saturated and

unsaturated standard cells, and solidstate standards, and for dc voltage MAP

services at the 1.02-volt level. The U.S.

Representation of the Volt is maintained

by monitoring the emfs of several groups of saturated standard cells in ovens on a monthly basis using the ac Josephson effect. Customer cells are calibrated by measuring the differ- ence between their emfs and those of

working groups of standard cells using

automated systems comprised of low

thermal emf, computer-controlled

switches and high-resolution digital voltmeters.

Special DC Voltage Measurements, by

Prearrangement (531 lOS)

The evaluation, testing, or calibration of

prototype dc voltage standards and measuring apparatus or unique voltage measurements are provided by this service. These measurements are performed only

when deemed reasonable by the appropriate technical staff and serving the best long-term interests of the client, the measurement community, and NIST.

Table 9.5. Expanded Uncertainties* of NIST DC Voltage

Measurement

(X lO-'j

Josephson Calibrations of Primary Cells (1.018 V)

Unsaturated Standard Cells Saturated Standard Cells

Volt Transfer Program (Saturated Standard Cells) Solid-State References (1.018 V, 10 V)

Solid-State References (5 V to 10 V)

0.04 > 50 >0.15

>0.20

>0.19

>0.19

Measurement Assurance Program

Service (53120M)

This MAP service provides a measure- ment of the error of dc voltage measure- ments in the customer laboratory at the

1.02-volt level, the uncertainty of the results, and an updated assigned value for the client's reference standards. A trans- port standard, which consists of a stan- dard cell enclosure containing four

saturated standard cells, maintaining

constant temperature via line and battery power, is used. Preferably, it is handcarried between NIST and the client laboratory, but arrangements may be made

for air shipment. The standard is cali- brated by NIST, the customer laboratory,

and again by NIST to obtain the required

data. The transport standard is capable of

performing at the relative expanded

uncertainty* level of 0.2 X 10^ to 0.3 X 10"^ when hand-carried, and

0.5 X 10"* to 0.8 X 10^ otherwise.

*See Chapter 1, Section H for more information about uncertainty.

140
531 lOSThe measurement uncertainty achieved

in this service contains primarily random

errors. The major components of random

error can be attributed to:

A. Day-to-day fluctuations in temperature-corrected cell emfs caused by

temperature-hysteresis effects; B. The finite resolution of the measurement apparatus at both the client lab- oratory and NIST;

C. Thermal emfs, unstable with time,

which occur in the measuring circuit due

to room temperature and humidity

changes and drafts; D. Temperature coefficients of the enclosures as a whole, not compensated

for by temperature corrections; E. Lack of resolution or instability of

the apparatus used to monitor the cell temperatures;

F. Slow changes in temperature gradients or enclosure temperatures possibly

due to atmospheric "pumping" of cool

air into the enclosures, or vibration

effects on the control circuitry; G. Controller instability caused by

power-line noise; H. Effects of electrostatic or electro- magnetic pick-up on the measuring

system;

I. Detector drift; and

J. Momentary upsets in cell emfs

caused by small electrical currents pass- ing through the cells.

The experimental design described for making the intercomparison measure- ments removes the effects of average

"left-right" or offset errors. One potentially significant source of error not

corrected for or quantified in the MAP

service is that caused by scale-factor

errors in the instrumentation used to measure the differences between cell emfs. An error from this source can be

eliminated by using calibrated instru- ments and applying the appropriate cali- bration corrections to the results. The transport standard is normally kept

in the client's laboratory for about

4 weeks, since eight to 12 measurement

sets are generally required. Data analysis

and issuance of the test report by NIST

takes 4 to 5 weeks following the return of

the transfer standards.

If the participating laboratory has a

quality instrument that has been accurately calibrated and also has quality

standards, the relative expanded uncertainty* of a single transfer of the unit of

voltage using NIST transport standards is generally of the order of 0.5 X 10"^ or

less. The best achievable long-term relative expanded uncertainty*, resulting

from five or more transfers over an ex- tended time, is of the order of 0.2 X 10"*

to 0.3 X 10^.

In this service, NIST provides detailed

instructions for carrying out the transfer and making the required measurements. The participant must have in-house

standards and instrumentation capable of

sustained performance at the 0.1 X 10^

level. When a new participant (or group

of participants) expresses a desire to use

the voltage MAP service, NIST requests

that a complete description of the participant's measurement system, including in- struments, standards, wires, switches, and

their use, be sent to the NIST technical

staff. This description enables NIST

personnel to assist in resolving measure- ment problems by telephone.

NIST requires evidence in the form of

control charts of the existence of a formal quality-control program in the laboratory as a prerequisite to participation in the service. This requirement has

been established to enable problems to be

addressed in advance of the transfer and

to reduce delays in returning the standards to NIST.

Saturated Standard Cells (53130C-53140C)

Routine calibrations of saturated standard

cells involve the following considerations:

A. Saturated standard cells of the unshippable type should always be trans- ported by messenger because such cells should never be tipped from an upright

position by more than 45° in any direction. Unshippable saturated cells contained in portable, temperature-regulated enclosures should also be transported by

messenger and with the enclosure acti- vated or under power if possible.

* See Oiapter 1 , Section H for more information about uncertainty.

141
B. Saturated standard cells of the shippable type housed in portable ther- moregulated enclosures should be packed

carefully and shipped under power if possible. Any liquid-in-glass thermometer mounted in such a device should be

removed and provided with additional

rigid packing for protection against

breakage. Enclosures having a nominal

cell temperature of 28 °C or lower

should not be transported during the summer due to the danger of overheating. Enclosures should not be energized

by using the ac power mains while

they are in shipping containers as heat from the transformer will cause them

to go over-temperature. C. Saturated standard cells, which

are maintained continuously at their nominal temperature of use during shipment, will undergo test starting 1 week

after receipt for a period not to exceed

6 weeks, unless other arrangements are made. If such cells perform abnormally, the owner will be notified. Arrangements for further testing may

be made at that time if desired. Cells will be returned as soon as possible after calibration. D. Saturated cells arriving at a temperature other than their nominal

temperature of use will be brought to

their use temperature as soon as possible

after receipt. Starting 1 month after they initially attain use temperature, daily

readings will be taken to observe the

stability of the cells. When the cells

stabilize, 10 daily readings will be

taken and averaged to assign values to them. This process will not exceed

90 days without special arrangements

being made.

E. For an additional fee, the temperature of air bath enclosures for satu- rated standard cells will be determined

using a calibrated NIST platinum

resistance thermometer (Service ID

Number 53140C). Daily readings are taken and reported. The reported cell emfs are assumed to correspond to the mean of the temperatures measured on

the same days as the emf readings were taken.

The client must understand that, when

this is done, the uncertainties of the reported emfs include the emf equivalent

of the uncertainty of the measured

temperatures in terms of the International Temperature Scale of 1990 (ITS-90).

Moreover, estimates of the uncertainties of any voltage measurements made by

clients using these cells as a reference must include corresponding uncertainties of their own temperature measurements.

F. NIST accepts cells used in oil baths for calibration in NIST oil baths maintained at 28 °C. Cells used in oil baths operating at other nominal temperatures can best be calibrated using

transport standards as in the MAP

service. (See 53120M above.)

Calibration relative expanded

uncertainties* generally range from

0.15 X 10^ to 0.50 X 10"*. The stated uncertainties are those of the NISTmeasured average values, i.e., they do

not reflect long-term behavior of the

cells, transportation effects, etc.

Unsaturated Standard Cells (53150C)

Unsaturated cells require approximately 3 weeks for a complete calibration. The emfs of such cells are read

daily for a minimum period of 10 days.

These cells are compared with NIST

saturated cells using a precision digital voltmeter to measure the difference emf directly. The calibration relative expanded uncertainty* is 0.(X)5 % of

the measured voltage unless the cell is abnormal. If the measured emf fluctuates unduly or is unusually low, or if the

cell behaves abnormally, the reported

uncertainty will be increased appropriately. Unsaturated cells are not likely to be injured by normal transportation

(mail or express) if they are packed

carefully. Because of the possible hazard

from freezing, shipment during ex- tremely cold weather should be avoided.

*See Chapter 1, Section H for more information about uncertainty.

142
5311 OS;-53190S

Solid-State Voltage Reference

Standards (53160C and 53161C)

Solid-state voltage standards with outputs

in the range from 1 V to 10 V are cali- brated using a self-calibrating automated

system which scales to any multiple up to 10 V of 1.018 V from the emf of a working group of NIST saturated standard

cells. It then measures the difference between the emf of the standard under

test and the emf of its own output closest

in voltage to that of the standard being

measured and computes its emf. Measurements are taken daily for 12 to 15 working days and the mean value of the

results reported.

Due to the limited battery life of many

commercial standards, special shipping

arrangements are advisable and can be

made by contacting the Electricity Division. Many solid-state standards have multiple outputs; to ensure proper testing, the outputs to be calibrated should be speci- fied on the shipping papers as well as on

the purchase order. Voltmeter calibrators, multirange in- struments with up to eight decimal digits

of adjustability, are not considered by

NIST to be standards and are not to be

submitted routinely for calibration under

this test category. Likewise, NIST will not accept component solid-state devices

for routine calibration. However, new,

state-of-the-art devices and instruments

may be accepted for test under special

circumstances (see Service ID Number

531 lOS) at the discretion of NIST

technical staff. The NIST calibration service for voltage is directly tied to NIST Josephson-junction voltage-standard arrays. This

1-V standard fabricated from niobium

trilayer resists the effects of cycling

between its operating temperature of

liquid helium and room temperature

better than previous designs.

References—Voltage Measurements

and Standards

Guidelines for Implementing the New

Representation of the Volt and Ohm

Effective January 1, 1990, N. B. Belecki, R. P. Dzuiba, B. E Field, and

B. W. Taylor, Natl. Inst. Stand. Technol., Tech. Note 1263 (June 1989).

NBS Measurement Services: Solid-State DC voltage Standard Calibrations, B. E. Eield, Natl. Bur. Sand. (U.S.), spec. Publ. 250-24 (Oct. 1987).

NBS Measurement Services: Standard

Cell Calibrations, B. E. Eield, Natl. Bur. Stand. (U.S.), Spec. Publ. 250-24

(Oct. 1987).

The NBS Josephson Array Voltage Stan- dard, C. A. Hamilton, R. L. Kautz,

E. L. Lloyd, R. L. Steiner, and B. E. Eield, IEEE Trans. Instrum. Meas. IM-36, 258 (June 1987).

A Sub-PPM Automated One-to-Ten Volt Measuring System, B. E. Eield, IEEE

Trans. Instrum. Meas. IM-34, 327

(1985).

Volt Transfer Program Instructions, NBS

Internal Document, Unpublished,

Revised (1983).

A High-Resolution Prototype System for Automatic Measurement of Standard

Cell Voltages, D. W. Braudaway and

R. E. Kleinmann, IEEE Trans. Instrum. Meas. IM-23, 282 (1974).

Volt Maintenance at NBS via 2e/h: A

New Definition of the NBS Volt, B. E. Eield, T. E. Einnegan, and J. Toots, Metrologia9, 155 (1973).

Designs for Surveillance of the Volt Maintained by a Small Group of Saturated Standard Cells, W. G. Eicke and

J. M. Cameron, Natl. Bur. Stand.

(U.S.), Tech. Note 430 (Oct. 1967).

Standard Cells Their Construction,

Maintenance, and Characteristics, W. J. Hamer, Natl. Bur. Stand. (U.S.),

Monogr. 84 (Jan. 1965).

143
53200S-53203S

C. Voltage Measurements

C.2 AC Voltage Measurements

Technical Contacts:

Nile M. Oldham Mark E. Parker

Tel:301/975-2408 'Itl:301A>75-2413 Email : nold ham@nist.gov Email: mparker@nist.gov

Denise Prather

Administration and

Logistics 1^1:301/975-4221 Email:dprather@nistgov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 53200S Special Tests of High-Accuracy Digital

Multimeters, Multifunction Calibrators, by Prearrangement

5320 1 S Special Tests of Low-Voltage AC-DC Transfer

Standards, by Prearrangement

53202S Special 25-Point Test of Digital Multimeters (DMMs),

by Prearrangement

53203S Each Additional DMM Test Point for 53202S

Digital Multimeters (DMMs) and

Multifunction Calibrators (53200S)

Voltage measurements are performed at dc at amplitudes between 1 mV and

1 kV. Relative expanded uncertainties* as low as 1 X 10"^ are possible in the mid-voltage range. Low-frequency (0.1 Hz to 100 Hz)

measurements of ac voltage are made be- tween 1 mV and 7 V using a NIST-developed calculable voltage standard in which waveforms are digitally synthesized using a lookup table and a digitalto-analog converter. Relative expanded

uncertainties* as low as 5 X 10"^ are possible around 7 V. Wideband ac voltage measurements

between 10 Hz and 30 MHz are made

between 1 mV to 1 kV using a thermal

voltage converter standard in an auto- matic calibration system.

Relative expanded uncertainties* range from 10 X 10^ to 0.2 %.

AC current measurements are per- formed on the same automatic calibration system using a thermal current converter. Current sources can be measured from

10 Hz to 100 kHz at current levels between 1 mA and 2 A. Digital multimeters (DMM) tests are normally limited to an upper frequency of 5 kHz; however,

special arrangements may be made for

tests at higher frequencies and currents. Realtive expanded uncertainties* are

typically less than 100 X 10"^. Direct current resistance measurements

are performed between 1 fi to 100 Mfi,

for both DMMs and calibrators. Relative expanded uncertainties* of 2 X 10"^ are possible for certain resistance values.

Low-Voltage AC-DC Transfer

Standards (53201S)

Measurements of the ac-dc difference of

low-voltage (1 mV to 200 mV) thermal

transfer standards, micropotentiometers,

and voltage dividers are also offered as a

Special Test in the dc to 1 MHz fre- quency range. Relative expanded uncertainties* of 15 X 10"^ are possible in the audio-frequency range at 100 mV.

Special 25-Point Test of Digital

Multimeters (DMMs), by

Prearrangement (53202S-53203S)

This is a special reduced cost, 25-point

test covering all five functions (ac and dc

voltage and current, and dc resistance) of most precision DMMs. DMMs submitted

for test must have an rEEE-488 interface bus, and a list of DMM bus commands

for the instrument may be required. The

25 test points available are shown in Table 9.6 below, together with the best possible expanded uncertainties*. Additional test points are available over a wide

range of amplitudes and frequencies.

* See Chapter 1 , Section H for more information about uncertainty.

144
531 lOS1-531 90S

Table 9.6. 25-Point Standard DMM Test

Point Function Magnitude Frequency Relative

(kHz) Expanded

Uncertainty*

(X 10^)

1 DC Voltage 0.1 V 4

2 DC Voltage 1 V 2

3 DC Voltage 10 V 1 4 DC Voltage 100 V 2

5 AC Voltage 0.1 V 0.3 50

6 AC Voltage 0.1 V 10.0 50

7 AC Voltage 0.1 V 1000.0 1000 8 AC Voltage 1 V 0.3 20

9 AC Voltage 1 V 10.0 20

10 AC Voltage 1 V 1000.0 500

11 AC Voltage 10 V 0.3 20

12 AC Voltage 10 V 10.0 20

13 AC Voltage 10 V 1000.0 500

14 AC Voltage 100 V 1.0 20

15 AC Voltage 100 V 100.0 50

16 DC Current 10 mA 10 17 DC Current 1 A 20

18 AC Current 10 mA 0.3 75

19 AC Current 10 mA 5.0 100 20 AC Current 1 A 0.3 100

21 AC Current 1 A 5.0 200

22 Resistance ion 8 23 Resistance 1 kn 3 24 Resistance 100 kn 5 25 Resistance 10 MO 30

* See Section H, Chapter 1 , for more information about uncertainty.

References—AC Voltmeters and

Sources

New Low-Voltage Standards in the DC to

1 MHz Frequency Range, N. M.

Oldham and R. M. Henderson, Conf.

Record of CPEM '90, Ottawa, Canada

(June 1990).

A Calculable, Transportable AudioFrequency AC Reference Standard, N. M. Oldham, R S. Hetrick, and X.

Zeng, IEEE Trans. Instrum. Meas. 38

(2), 368-371 (April 1989).

A High-Accuracy, 10 Hz- 1 MHz Automatic AC Voltage Calibration System, N. M. Oldham, M. E. Parker, A.

Young, and A. G. Smith, IEEE Trans. Instrum. Meas. 36, 883-887 (Dec.

1987).

145
53310S-53352C

C. Voltage Measurements

C.3 AC-DC Thermal Voltage and Current

Converters (to 1 MHz)

Technical Contacts:

Joseph R. Kinard Thomas E. Lipe

Tel : 30 1/975-4250 Tel :30 1/975-425

1

Email :joseph.kjnard@ Email:thoma$.lipe@

nistgov nist.gov

Denise D. Prather

Administration and

Logistics Tel:30 1/975-4221 Email:denise.prather@ni$t.gov

Mailing Address: Building 220, Room B 1 46,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 533 lOS Special AC-DC Measurement Services,

by Prearrangement

53350C Set-up (No Test Points Included) for an AC-DC Difference

Calibration of a Standard or Set of Standards (Voltage or

Current) 5335 IC First Frequency Point for Each Applied Voltage or

Current Level 53352C Additional Points for Each Applied Voltage and Current Level (Additonal Frequency/Voltage

or Frequency/Current Points)

General Information—Thermal

Voltage and Current Converters

Alternating voltage and current are most

accurately measured by comparing the heating effect of the alternating quantity

to the average heating effect of both polarities of the direct quantity using ther- mal transfer standards. These devices

may be simple thermoelements, thermal

voltage converters consisting of high-performance thermal sensors and resistors, or thermal current converters consisting

of a precision shunt used with a thermal

sensor. Good quality thermal converters

generally have small ac-dc differences which are constant with respect to fre- quency in the range from about 1 00 Hz

to 20 kHz at voltages from about 0.5 V

to ICXD V or currents up to about 5 A.

The ac-dc differences generally increase

(to large values in some cases) as the applied voltage or current is increased, or

as the frequency departs from the audio

region.

Special AC-DC Measurement Services,

by Prearrangement (53310S)

This service provides for the measure- ment or evaluation of prototype ac

voltage or current standards, sources, or measurement instrumentation, and for other measurements of alternating

voltage, alternating current, or ac-dc

difference not provided for below, at the discretion of NIST technical experts.

Components used for ac-dc conversions

will generally not be tested unless they

show promise of standards-level behavior. Even then, such components will only be

tested in very limited numbers to explore

their possible use for precision measurements.

Special ac-dc difference calibrations of

appropriate thermal voltage and thermal

current converters are now offered with a

relative expanded uncertainty* of

0.8 X 10^. This calibration service is the

result of an extensive study of the group

of multijunction thermal converters that make up the NIST primary standards. Thermal converters will be accepted for calibration with the 0.8 X 10"^ expanded

uncertainty* provided that their perfor- mance, including stability and square-law

response, is compatible with the NIST

standards and high-precision comparator

system. In general, the uncertainty below

1 X 10"^ is available for voltages from

2 V to 1 2 V, currents from 5 mA to 20 mA, and frequencies from 30 Hz to 10 kHz. As in the case of the other

special ac-dc difference calibrations with

reduced uncertainty, an additional cost and an extended turnaround time at NIST

are required. Prospective clients are asked

to contact J. R. Kinard to discuss the requirements and arrangements related to

this service.

*See Chapter 1, Section H for more information about uncertainty.

146
53310S-53352C

AC-DC Difference Calibration of a Standard or Standards Set (Voltage or Current) (53350C-53352C)

This service covers the calibration of

thermal voltage and current converters, ac shunts, and primary standard ther- moelements covering the ranges 2 Hz to

1 MHz, 1 mA to 20 A, and 0.2 V to 1000 V. Measurements are recommended

at all voltages or currents and frequencies where the transfer standard is used

by the customer. In addition, if 1 000 V

or 1 200 V ranges are measured, tests at 600 V are recommended to evaluate

the effect of self-heating on the ac-dc

difference of the resistor. Since some

thermal transfer standards show large ac- dc differences at frequencies below

about 40 Hz, additional measurements may be required to define the low-fre- quency performance of the instrument. Unless the instrument has a previous

calibration history, the user may wish to discuss the calibration parameters with

the appropriate NIST staff. The uncertainties offered and

parameter space covered in Table 9.7 for

this calibration service are presently

being reevaluated. Significant reductions

in the uncertainties and expansion of

the parameter space are expected. To obtain the most recent information, cus- tomers are requested to contact the NIST

staff. Routine calibrations of thermal

voltage and current converters generally

are carried out on a demand basis. However, occasional extensive calibration requests may create scheduling problems; therefore, to facilitate rapid

turnaround, please contact T. E. Lipe

or J. R. Kinard at the telephone numbers/

addresses cited above before sending

the equipment.

Ongoing research at NIST will help

to improve the Nation's capability to provide accurate alternating voltage

and current and ac-dc difference calibrations to NIST customers. The present

research focuses on the development of

cryogenic resistive transition-edge sensors as new primary standards of ac-dc

difference, and the design and fabrication of thin-film multijunction converters as working standards for ac-dc difference measurements. Ac-dc difference calibrations at fre- quencies above 1 MHz are performed in the NIST Boulder Laboratory.

Ibble 9.7. AC-DC Difference Calibration Service"'

Frequency: 2 Hz 5 Hz 10 Hz 20 kHz 50 kHz 100 kHz

to to to to to to 5 Hz 10 Hz 20 kHz*"' 50 kHz 100 kHz'"' 1 MHz

Voltage Limits (V) 50 100 1000 1000 1000 100

Current Limits (A) 0.05 20 20 20

Relative Expanded Uncertainties* (XJO

Multirange Thermal Voltage Converters (TVCs) > 100 V 30 50 70 < 100 V 200 100 20 30 50 100

Coaxial Single Range TVCs

> lOOV 20 30 50 < 100 V 200 100 15"" 25 40 70

Special'"'

10 V 100 V 10 lV<x< lOV 5

Thermal Current Converters (TCCs) >5 A 100 150 (a.b) s 50 mA <;c £ 5 A 50 70 (a.b) <50mA 200 100 50 70 (a.b)

'''The uncertainties offered and parameter space covered in the table for this calibration service are presently being reevaluated. Significant reductions in the uncertainties and expansion of the parameter space are expected. To obtain the most recent information, customers are requested to contact the NIST staff.

'*' Some voltage, current, and frequency combinations in this range are available only

as a special test with uncertainty determined on an individual basis.

'" The lower uncertainty applies at the crossover frequencies. Uncertainties may be in- creased if the ac-dc differences are large or affected by self heating or other instability.

"" 20 X 10-^ from 20 Hz to 100 Hz, 15 X lO"* at 100 Hz and above.

'" Normally available by prearrangement for coaxial, single-range TVCs between

100 Hz and 20 kHz, at additional cost and a longer turnaround time at NIST.

*See Chapter 1, Section H for more information about uncertainty.

147
53310S-53352C

References—AC-DC Thermal

Converters (to 1 MHz)

Extension of the NIST AC-DC Differ- ence Calibration Service for current to 100 kHz, J. R. Kinard, T. E. Lipe, and

C. B. childers, J. Res. Nad. Inst. Stand. Technol. 102 (1), 75 (Jan.-Feb. 1997).

A Reevaluation of the NIST Low-Fre- quency Standards for AC-DC Differ- ence in the Voltage Range 0.6-100 V,

T. E. Lipe, IEEE Trans. Instrum. Meas. IM-45 (6), 913 (Dec. 1996).

Performance of Multilayer Thin-Film

Multijunction Thermal Converters, J. R. Kinard, D. X. Huang, and D. B. Novotny, IEEE Trans. Instrum. Meas. IM-44 (2), 383 (April 1995).

AC-DC Difference Characteristics of

High-Voltage thermal Converters, D. X. Huang, T. E. Lipe, J. R. Kinard,

and C. B. Childers, IEEE Trans. Instrum. Meas. IM-44 (2), 387 (April

1995).

AC-DC Difference Characteristics of

High-Voltage Thermal Converters, D. X. Huang, T. E. Lipe, J. R. Kinard,

and C. B. Childers, IEEE Trans. Instrum. Meas. IM-44 (2), 387 (April

1995).

NIST Measurement Services: AC-DC

Difference Calibrations, J. R. Kinard, J. R. Hastings, T. E. Lipe, and

C. B. Childers, Natl. Inst. Stand. Technol., Spec. Publ. 250-27 (May

1989).

Determination of AC-DC Difference in the 0.1-100 MHz Frequency Range,

J. R. Kinard and T. X. Cai, IEEE

Trans. Instrum. Meas. IM-38 (2), 360 (April 1989).

Recharacterization of Thermal Voltage Converters after Thermoelement

Replacement, J. R. Kinard and T. E.

Lipe, IEEE Trans. Instrum. Meas. IM-38 (2), 351 (April 1989).

148
53405S-53445S

C Voltage Measurements

C.4 RF-DC Thermal Voltage and Current

Converters (100 Hz-1 GHz)

Technical Contacts:

George M. Free Earle S. Pittman Paula M. HewiR

'Ilel:30a/497-3609 T?l:303/497-5593 Administration and Logistics Eniail:gfree@nist.gov Email :epittnian@ni$t.gov Tel:303/497-57S3 Email:paula.hewitt@nist.gov Fax:303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items 53405S Special Tests of AC Thermal Voltage Converters, by Prearrangement

53410C Low-Frequency TVC Calibration at One Frequency

Selected from Those Given in Table 9.8 at Rated

Voltage in the Range 0. IV to 50 V

5341 IC Additional Frequency Selected from Table 9.8 for Same TVC as in 5341 OC

53412S Same as 534 IOC, Except Customer Designates a

Single Frequency (in Same Frequency Range) Other Than Those Given in Table 9.8 5341 3C Low-Frequency TVC Calibration at One Frequency

Selected from Those Given in Tkble 9.8 at Rated

Voltage in the Range 50-200 V

53414C Additional Frequency Selected from Table 9.8 for Same TVC as in 5341 3C

53415S Same as 5341 3C, Except Customer Designates a

Single Frequency (in Same Frequency Range) Other Than Those Given in Table 9.8 53420C High-Frequency TVC Calibration at One Frequency

Selected from Those Given in lkb\e 9.9 at Rated

Voltage in the Range 0.2 V to 7.0 V

5342 IC Additional Frequency Selected from Tkble 9.9

for Same TVC as in 53420C

53430S Peak-to-Peak Detector Calibration at One Frequency

Selected from Those Given in T&hle 9.10 at 1.2 V

Peak-to-Peak Applied Rf Voltage

5343 IS Additional Frequency for Peak-to-Peak

Detector in 53430S

53440S Special Tests of RF Micropotentiometers, by

Prearrangement 53441 C RF Micropotentiometer Calibration at One Frequency

Selected from the Frequency Bands Given in Table 9. 1

1

53445S Special Calibration of RF Micropotentiometer

(Output Voltage Range, 200 to 200 000 |xV at Frequency Range, 0.05 MHz to 1000 MHz) with Reduced

Limits of Uncertainty

General Information—RF-DC

Thermal Voltage and Current

Converters, 100 Hz to 1 GHz (53405S53445S)

Services are available for three types of

electromagnetic voltage measuring

devices: ( 1 ) Thermal Voltage Converters (TVCs), (2) Peak-to-Peak Detectors, and

(3) Voltage Comparators and one type of

electromagnetic generating device: RF

Micropotentiometers. Assurance of device stability can be

obtained by intercomparing a micropot

or TVC with another similar device

where voltage ranges overlap. For example, a 1 V TVC can be compared with a

3 V TVC at 1 V, etc. TVC calibrations requiring relative uncertainties* less than 0.05 % at frequencies below 1 MHz are performed

at NIST Gaithersburg in the Electricity

Division (Service ID Nos. 53350C,

53351C, 53352C).

RF Voltage Comparators (53405S)

Special tests are performed on rf voltage

comparators using TVCs and micropotentiometers at selected frequencies from

100 kHz to 1 GHz at voltages ranging

from 10 mV to 20 V. Several calibration options are available to the customer.

Therefore, consultation by telephone or

written correspondence is recommended

before the comparator is submitted for

calibration.

Thermal Voltage Converters (TVCs)

(53410C-53421C)

TVCs also include other devices such as Rawson rf voltmeters, thermal transfer standards, rf voltage standards, and ac-dc

transfer standards. Most converters have rf-dc differences within 0.01 % of zero at 1 MHz and below. Converters with previous calibration

history that are submitted for recalibration should be evaluated at 1 MHz and

results compared to prior data. If the dif- ference is negligible, no further calibrations are usually necessary below 1 MHz.

*See Chapter 1, Section H for more information about uncertainty.

149
53405S-53445S

The quantity measured by this calibration service is the rf-dc difference, defined as the percentage difference between the rf and dc input voltages required to produce

the same thermocouple output, e.g.,

RF-DC Difference (%) =

d£ X 100.

Services available for low-frequency

TVCs without a built-in T connector are given in Table 9.8. For high-frequency

TVCs with a built-in T connector, the services available are given in Table 9.9. Calibrations above 100 MHz are per- formed only on the new high-frequency

TVCs with a T connector as an integral

Table 9.8. Measurement Ranges and Uncertainties for LowFrequency TVC Services

Recommended

Frequencies

(MHz)

RF Voltage

Range

(V)

Relative Expanded

Uncertainty*'^'

(%)

0.03, 0.1,0.3, 1 0. 1 to 200 0.04

3 and 10 0. 1 to 200 0.08 30 0.1 to 200 0.16 100 0.1 to 200 0.8

Rf-dc differences greater than 20 % will not be reported. This normally limits the calibrations to 100 MHz and below. *See Chapter 1, Section H for more information about uncertainty.

Table 9.9. Measurement Ranges and Uncertainties for HighFrequency TVC Services

Frequency

(MHz)

10 30

100, 200, 300, 400

500, 600, 700

800, 900, 1000

RF Voltage

Range

(V)

Relative Expanded

Uncertainty*'^'

(%)

0.2 to 7.0 0.2 to 7.0 0.2 to 7.0 0.2 to 7.0 0.2 to 7.0

0.12 0.24

1 .20

1 .20

1 .20

Rf-dc differences greater than 20 % will not be reported. *See Chapter 1, Section H for more information about uncertainty.

part of the converter housing. The

measurement reference plane is at the Type N male output connector of the converter.

Peak-to-Peak Detectors (53430S53431S)

Measurements on peak-to-peak detectors

are performed from 100 kHz to 500 MHz

and are referenced to the center of a GR 874 T connector. The quantity measured by this service is the rf-ac difference, defined as the percentage of

difference between the rf and the ac input

voltages required to produce "zero" dc

detector output. A 50-kHz ac reference

signal is applied instead of dc. The

services available are specified in Table 9.10.

Table 9.10. Measurement Ranges and Uncertainties for Peak-to-Peak Detector Services

Relative Applied RF Voltage Expanded

Frequency for "0" Detector Output Uncertainty

(MHz) (Vp_p) (%)

0.1,0.3,1.0 1.2

3, 10 1.2 30 1.2 50 1.2 100,200,300,400,500 1.2

0.08

0.13 0.24

0.58

1.20

*See Chapter 1, Section H for more information about uncertainty.

RF Micropotentiometers

(53440S-53445S)

Radiofrequency micropotentiometers are usually calibrated at their nominal rated output voltages. Frequencies suggested

for a normal calibration are (5, 100, 300,

400, 500, 700, and 900) MHz. Special

arrangements may be made for calibrations up to 1000 MHz with reduced

limits of uncertainty.

Radio frequency micropotentiometers

having resistive elements greater than

1 0 mil in combination with thermoelement housings between 5 mA and

1 00 mA, usually have rf-dc differences within 1 % at 5 MHz. Since the

rf-dc difference approaches zero below

150
53405S-53445S

5 MHz, calibrations at 50 kHz and

5 MHz would suffice to determine inter- polated points of interest between 50 kHz

and 5 MHz, with no appreciable loss of

accuracy. Uncertainties are shown in Table 9.11. An rf-dc difference of about 5 % at

1 MHz usually results from the effect of

a 1 mfl resistive element with a thermoelement rated between 5 mA and

100 mA inclusive. Interpolation below

1 MHz is not recommended in this case. The rf-dc difference is defined as the percentage difference between the rf and

dc output voltages required to produce

the same thermocouple output, with the

resistive element terminated in 50 ohms,

e.g..

Table 9.11. Measurement Ranges and Uncertainties for RF

Micropotentiometer Calibrations

Any Frequency

within Band

(MHz)

RF Voltage

Range

(|JiV)

Relative Expanded

Uncertainty*'"'

(%)

0.05 to 100 1 to 100,000 2 100 to 500 1 to 100,000 3 500 to 900 1 to 100,000 6

For rf-dc differences greater than 20 %, the estimated limits of uncertainty

are larger than those listed. *See Chapter 1 , Section H for more information about uncertainty.

RF-DC difference (%)

X 100.

As a special service, rf micropotentiometers with rated output voltage

greater than 200 p,V can be calibrated from 0.05 MHz to 1000 MHz, with

reduced limits of relative expanded

uncertainty* from 0.2 % to 2 %. This

uncertainty is dependent on frequency,

output voltage level, and the rf-dc differ- ence vs frequency response. For further

details, consult the technical contact cited

at the beginning of this section.

References—RF-DC Voltage and

Current Converters (100 Hz-1 GHz)

RF-DC Differences of Thermal Voltage Converters Arising from Input Connectors, D. X. Huang, J. R. Kinard,

and G. Rebuldela, IEEE Trans. lu- strum. Meas. 40 (2) (April. 1991).

NBS RF Voltage Comparator, L. D.

Driver, F. X. Ries, G. Rebuldela, Natl. Bur. Stand. (U.S.), NBSIR 78-871

(Dec. 1978).

High-Frequency Microvolt Measurements, F. X. Ries and

G. Rebuldela, ISA Proc, 18, 1, 37.2.63, Instrum. Soc. of Amer. Res. Triangle Park, NC (Sept. 1963).

Thermal Voltage Converters for Accurate

Voltage Measurements to 30 Megacycles Per Second, F. L. Hermach and E. S. Williams, Trans. AIEE, Pt. 1 , Commun. Elect. 72, 200

(July 1960). Accurate Radio Frequency Microvoltages, M. C. Selby, Trans. AIEE, Pt.

1, Commun. Elect. 72, 158 (May

1953).

Thermal Converters as AC-DC Transfer Standards for Current and Voltage

Measurements at Audio Frequencies,

F. L. Hermach,

J. Res. Natl. Bur. Stand. (U.S.), 48, 121 (1952).

*See Chapter 1 , Section H for more information about uncertainty.

151
53500S

C. Voltage MeasurementsC.5 Data Converters (53500S)

Technical Contacts:

John P. Deyst

1tl:30 1/975-2437 Email :jdeyst@

nistgov

T. Michael Souders

1tl:301A>75-2406 Email:t.souders@

nistgov

Denise Prather

Administration and Logistics

Te!I:301/975-4221 EmaiI : dprather@nist.gov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

References—Data converters

IEEE Standard for Digitizing Waveform

Recorder, IEEE Std. 1057-1994, Dec.

1994. A Custom Integrated Comparator for High Performance Sampling Applications, O. B. Laug, et al., IEEE Trans. Instrum. Meas. 41, 850-856, (Dec.

1992). Accurate Frequency Response Determinations from Discrete Step Response

Data, T. M. Souders and D. R. Flach,

Trans. Instrum. Meas. 36, 433-439

(June 1987).

Service ID No. Items 53500S Special Data Converter Services, by Preanangement

General Information—Data

Converters

NIST has an active research program in the area of data converters and digital

waveform recorders. For D/A converters,

special tests of voltage settling response

are currently available. For A/D converters, a test bed is under development,

having resolution up to 14 bits and sampling rates up to 10' samples/s. Test waveforms will include spectrally pure

sinewaves, and fast settling step-like

waveforms. Available services will include determinations of signal-to-noise

ratio and harmonic distortion, as well as determinations of step and impulse

response, and frequency response as computed from step response. Prospective clients are asked to contact Michael

Souders or John Deyst to discuss the requirements and arrangements related to these services.

152
54110S-54131C

D. Precision Ratio Measurements

D. 1 Inductive Dividers

Technical Contacts:

Norman B. Belecki TO: 301/975-4223 Email :nbelecki@

nistgov

Andrew J. Secula

"^1:30 1/975-4243 Email:asecula@

nist.gov

Denise B. Prather

Administration and Logistics

Tel: 301/975-4221 Email:dprather@nisLgov

Mailing Address: Building 220, Room B 146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items

541 lOS

54120C

54121C

54130C

54131C

Special Ratio Measurements and Tests of Inductive Voltage Dividers, by Prearrangement

Inductive Voltage Dividers—(Single Frequency,

Voltage To Be Specified, Each Setting of 3 Most

Significant Dials) Additional Frequency Points

Inductive Voltage Dividers—(Single Frequency,

Voltage To Be Specified, Each Setting of Most

Significant Dial Only)

Additional Frequency Points

Special Ratio Measurements and Tests of Inductive Voltage Dividers,

by Prearrangement (541 lOS)

This service category provides for the measurement and/or evaluation of prototype ratio devices and inductive voltage

dividers based on new principles, and for unique ratio measurements at the highest accuracy levels, such as the determination of the ratios of Hamon resistance transfer devices or Silsbee-type voltage

ratio standards. Such measurements are undertaken at the discretion of NIST

technical staff and only when the need

for them can be clearly demonstrated.

Inductive Voltage Dividers

(54120C-54131C)

Inductive voltage dividers (decade trans- former dividers) are accepted for calibration only at (50, 60, 100, 120, 400, 1000,

5000, and 10 000) Hz. The most signifi- cant dial only can be calibrated at 15 kHz

and 20 kHz.

Calibration voltages may be specified

up to 100 V or the manufacturer's specified limit, whichever is lower. The largest

contribution to instability in undamaged

inductive voltage dividers is wear or dirt in the decade switches. Variable contact

resistance in these switches sometimes

affects the stability of voltage-ratio measurements to a significant extent but is most evident by its effect on the phase

angle. When a decade inductive voltage divider exhibits large changes in phase

angle for repeated measurements after the switches have been disturbed, the di- vider should no longer be considered sat- isfactory for use as a voltage-ratio reference standard. Inductive voltage di- viders that use pushbutton switching or

incorporate a resistive divider as a fine adjustment usually are not accepted for

calibration. Corrections to the separate decades of an inductive divider, in general, cannot be simply combined. However, the correction to a step setting of one of the higher decades usually is independent of

the setting of the lower decades. The

effects of stray impedances must be cor- rected by connecting the case to the di- vider at one point, and unless otherwise

specified, the case will be connected to one of the "common" terminals, typically

marked "GRD," "Case GND," or "Case

GRD." Decade inductive voltage dividers

are calibrated at NIST at room temperature (22 °C to 24 °C) by comparison with

a two-stage, three-decade transformer of

known ratios.

153
References—Inductive Dividers

American National Standard for Decade

Transformer Dividers (Voltage Type),

ANSI CI 00, 1-1972 Amer. Natl. Stand. Inst., New York, NY (Jan. 1972).

Instructions for the Use of the NBS Ref- erence Inductive Divider, Wilbur C.

Sze, Natl. Bur. Stand. (U.S.), NBSIR,

unpublished (1970). (Available from

NIST.)

Two-Stage, Guarded Inductive Voltage

Divider for Use at 100 kHz, D. H. Hamon and T. L. Zaf, ISA Transactions, 9, 3, Instrum. Soc. of Amer.

Res. Triangle Park, NC (1970).

Comparator for Calibration of Inductive

Voltage Dividers from 1 to 10 kHz,

W. C. Sze, ISA Transactions 6, 4, Instrum. Soc. of America, Res.

Triangle Park, NC (1967).

154
54210C-54214S

D. Precision Ratio Measurements

D.2 Resistive Dividers

Technical Contacts:

Martin Misakian (DC Measurements)

Ttl: 301/975-2426 Email:mmisakian@

nistgov

Gerald J. FitePatrick (60-Hz/Pulsed Measurements)

1^1:301/975-2737 Email tgfi tzpatrick@nist.gov

Denise D. Prather

Administration and

Logistics Tel:30 1/975-4221 Email:dprather@

nist.gov

Mailing Address: Building 220, Room B 146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

[For 54210C-54211S:

Attn: M. Misakian, Bldg. 220, Room B351, ext. 2426]

[For 54212C-54213S:

Attn: G. J. FitzPatrick, Bldg. 202, Room 167, ext. 2437]

[For 54214S:

Attn: G. J. FitzPatrick, Bldg. 202, Room 106, ext. 2737]

1-270 at Quince Orchard Road,

Gaithersburg, MD 20899-0001

Service ID No. Items 542 IOC Resistor and Resistive Dividers, Total Resistance or Voltage Ratio, Two Direct Voltage Levels between

10 kV and 150 kV

5421 IS Special Tests of Resistor and Resistive Dividers at Direct Voltage Levels, by Prearrangement

542 12C Resistor and Resistive Dividers at 60 Hz, Voltage

Ratio and Phase Angle, between 10 kV and

100 kV rms

542 13S Special Tests of Resistor and Resistive Dividers at 60 Hz, by Prearrangement

542 14S Special Tests of Resistor and Resistive Dividers Under Pulsed High-Voltage Conditions, by

Prearrangement

Resistor and Resistive Dividers, DC

Measurements (54210C-54211S)

A calibration service is maintained at NIST to determine the dc voltage ratio of

resistive dividers. The routine calibration service is available for applied voltages

from 10 kV to 150 kV. The calibrations are performed with a measurement

system which has a relative expanded

uncertainty* of 0.006 % of the voltage

ratio. To assure adequate sensitivity at the lowest applied voltage levels, calibrations are performed routinely only on dividers with ratios of 10^:1 or smaller. The routine calibration service is also restricted to dividers with nominal ratios of 10^:1,

lOM, or 10^:1. Resistive dividers are accepted for cali- bration only if they are nearly corona free

at the rated operating voltage and are de- signed to have small temperature and

voltage coefficients. Specifically, a device

is not generally suitable for calibration by

NIST if these coefficients produce a change in the ratio of 0. 1 % over the normal range of operating voltages. At a given voltage, dividers should not exhibit

instabilities in their ratio value in excess of 0.005 %. NIST staff can provide some

assistance in the identification of other

calibration laboratories capable of certi- fying the response of less accurate di- viders.

Resistor and Resistive Dividers, 60 Hz

Measurements (54212C-54213S)

Resistive dividers of sufficient quality to be considered as transfer standards are calibrated at 60 Hz for applied voltages

between 10 kV and 100 kV rms. Highvoltage dividers may perform satisfactorily as standards under dc voltages but do

not perform well enough to be considered as standards when excited by 60-Hz

voltages. The design of an ac divider requires special features, beyond those of

a dc divider. In particular, ac dividers

*See Chapter 1, Section H for more information about uncertainty.

155
designed to be used as transfer standards may have to be equipped with external

shielding to minimize the effects of

capacitive coupling to surrounding

objects.

If the device is not properly shielded, the effects of proximity to surrounding

objects and pickup from high-voltage

conductors can introduce large uncertainties into the measured value of the di- vider ratio. In such cases, the measurement of the ratio for one configuration would not necessarily be valid for another configuration. Consequently, a meaningful calibration of the device is difficult or impossible.

We therefore recommend that the fol- lowing two preliminary proximity tests be performed before an ac divider is sub- mitted for test to determine the suitability

of the device as a transfer standard. Place

the divider about 2.0 m from a vertical ground plane as measured from the center of the device. Energize the divider to some safe high-voltage level and measure

the divider ratio. Repeat the measurement

with the same applied high voltage but

with the vertical ground plane (or

divider) moved into a position 1 .0 m

from the center of the divider. If the measured divider ratio changes by 0.1 %

or more, the device has excessive capacitive coupling and is not suitable as a

transfer standard. To test for pickup, remove the highvoltage connection to the top of the di- vider and then connect the top of the divider to ground with a thin wire. Measure the output voltage of the divider under these conditions both with and

without the high-voltage source energized. If the resulting change in the out- put voltage exceeds 0.1 % of the expected output voltage when the high

voltage is connected to the divider, then,

again, there is excessive coupling,

indicating that the device is not suitable as a transfer standard. High-voltage ac dividers sent to NIST

are first subjected to tests like those described above before any measure- ments are attempted. If such tests show

variations in the measured ratio of more

than 0.1 % for either proximity or

pickup, then no further tests will be

performed and the device will be

returned. Prior to performing any measurements, dividers sent to NIST will also be subjected to a breakdown test at the highest voltage for which measure- ments are requested. The customer will be charged for the cost of these tests. NIST calibration of voltage transformers at 60 Hz is generally more accurate than its calibration of dividers at the same frequency. Therefore, customers

having a requirement for a calibrated divider may find it advantageous to use a

voltage transformer as the transfer stan- dard and to use that transformer to cali- brate the divider in their own facilities. Routine tests are carried out for voltages between 10 kV and 100 kV rms

and are performed with a measurement

system having relative expanded uncertainties* of 0.03 % in the determination

of the ratio and 0.3 mrad in the determination of the phase angle.

Resistor and Resistive Dividers, Pulsed

High-Voltage Conditions (542 148)

Resistive divider ratios are also deter- mined under pulsed high-voltage conditions. All pulsed measurements are by

prearrangement. Determinations employ

special-design pulse dividers and cali- brated Kerr cells as reference standards. A variety of pulses may be applied to simulate the conditions under which the divider will be used. Calibrations are made at selected voltage intervals from

20 kV to 300 kV as requested and up to 500 kV with certain pulse shapes. The

typical relative expanded uncertainty* is 2 % of the voltage ratio although smaller

uncertainties can occasionally be re- ported as a special test.

Shipping:

Dividers can be hand-carried or shipped prepaid to NIST. Shipped

dividers should be packaged in sturdy

reusable containers with convenient

*See Chapter 1, Section H for more information about uncertainty.

156
54210C-54214S

access to the divider. The design of many

high-voltage dividers makes them vulnerable to shear-type forces, so provisions

should be made to minimize the likeli- hood of damage due to such forces when

the device is in the shipping container.

References—Resistive Dividers

High-Voltage Divider and Resistor Calibrations, M. Misakian, Natl. Bur.

Stand. (U.S.), Tech. Note 1215 (July

1985).

Evaluation of a Multimegavolt Impulse

Measurement System, R. E. Hebner, D. L. Hillhouse, and R. A. Bullock,

Natl. Bur. Stand. (U.S.), NBSIR 77- 1933 (Nov. 1979).

Calibration of High-Voltage Pulse Measurement Systems Based on the KenEffect, Natl. Bur. Stand. (U.S.),

NBSIR 77-1317 (Sept. 1977).

Special Shielded Resistor for HighVoltage Measurements, J. H. Park, J. Res. Natl. Bur. Stand. (U.S.), 66C (1), 19(Jan.-Mar. 1962).

Comparative High Voltage Impusle

Measurement, G. J. FitzPatrick and

E. F. Kelley, J. Res. Natl. Inst. Stand. Technol. 101 (5), 639 (Sept.-Oct.

1996).

157
54310S-54311S

D, Precision Ratio Measurements

D.3 Capacitive Dividers

Technical Contacts:

Gerald J. FitzPatrick (60 Hz/Pulsed Measurements)

Tel:301/!>7S-2737 Email :gfi tzpatrick@nist.gov

James K. Oltlioff Tel:30 1/975-2431 EmaiI:jolthoff@

nist.gov

Denise D. Prather

Administration and

Logistics 1fel:301A»7S-4221 Email:dprather@nist.gov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

[For 54310S:

Attn: G. J. FitzPatrick, Bldg. 202, Room 16"^, ext. 2737]

[For 54311S:

Attn: G. J. Fitzpatrick, Bldg. 202, Room 106, ext. 2737]

1-270 at Quince Orchard Road,

Gaithersburg, MD 20899-0001

Service ID No. Items

5431 OS

5431 IS

Special Tests of Capacitive Dividers at 60-Hz,

by Prearrangement

Special Tests of Capacitive Dividers Under Pulsed High-Voltage Conditions, by Prearrangement

Capacitive Dividers, 60-Hz Measurements (54310S)

Determinations of capacitive divider

ratios at 60-Hz ac employ the same

equipment used for the calibration of ac

resistive dividers (see 54212C). The

same limitations pertain to shielding

(proximity and pickup effects). The

NIST measurement system imposes a

negligible burden on the divider if its output voltage is 100 volts or less. Otherwise, the burden is equivalent to a 1000-pF capacitor.

Capacitive Dividers, Pulsed

High-Voltage Conditions (54311S)

Determinations of capacitive divider

ratios under high-voltage pulse conditions

employ special-design pulse dividers and

calibrated Kerr cells as reference stan- dards. A variety of pulses may be applied

to simulate the conditions under which

the divider will be used. Calibrations are made at selected voltage intervals from

20 kV to 300 kV as requested and up to 500 kV with certain pulse shapes. The

typical relative expanded uncertainty* is 2 % of the voltage ratio although smaller

uncertainties occasionally may be

negotiated.

References—Capacitive Dividers

Comparative High Voltage Impulse

Measurement, G. J. FitzPatrick and

E. F. Kelley, J. Res. Natl. Inst. Stand. Technol. 101 (5), 639 (Sept.-Oct.

1996).

High-Voltage Divider and Resistor Calibrations, M. Misakian, Natl. Bur.

Stand. (U.S.), Tech. Note 1215 (July

1985).

Evaluation of a Multimegavolt Impulse

Measurement System, R. E. Hebner, D. L. Hillhouse, and R. A. Bullock,

Natl. Bur. Stand. (U.S.), NBSIR 79- 1933 (Nov. 1979).

Calibration of High-Voltage Pulse Measurement Systems Based on the Kerr Effect, Nad. Bur. Stand. (U.S.),

NBSIR 77-1317 (Sept. 1977).

Special Shielded Resistor for HighVoltage Measurements, J. H. Park, J. Res. Nad. Bur. Stand. (U.S.), 66C (1), 19 (Jan.-Mar. 1962).

*See Chapter 1, Section H for more information about uncertainty.

158
D. Precision Ratio Measurements

D.4 Mixed Dividers

Technical Contacts:

Gerald J. Fitzpatrick

TbI: 3017975-2737 Email :gritzpatrick@nist.gov

James K. OlthofT

Tel:30 1/975-2431 Email :jolthofT@nistgov

Denise D. Prather

Administration and

Logistics Tel:301/!>75-4221 Email:dprather@

nist.gov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

[Attn: G. J. FitzPatrick, Bldg. 202, Room 106, ext. 2737]

1-270 at Quince Orchard Road,

Gaithersburg, MD 20899-0001

References—Mixed Dividers

Comparative High Voltage Impulse Measurement, G. J. FitzPatrick and E. F. Kelley, J. Res. Natl. Inst. Stand. Technol. 101 (5), 639 (Sept.-Oct. 1996).

Evaluation of a Multimegavolt Impulse

Measurement System, R. E. Hebner,

D. L. Hillhouse, and R. A. Bullock,

Natl. Bur. Stand. (U.S.), NBSIR 79- 1933 (Nov. 1979).

Calibration of High-Voltage Pulse Measurement Systems Based on the KenEffect, Natl. Bur. Stand. (U.S.),

NBSIR 77-1317 (Sept. 1977).

Special Shielded Resistor for HighVoltage Measurements, J. H. Park, J. Res. Natl. Bur. Stand. (U.S.), 66C (1), 19 (Jan.-Mar. 1962).

Service ID No. Items 54410S Pulse Voltage Measuring Systems,

Including Kerr Cells

Mixed Dividers (54410S)

A mixed divider is one constructed of

resistors and capacitors. Ratios of mixedvoltage dividers are determined under

pulsed, high-voltage transient conditions. Determinations employ speciallydesigned pulse voltage dividers and

calibrated Kerr cells as reference stan- dards. A variety of pulse waveshapes

may be applied to simulate the conditions under which the divider will be

used. Calibrations are made at selected voltage intervals from 20 kV to 300 kV

as requested and up to 500 kV with

certain pulse shapes. The typical relative expanded uncertainty* is 2 % of the voltage ratio although smaller

uncertainties can occasionally be

reported as a special test.

*See Chapter 1, Section H for more information about uncertainty.

159
54510C-54600S

D. Precision Ratio Measurements

D.5 Voltage and Current Transformers

Technical Contacts:

Eric D. Simmon

(Voltage Transformers)

1fel:30 1/975-3956 Email:esimmon@

nistgov

Thomas L. Nelson (Current TWinsformers)

Tel:301/975-2986 Email:tnel$on@nisLgov

Denise D. Prather

Administration and Logistics

1fel:30 1/975-4221 Email :dprather@nist.gov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

[For 54510C-54513C:

Attn: E. D. Simmon, Bldg. 202, Room 167, ext. 3956]

[For 54520C-54522C:

Attn: T. L. Nelson, Bldg. 220, Room B165, ext. 2986]

1-270 at Quince Orchard Road,

Gaithersburg, MD 20899-0001

Service ID No. Items

545 IOC Voltage Transformer, Ratio & Phase Angle, at 60 Hz

on 1 Range, 1 Secondary Voltage, 1 Burden

Primary V^s « 150 kV

545 1 IC Same as 545 IOC, Additional Similar Transformer at Same Time

545 12C Same as 545 IOC and 545 1 IC, Additional Burden or Range

545 13C Same as 545 lOC-545 12C, at Each Additional Secondary Voltage

54520C Current Transformer, Ratio & Phase Angle, 1 Range

at 1 Frequency and 1 Burden, Secondary Currents (0.5,

1, 2, 3, 4, 5) A, Primary Current Not Over 12 000 A

54521C Current Transformer, Ratio & Phase, 1 Secondary

Current, Additional Combination of Range,

Frequency, and Burden, Primary Current Not Over 12 000 A

54522C Current Transformer, Ratio & Phase at Each

Additional Secondary Current, Same Combination

of Range, Frequency, and Burden as 54520C

or 5452 IC 54600S Special Tests of Dividers and Transformers, by

Prearrangement

Voltage Transformers

(54510C-54513C)

NIST provides routine services for the measurement of complex voltage ratios (magnitude and phase angle) of trans- formers for primary voltages up to 150 kV and for secondary voltages above

50 V, subject to some constraints as to the maximum physical size of the device. Results of these routine tests are reported with expanded uncertainties* of 0.03 % for ratio and 0.3 mrad

(1 mrad = 3.438 min) for phase angle. If the test conditions and the device under

test warrant, special tests with smaller

uncertainties can be performed. These

special tests may require an extra fee. The customer must specify the secondary

voltage and the secondary burden for each transformer or for each range of a multirange transformer. Ambiguity can

be avoided if the impedance and power

factor, or the resistance and reactance,

are specified, rather than the volt-ampere

rating of each burden.

The customer should note that the NIST calibration system represents a minimum burden of lOCX) pF for routine

calibrations. The customer should give some care to the specification of a bur- den recognizing that the use of the trans- former with a burden different from that used in the calibration can result in sig- nificant error. Calibrations of voltage transformers

are performed routinely only at 60 Hz. Measurements are made with one side of

both the primary and secondary windings

connected together and to ground.

NIST does have some capability to perform measurements at voltages,

frequencies, and burdens outside of the ranges described above. Calibrations can

occasionally be provided at these nonroutine test points as a special test for an in- creased fee.

*See Chapter 1, Section H for more information about uncertainty.

160
545 IOCCurrent Transformers

(54520C-54522C)

Normally NIST calibrates only current transformers of high quality for use as reference standards. The NIST equipment

is designed to test current transformers

with a rated secondary current of 5 A,

with test points chosen to be one or more of the following values: (0.5, 1, 2,

3, 4, 5) A.

Routine tests are carried out at 50 Hz,

60 Hz, and 400 Hz. For measurements at 50 Hz or 60 Hz, the results are generally

reported with expanded uncertainties* of

0.01 % in ratio and 0.1 mrad in phase angle. For measurements at 400 Hz, the reported expanded uncertainty* is 0.03 % in ratio and 0.3 mrad in phase

angle.

The customer must specify the test frequency, the secondary currents, and

the secondary burdens for each trans- former or for each range of a multirange

transformer. Current transformers should

be tested with burdens equivalent to those which are imposed when the device is used as a transfer standard. Routine cali- bration using the burdens specified in the American National Standards Institute (ANSI) Standard C-57.13 is not recom- mended unless these burdens are subsequently used in the customer's factory or

laboratory. Large errors can result if the values of ratio and phase angle obtained

with an ANSI recommended burden are used for the transformer when it is connected to a different burden.

The burden is preferably specified in terms of the measured resistance and in- ductance. These values should include

the effects of the leads used to make a connection to the transformer secondary.

An alternative, which is sometimes feasible, is to submit the transformer together

with its normal leads and connected bur- den for calibration as a unit. If neither of

the above are possible, the burden may be

stated in terms of the voltampere product

and the power factor of the secondary

circuit at the test frequency.

*See Chapter 1, Section H for more information about uncertainty.

For reference, it should be noted that the

test equipment regularly used at NIST

represents a minimum test burden of

about 0.03 fl with a inductance of about

10 ^iH. Because of contact resistance and current rectification, loose or dirty primary

and secondary terminations may affect the measurement results. These surfaces should be tight and clean when the trans- former is shipped to NIST to minimize

this source of error. Unless otherwise specified, current transformers are demagnetized prior to calibration. If it is desired to have a trans- former tested as submitted (without de- magnetization), this requirement should

be stated on the purchase order and NIST

staff should be informed by telephone

before the transformer is shipped.

Many current transformers are not de- signed to be used as transfer standards,

and most of these do not require calibration at NIST. NIST staff can provide some assistance in the assessment of the appropriateness of the device for NIST

calibration and in the identification of

alternative calibration sources. If NIST is required to perform laboratory measure- ments to determine whether or not a

particular device can be calibrated, a charge for the cost of these measurements will be made.

Special Tests of Dividers and

Transformers (54600S)

NIST maintains an active program of

research and development in the area of

electrical measurements at high-voltage

levels. For this reason, NIST often is able

to provide measurement support for highvoltage devices other than those listed above in this section. Special tests will generally be conducted by NIST, if the following criteria are met: A. The requested tests are fully

developed and documented.

161
B. There is a significant technical or economic justification for traceability of

the test on the item to national standards. C. There has not been a routine or

recurrent need for the test.

References—Voltage and Current

Transformers

A Calibration Service for Current

Transformers, J. D. Ramboz and

O. Petersons, NIST Spec. Publ. 250-36

(June 1991).

A Calibration Service for Voltage Trans- formers and High-Voltage Capacitors,

W. E. Anderson, Natl. Bur. Stand.

(U.S.), Spec. Publ. 250-33 (June

1988).

An Electronic Ratio Error Set for Current Transformer Calibrations, R. L. Kahler, IEEE Trans. Instrum. Meas. IM-28 (2), 162 (June 1979).

A Wide-Range High-Voltage Capacitance

Bridge with One-ppm Accuracy, O.

Petersons and W. E. Anderson, IEEE

Trans. Instrum. Meas. IM-24, (4), 336

(Dec. 1975).

Wide-Band Two-Stage Current Trans- formers of High Accuracy, T. M.

Souders, IEEE Trans. Instrum. Meas. IM-21 (4), 340 (Nov. 1972).

162
55110S-55141C

£ Phase Meters and Standards and VOR

Measurements

Technical Contacts:

Nile M. Oldham

'Ifel:30I/5>75-2408 Eniail:noldhain@nist.gov

Mark E. Parker

TbI:30 1/975-2413 Email:mparker@nist.gov

Denise D. Prather

Administration and

Logistics Tel:301/97S-4221 Email:dprather@nistgov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items

55 1 1 OS Special Tests of Phase Standards and Related

Instruments, by Prearrangement

55120C Phase Meters—One Combination of Input Voltages

(0.5 V to 120 V) at One Frequency (2 Hz to 100 kHz)—The Input Voltage Ratio Shall Not Exceed 10 55121C Phase Meters—Each Additional Combination of

Input Voltages (0.5 V to 120 V rms) at the Same or at a

Different Frequency (2 Hz to 100 kHz); The Input Voltage Ratio Shall Not Exceed 10 55130C Phase Meters—One Combination of One Input Voltage (0.5 V to 120 V) and One Input Current

(1 A to 5 A) at One Frequency (2 Hz to 5 kHz)

55131C Phase Meters—Each Additional Combination of One

Input Voltage (0.5 V to 120 V) and One Input Current (0.5 A to 5 A)

55 1 40C Phase Meters—One Input Voltage ( 1 20 V to 240 V) and Another Input Voltage (120 V to 240 V) at One

Frequency (2 Hz to 5 kHz)

55141C Phase Meters—Each Additional Combination of One

Input Voltage (120 V to 240 V) and Another

Input Voltage (120 V to 240 V) at the Same or at a Different Frequency (2 Hz to 5 kHz)

Special Tests of Phase Standards

and Related Instruments,

by Prearrangement (55110S)

Sinusoidal Phase Measurements

NIST will perform special-test phase

angle measurements on phase angle

generators, quadrature detectors, and

phase bridge-networks. Restrictions

apply, and technical limitations and

arrangements for these tests should be

discussed with NIST; prior arrangements

are essential. VOR Measurements

The NIST Special Tests for VOR (Veryhigh-frequency Omnidrectional Range)

air navigation signals are described in detail in VOR Calibration Service, NBS

Technical Note 1069 (see references).

Two services are offered to support the

calibration of VOR phase meters and

generators. NIST has designed and built a standard VOR audio generator, used to calibrate unknown VOR phase meters,

and a standard VOR phase meter, used to calibrate unknown audio generators.

Direct generation or measurement of

standard VOR rf signals are not a part of

the service.

Phase Meters (55120C-55141C)

NIST has a capability for characterizing

audio frequency phase meters over a fre- quency range of 2 Hz to 50 kHz. The

standard used is a microcomputer-based

system that synthesizes two sinusoidal voltages by means of digital techniques.

The two signals are displaced relative to one another by a precisely known phase

angle. Phase angles can be set with a res- olution of 0.002° up to 5 kHz and 0.005° above 5 kHz. The amplitude of the two

output signals can be varied independently from 0.5 V to 100 V rms. At

power frequencies, one of the signals can

be a current from 0.5 A to 5 A. The ex- panded uncertainty* in setting the stan- dard is less than 0.01° below 5 kHz and

increases to 0.04° at 50 kHz if the two

output signals have the same amplitude.

For unequal amplitudes, this uncertainty

increases to 0.015° and 0.09° respectively,

if the amplitude ratio is less than 10:1. Measurements at amplitude ratios up to 100:1 are performed as Special Tests.

*See Chapter 1, Section H for more information about uncertainty.

163
Although the accuracy of the phase angle

standard does not rely on the stability of

the frequency, the generated output,

which can be varied in steps of 1 Hz, is locked to a crystal-controlled frequency

synthesizer.

Special requirements for this service

are as follows: A. The voltage inputs of the phase meter to be tested must have impedances

such that the current is limited to a few

milliamperes at any applied voltage re- quested. Current inputs must have

impedances low enough so that the compliance voltage does not exceed 2 V. B. NIST will test the instrument in the as-received condition, without making

adjustments other than those normally re- quired for testing. Meters that are not in operating condition upon receipt at NIST

will be returned to the owner.

C. In some cases, the response of

phase meters involves significant time

constants; in these cases, readings will be

taken 30 s after the setting of the stan- dard. D. For given voltage and frequency

settings, at least three readings will be

taken at each specified phase angle. The

order of readings will be randomized.

E. The experimental data are fitted to a mathematical model from which the phase meter response can be predicted.

From the closeness of fit to the model, it can be determined whether observed deviations from the predicted values are

significant.

F. Each phase meter will be operated under power for at least 2 h before

test data are taken. G. Meters that are not in operating

condition upon receipt at NIST will be

returned to the owner without repairs.

References—Phase Meters

Characterized Generator Extends Phase Meter Calibrations from 50 kHz to 20 MHz, N. M. Oldham and P S. Hetrick, IEEE Trans. Instrum. Meas. 42 (2), 311-313 (Apr. 1993).

The NIST Sampling System for the Calibration of Phase Angle Generators

from 1 Hz to 100 kHz, B. C. Waltrip, M.

E. Parker, N. M. Oldham, and B. A.

Bell, Proc. 1992 NCSL Workshop and

Symp., 613-616 (July 1992).

NBS Measurement Services: Phase Angle Calibration Services, R. S. Turgel,

J. M. Mulrow, and D. F. Vecchia, Natl. Bur. Stand. (U.S.), Spec. Publ. 250-26

(May 1988).

Phase Meter Calibrations at NBS, R. S. Turgel, J. Res. Natl. Bur. Stand.

(U.S.), 93 (1), 53-59 (Jan. 1988).

Precision Calibration of Phase Meters, R.

S. Turgel and D. F. Vecchia, IEEE

Trans. Instrum. Meas., 36 (4), 915-922

(Dec. 1987).

NBS 50-kHz Phase Angle Calibration

Standard, R. S. Turgel, Natl. Bur.

Stand. (U.S.), Tech. Note 1220 (Apr.

1986).

A Wideband Transconductance Amplifier

for Current Calibrations, O. B. Laug,

IEEE Trans. Instrum. Meas. 34 (4), 639-643 (Dec. 1985).

A Precision Phase Angle Calibration

Standard for Frequencies Up to 50

kHz, R. S. Turgel, IEEE Trans. In- strum. Meas. 34 (4), 509-516 (Dec.

1985).

NBS Phase Angle Calibration Standard, R. S. Turgel, N. M. Oldham, G. N.

Stenbakken, and T. H. Kibalo, Natl. Bur. Stand. (U.S.), Tech. Note 1 144

(July 1981).

A High-Performance Phase-Sensitive Detector, L. A. Marzetta, IEEE Trans. In- strum. Meas., 27 (4), 460-464 (Dec.

1978).

High-Precision Audio-Frequency Phase

Calibration Standard, R. S. Turgel and N. M. Oldham, IEEE Trans. Instrum. Meas. 27 (4), 460-464 (Dec. 1978).

VOR Calibration Services, N. T. Larsen, D. F. Vecchia, and G. R. Sugar, Natl. Bur. Stand. (U.S.), Tech. Note 1069

(April 1985).

Fourier Transformation of the Nonlinear

VOR Model to Approximate Linear

Form, D. F. Vecchia, Natl. Bur. Stand.

(U.S.), Tech. Note 1021 (June 1980).

A Wide-Range Current Comparator System for Calibrating Current Transformers, T. M. Souders, IEEE Trans. Power

Appar. Syst. 90 (1), 318 (Jan.-Feb.

1971).

164
56110S-56220S

Power and Energy Measurements,

Low-Frequency

Technical Contacts:

Thomas L. Nelson

Tbl: 301/975-2986

Eniail:tnelson@ nistgov

Lisa S. Snider

1tl:30 1/975-4688 Eniail:Isnider@nistgov

Denise D. Prather

Administration and Logistics 1tl:30 1/975-4221 Email:dprather@nist.gov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Shipping Address:

National Institute of Standards and Technology,

[Attn: T. L. Nelson, Bldg. 220, Room B165, ext. 2986]

1-270 at Quince Orchard Road,

Gaithersburg, MD 20899-0001

Test No. Items

561 1 OS Special Tests of AC-DC Wattmeters, by

Prearrangement

56200C Watt, Watthour, Var or Varhour Meter, Initial Two

Determinations of Percentage Registration of Same Meter at 60 Hz

5620 IC Each Additional Determination of Percentage

Registration of Same Meter at 50/60 Hz

56202C Initial Two Determinations of One or Two

Meters Run Simultaneously with the First (56200C) 562 lOM Measurement Assurance Program for Watthour Meters 56220S Fast Turn-Around Energy Measurements, Low Frequency

Special Tests of AC-DC Wattmeters

(561 lOS)

Wattmeter calibrations at other than

power frequencies are considered Special

Tests and must be arranged on an individ- ual basis. The following limitations apply:A. Instruments must have separate

voltage and current input terminals. B. The instrument must have a self- contained power indicator, or provide a

direct current or voltage signal which is proportional to power, or provide an out- put frequency which is proportional to the power.

C. Measurements are generally limited to sinusoidal signals at frequencies

between dc and 100 kHz. Input signal

levels should not exceed 240 V and 5 A. D. Instruments will be tested in the as-received condition, and test uncertainties will be based in part on the perfor- mance of the instrument during the test.

Power and Energy Measurements,

Low-Frequency (56200C-56202C)

Only standard electronic-type watt, watthour, var and varhour meters are accepted for test. Rotating types are no

longer accepted except by special

arrangement. If necessary, the meters

should be cleaned or adjusted by the customer before they are shipped to NIST. NIST does not adjust meters and

does not knowingly begin tests of faulty meters. The test conditions must be specified

by the customer. These include the current and voltage ranges to be tested, the frequency, the applied voltages, the applied currents, and the power factors. Values of these parameters which are

available for routine testing are summarized in Table 9.12.

Table 9.12. Available Values of the Parameters for Routine Wattmeter, Watthour, Varmeter and Varhour

Testing

Parameter Available Values

Voltage (V)

Current (A) Power Factor

Phase Angle

Frequency (Hz)

69 to 480

0.5 to 30 Oto 1.0

0 to 360°

50*, 60,400*

* Tests at 50 and 400 Hz are limited to voltages of 240 V or less and currents of 5 A or less.

If necessary, measurements can sometimes be made at other values of these parameters. These would, however, be

considered special tests. Separate,

specific arrangements and a higher fee

will be charged than for a routine calibration.

165
Prior to the calibration, the meters are energized for between 1 h and 4 h at rated voltage and current on one range. A

calibration consists of at least two sets of measurements taken over a minimum

period of 2 d. For wattmeters, the values of the reported corrections (in watts) generally

have relative expanded uncertainties* of

0.05 % of the full scale range in volt- amperes. For watthour meters, the reported values of the percentage regis- tration generally have relative expanded

uncertainties* of 0.05 % of the indicated

value. Special, higher accuracy tests can be arranged for an additional fee. The

relative expanded uncertainties* for power or energy measurements in these

special tests may be as low as 0.005 % if the short-term standard deviation of the device under test is appropriately small. For the highest accuracy, voltages are limited to 1 20 V and currents to 5 A.

Measurement Assurance Program for Watthour Meters (56210M)

The Measurement Assurance Program

for electric energy is designed to evaluate

the performance of energy-measuring

systems at the customer's laboratory. A

NIST-owned, transport standard watthour meter of known stability is measured by

NIST. It is then shipped to and measured

by the customer, and shipped back to NIST. NIST analyzes the data and pro- vides a report to the customer indicating

the total uncertainty of the customer's measurement. This procedure enables the customer's standards to be measured rel- ative to NIST standards without the downtime encountered when the cus- tomer's standards are shipped to and

calibrated by NIST. In addition, and more

important to those who calibrate standard watthour meters, the NIST MAP standard can be used by customers to evaluate

their measurement process in a convenient and cost-effective way.

*See Chapter 1, Section H for more information about uncertainty.

The uncertainty of a MAP includes

the effects of the long-term and short- term instabilities of the NIST calibration system, the customer's calibration system,

and the transport standard. Typically, the

relative expanded uncertainty* in a well- controlled comparison ranges between

0.03 % and 0.05 %.

The Electricity Division maintains an

active program of research and development in the area of electric power and

energy measurements. This program

often enables NIST to provide measure- ment support for watt and watthour meters beyond that listed in this section. Special tests will generally be conducted

when the following conditions prevail: A. The requested tests are fully

developed and documented.

B. There is a significant technical or economic justification for traceability of

the test on the item to national standards. C. There has not been a routine or

recurrent need for the test.

Fast Turn-Around Energy Measurements, Low-Frequency (56220S)

This calibration service is offered for customers interested in a fast turn-around

time, and reduced service cost for a limited number of specific test points. The

three test points measured for this service

are at 120 V and 5 A with power factors of unity, 0.5 lag, and 0.5 lead. These are the only test points offered for this ser- vice. If the customer requests additional

test points, the price and turn-around

time will be those for the routine calibration service (see Service ID Number

56200C). The relative expanded uncertainty* assigned to a watthour meter for

this service is 0.02 %. This service will only accept standard watthour meters that have a pulse output. The turn-around

time will be two weeks. Due to the short turn-around time of this service, the cus- tomer will need to schedule this calibration with the appropriate contact, and a purchase order must be submitted either with the instrument, or be received before

the instrument arrives at NIST.

166
5611 OSi-56220S

References—Power and Energy

Measurements, Low Frequency

Digitally Synthesized Power Calibration Source, N. M. Oldham, O. B. Laug,

and B. C. Waltrip, IEEE Trans. Instrum. Meas. IM-36 (2), 341 (June

1987).

NBS Wideband Sampling Wattmeter, G. N. Stenbakken, O. B. Laug, A. G.

Perry, B. A. Bell, and T. H. Kibalo,

Natl. Bur. Stand. (U.S.), Tech. Note

1221 (May 1987).

A Wideband Sampling Wattmeter, G. N. Stenbakken, IEEE Trans. Power

Appar. Syst. PAS-103 (10), 2919 (Oct.

1984).

A Calibration Service for Wattmeters and

Watthour Meters, J. D. Ramboz and

R. C. McAuliff, Natl. Bur. Stand.

(U.S.), Tech. Note 1 179 (July 1983).

A Measurement Assurance Program for Electric Energy, N. M. Oldham, Natl. Bur. Stand. (U.S.), Tech. Note 930

(Sept. 1976).

Transfer of the Kilowatthour, S. R. Houghton, IEEE Trans. Power Appar.

Syst. PAS-94 (4), 1232 (July-Aug.

1975).

Sampling Techniques for Electric Power

Measurement, R. S. Turgel, Natl. Bur.

Stand. (U.S.), Tech. Note 870 (June

1975).

A Current Comparator System to Establish the Unit of Electrical Energy at 60 Hz, K. J. Lentner, IEEE Trans. Instrum. Meas. IM-23 (4), 334 (Dec.

1974).

167
61110S-61190S

G.

RF, Microwave and Millimeter-Wave

Measurements

G. 1 Thermistor Mounts

Technical Contacts:

John R. Juroshek

Tel:303/497-5362 Email:jjuroshek@

nistgov

Ronald A. Ginley

Tel:303/497-3634 Email:rginley@

nistgov

Fred R. Clague

Tel:303/497-S778 Email:fclague@

nist.gov

George M. Free

Tel:303/497-3609 Email:gfree@

nistgov Wayde Allen Tel:303/497-3753 Email:vfallen@ni$tgov

Paula M. Hewitt Administration and Logistics Tel:303/497-37S3 Email:paula.hewitt@nistgov

Fax:303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328.

Service ID No. Items The following tests are for thermistor mounts with coaxial connectors. 61 llOS Coaxial Mounts at a Single Frequency in the Range

of 0.1 MHz to 10 MHz

6 11 1 1 S Each Additional Frequency for 6 1 1 1 OS

61 120S Coaxial Mounts at 10 MHz Intervals within the Frequency Range of 10 MHz to 100 MHz

61 121S Additional Mount at the Same Frequencies as 61 120S

61 122S Coaxial Mounts at 50 MHz Intervals within

the Frequency Range of 100 MHz to 1 GHz

61 123S Additional Mount at the same Frequencies as 61122S

61 124S Coaxial Mounts at 10 MHz Intervals within the Frequency

Range of 10 MHz to 100 MHz, and 50 MHz

Intervals within the Frequency Range of 100 MHz

to 1 GHz

61 125S Additional Mount at the same Frequencies as 61 124S

61 126S Coaxial with GPC-7 Connectors at Frequencies shown

in Table 9.13 from 10 MHz to 18 GHz

61 127S Additional Mount at the same Frequencies as 61 126S

61 128S Coaxial Mounts with GPC-7 Connectors at 1 GHz

Intervals within the Frequency Range of 1 GHz to 18 GHz

6 1 1 29S Additional Mount at the same Frequencies as 6 1 1 28S

61 130S Coaxial Mounts with Type N Connectors at Frequencies

shown in Table 9.13 from 10 MHz to 18 GHz

61 13 IS Additional Mount at the same Frequencies as 61 BOS

61 132S Coaxial Mounts with Type N Connectors at 1 GHz

Intervals within the Frequency Range of 1 GHz to 18 GHz

61 133S Additional Mount at the same Frequencies as 61 132S

61 134S Coaxial Mounts with 3.5 mm Connectors at 1 GHz

Intervals within the Frequency Range of 2 GHz to 18 GHz

Service ID No. Items

61 135S Coaxial Mounts with 3.5 mm Connectors at 1 GHz

Intervals within the Frequency Range

of 18 GHz to 26 GHz

61 136S Additional Mount at the same Frequencies as 61134S and61135S

6 1 1 37C NIST Model CN Coaxial Mounts at 1 24

Frequencies within the Frequency Range of 50 MHz to 18 GHz

6 1 1 38C NIST Model CN Coaxial Mounts at Customer

Selected Frequencies within the Frequency Range

of 50 MHz to 18 GHz

The following tests are for thermistor mounts with waveguide flanges. 6 1 1 44S Rectangular Waveguide Mounts with WR90

Flanges at 200 MHz Intervals within the Frequency

Range of 8.2 GHz to 12.4 GHz

61 145S Additional Thermistor Mount at the Same

Frequencies as 6 1 1 44S

61 146S Rectangular Waveguide Mounts with WR62

Flanges at 250 MHz Intervals within the Frequency Range of 12.4 GHz to 18.0 GHz

61 147S Additional Thermistor Mount at the Same

Frequencies as 61 146S

6 1 1 48S Rectangular Waveguide Mounts with WR42

Flanges at 1 GHz Intervals within the Frequency

Range of 18 GHz to 26.5 GHz

61 149S Additional Thermistor Mount at the Same

Frequencies as 61 148S

6 1 1 50S Rectangular Waveguide Mounts with WR28

Flanges at 1 GHz Intervals within the Frequency

Range of 26.5 GHz to 40 GHz

6 1 1 5 1 S Additional Thermistor Mount at the Same

Frequencies as 61 150S

61 152S Rectangular Waveguide Mounts with WR22 Flanges

at 1 GHz Intervals within the Frequency Range of 33 GHz to 50 GHz

61 153S Additional Thermistor Mount at the Same

Frequencies as 61 152S

61 154S Rectangular Waveguide Mounts with WR15

Flanges at a Single Frequency within the Frequency

Range of 50 GHz to 75 GHz

61 155S Rectangular-Waveguide Mounts with WRIO

Ranges at a Single Frequency within the Frequency Range of 92 GHz to 98 GHz

High Power Wattmeters

6 1 1 60S Calibration Factor of Continuous Wave (CW)

High Power Wattmeters at Several Points within

the Frequency Range of 2 MHz to 30 MHz ( 1 watt

to 1000 watts) and 30 MHz to 400 MHz (1 watt

to 500 watts) 6 1 1 90S Special Microwave and RF Power Measurement

Services, by Prearrangement

168
611105-611908

General Information

Calibration services are available for ther- mistor mounts with GPC-7, Type N, and

3.5 mm coaxial connectors and several waveguide sizes (8.2 GHz to 96 GHz).

Assistance is available for applying

published, technically valid measurement

techniques in lieu of previously available NIST calibration services for coaxial and

waveguide calorimeters, thermoelectric

power meters, and bolometer coupler

units. The attainable limits of measure- ment uncertainty using these techniques

are comparable to those of the previously

available calibration services for these devices. The Reports of Calibration and Special

Test give the magnitude and phase of the

reflection coefficient, effective efficiency,

and calibration factor of the thermistor mount.

Definitions:

Effective Efficiency rje The effective efficiency rje is the ratio of the bolometrically substituted dc

power in the thermistor mount to the net CW rf microwave power delivered

to the thermistor mount.

Bolometrically Substituted dc Power

The bolometrically substituted dc

power is the change in dc (or audio

frequency) bias power required to maintain the resistance of the thermistor element at a constant value follow- ing the application of rf or microwave

power.

Calibration Factor, The calibration factor is the ratio of the bolometrically substituted dc power in the thermistor mount to the CW rf microwave power incident upon the thermistor mount. Kb = r]ci\ — \r\^).

Reflection Coefficient Magnitude,

|r| and Arg (D

The reflection coefficient magnitude

and phase (argument of reflection coefficient) is the ratio of the reflected wave voltage amplitude to the incident wave voltage amplitude

and phase.

Commercial Coaxial Thermistor

Mounts (611 108-61 136S)

Specify frequencies in the range from

0.1 MHz to 10 MHz for special low- frequency thermistor mounts (Service

ID Number 61 1 lOS). Values for -q, and

I r| are calculated from voltage and

resistance measurements.

-i?c = (PdcViPrf), where = V'/Rp, and

Rp is the parallel equivalent resistance,

and Pdc is the bolometrically substituted dc power in the bolometer.

The following table lists the frequencies at which measurements are made on

thermistor mounts with GPC-7 or Type

N connectors.

Table 9.13. Measurement Ranges and Uncertainties for Coaxial Thermistor Mounts

Relative Expanded

Frequency Interval Uncertainty*"

Range in T)e (%)

10 MHz to 100 MHz 10 MHz Intervals 0.3 to 0.5 100 MHz to 1 GHz 50 MHz Intervals 0.3

I GHz to 2 GHz 50 MHz Intervals 0.3 2 GHz to 4 GHz 100 MHz Intervals 0.3 4 GHz to 8 GHz 200 MHz Intervals 0.4

8 GHz to 12.4 GHz 200 MHz Intervals 0.4

12.4 GHz to 18 GHz 250 MHz Intervals 0.5 to 0.7

^ These expanded uncertainties are typical for thermistor mounts with Type N

connectors.

* See Chapter 1, Section H for more information about uncertainty.

169
61110S-61190S

08

t-z

UJo

(C 0.6

UJ

Q.

Z 0.4 <

Uio

zD

02 -

001

Uncertainties for the effective effi- ciency and calibration factor depend on

the frequency and the characteristics of

the unit being calibrated such as connector type, reflection coefficient, and

repeatability.

NIST Model CN Reference Standard

(61137C-61138C)

This premium service provides tje measurements as a function of frequency

for a NIST-designed coaxial reference

standard with a Type N connector. The

reference standard, designated Model CN

(Coaxial with a Type N connector), is a bolometric, dc-substitution power detector that must be used with a NIST

Type IV power meter (available from

several commercial sources). The

mount is designed as an optimum transfer standard which can be measured

directly in the NIST coaxial microcalorimeter. To use this service, the customer needs to have a CN mount

(contact Fred R. Clague for information).

I-TTTTI 1 I

1 1 I I I ll.l

TYPICAL REGULAR CALIBRATION CN PREMIUM SERVICE

-I ' 01 10 30 FREQUENCY. OHz

Figure 9. 1 . Expanded Uncertainty in rje

Measurements are made at 124 fre- quencies over the range from 50 MHz to 18 GHz (Service ID Number 61 137C) or customer specified frequencies (Service

ID Number 61 138C). Figure 9.1 compares the expanded uncertainty of the premium service with that of the regular

service for coaxial thermistor mounts.

Waveguide Thermistor Mounts

(61144S-61155S)

Measurements of effective efficiency,

efficiency factor, and reflection coefficient are made for various waveguide

sizes as follows:

Table 9.14. Measurement Range and Uncertainties for Waveguide Thermistor Mounts

Wave- Frequency Measurement Expanded

guide Range Frequency or Uncertainty'

Band (GHz) Interval in r/e (%)

WR90 8.2 to 12.4 200 MHz Intervals 1.1 WR62 12.4 to 18 250 MHz Intervals 1.1 WR42 18 to 26.5 1 GHz Intervals 1.1 WR28 26.5 to 40 1 GHz Intervals 1.1 WR22 33 to 50 1 GHz Intervals 2.6 WR15 50 to 75 Specify Frequency 1.3 WRIO 92 to 98 Specify Frequency 2.1

*See Chapter 1, Section H for more information about uncertainty.

170
61110S-61190S

High-Power Wattmeter (61160S)

A Special Test service is available for continuous wave (CW) high power

wattmeters. Measurements are avail- able at several frequencies from 1 MHz

to 30 MHz (1 W to 1000 W) and

30 MHz to 400 MHz (1 W to 500 W).

Wattmeters must be controllable via an IEEE-488 bus, have a Type N male input

connector, and either have a Type N

female output connector or an appropriate termination. The calibration factor, defined as the ratio of the wattmeter

reading to the power incident upon it, will be supplied at each measurement

point. The relative expanded uncertainty* is typically less than 2 %,

depending on frequency, power level and electrical characteristics of the wattmeter/load combination. Call the technical contact for further information.

References—Thermistor Mounts

Direct Comparison Transfer of

Microwave Power Sensor Calibration,

M. Weidman, Natl. Inst. Stand. Technol. (U.S.), Tech. Note 1379

(January 1996).

A Calibration Service for Reference

Standards for Microwave Power, F. Clague, Nad. Inst. Stand. Technol., Tech. Note 1374 (May 1995).

Microcalorimeter for GPC-7 Coaxial

Transmission Line, F. Clague, Natl.

Inst. Stand. Technol., Tech. Note 1358

(August 1993).

Coaxial Reference Standard for Microwave Power, F. Clague and P. Voris, Nad. Inst. Stand. Technol, Tech. Note 1357 (April 1993).

Measurement Service for High-Power

CW Wattmeter at the National Insti- tute of Standards and Technology,

J. A. Jargon and G. Rebuldela, Proc. of

the Meas. Sci. Conf., Anaheim, CA

(Jan. 1993).

Basic RF and Microwave Measurements: A Review of Selected Programs, A. J. Estin, J. R. Juroshek, R. B. Marks, F. R. Clague, and J. Wayde Allen,

Metrologia 29, 135-151 (1992).

High Power CW Wattmeter Calibration at NIST, G. Rebuldela and J. A. Jargon,

J. Res. Natl. Inst. Stand. Technol., 97

(6), pp. 673-687 (Nov.-Dec. 1992).

WR-10 Millimeter Wave Microcalorimeter, M. Weidman and P. Hudson, Natl. Bur. Stand. (U.S.), Tech. Note 1044

(June 1981).

A Semiautomated Six-Port for Measuring Millimeter-Wave Power and Complex Reflection Coefficient, M.

Weidman, IEEE Trans. Micro. Theory

Tech. MTT-25, 12 (Dec. 1977).

Performance Characteristics of an Auto- mated Broad-Band Bolometer Unit

Calibration System, E. Komarek,

IEEE Trans. Micro. Theory Tech. MTT-25, 12 (Dec. 1977).

Theory of UHF and Microwave Measure- ments Using the Power Equation Concept, G. F. Engen, Natl. Bur. Stand.

(U.S.), Tech. Note 637 (Apr. 1973).

Application of an Arbitrary Six-Port

Junction to Power Measurement Problems, G. Engen and C. Hoer, IEEE

Trans. Instrum. Meas. IM-21, 470

(Nov. 1972).

WR-15 Microwave Calorimeter and

Bolometer Unit, M. Harvey, Natl. Bur.

Stand. (U.S.), Tech. Note 618 (May

1972). Accurate Microwave High-Power Measurements Using a Cascaded Coupler

Method, K. E. Bramall, J. Res. Natl. Bur. Stand. (U.S.), 75C (3 and 4), 185

(July-Dec. 1971).

*See Chapter 1, Section H for more information about uncertainty.

171
-~ 61210S-61297S

G. RF, Microwave, and Millimeter-Wave

Measurements

G.2 Scattering Parameters of Passive

Multi-Port Devices

Technical Contacts:

John R. Juroshek Ronald A. Ginley Paula M. Hewitt

1^1:303/497-5362 Tel:303/497-3634 Administration and Logistics Eniail:jjurosiiek@ Email:rginley@ Tel:303/4!>7-37S3 nistgov nist.gov Eniail:paula.hewitt@nist.gov Fax:303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items The following tests are for two-port devices tvith coaxial connectors. See Table 9.15 for Measurement

Ranges and Uncertainties.

61210S Coaxial Fixed and Variable Attenuators with GR900

Connectors 612 lis Additional Two-Port Device at the Same Frequencies

as 61210S

6 1 2 1 2C Coaxial Fixed and Variable Attenuators with GPC-7

Connectors 61213S Additional Two-Port Device at the Same Frequencies

as 61212S

61214S Coaxial Fixed and Variable Attenuators with Type N

Connectors 61215S Additional Two-Port Device at the Same Frequencies

as 61214S

61216S Coaxial Fixed and Variable Attenuators with 3.5 mm

Connectors [27 GHz to 33 GHz available by special

request]

612 17S Additional Two-Port Device at the Same Frequencies

at 61216S

61218S Coaxial Fixed and Variable Attenuators with 2.92 mm

Connectors 612 19S Additional Two-Port Device at the Same Frequencies

as 61218S

61220S Coaxial Fixed and Variable Attenuators with 2.4 mm

Connectors

6 122 IS Additional Two-port Device at the Same Frequencies

as 61220S

The following tests are for two-port devices with waveguide connectors. See Table 9.16 for Measurement Ranges and Uncertainties.

61230S WR90 Rectangular Waveguide Fixed and Variable Attenuators

Service ID No. Items

6 123 IS Additional Two-Port Device at the Same Frequencies

as61230S

6 1 232S WR62 Rectangular Waveguide Fixed and Variable

Attenuators 61233S Additional Two-Port Device at the Same Frequencies as 61232S

6 1 234S WR42 Rectangular Waveguide Fixed and Variable

Attenuators 61235S Additional Two-Port Device at the Same Frequencies

as61234S

6 1 236S WR28 Rectangular Waveguide Fixed and Variable

Attenuators 61237S Additional Two-Port Device at the Same Frequencies as 61236S

6 1 238S WR22 Rectangular Waveguide Fixed and Variable

Attenuators 61239S Additional Two-Port Device at the Same Frequencies

as 61238S

61240S WR15 Rectangular Waveguide Fixed and Variable

Attenuators 6 124 IS Additional Frequencies for Same Device Done on 61240S

6 1 242S WR1 0 Rectangular Waveguide Fixed and Variable

Attenuators 61243S Additional Frequencies for Same Device Done on 61242S

6 1 249S Special Attenuation Measurements, by Prearrangement

61250S Time Delay, Coaxial and Waveguide, by Prearrangement

The following tests are for one-port devices with coaxial

connectors. See Table 9.17 for Measurement Ranges

and Uncertainties. 61260S Coaxial One-Port Devices with GR900 Connectors 6 126 IS Additional One-Port Device at the Same Frequencies as 61260S

61262C Coaxial One-Port Devices with GPC-7 Connectors 61263S Additional One-Port Device at the Same Frequencies as 61262S

61264S Coaxial One-Port Devices with Type N connectors 61265S Additional One-Port Device at the Same Frequencies as 61264S

61266S Coaxial One-Port Devices with 3.5 mm Connectors 61267S Additional One-Port Device at the Same Frequencies as 61266S

61268S Coaxial One-Port Devices with 2.92 mm Connectors 61269S Additional One-Port Device at the Same Frequencies as 61268S

61270S Coaxial One-Port Devices with 2.42 mm Connectors

6 1 27 1 S Additional One-Port Device at the Same Frequencies as 61270S

172
61210S-61297S

Service ID No. Items

The following tests are for one-port devices with waveguide

connectors. See Table 9.18for Measurement Ranges and Uncertainties.

61280S WR90 Rectangular Waveguide

6 128 IS Additional One-Port Device at the Same Frequencies as 61280S

61282S WR62 Rectangular Waveguide 61283S Additional One-Port Device at the Same Frequencies as 61282S

61284S WR42 Rectangular Waveguide 61285S Additional One-Port Device at the Same Frequencies as 61284S

6 1 286S WR28 Rectangular Waveguide 61287S Additional One-Port Device at the Same Frequencies as 61286S

61288S WR22 Rectangular Waveguide 61289S Additional One-Port Device at the Same Frequencies as 61288S

61290S WR15 Rectangular Waveguide

61 29 IS Additional Frequencies for same Device Done on 61290S 61292S WRIO Rectangular Waveguide 61293S Additional Frequencies for same Device Done on 61292S 61294S Special Reflection Coefficient Measurements, by Prearrangement 61295S Coaxial Fixed and Variable Phase Shifters; Frequency Range 1 GHz to 50 GHz, Phase Range 0° to 360° 61296S Waveguide Fixed and Variable Phase Shifters; Specify Frequencies for Waveguide Sizes WRIO, WR15, WR22, WR28, WR42, WR62,

and WR90

61297S Special Tests of Phase Shifters, by Prearrangement

General Information

Microwave devices are characterized by

their reflection and transmission properties. Single port devices such as matched terminations and offset shorts

are characterized by measuring their reflection properties or voltage reflec- tion coefficient. Multiport devices such

as attenuators are characterized by

measuring both their reflection and

transmission properties.

Figure 9.2 shows the reflected and trans- mitted voltage waves for a typical twoport device. The voltage waves incident

to the device are defined as a; and Ui. The voltage waves reflected from the device are defined as b\ and bi.

DUT

bi ai 32 b2

Figure 9.2. Reflected and Transmitted

Voltage Waves for a Typical Two-Port

Device.

The scattering parameters specify

the relationship between the incident and reflected waves. In the case of the two-port in Figure 9.2, the scattering

matrix is.

Sn

.b2. 522. a2_

The scattering matrices shown are complex quantities conveying information on both the magnitude and phase

of the quantities of interest. The attenuation of a two-port device

is defined as 5,2 and 52 1. Most passive

microwave devices are reciprocal

where 5,2 = 52i. The magnitude of the attenuation for a reciprocal device is commonly expressed in dB as

A =-20 log,o(|5,2|), dB

= -20 log,o(|52,|),dB

173
Similar definitions exist for single port

devices such as terminations and offset shorts. A one port device can be thought

of as the special case of a two port

device where = S21 = 0. The voltage

reflection coefficient for a one port

device is commonly given as

where a is the voltage wave incident on

the device, and b is the voltage wave

reflected from the device. All scattering parameters are refer- enced to some idealized transmission

line. At NIST, all coaxial measurements

are referenced to an idealized, air dielectric, 50 n transmission line of specified

dimensions. Similarly, all waveguide

measurements are referenced to an ideal- ized, air dielectric, precision waveguide

section of specified dimensions. Details of the reference standard are available on

request.

Standards submitted for calibration should be in good repair and require only very minor cleaning of connector

surfaces. NIST does not provide repair

services. Items received requiring

maintenance will be returned to the customer, and a handling fee will be

charged.

Coaxial Fixed and Variable Attenuators (61210S-61221S)

Coaxial fixed and variable attenuators are measured on either a NIST Dual Six-Port Vector Network Analyzer (VNA) over the frequency range from 10 MHz to 26.5 GHz or on a commercial VNA over

the frequency range from 50 MHz to 50 GHz.

Coaxial attenuators are normally measured relative to a reference characteristic impedance of 50 fi. For fixed coaxial at- tenuators, the complete set of complex

scattering parameters are measured. For

reciprocal devices, the Reports of

Calibration give the magnitude and phase

of S]u S22 and Sn = S21.

For variable attenuators, normally only

the change in attenuation from the zero

setting is of interest. The test report for variable attenuators show the change in the magnitude of Si 2 from the zero

setting versus frequency for selected attenuator settings. Complete scattering

parameter measurements for variable attenuators are available by special

request. Uncertainties depend on the nominal attenuation, connector type, and

frequency.

Attenuation measurements are avail- able for devices with 2.4 mm, 2.92 mm,

3.5 mm, GPC-7, 14 mm, and Type N

connectors as shown in Table 9.15. Measurements not listed may be available and

you should call the technical contact to discuss the availability. The cost of such

services must be negotiated and will, in general, be higher than other established

services. Consultation is available by

telephone.

Table 9.15. Measurement Ranges and Uncertainties for Coaxial

Two-Port Devices

Coaxial Frequency Attenuation Expanded

Connector Range Range Uncertainty*

Type (dB) 1 S12I = 1 S21I (dB)

GR900 10 MHz to 8.5 GHz 0 to 60 0.01 to 0.2 GPC-7 10 MHz to 18 GHz 0 to 60 0.01 to 0.2 Type N 10 MHz to 18 GHz Oto 60 0.01 to 0.2

3.5 mm 10 MHz to 33 GHz 0 to 60 0.01 to 0.2 2.92 mm 10 MHz to 40 GHz 0 to 60 0.01 to 0.2 2.4 mm 10 MHz to 50 GHz 0 to 60 0.01 to 0.2

*See Chapter 1, Section H for more information about uncertainty.

Rectangular Waveguide Fixed and

Variable Attenuators (61230S-61249S)

Fixed and variable (usually rotary vane)

waveguide attenuators are calibrated on

the NIST Dual 6-Port VNA. Service is available for frequencies corresponding to waveguide sizes WRIO, WR15, WR22,

WR28, WR42, WR62, and WR90 as shown in Table 9.16.

174
61210S-61297S

Table 9.16. Measurement Ranges and Uncertainties for Waveguide Two-Port Devices

Waveguide Frequency Intervals Attenuation Expanded

Band Range Range Uncertainty*

(GHz) (dB)

(dB)

WR90 8.2 to 12.4 200 MHz Oto 60 0.02 to 0.2 WR62 12.4 to 18 250 MHz 0 to 60 0.02 to 0.2 WR42 18 to 26.5 1 GHz Oto 50 0.02 to 0.3 WR28 26.5 to 40 1 GHz 0 to 50 0.02 to 0.3 WR22 33 to 50 1 GHz Oto 50 0.02 to 0.5 WR15 50 to 75 Specify Oto 50 0.02 to 0.5 WRIO 92 to 98 Specify 0 to 40 0.03 to 0.5

*See Chapter 1, Section H for more information about uncertainty.

Time Delay, Coaxial and Waveguide

(61250S)

Time delay calibration services are avail- able for both coaxial and waveguide delay

lines. The time delay for the device under

test is determined from phase measure- ments that are made on a vector network

analyzer. The frequency range for the measurements ranges from 0.1 GHz to 100 GHz depending on the connectors

involved. Devices submitted for calibration should be equipped with either preci- sion coaxial connectors or precision

waveguide flanges. The length of the device should typically be less than

30 cm. However, delay measurements can

be made on longer devices in certain circumstances. Because of the special- ized nature of these measurements, prior

discussions should be held with NIST

staff before submission of any device for

testing.

Coaxial One-Port Devices (61260S to 61271S)

Services are available for complex reflection coefficient of passive devices with

2.4 mm, 2.92 mm, 3.5 mm, GPC-7,

Type N and GR900 connectors. Available

calibration frequencies are listed in Table 9.17.

Table 9.17. Measurement Ranges and Uncertainties for Coaxial One-Port Devices

Coaxial Frequency Expanded

Connector Range Uncertainty*

Type 1 Sill and 1 S22I (dB)

GR900 10 MHz to 8.5 GHz 0.002 to 0.004 GPC-7 10 MHz to 18 GHz 0.003 to 0.005 Type N 10 MHz to 18 GHz 0.003 to 0.007

3.5 mm 10 MHz to 33 GHz 0.006 to 0.013

2.92 mm 10 MHz to 40 GHz 0.008 to 0.020

2.4 mm 10 MHz to 50 GHz 0.014 to 0.038

*See Chapter 1, Section H for more information about uncertainty.

Waveguide One-Port Devices (61280S61294S)

The terminations must be fitted with

standard waveguide flange connectors. The faces of these flanges should be machined flat and smooth and should not

contain protrusions or indentations. Considerable care must be exercised in keeping the mating connector flange surfaces smooth and clean. Accurate alignment of

the waveguide joint and flanges is also very important. The back of the flange

which makes contact with the connecting

bolts should be nominally flat and free of

soft materials, including paint. The connecting holes of the flange should be

symmetrically and accurately aligned to the rectangular waveguide opening.

Available calibration frequencies are

listed in Table 9.18.

175
61210S-61297S

Table 9.18. Measurement Ranges and Uncertainties for Waveguide One-Port Devices

Wnvppiiilip Frpniipnrv Tntprvfilc 1.11 I^Vl VC119 Band Range Uncertainty*

(GHz) 1 Sill and 1 S22I (dB)

WR90 8.2 to 12.4 200 MHz 0.005 WR62 12.4 to 18 250 MHz 0.002 WR42 18 to 26.5 1 GHz 0.004 WR28 26.5 to 40 1 GHz 0.004 WR22 33 to 50 1 GHz 0.009 WR15 50 to 75 Specify 0.009 WRIO 92 to 98 Specify 0.012

•'See Chapter 1, Section H for more information about uncertainty.

Phase Shifters, RF and Microwave

(61295S-61297S)

The specific phase shift ser/ices are

available on a limited basis. Because of

the specialized nature of coaxial phase

shifting components, prior discussions should be held with NIST staff before submission of any devices to NIST. Items

to be calibrated must be fitted with connectors having a know plane of reference,

such as sexless precision connectors, or Type N connectors meeting Mil. Std. C39012. The phase angle measured is ^ + 360 n , where n is an integer. The

value of n is not determined. The ex- panded uncertainty* is 0.5°. For rectangular waveguide, the measurement services are normally limited to phase shift difference. Measurements are made on continuously variable waveguide

phase shifters with the zero value of the

scale as the nominal reference position.

The expanded uncertainty* is typically

0.5°.

References—S -Parameters of Passive

1- and 2-Port Devices

Measurements of the characteristic Impedance of coaxial Air Line Stan- dards, J. R. Juroshek and G. M. Free, IEEE Trans, on MTT, 42 (2), 186-191

(Feb. 1994).

Basic RF and Microwave Measurements: A Review of Selected Programs, A. J. Estin, J. R. Juroshek, R. B. Marks, F. R. Clague, and J. Wayde Allen,

Metrologia 29, 35-151 (1992).

"Thru-Reflect-Line": An Improved Technique for Calibrating the dual Six-Port

Automatic Network Analyzer, G. F. Engen and C. A. Hoer, IEEE Trans. Micr. Theory Tech. MTT-27, 987

(Dec. 1979).

A Network Analyzer Incorporating Two

Six-Port Reflectometers, C. A. Hoer,

IEEE Trans. Micr. Tech. MTT-25,

1070 (Dec. 1977).

The Six-Port Reflectometer: An Alternative Network Analyzer, G. F. Engen,

IEEE Trans. Micr. Theory Tech. MTT-25, 1075 (Dec. 1977).

Application of Waveguide and Circuit Theory to the Development of Accurate Microwave Measurement Methods

and Standards, R. W. Beatty, Natl. Bur.

Stand. (U.S.), Monogr. 137 (Aug.

1973).

Specifications and Test Methods for Fixed and Variable Attenuators, dc to 40 GHz, IEEE Standard 474 (1973).

Basic Theory of Waveguide Junctions

and Introductory Microwave network

Analysis, D. M. Kearns and R. W.

Beatty, Intl. Ser. of Monogr. in Elec- tromag. Waves 13, 59, Pergammon

Press, New York, NY (1967)

Electrical Parameters of Precision Coaxial, Air Dielectric Transmission Lines, R. E. Nelson and M. R. Coryell, Natl. Bur. Stand. (U.S.), Monogr. 96 (June

1966).

*See Chapter 1 , Section H for more information about uncertainty.

176
61310S-61350S

G. RF, Microwave, and Millimeter-Wave

Measurements

G.3 High Accuracy Attenuation

Measurements

Technical Contacts:

Ronald A. Ginley

1^1:303/497-3634 Email:rginley@nistgov

Jeff A. Jargon

TbI:303/497-3596 Email:jjargon@ni$t.gov

Paula M. Hewitt Adminstration and

Logistics Hel:303/497-3753 Eniail:paula.hewitt@nistgov

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items 613 IOC Coaxial Fixed and Variable Attenuators Measured

at 30 MHz, Attenuation 0 dB to 120 dB

61320C Waveguide Below-Cutoff (Piston) Attenuators, Coaxial Connectors Measured at 30 MHz,

Attenuation 0 dB to 120 dB (Total Insertion Lx)ss) 61330S Attenuation Measurements of Three-Port and Two-Port Devices at 1 .25 MHz, 0 dB and 6 dB

61350C Coaxial Fixed and Variable Phase Shifters; Characteristics Phase Shift Difference; Precision Connectors; Measured at 30 MHz, Range 0° to 360°

Coaxial Fixed and Variable Attenuators (61310C)

Coaxial fixed and variable attenuators are measured with reference to the NIST

waveguide-below-cutoff (piston) attenuator at a fixed frequency of 30 MHz.

Coaxial attenuators are normally

measured in a system having a characteristic impedance of 50 fl. Typical

expanded uncertainties* range from

0.01 dB to 1 dB depending on the nominal attenuation and connector

repeatability.

Waveguide-Below-Cutoff (Piston) Attenuator Measurements at 30 MHz

(61320C)

Incremental attenuation is the change in attenuation of an adjustable attenuator

between a reference setting (usually zero)

and any other setting. The same restraints of system conditions apply as for attenuation. The term "attenuation difference" is sometimes applied to this case and usually refers to two nonzero settings.

Measurements on waveguide belowcutoff (piston) attenuators are performed

at 30 MHz. In any measurement, the maximum power delivered to the test at- tenuator is 400 mW. If the attenuator cannot tolerate this power level, some

reduction of measurement range will be

required. Piston attenuators are normally cali- brated in a system having a characteristic impedance of 50 CL. Since only measure- ments of incremental attenuation are made on this type of attenuator. Type

BNC, C, TNC, and similar connectors

are acceptable, but precision connectors

are preferred to reduce rf leakage. The

uncertainties depend upon the quality of

the attenuator and connectors, as well as upon the VSWR (voltage standing-wave

ratio) of the attenuator, and the magnitude of attenuation. Typical Type B

standard uncertainties* range from

0.003 dB to 0.005 dB per 10 dB of atten- uation. Total insertion loss must be less than 120 dB.

Attenuation Measurements at 1.25 MHz (61330S)

An additional measurement service is available for attenuation measurements of

special three-port devices at 1.25 MHz.

A measurement system has been devel- oped to measure the change in the ratio Sii/Sy] of special stable two-position,

three-port devices sometimes called voltage doublers, at 1 .25 MHz. The

device must have an input for a

1.25 MHz source (port 1), a reference output (port 3), and an output (port 2) with a level switchable to two different values. The two levels of the bi-level output have a nominal ratio of 6.0206 dB.

* See Chapter 1 , Section H for more information about uncertainty.

177
If Pri is the reference power level when

the bi-level output is at level 1 (Pbi), and

Pr2 is the reference power level when the

bi-level output is at level 2 {Pbi), then the parameter measured is given by the following equation:

101og,o(^)-101og,o(^), dB

where the subscripts (1) and (2) refer to the switch positions 1 and 2, respectively.

The above is equivalent to

52.(1)/ 53,(1) 2 lOlogio e /owe- •

The loads presented to the two outputs

are 50 fl. The device must allow the sig- nal input to be of such strength that the

bi-level output is at least 10 mW in the

high-level position.

The Type A standard uncertainty* of

the measurement system in measuring a 6 dB change in attenuation is 8.2 |jlB.

Typical Type B standard uncertainties*

are on the order of 0.3 |xB to 0.5 |xB

(1 (xB = 10"' dB). Two-port step attenuators having a nominal change in attenuation of 6 dB can also be measured by this system at 1 .25 MHz.

Phase Shifters (61350C)

The specific phase shift services are

available on a limited basis depending on

other demands and staff availability.

Measurements not listed may possibly be

provided if sufficient advance notice is

given. The cost of such services must be

negotiated and will, in general, be higher

than the established phase shift services. Consultation by telephone or written

correspondence is suggested. Often a measurement technique can be suggested

that will permit the customer to perform

calibrations in-house with appropriate

reference to other NIST-supported

standards. The expanded uncertainty* is 0.5°.

References—High Accuracy Attenuation Measurements

A 30 MHz Comparison Receiver, J. A.

Jargon, Asia-Pacific Microwave Conf.

Proc, Taejon, Korea (Oct. 1995).

A Revised Uncertainty Analysis for the NIST 30 MHz Attenuation Calibration

System, J. A. Jargon, Proc. of the Meas. Sci. Conf., Pasadena, CA (Jan. 1994).

Basic RF and Microwave Measurements: A Review of Selected Programs, A. J. Estin, J. R. Juroshek, R. B. Marks,

F. R. Clague, and J. Wayde Allen,

Metrologia 29, 135-151 (1992).

A Calibration Service for 30 MHz Attenuation and Phase Shift, R.T. Adair and

D. H Russell, Natl. Bur. Stand. (U.S),

SP 250-32 (1988)

1 .25 MHz Attenuation Measurement

System, R. A. Ginley and C. M.

Allred, IEEE Trans. Instrum. Meas.,

IM-35 (4), Pt. 1 (Dec. 1986).

Specifications and Test Methods for Fixed and Variable Attenuators, dc to 40 GHz, IEEE Standard 474 (1973).

UHF and Microwave Phase Shift Measurements, D. A. Ellerbach, Proc. IEEE 55 (6), 960 (June 1967).

*See Chapter 1, Section H for more information about uncertainty.

178
61410S-61495S

G. RF, Microwave, and Millimeter-Wave

Measurements

G.4 Thermal Noise Measurements

Technical Contacts:

James P. Randa

TleI:303/497-31S0 Email :jranda@nist.gov

Chriss Jones

1^1:303/497-5958 Email:jones@boulder.

nisLgov

Paula M. Hewitt Adminstration and

Logistics TbI:303/497-3753 Email:paula.hewitt@

nist.gov Fax:303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Frequency Connector Device Requirements/

Service

61410S

61420S

61425S

61430S

61450S

30 MHz

60 MHz

1 .0 GHz to 12.0 GHz

Continuous

Frequencies

1 GHz to 4 GHz

12.4 GHz to 18.0 GHz

Continuous

Frequencies

18.0 GHz to 26.0 GHz

Continuous

Frequencies

8.2 GHz

9.0 GHz

9.5 GHz

9.8 GHz

10.0 GHz

10.5 GHz

11.2 GHz

11.8 GHz

12.4 GHz

Coaxial N Precision (PIN) GPC 3.5 (PIN) GPC7

14 mm

Coaxial N Precision (PIN GPC 3.5 (PIN) GPC 7

14 mm

Coaxial N Precision (PIN) GPC 3.5 (PIN) GPC 7

Coaxial GPC 3.5 (PIN)

Temperature < 1 5 000 K (ENR< 17 dB) VSWR < 1.2

Temperature < 15 000 K (ENR< 17 dB)

Reflection Coefficient < 0.2

V/aveguide WR90

Temperature < 1 5 000 K (ENR< 17 dB)

Reflection Coefficient < 0.2

Temperature < 15 000 K (ENR< 17 dB)

Reflection Coefficient < 0.2

Temperature between 9 000 K and 17 000 K

(14.6 dB<ENR<17dB)

Reflection Coefficient < 0.09

Service ID No. Frequency Connector Device Requirements/

Service

61455S

61460S

61465S

61495S

Waveguide

WR62

Temperature < 1 5 tXiO K

(ENR < 17 dB)

Reflection Coefficient < 0.2

12.4 GHz to 18.0 GHz

Continuous

Frequencies

18.0 GHz to 26.0 GHz

Continuous

Frequencies

26.5 GHz to 40.0 GHz

Continuous

Frequencies

Special Noi.se Temperature Measurements, by Prearrangement

Waveguide

WR42

Waveguide

WR28

Temperature < 1 5 000 K

(ENR < 17 dB)

Reflection Coefficient < 0.2

Temperature < 15 000 K

(ENR< 17 dB)

Reflection Coefficient < 0.2

Noise Temperature Measurements

(61410S—61465S)

Noise temperature measurements are available on single-port, coaxial and

rectangular-waveguide noise sources under conditions of continuous,

unmodulated operation. Precision

coaxial connectors or clean, smooth, and

flat standard ElA waveguide flanges

are required. Measurement results on

devices submitted with adapters attached may apply only to the source/

adapter combination. Complete operating instructions and special electronic connectors should be supplied, and

pertinent operating conditions (voltages,

circuits, etc.) should be specified for the noise source to be measured. Devices

submitted that are not of sufficient quality or not mechanically compatible

with the measuring system will be re- jected, and an appropriate fee will be

charged. Availability of measurements

at specific frequencies and for various connector types are specified above.

An attempt is being made to expand

services to include additional types of

precision connectors and waveguide

sizes.

179
The measurement uncertainty varies with noise temperature, reflection coefficient, and source and connector stability. The relative expanded uncertainty*

typically lies between 0.9 % and 1 .5 %

of the noise temperature.

Special Noise Temperature Measurements (61495S)

Measurements of electromagnetic ther- mal noise other than those listed above can sometimes be arranged on a case-bycase basis. These may include measurements through adapters, measurements out of the parameter ranges

specified above, and measurements on

systems currently under development.

Such measurements should be discussed

with one of the technical contacts before submitting a device for calibration.

References (Noise Temperature

Measurements)

Radiometer Equation for Noise Comparison Radiometers, D. F. Wait, IEEE

Trans, on Instr. & Meas. 44(2), pp. 336-339 (April, 1995).

Uncertainties of the NIST Coaxial Noise

Calibration System, S. P. Pucic, 1994

Conference on Precision Electromagnetic Measurements Digest, (Boulder,

CO, 6/27/94-7/1/94) 254-255.

Basic RF and Microwave Measurements: A Review of Selected Programs, A. J. Estin, J. R. Juroshek, R. B. Marks,

F. R. Clague, and J. Wayde Allen,

Metrologia 29, 135-151 (1992).

Radiometer Equation and Analysis of

Systematic Errors for the NIST

Automated Radiometers, W. C. DayWitt, NIST Tech. Note 1327

(March, 1989).

Horn Design Equations for the NBS

Horn-Type Nose Standards, W. C. Daywitt, NBS Internal Report NBSIR

87-3073 (August 1987).

A Coaxial Noise Standard for the 1 GHz

to 12.4 GHz Frequency Range, W. C. Daywitt, NBS Tech. Note 1074

(March, 1984).

Noise Standards, Measurements, and

Receiver Noise Definitions, C. K. S. Miller, W.C. Daywitt, and M. G.

Arthur, Proc. IEEE 55 (6), 865-877 (June 1967).

*See Chapter 1 , Section H for more information about uncertainty.

1 80
GRF, Microwave and Millimeter Wave

Measurements

G.5 Dimensional Veriflcation of

Coaxial Air Line Standards

Technical Contacts:

George M. Free John R. Juroshek Glen V. Sherwood

Tel:303/497-3609 Tel:303/497-S362 Tel:303/497-3939 Email :gfree@nist.gov Email:jjuroshek@nistgov Email:gsherwood@nistgov

Paula M. Hewitt Administration and Logistics Tel:303/497-37S3 Email:paula.hewitt@nistgov

Fax:303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items 61510S Dimensional Measurement of Air Lines and

Verification of Characteristic Impedance

from Dimensional Measurements, by Prearrangement

Coaxial Air Lines (61510S)

Dimensional measurements are made on

the inner and outer conductors

of a headless, coaxial, air line standard. The characteristic impedance

of the air line standard is then computed

from these dimensional measurements. The service is currently available for 1.85 mm, 2.4 mm, 2.92 mm, 3.5 mm,

GPC-7, 14 mm, and Type N air line standards. The computations for characteristic impedance is made over

the normal operating frequency range of the air line standard. Consultation is available by telephone.

181
61620S-61640S

GRF, Microwave, and Millimeter Wave

Measurements

, G.6 Dielectric and Magnetic Material

Measurements

Technical Contacts:

Claude M. Weil Andrew G. Repjar Paula M. Hewitt

Tel:303/497-5305 Tel:303/497-5703 Administrative and

Einail:cweil@nist.gov Email:arepjar@nist.gov Logistics 1tl:303/497-37S3 Email:paula.hewitt@nist.gov Fax:303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items 61620S Special Tests for Dielectric and Magnetic Materials

1 kHz to 60 GHz

61640S Special Consulting and Advisory Services for Dielectric and Magnetic Materials, by Prearrangement

Special Tests for Dielectric and

Magnetic Materials (61620S)

A special-test measurement service is available for measuring the complex permittivity, 6* and permeability, /a* of

dielectric and magnetic materials, as well

as the surface resistance of conductors,

at selected RF/microwave frequencies in the spectral range 1 kHz to 60 GHz.

The service is capable of characterizing

fluids, powders, or bulk solids at room

temperatures (23 °C) and, in some cases, over a temperature range of approximately - 80 °C to 150°C. Customers

interested in high frequency material

characterization measurements should

contact NIST staff to discuss their specific needs. The optimal measurement

technique used is selected from a number of measurement techniques developed

at NIST. The selection depends on a number of factors including whether the material is in fluid, powder or solid form, the volume of material available,

its shape factor (for solids), its antici- pated loss factor, whether the material is

anisotropic, and the desired measurement

frequencies and ambient temperature.

The resulting measurement uncertainties depend on the technique selected as well as the nominal permittivity of the material under test. Upon request, NIST staff will prepare

a detailed cost quotation that includes

estimates of the measurement uncertainties. For the case of solids, each measurement method requires accurately

machined test samples with optical- standard tolerances for dimensions, flat- ness and parallelism. NIST can either perform the machining of test samples,

the cost of which is included in the

price quotation, or furnish drawings of

sample specifications for the customer

to perform the necessary machining.

The measurement techniques available

at NIST can be divided into three categories: a) cavity resonator methods for low-loss materials (tan 8 < 0.01),

b) broadband transmission line methods

for medium to high-loss materials, and

c) low-frequency impedance measuring

methods. Most cavity resonators operate at frequencies above 100 MHz and

usually provide single-frequency data, unless the resonators are tunable or can

be operated on higher-order modes.

Data are usually provided in tabular form. In general, better measurement

uncertainties* are achievable using cavities and are about 0.5 % for e'. Broadband transmission line tech- niques include coaxial air lines and

waveguides of various dimensions, as well as 1 - and 2-port open-ended

coaxial probe methods. Measured broadband data are normally provided as

linear or logarithmic plots of e', e" and

/u.', /i," as a function of frequency with

uncertainties included; relative uncertainties of 5 % to 10 % are typical. The

low-frequency impedance measuring

methods typically cover the frequency

range 1 kHz to 1 0 MHz and involve measuring capacitance changes for dielectric materials and inductance changes for magnetic materials.

*See Chapter 1, Section H for more information about uncertainty.

182
61620S-61640S

References—Dielectric and Magnetic

Material Measurements

Complex Permeability of Demagnetized

Microwave Ferrites Near and Above

Gyromagnetic Resonance, J. Krupka et

al, IEEE Trans. Mag. 32 (3) pp. 1924-

1933 (May 1996).

Dielectric and Magnetic Measurements

from - 50 °C to 200 "C and in the Frequency Band 50 MHz to 2 GHz,

J. Baker-Jarvis et al, NIST Internal Report 5045 (March 1996).

Dielectric Measurements of Printed- Wiring and Circuit Boards, Thin

Films, and Substrates: An Overview,

J. Baker-Jarvis et al, MRS Symp. Proc. 381, pp. 153-164 (April 1995).

Analysis of an Open-Ended Coaxial

Probe with Lift-Off for Nondestructive

Testing, J. Baker-Jarvis et al, IEEE Trans I&M, 43 (5) pp 71 1-718 (Oct. 1994).

Transmission/Reflection and ShortCircuit Line Methods for Measuring

Permittivity and Permeability,

J. Baker-Jarvis et al, NIST Tech. Note 1355-R (Dec. 1993).

The NIST 60-mm Diameter Cylindrical

Cavity Resonator: Performance

Evaluation for Permittivity Measurements, E .J. Vanzura et al, NIST

Technical Note 1354 (Aug. 1993).

NIST Measurement Service for Electro- magnetic Characterization of

Materials, J. H. Grosvenor, NIST

Internal Report 5006 (Aug. 1993).

Shielded Open-Circuited Sample Holders

for Dielectric and Magnetic Measure- ments of Liquids and Powders,

J. Baker-Jarvis et al, NIST Internal Report 5001 (March 1993).

183
63100S-63400S

H. Electromagnetic Field Strength

and Antenna Measurements

H. 1 Microwave Antenna Parameter

Measurements

Technical Contacts:

Andrew G. Repjar (63100S-63400S)

Tel:303/497-5703

Eniail:arepjar@nist.gov

Katherine MacReynolds

(63100S)

Tel:303/497-3471 Email:kinacreynold$@

nist.gov

Michael H. Francis (63200S)

Tel:303/497-5873 Eniail:mfrancis@nist.gov

Paula M. Hewitt

Administration and Logistics Tel:303/497-3753 Eniail:paula.hewitt@nistgov Fax:303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Shipping Address: Room 1300, Bldg. 24,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items 63100S Gain and Polarization Calibrations of Standard Antennas Using Extrapolation Range

63200S Measurement of Pattern, Gain, and Polarization of

Arbitrary Antennas Using Near-Field Scanning Techniques

63300S Special Test Service for Calibration of Probes Used with Near-Field Scanning Facilities 63400S Special Consulting, Advisory, and Other Services

Antenna Parameter Measurements

(Microwave)—General Information

Accurate measurements of antenna gain,

pattern, and polarization are generally

available from about 1 GHz to about

75 GHz. However, because the measure- ment accuracy, capability, and cost depend on the frequency, type, and size of antenna, and the parameters to be

measured, a particular measurement

service must be negotiated in advance.

Antennas submitted for evaluation should

be mechanically and electrically stable in order to retain a calibration for a signifi- cant length of time. Antennas with either coaxial or waveguide connectors can be

measured; however, if coaxial connectors

are employed, they should be precision connectors to minimize uncertainties due

to a lack of connector repeatability. In

particular, the use of SMA and APC-7

connectors is strongly discouraged be- cause of poor connector repeatability.

The following methods and facilities are used for these measurements.

Gain and Polarization Calibrations of

Standard Antennas Using Extrapolation Range (63100S)

This calibration service is offered primarily for determining the absolute on-axis

gain and polarization of standard gain

horns, which, in turn, are used as refer- ence standards in determining the gain

and polarization of other antennas by the gain comparison technique. In the extrapolation method, three antennas are normally utilized, and three pairwise

combinations are determined. The

received signal transmitted between each

pair of antennas is measured as a function of the separation distance between

the antennas. The antennas need not be

identical, and no assumptions concerning

the polarization are required. The method

is not well suited for pattern measure- ments but is the most accurate technique

known for absolute gain and polarization measurements. For gain measurements from 2 GHz to 30 GHz, the uncertainties

are typically 0.10 dB; above 30 GHz, the

uncertainties are typically 0.15 dB.

Uncertainties of 0.05 dB/dB for polarization axial ratio measurements are typical.

There are antenna size limitations associ- ated with existing NIST extrapolation ranges. These limitations depend on the type of antenna, the frequency, and the desired measurements and accuracies. Therefore, negotiations must be

conducted prior to submitting antennas

for calibration to ascertain whether all requirements can be met.

184
63100S-634(X)S

Measurement of Pattern, Gain, and

Polarization of Arbitrary Antennas

Using Near-Field Scanning

Techniques (63200S)

With this technique, gain, pattern, and

polarization parameters are calculated from near-field amplitude and phase measurements taken over a surface close

to the test antenna. The absolute gain can

be determined to within about 0.2 dB,

the polarization axial ratio to within

about 0.10 dB/dB, and side lobe levels can be obtained down to -50 dB or -60 dB. The exact uncertainties in these parameters will depend on such factors as the frequency, type and size of

antenna. Antennas with apertures up to about 3 m in diameter can be managed.

Measurements can be made from about

1 GHz to about 75 GHz. Measurements

are most commonly made over a plane

surface in front of the antenna being

evaluated, but the capability also exists for measuring over a cylindrical or

spherical surface surrounding the antenna when it is advantageous to do so. Calibrated probes are normally required

for these measurements. These near-field scanning measurements are offered as a

special-test service because nearly every measurement is unique and it is difficult to build up a statistical history as required

for a regular calibration service.

Special-Test Service for Calibrating

Probes Used with Near-Field Scanning

Facilities (63300S)

This special-test service is available to support those organizations that have es- tablished their own near-field measure- ment facilities and need to characterize

the probes used in performing the nearfield measurements. In order to achieve accurate results with either the planar,

cylindrical, or spherical near-field method, the transmitting or receiving

properties of the probe must be known.

With this information, the measured data can be corrected for the nonideal pattern

and polarization properties of the probe.

Probes are characterized by a three-step process: (1) The on-axis gain and polarization properties are measured using the extrapolation technique described above;

(2) the far-field amplitude and phase

patterns are measured for two nominally

orthogonal polarizations of the incident

field; and (3) the on-axis and pattern data are combined to obtain the probe

correction coefficients at the desired

lattice points for the measurement

surface specified by the customer. The

final output consists of a computer disk containing the measured far-field patterns and the calculated probe

coefficients. Typical types of probes

are open-ended waveguides and small

horns. Both linearly and circularly

polarized probes can be evaluated.

Special Consulting, Advisory, and

Other Services (63400S)

A variety of special consultation and

advisory services related to the measure- ments described above are available upon

request. These services are offered to disseminate NIST technologies and to

assist other organizations in establishing

their own measurement facilities and

capabilities. Included are cooperative

measurement programs. A customer

actually participates directly in the measurement of his device in order to become familiar with the measurement

methods and assist in the analysis of the

results. This is a useful approach when

one is attempting to establish a new

measurement capability that is related to or based upon NIST measurement

techniques.

References—Microwave Antenna

Parameter Measurements

A Certification Plan for a Planar NearField Range Used for HighPerformance Phased-Array Testing,

M. H. Francis, A. G. Repjar, and

D. P Kremer, NIST Internal Report

3991 (July 1992).

185
Improvements in Polarization Measurements of Circularly Polarized Probes, A. C. Newell, D. R Kremer, J. R.

Guerrieri, Proceedings of the Antenna

Measurement Techniques Association,

pp. 1-30 through 1-35 (October 1989).

Antenna Calibrating Standards Using

CW and Pulsed-CW Measurements

and the Planar Near-Field Method,

D. P. Kremer and A. G. Repjar,

Proceedings, Antenna Meas. and Techniques Assoc., pp. 13-21 through 13-

29 (September 1988). Effect of Random Errors in Planar NearField Measurement, A. C. Newell and

C. F. Stubenrauch, IEEE Trans. Antennas and Propagation, Special Issue on

Near-Field Scanning, 36 (6), 769-773

(June 1988). Accurate Determination of Planar NearField Correction Parameters for Linearly Polarized Probes, A. G. Repjar, A. C. Newell, and M. H. Francis, IEEE

Trans. Antennas and Propagation,

Special Issue on Near-Field Scanning,

36 (6), 855-868 (June 1988).

Improved Polarization Measurements

Using a Modified Three-Antenna

Technique, IEEE Trans. Antennas and

Propagation, Special Issue on NearField Scanning, 36 (6), 852-854 (June

1988).

Gain and Power Parameter Measurements

Using Planar Near-Field Techniques, A. C. Newell, R. Ward, and E. McFarlane, IEEE Trans. Antennas and Propagation, Special Issue on Near-Field

Scanning, 36 (6), 792-803 (June

1988).

Error Analysis Techniques for Planar

Near-Field Measurements, A. C. Newell, IEEE Trans. Antennas and

Propagation, 36, 754-768 (June 1988).

Extrapolation Range Measurements for Determining Antenna Gain and Polarization, A. G. Repjar, A. C. Newell,

and D. T. Tamura, NBS Tech. Note

1311 (August 1987).

The Determination of Near-Field Correction Parameters for Circularly Polar- ized Probes, A. C. Newell, M. H.

Francis, D. P. Kremer, Proceedings

Antenna Measurement Techniques

Assoc. , pp. 3A3-1 through 3A3-29

(October 1984).

A Method of Determining the Mismatch

Correction in Microwave Power Measurements, G. Engen, IEEE Trans. Instrum. Meas. IM-17, 4 (Dec. 1968).

Bolometric Microwave Power Calibration

Techniques at the National Bureau of

Standards, R. F. Desch and R. E. Larson, IEEE Trans. Instrum. Meas. IM-12, 1 (June 1963).

A Bolometer Mount Efficiency Measure- ment Technique, G. Engen, J. Res.

Natl. Bur. Stand. (U. S.), 65C, 1 13

(Apr. -June 1961).

A Transfer Instrument for the Intercomparison of Microwave Power Meters, G. Engen, IRE Trans. Instrum. Meas.

19, 202 (Sept. 1960).

A Refined X-Band Microwave

Microcalorimeter, G. Engen, J. Res.

Natl. Bur. Stand. (U.S.), 63C, 77

(1959).

186
64100S-64300S

H. Electromagnetic Field Strength

and Antenna Measurements

H.2 Field Strength Parameter

Measurements

Technical Contacts:

Kenneth H. Cavcey

1^1:303/497-3995 Email :cavcey@ni$t.gov

Motohisa Kanda

Tel:303/497-5320 Eniail:mkanda@nistgov

Paula M. Hewitt

Administration and

Logistics TbI:303/497-3753 Email:paula.hewitt@

nistgov Fax:303/497-3970

Mailing Address: M.C. 813.10,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items 64100S Special-Test Service for Antennas/Field Strength

Measurements, Utilizing the Transverse Electromagnetic (TEM) Cell Method (10 kHz to 300 MHz)

64200S Special-Test Service for Antennas/Field Strength

Measurements, Utilizing the Open Area Test Site and Standard Antenna Method

64300S Special-Test Service for Antennas/Field Strength/

Reflectivity Measurements, Utilizing the Anechoic

Chamber and Standard Field Method

Special-Test Service for Antennas/Field

Strength Measurements, Utilizing the Transverse Electromagnetic (TEM)

Cell Method (64100S)

Standard electromagnetic fields are generated in TEM cells and used to calibrate

electrically small antennas and antenna

systems used for electromagnetic field probes in the frequency range 10 kHz to 300 MHz.

Special-Test Service for Antennas/Field

Strength Measurements, Utilizing the

Open Area Test Site and Standard

Antenna Method (64200S)

These measurements include calibration of antenna factor and gain of antennas used in conjunction with field strength

meters, and of electrically small antennas used in electromagnetic field probes. The

following methods and facilities are used

for these measurements: A. Dipoles, log-periodic, and other antennas (25 MHz to 1000 MHz) are used to generate electromagnetic fields which are used for calibrating various antennas and electromagnetic field probes. The field strength is established using the standard receiving antenna method.

B. Monopoles (30 kHz to 300 MHz)

are used to generate standard electric

fields for calibrating antennas and

electromagnetic field probes. C. Loop antennas (14 kHz to 50 MHz) are used to generate standard magnetic fields for calibrating loop

antennas used in conjunction with field strength meters.

Special-Test Service for Antennas/Field

Strength Measurements, Utilizing the

Anechoic Chamber and Standard

Field Method (64300S)

A. Open-end waveguides (200 MHz to 450 MHz) are used to generate standard electromagnetic fields for calibrating an- tennas and electromagnetic field probes. B. Pyramidal horns (0.45 GHz to 40 GHz) are used to generate standard electromagnetic fields for calibrating antennas and electromagnetic field probes.

Table 9.19 summarizes the field parameters, frequency ranges, and radiat- ing antenna sources for the various NIST

field strength measurement facilities.

187
641008-643008

Table 9.19. 8ummary of NI8T 8tandard Field 8trength

Facilities

Type of Radiating

Field IVleasureinent Frpniipnpv Parameter Facility Range Source un Wnnrt TLoop r\rtr\ OH (^t-r»\ Liu) building 50 MHz

E (vertiCtil) ^_/pcn /\rca icsi oiic J\J KnL 10 QUr\rt onori

(ground screen) 30 MHz monopole E (vertical) Open Area Test Site 30 kHz to Quarter wave

(ground screen) 30 MHz length monopole E (horizontal) Open Area Test Site 30 MHz to Dipole, log- (ground screen) 300 MHz periodic antenna, etc. EandH TEM cell 25 MHz to 1000 MHz

Power Density Anechoic 200 MHz to Open-end

chamber 450 MHz waveguide Power Density Anechoic 0.45 GH to Pyramidal chamber 46 GHz horn

References—Electromagnetic Field

Strength Parameter Measurements

Methodology for Standard Electromagnetic Field Measurements,

N. S. Nahman, M. Kanda, E. B.

Larsen, and M. L. Crawford, IEEE

Trans. Instrum. Meas. IM-34, 4

(Dec. 1985).

A Review of Electromagnetic Compatibility/Interference Measurement

Methodologies, M. T. Ma,

M. Kanda, M. L. Crawford, and E. B.

Larsen, Proc. IEEE, 73, 3, 388 (Mar.

1985).

188
65100S-654O0S

/.

Pulse Waveform Measurements

Technical Contacts:

John P. Deyst

1fel:301/97S-2437 Email:john.deyst@nistgov

T. Michael Souders

1tl:301A>75-2406

Einail:tsouders@nist.gov

Denise D. Prather

Administration and

Logistics

11bI:30 1/975-4221 Eniail:dprather@

nist.gov

Mailing Address: Building 220, Room B146,

National Institute of Standards and Technology,

Gaithersburg, MD 20899-0001

Service ID No. Items 65100S Impulse Spectrum Amplitude (50 Cl) 65200S Fast Repetitive Pulse Transition Parameters (50 fl) 65250S Fast Repetitive Pulse Settling Parameters (50 Cl) 653(X)S Network Impulse Response (Transfer Function) of Coaxial Networks

65400S Pulse Time Delay Interval

Pulse Waveform Measurements

General Information

NIST offers special-test services for a number of baseband pulse parameters.

These are broken down into five categories: impulse spectrum amplitude, fast repetitive pulse transition parameters, fast repetitive pulse settling parameters,

network impulse response, and pulse

time delay interval. All of the special test services except the fast repetitive pulse

settling parameters service are performed

using the NIST Automatic Waveform

Analysis and Measurement System

(AWAMS). The AWAMS consists of a

pulse generator, a calibrated wide-band

sampling oscilloscope (input impedance

50 Cl, and nominal bandwidth of dc to 20 GHz, equivalent to a step response

transition duration of 17.5 ps), and dedi- cated microcomputer system interfaced to the oscilloscope. The fast repetitive pulse

settling parameters test service uses the NIST Sampling Comparator System

(SCS), a NIST-designed sampling comparator oscilloscope, controlled by a microcomputer. The SCS has a 50 H

input impedance, nominal bandwidth of

dc to 2.5 GHz (equivalent to a step re- sponse transition duration of 1 40 ps), and

settling < 1 % within 1 ns and to 0.1 %

within 10 ns. All of these special tests are performed at cost, and by prearrange- ment. References pertaining to these four services are located at the end of this section.

Impulse Spectrum Amplitude (65100S)

In response to calibration needs from the electromagnetic interference (EMI)

community, NIST has a special-test service to calibrate the broadband

spectrum amplitude output from impulse

generators. Such generators can then be

used as transfer standards of broadband

impulsive noise for field calibration of

spectrum analyzers and field intensity meters. The NIST special-test service uses the time-domain measurement/

frequency-domain deconvolution computational method for calibration of impulse

generators. The AWAMS wideband (dc to 20 GHz) sampling oscilloscope is used to measure the time-domain waveform from

the impulse generator. The spectrum amplitude, S(f), versus frequency is then computed using fast Fourier transform

(FFT). NIST will provide 50 to 200 data

points over a wide frequency range for a

single fee. NIST impulse spectrum

amplitude measurement service capabilities are shown in Table 9.20.

189
65100S-65400S

Table 9.20. NIST Impulse Generator Spectrum

Amplitude Measurement Service Capabilities

Parameter Limits Notes Maximum impulse

amplitude without

attenuators Maximum impulse

amplitude with

external attenuators

S(f) range

S(f), expanded

uncertainty*

Frequency range Frequency spacing

Frequency, expanded

uncertainty

Load impedance

Load impedance,

expanded uncertainty

Trigger pulse amplitude

Trigger pulse transition duration Trigger to impulse

delay interval Trigger to impulse

jitter

600 mV

1.2 kV

- 15 dB (|xV/MHz)

<lS(f)-So] < + 5 dB (p-V/MHz)

Nominally /< 100 MHz, 0.6 dB,

100 MHz </<10 GHz, 0.3 dB

4GHz</<10 GHz, 2.0 dB

10 MHz to 10 GHz

A/> 10 MHz

Nominally 0.3 %

50.0 n

Nominally 0.5 Cl

< 1.0 V

< 5 ns

> 45 ns

< 10 ps, rms

1,2

2,3

4, 5

4,5,7

4,5,7 7

5,8

9

9

9

9

See Chapter 1 , Section H for more information about uncertainty.

Notes:

1. Impulse generator with an adjustable-amplitude impulse output will be

calibrated with the generator adjusted to give a peak amplitude in the range of 300 mV to 500 mV.

2. Impulse generators with fixed output amplitudes greater than 600 mV

must have the impulse attenuated to a level of 300 mV to 500 mV by 50 fl wideband coaxial attenuators.

3. Either customer-supplied or NIST attenuators may be used.

4. Data will not be given in the first spectrum null or at frequencies above.

Typically about 100 data points are supplied.

5. Only for impulse amplitudes less than 600 mV.

6. If external attenuators and/or a delay-line network are used, then the uncertainties associated with the attenuator and/or network calibration are added to these values.

7. Measurements at frequency spacing less than 10 MHz are available as a special test. 8. Load impedance uncertainty depends upon input impedance of external attenuators when used.

9. If the impulse generator does not supply a trigger output or if the trigger output does not have the proper characteristics, then a delay-line network will be used to provide a suitable trigger pulse.

Fast Repetitive Pulse Transition

Parameters, 50 n (65200S)

NIST offers a special-test service for fast repetitive pulses, for parameters related

to the pulse transition. These parameters

are measured with the NIST iWAMS

described above. This service is optimized for measuring the durations of

very fast pulse transitions (transition

durations less than 350 ps, i.e., bandwidths greater than 1 GHz). The

parameters, ranges, and estimated

uncertainty limits for this service are

listed in Table 9.21.

Table 9.21. Uncertainty for Calibration of Fast

Repetitive Pulse Transition Parameters

Typical

Expanded

Parameter Range Uncertainty*

Pulse Baseline (0% level) Pulse Topline

(100% level) Pulse Amplitude

Pulse First Transition Duration (Rise Time)

Pulse Second Transition Duration (Fall Time)

Pulse Duration (Between 50% levels)

±500 mV

±500 mV

±500 mV

10 ps to 100 ns

10 ps to 100 ns 10 ps to 100 ns

(0.5 %V -I- 2 mV)

(0.5 % V -I- 2 mV)

(0.5 %V + 2 mV)

(0.5 % r -I- 3 ps)

(0.5 % / -I- 3 ps)

(0.5 %t + 3 ps)

See Chapter I , Section H for more information about uncertainty.

190
6510OS-654OOS

Restrictions and Notes:

1 . Customer's device must generate a

repetitive pulse with repetition rate between 100 Hz and 1 GHz.

Alternatively, NIST can provide a range of trigger signals.

2. Customer's device must have a nominal output impedance of 50

ohms.

3. Customer's device must have a precision coaxial output connector,

e.g., SMA, APC-7, Type N,

APC-3.5, etc.

4. Maximum pulse amplitude measurable without attenuators is 600 mV. For larger pulse amplitudes, the customer shall supply an attenuator to decrease the pulse

amplitude to 600 mV or less. 5. Pulse topline is measured only for "step-like" pulses.

6. Pulse second transition duration

and pulse duration are measured

only for "impulse-like" pulses.

Measurements of other pulse parameters

or parameter ranges may be provided by

special arrangement. Consulting and ad- visory services also are available.

Repetitive Pulse Waveform Measurements, Including Settling Parameters

(65250S)

NIST offers a special-test service for measurement of repetitive pulse wave- forms whose major frequency components are below 1 GHz. Waveform

measurement data can be provided on

diskette, along with a report of measure- ment uncertainties as a function of the duration from the mesial (50 %) point of

the pulse transition. When required, certain derived waveform parameters can

also be provided. For step-like waveforms, these include waveform settling

errors, with respect to a defined refer- ence level. For impulse-like waveforms,

pulse energy into an ideal 50 (1 load can

be provided. The waveforms are measured with the NIST Sampling Comparator System described above. Waveforms

within ± 2 V into 50 Cl can be accom- modated directly. Higher amplitudes

require the use of external attenuators. Both 50 n and 2 kfi attenuators are

available for amplitudes up to 20 V peak;

however, the 2 kil attenuator substantially reduces the bandwidth of the measurement system. Typical measurement

epochs range from 10 ns to 1 |jls, and

record lengths range from 1000 to 4000

samples.

Representative uncertainties for set- tling parameter measurements are listed in Table 9.22.

Table 9.22. Uncertainty for Measurement of Repetitive

Pulse Setding Parameters

Duration from Typical Expanded

Pulse Amplitude Mesial Point Uncertainty*

(V) (ns) (% of pulse

amplitude)

0.25

0.5 to 2.0

1 1.0 2 0.3 5 0.1 10 0.1 100 0.05 1000 0.02

1 0.5 2 0.2 4 0.1 5 0.06 6 0.05

8 . 0.03 10 0.02 20 0.02 50 0.02 100 0.01 1000 0.01

*See Chapter 1, Section H for more information about uncertainty.

191
Restrictions and Notes:

1 . All measurements are performed

with a 50 n input impedance. The

input connector is a female SMA

type. The sampling probe is connected direcdy to the output connector of the waveform source; no

intervening cables are used unless they are specifically provided for

this purpose by the customer.

2. The settling error at time t (measured from the mesial point) is defined as the largest absolute difference between the waveform

and the reference level occurring

in the interval from time t to the end of the data record.

3. Unless otherwise requested, the reference level is the final dc or steady state value of the final

level. This level is measured by in- putting a steady state logic level to the generator under test corre- sponding to the final level.

4. Short term settling can also be

measured with respect to the final

level in a specified time epoch, if requested. In this case, long term

settling error—the difference be- tween the value at the end of the specified epoch and the dc

value—also will be reported.

5. Pulse generators that are internally

clocked must provide a separate

trigger output pulse. For best results, this should lead the wave- form under test by at least 35 ns.

If the trigger pulse leads by less than 35 ns, the waveform measurement will begin one cycle

later, with a resulting increase in

jitter and time-quantization errors. If the pulse generator can be

clocked externally, NIST will provide the clock signal and the necessary trigger output signal,

when required.

6. The clock pulse requirements

should be specified including high

level, low level, repetition rate, and

duty cycle. Repetition rates be- tween 10 kHz and 10 MHz are preferred.

Measurements of other pulse parameters

or parameter ranges may be provided

by special arrangement. Consulting and

advisory services also are available.

Network Impulse Response (65300S)

The network time-domain impulse

response measurement service for coaxial networks has been offered previously at NIST; currently the service is being reworked and is not being offered,

except by special arrangement. When

available, the measurements will be

accomplished by use of the NIST

PWAMS described above. Two wave- forms are measured, one with the pulse generator connected directly to the oscilloscope, and the other with the unknown network inserted between the generator and the oscilloscope. The

time-domain impulse response function

and/or the frequency domain scattering

parameter, S2\(f), are then calculated using an NIST-developed deconvolution algorithm. A wide variety of connectors can be accommodated. The

resulting data are in the form of a dis- crete waveform vector, normally 1024

points in length, with a time window

range from 1 ns to 100 ns. Also, using

discrete Fourier transforms, the associ- ated frequency-domain transfer function data {Siilf]) are provided over a frequency range of 10 MHz to 10 GHz

and a gain or loss range of 0 dB to 40 dB. The approximate limits of the expanded uncertainty* are expected to be less than 2 % for all parameters.

Pulse Time Delay Interval (65400S)

NIST offers a special-test service for measuring pulse time delay interval, using the NIST AWAMS described above. The pulse time delay interval range is 10 ps to 100 ns with typical expanded

uncertainties* of (0.2 % t + \ ps).

*See Chapter 1, Section H for more information about uncertainty.

192
651fX)S-65400S

Restrictions:

1. Customer's device must utilize precision coaxial connectors for both delay ports, e.g., SMA,

APC-7, Type N, APC-3.5, etc.

2. Customer should provide the driv- ing pulse generator if possible.

First transition duration (rise time)

of the driving pulse generator

should not exceed 10 % of the pulse time delay interval to be

measured.

Measurements for other ranges and

configurations may be made by special

arrangement. Consulting and advisory

services are available.

References—Pulse Waveform

Measurements

A Custom Integrated Circuit Comparator

for High-Performance Sampling Applications, O. B. Laug, T. M. Souders,

and D. R. Flach, IEEE Trans. Instrum. Meas. 41 (6), 850 (Dec. 1992).

Dynamic Calibration of Waveform

Recorders and Oscilloscopes Using

Pulse Standards, W. L. Cans, IEEE

Trans. Instrum. Meas, 39 (6), 952

(Dec. 1990).

Characterization of a Sampling Voltage

Tracker for Measuring Fast, Repetitive

Signals, T. M. Souders, H. K. Schoenwetter, P. S. Hetrick, IEEE Trans.

Instrum. Meas. IM-36 (4), 956

(Dec. 1987).

Calibration and Error Analysis of a Picosecond Pulse Waveform Measure- ment System at NBS, W. L. Cans,

Proc. IEEE, 74 (1), 86 (Jan. 1986).

Deconvolution of Time Domain Waveforms in the Presence of Noise, N. S. Nahman and M. E. Guillaume, Natl. Bur. Stand. (U.S.), Tech. Note 1047

(Oct. 1981).

Spectrum Amplitude Definition, Generation, and Measurement, J. R. Andrews

and M. G. Arthur, Natl. Bur. Stand.

(U.S.), Tech. Note 699 (Oct. 1977).

IEEE Standard Pulse Terms and Definitions, IEEE Std. 194-1977; and IEEE

Standard on Pulse Measurement and

Analysis by Objective Techniques,

IEEE Std. 181-1977, Inst. Electrical and Electronic Engrs., New York, NY

(July 1977).

Impulse Generator Spectrum Amplitude

Measurement Techniques, J. R. Andrews, IEEE Trans. Instrum. Meas.,

IM-25 (4), 280 (Dec. 1976). Present Capabilities of the NBS Automatic Pulse Measurement System, W.

L. Gans, IEEE Trans. Instrum. Meas. IM-25, 384 (Dec. 1976).

Time Domain Automatic Network Analyzer for Measurement of RF and Microwave Components,

W. L. Gans and J. R. Andrews, Natl. Bur. Stand. (U.S.), Tech. Note 672

(Sept. 1975).

Pulsed Wavemeter Timing Reference for Sampling Oscilloscope Calibration, J. R. Andrews and W. L. Gans, IEEE

Trans. Instrum. Meas. IM-24, 82

(Mar. 1975).

Pulse Techniques and Apparatus, Part

1 : Pulse Terms and Definitions; Part

2: Pulse Measurements and Analysis,

General Considerations, lEC Publications 469-1 and 469-2, Intl. Electrotech. Com. (lEC), Geneva,

Switzerland (1974).

193
Broadcast and Measurement Services

Characterization of Oscillators
Time and Frequency Measurements 76100S-76110S

A. Broadcast and Measurement Services

Technical Contacts:

Miahael A. Lombard!

(Frequency)

1^1:303/497-3212 Emaihmichael. lombardi@nisLgov

Marc A. Weiss (Time)

Ttl:303/497-3261 Emaihmarc.weiss

@iiistgov

D. Wayne

Hanson

(Broadcast

Services) 1tl:303/497-5233 Email:d.hanson@

nist.gov

Paula Hewitt

Administration and

Logistics T1el:303/497-3753 Emailrpaula.

hevi'itt@nistgov

Mailing Address: M.C. 847.40,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Shipping Address: M.C. 847.40, Room 4039,

National Institute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items

Broadcast Services (WWW, WWVH, WWVB, GOES,

ACTS, and NTS)

76100S Frequency Measurement Service (Frequency Delivered to User's Site) 761 1 OS Global Time Service (Frequency and Time Delivered to User's Site)

NIST Broadcasts of Time and

Frequency Signals

NIST time and frequency broadcast ser- vices are available free of charge to the general public. Services are provided via HF, LP, and UHF radio, as well as via telephone lines and Internet connection.

NIST broadcast services are coordinated

with similar services in other countries. Commercial receivers (for radio signals)

and software packages (for computer

time services) are available from several manufacturers. NIST publications are

available that explain how to use these

services. HF Signals—Broadcasts from WWV

(Fort Collins, Colorado) and WWVH

(Kauai, Hawaii) can be received on

conventional shortwave receivers nearly

anywhere in the world. Broadcast

frequencies are 2.5 MHz, 5 MHz,

10 MHz, and 15 MHz for both stations and 20 MHz for WWV only. Standard

uncertainties of 1 ms to 10 ms in time

and a relative standard uncertainty* in frequency of 1 X 10"^ are typical from

these broadcasts. The HF broadcasts provide standard frequencies, standard time intervals, time-of-day announcements, a binary-coded-decimal (BCD)

time code, astronomical time corrections,

and public service announcements for other government agencies. For individuals without receivers, the audio from both

stations is simulcast by telephone. The

telephone signal has a standard uncertainty* of 30 ms or less due to delays in cross-country telephone line routings.

The phone numbers (not toll free) are (303) 499-71 1 1 for WWV and

(808) 335-4363 for WWVH.

LF Signals—Radio station WWVB

(Fort Collins, Colorado) provides stan- dard uncertainties of 0.5 ms in time and a

relative standard uncertainty* in fre- quency of 1 X 10 ". The station broadcasts a 60 kHz carrier and a BCD time

code. Effective January 1, 1998, the transmitted power of WWVB will in- crease by 6 dB to approximately 50 kW

and the coverage area will include most

of North America.

GOES Satellite—The GOES satellites (Geostationary Operational Environmental Satellite) broadcast NIST time on a frequency of about 468 MHz. The signals are usable in North and South America

with a standard uncertainty of 1 00 [xs. Two satellites (GOES-East and GOESWest) are used for this service. The satellites are located at approximately 75° and

135° west longitude, respectively.

Automated Computer Time Service

(ACTS)—This service allows computer

users with modems to synchronize their clocks by telephone. The phone number

for ACTS is (303) 494-4774. Users can

connect at speeds of up to 9600 baud

and obtain time signals with standard uncertainty* of 5 ms. Network Time Service (NTS)—This

service allows users to synchronize

computer clocks via the Internet. The

service responds to time requests from any

* See Qiapter 1 , Section H for more information about uncertainty.

195
Internet client in several formats

including the Daytime (RFC-867),

Time (RFC-868), and Network Time

Protocol (NTP, RFC- 1305). The

service is being expanded and uses multiple time servers (call for current server addresses).

Frequency Measurement Service

(76100S)

Frequency calibrations with a relative standard uncertainty* of 5 X 10''^ can be obtained using the NIST Frequency

Measurement Service (FMS). The

FMS uses signals from Global Position- ing System (GPS) satellites as refer- ence frequency. Subscribers to the FMS

receive a complete frequency measure- ment system which they install in their lab (the equipment remains the property of NIST). The system inciudes a GPS receiver and all of the hardware

and software necessary to automate the calibration process. The system can

simultaneously calibrate up to five fre- quency standards (quartz, rubidium or cesium), and graphically display the results. NIST provides all of the equipment,

documentation, supplies, and technical support needed to operate the FMS, and

offers a free training seminar to teach

the subscriber. The subscriber's only

requirements are to supply the fre- quency standards to be measured, and a dedicated phone line. The phone line allows NIST personnel to call each sys- tem to verify and analyze the data, and

quickly troubleshoot any problems that might arise. If any component fails, NIST replaces it immediately using an

overnight delivery service. Each subscriber receives a monthly certificate of

calibration which certifies that their primary frequency standard is traceable

to NIST. This traceability can assist customers seeking accreditation through

NVLAP (National Voluntary Laboratory Accreditation Program) or seeking

compliance with ISO requirements.

* See Chapter 1 , Section H for more information about uncertainty.

Global Time Service (761 lOS)

This service uses the Global Position- ing System (GPS) satellites in a common-view mode and provides better time and frequency transfer than is afforded directly by GPS. Data from a receiver located at the user's facility are automatically downloaded (by phone)

to a NIST computer. The computer stores the data, determines which data are suitable for time transfer calculations,

and provides optimally filtered values

for the time and frequency of the user's clock relative to UTC (NIST). Monthly

reports are sent to the user, and users also receive an account on a NIST

computer that allows them to access a

daily, preliminary analysis. Tests between widely separated

receivers have demonstrated standard

uncertainties* for time comparisons of

less than 10 ns and relative standard

uncertainties* for frequency comparisons

of less than 1 X 10 ", both for averaging times of 1 d. The uncertainty

decreases as the averaging time

increases. The frequency uncertainty is limited by the relative standard uncertainty of the NIST primary frequency

standard which is 5 X 10

References—Broadcast and

Measurement Services

An Introduction to Frequency Calibration: Part I, M. A. Lombardi, Cal. Lab. Int. J. Metrology, pp. 17-28

(Jan.-Feb. 1996).

An Introduction to Frequency Calibration: Part II, M. A. Lombardi, Cal. Lab. Int. J. Metrology, pp. 28-34

(Mar.-Apr. 1996).

NIST Time and Frequency Services, R. Beehler and M. A. Lombardi,

Natl. Inst. Stand. Technol., Spec.

Publ. 432 (1991).

Accuracy of International Time and

Frequency via Global Positioning

System Satellites in Common View,

D. W. Allan, M. A. Weiss, D. D.

Davis, and A. V. Clements, IEEE

Trans. I & M, IM-34, 1 18 (June

1985).

196
77100C-77140S

B. Characterization of Oscillators

Technical Contacts:

Fred L. Walls

1fel:303/497-3207 Email:fred.walls@

nistgov

James E. Gray

Ttl: 303/497-3209

Einail:jaine$.gray@ nistgov

Paula Hewitt

Administration and Logistics 1tl:303/487-37S3 Email:paula.hewitt@nist.gov

Mailing Address: M.C. 847,

National Insitute of Standards and Technology,

325 Broadway,

Boulder, CO 80303-3328

Service ID No. Items 77100C Oscillator Frequency Calibration 771 IOC Characterization of Atomic Frequency Standards 77 1 20C Characterization of Oscillators: Time Domain

77130C Characterization of Oscillators and Amplifiers: Phase

Noise in the Frequency Domain

77 13 IC Characterization of Oscillators and Amplifiers:

Amplitude Noise in the Frequency Domain

77 1 35C Tests of RF PM/AM Noise Measurement Systems: On-Site Tests 77 1 36C Tests of Microwave PM/AM Noise Measurement

Systems: On-Site Tfests 77140S Special Time/Frequency Measurements:

Oscillators and Other Components

Oscillator Frequency

Calibration (77100C)

Oscillators with an output frequency of

1 MHz to 50 GHz can be sent to NIST

for calibration. The relative standard uncertainty* is nominally that of the NIST

frequency standard, which is 5 X 10"'^ but is limited by noise in the oscillator under test. The frequency stability of the

oscillator can also limit the calibration,

since oscillators often change frequency

during shipment. Higher frequencies

(50 GHz to 1 10 GHz) are covered under

Service ID Number 77140S.

Characterization of Atomic Frequency

Standards (77 HOC)

An atomic standard is characterized by

introducing it as a member of the NIST

time scale system. The output of the stan- dard is sampled every 2 h in sequence

with the other clocks in the time scale, and the performance of the standard under test is readily determined. The

standard test involves 30 d of measurements. The square root of the Allan variance cry(T) is measured to 3 X 10"'^ for averaging times of 7200 s to 10^ s. The relative standard uncertainty* of the time scale is 5 X 10"'^ and

the fractional frequency drift is less than 2 X 10"" per day. The actual values

transferable to the standard are often limited by the oscillator's stability and noise

properties.

Characterization of Oscillators: Time

Domain (77120C)

For oscillator frequencies of 5 MHz,

10 MHz, and 100 MHz, the stability in terms of the square root of the Allan

deviation o-yir) is determined by repeated measurements at 0.5 s intervals. cTyiT)

is determined to 4 X 10"'^/t""^ for aver- aging times of 0.5 s to 10 000 s and fre- quency offset is measured with a relative standard uncertainty* of 5 X10~'^ limited by the noise level and type in the

oscillator under test. The frequency measurement transferable to the oscillator is often limited by the oscillator's stability

due to transport between laboratories and

on-off cycling. Measurements of Allan

deviation from approximately 1 jjls to 0.5 s can be determined by integration of

the oscillator phase noise. This inversion of the data is performed by NIST. Thus, measurements in this range should be

done under Service ID Numbers 77 DOC

or 77140S. Characterization of time

domain stability at other frequencies is covered under Service ID Number

77140S.

* See Chapter 1 , Section H for more information about uncertainty.

197
Characterization of Oscillators and

Amplifiers: Phase Noise in the

Frequency Domain (77130C)

For frequencies of 5 MHz to 26 GHz,

phase modulation (PM) noise 5^(/) of

single oscillators and amplifiers can be

determined for Fourier frequency offsets from the carrier of 0.1 Hz to 10 MHz.

The PM noise is measured for only a few

user-specified frequency offsets (typically 3 points per decade). All measure- ments of phase noise are made relative to

1 radVHz. At a carrier frequency of

5 MHz, S^(f) can be measured to - 1 45 dB for a frequency offset of 1 Hz

and - 190 dB for an offset of 10 kHz. At

a carrier frequency of 100 MHz, 5<^(/) can be measured to - 150 dB for a fre- quency offset of 1 Hz and - 190 dB for an offset of 50 kHz. A typical value of

standard uncertainty* is 1 dB, out

specific values depend on the carrier fre- quency and the offset frequency. Specific

measurement requirements should be dis- cussed prior to placing an order. PM

noise for frequencies above this range

(but less than 1 10 GHz) are covered

under Service ID Number 77140S.

Characterization of Oscillators and

Amplifiers: Amplitude Noise in the

Frequency Domain (77131C)

For frequencies from 1 MHz to 26 GHz,

amplitude modulation (AM) noise 5^ (f) of single oscillators and amplifiers can be

determined for Fourier frequency offsets from the carrier of 0.1 Hz to 10 MHz.

The AM noise is measured for only a few

user specified frequency offsets (typically 3 points per decade). All measure- ments of amplitude noise are made

relative to 1 Hz. At a carrier frequency of

5 MHz, Sa(f) can be measured to - 1 40 dB for a frequency offset of 1 Hz,

and - 180 dB for an offset of 10 kHz. At

a carrier frequency of 100 MHz, Sa(f) can be measured to - 1 30 dB for a frequency offset of 1 Hz and - 1 80 dB

for an offset of 50 kHz. A typical value of standard uncertainty* is 1 dB, but

specific values depend on the carrier frequency and the offset frequency.

Specific measurement requirements

* See Chapter 1, Section H, for more information about uncertainty.

should be discussed prior to placing an

order. AM noise for frequencies above

this range (but less than 1 10 GHz) are covered under Service ID Number

77140S.

Tests of RF PM/AM Noise Measurement Systems: On Site Tests (77135C)

The noise floor and performance of PM

and AM noise measurement systems can be evaluated at the customer's site using NIST's portable PM/AM noise standard for carrier frequencies of

5 MHz, 10 MHz, and 100 MHz. The

PM/AM noise standard produces two

signals with approximately 10 dB to 15 dB power (relative to 1 mW). The

residual PM noise between the two

outputs (relative to 1 rad^/Hz) is typically

less than - 190 dB for a frequency

offset from the carrier of 100 kHz for the three rf carrier frequencies. The

calibrated PM or AM noise is typically constant with Fourier frequency offset to ± 0.1 dB out to 3 % of the carrier frequency. After each calibration a cal- ibration report is issued which certifies that the specific measurement system

is traceable to NIST for PM and/or AM

measurements at the frequencies

tested. This traceability can serve as a

solid basis for meeting NVLAP

(National Voluntary Laboratory

Accreditation Program) and ISO re- quirements.

Tests of Microwave PM/AM Noise

Measurement Systems: On Site Tests (77136C)

The noise floor and performance of PM

and AM noise measurement systems can be evaluated at the customer's site using NIST's portable PM/AM noise standard for carrier frequencies of

10.6 GHz, 21.2 GHz, and 42.4 GHz.

The PM/AM noise standard produces

two signals with approximately + 10 dB power (relative to 1 mW). The

residual PM noise between the two

outputs (relative to 1 rad^Hz) is typically less than - 1 76 dB for a frequency offset from the carrier of

10 kHz and - 190 dBc/Hz for offsets of

198
77](X)C-77140S

1 MHz from the carrier frequency. The

calibrated PM or AM noise is typically constant with Fourier frequency offset to ± 0.2 dB out to 100 MHz. After each

calibration a report is issued which certifies that the specific measurement

system is traceable to NIST for PM

and/or AM measurements at the fre- quencies tested. This traceability can

serve as a solid basis for meeting

NVLAP (National Voluntary Laboratory

Accreditation Program) and ISO

requirements.

Special Time/Frequency Measurements: Oscillators and Other

Components (77140S)

Frequency and time domain measure- ments can be made at frequencies other than those cited in the above

tests up to 110 GHz, but the uncertainty and cost are dependent upon the specific user requirements. Given two

or more oscillators, synthesizers, fre- quency multiplier/dividers, or amplifiers, relative phase noise can be measured

with low uncertainty and the frequency

for the measurement is not as restrictive as above. Also, the 1 pulse per second

output of atomic frequency standards can be measured with a standard uncertainty of 0.5 ns given an adequately

defined pulse. Limited frequency and

PM/AM noise measurements can be

made from 75 GHz to 110 GHz.

Please call to discuss your requirements.

References—Characterization of

Oscillators

Secondary Standard for PM and AM

Noise at 5, 10, and 100 MHz, F. L. Walls, IEEE Trans. I&M 42, 126

(Apr. 1993).

Introduction to the Time Domain Characterization of Frequency Standards,

J. Jesperson, Proc. 25th Annu. Precise Time and Time Interval (PTTI)

Meeting, Pasadena, CA, 83-102 (Dec.

1991).

An Introduction to Frequency Standards,

L. Lewis, Proc. IEEE 79 (7), 927-935 (July 1991).

Properties of Signal Sources and Measurement Methods, D. A. Howe, D. W.

Allan, and J. A. Barnes, in Characterization of Clocks and Oscillators,

edited by D. B. Sullivan, D. W.

Allan, D. A. Howe, and F. L. Walls,

Natl. Inst. Stand. Technol. Tech. Note 1337, 14-16 (1990).

Characterization of Clocks and Oscillators, D. B. Sullivan, D. W. Allan, D. A. Howe, and F. L. Walls, eds., NIST Tech. Note 1337 (Mar. 1990).

Frequency and Time—Their Measure- ment and Characterization, S. R. Stein,

Precision Frequency Control, Vol. 2, edited by E. A. Gerber and A. Ballato (Academic Press, NY), 191-232

(1985).

199

ALPHABETICAL CROSS-INDEX

Item Service ID

Number or Other Reference

Absolute pressure transducers 30010C-3001 IC

Accelerometers 24010C-24060S

Ac-dc thermal converters (to IMHz) 53350C-53352C

Ac-dc thermal converters (100 Hz to 1 GHz) 53405S-53445S

Ac-dc watthour or varhour meters 561 10S-56210M

Ac voltage, high accuracy 53200S-53203S

Acoustic devices 25060S

Acoustic emission transducers and sensors 26200C

Acoustic measurements 25010C-25070S

Activation detector dosimetry 44070C-44090C

AID or D/A data converters 53500S-53540S

Air navigation aids 55210S-55230S

Air-speed indicators 19010C-19040S

Alpha-particle-emitting solid sources 43030C-43050C

Aluminum ultrasound reference blocks 26030S,26050S,

26070S

American Petroleum Institute gages 120 IOC

Analog-to-digital data converters 53500S

Anechoic chambers 25010C-25070S

Anemometers 19010C-19040S

Angle gage blocks 140 IOC

Angular measurements 14010C-14O50S

Antenna parameter measurements, microwave 63100S-634O0S

Attenuators, rf and microwave 61210S-61250S

Audio-frequency phase meter 55120C-55141C

Audiometers 25070S

Ball plates 11050S

Balls 11030S

Barometers 29035C,30010C30011C

Beckman thermometers 311 SOS

Bellprovers 180 IOC

Beta particle applications 47030C-47040S

Beta-particle emitting sources 43060S,43070S

47030C-47040S

Bolometer units, rf and microwave 611 lOS-61 138C

Calorimeter, coaxial and waveguide 611 lOS-61 155S

Calorimeter thermometers 311 70S

Capacitance and inductance measurements, high frequency 52210S-52310S

Capacitance and inductance measurements, low frequency 521 10S-52181C

Capacitive voltage dividers 54310S-5431 IS

201
Capacitors, dielectric 52130C

Capacitors, high frequency 52210S-52221S

Capacitors, low frequency 52110S-52171C

Capacitors, power frequency 524(X)C

Coaxial air line standards 61 51 OS

Coaxial attenuators 61210S-61211C

Coaxial terminations and reflection coefficients 61 3 IOC

Coaxial thermistor mounts 611 lOS-61 138C

Color temperature 37010C-37050S

Complex dimensional standards 12010C-12040S

Converters, A/D and D/A 53500S-53540S

Coordinate measuring machines 1 1050S,12040S,

15010C-15040C

-software algorithms 10070S-10081S - socketed ball bars SRMs (p. 2) - probe performance spheres SRMs (p. 2)

Cryogenic flow measurements 18800S

Current and voltage transformers 54510C-54600S

Data converters, A/D and D/A 53500S

Dc resistance measurements 51 lOOS-51 163C

Dc voltage measurements 531 10S-53190S

Deadweight piston gages 29010C

Deadweight tester, ball type 30025C

Density measurements, liquids 17040S

Detector standards, windowed photodiode 40560C-40561C

Detector standards, windowless photodiode 40510C—40540C

Detectors, IR 39080S

Detectors, near ultraviolet to soft x-ray region 40599S

Detectors, radiometric 39080S

Detectors, spectroradiometric 39071S-39090S

Detectors, used with lasers 421 10C-42180S

Deuterium arc lamps 4O030C

Deuterium lamps 39050C

Dew-point hygrometers 360 1 0C-36020C

Diameter measurements 1 lOlOS-1 1060S

Dielectric and magnetic materials 61620S

Differentia] pressure transducers 30020C-30021C

Digital multimeters, low frequency 53200S-53203S

Digital-to-analog data converters 53500S

Dimensional metrology 10010C-14050S

Dividers, capacitive 54310S-54311S

Dividers, inductive 541 10S-54131C

Dividers, mixed 54410S

Dividers, resistive 54210C-54214S

Dosimeters, electron beam 48010M-48020S

Dosimeters, high dose 49010C-49050S

Dosimeters, neutron 441 OOS

Dosimeters, radiochromic 49010C-49030C

202
Dosimeters, spectrophotometric reading 49040S-49041S

Dosimeters, x-ray, gamma-ray, and electron 46010C-48020S

Dosimetry, neutron 44010C-44100S

Earphones 25070S

Electromagnetic field-strength parameter measurements 641005-643005

Electrometers 460305

Electron beam dosimetry 48010M-48020S

End standards 100505

Energy and power measurements, low frequency 561 1 05-562 lOM

Ferrous-ferric dosimeters 48010M-48011M

Fiber optic power meters 42130C-421805

Field strength measurements, electromagnetic 641005-643005

Filament lamps, ribbon 35050C, 35060C,

39010C-39030C

Filters, spectral transmittance 38010C-3804OC

Fixed-point devices, thermometric 333605

Flashing-light photometers 371105

Flats, optical reference 130105

Flow measurements, cryogenic 188005

Flowrate meters, liquid and gas 180 IOC- 180505

Fluorescent lamps 370605

Flux, luminous 370605

Force transducers 23010C-232605

Frequency and time measurement services 761005-761105

Frequency domain 77131C

Gage blocks 100 IOC

Gages, API 120 IOC

Gages, ionization 30034C-30038C

Gages, low pressure 300405

Gages, molecular drag 30029C-3003 1

C

Gages, piston 29010C-29020C

Gages, plug 110105

Gages, plug and ring 1 20205

Gages, pressure 29010C-290405

Gages, ring 110405

Gages, step 110605

Gages, two dimensional 1 20305

Gages, vacuum 30O10C-30O505

Gamma-ray dosimeters 46010C-46021C

Gamma-ray emitting sources 43010C-43020C,

47010C-47011C

Gas flowmeters 180 IOC, 180505

Gear measuring wires 11 020C

Germanium resistance thermometers 33140C

Global time service 761 105

Grid plates 110505

Helium permeation leaks 300605-300625

High dose dosimetry 49010C-490505

203
High-frequency standard capacitors and inductors 52210S-52310S

High-frequency standard resistors 51310S

High-vacuum gages 30029C-30038C

High-voltage resistors 51210C

Humidity measurements 36010C-36070S

Hydrometers 160 IOC

Hygrometers 36010C-36070S

Illuminance meters 37090S

Impedance measurements 5211 OS

Impulse generator spectrum amplitude 65100S

Impulse response of coaxial networks 65300S

Incandescent lamps 37060S

Indexing tables 14O30S

Inductance and capacitance measurements, low frequency 521 10S-52181C

Inductance and capacitance measurements, high frequency 52210S-52310S

Inductive voltage dividers 541 10S-54131C

Industrial grade thermometers 31010C-31 180S

Intensity, luminous 37010C-37020S

Interferometry 100 IOC

Internal diameter standards 1 1040S

Ionization chambers 47036C

Ionization gages 30034C-30038C

Irradiance sources 39040C-39050C,

4001 OC, 40030C

Kerr cells 54410S

Laboratory thermometers 31010C-31 180S

Lamps, deuterium arc 39050C, 40030C

Lamps, incandescent 37060S

Lamps, quartz halogen 39040C-39045C

Lamps, ribbon filament 35050C-35060C,

39010C-39030C

Laser frequency/wavelength 1451 OS

Laser power and energy measurements 421 10C-42180S

Leak artifacts 30060S-30062S

Length and diameter 1 1050S

Length measurements 10010C-10060S

Length standards 10050S

Line standards 10020C

Liquid flow meters 18010C-18050S

Liquid-in-glass thermometers 31010C-31 180S

Load cells 23010C-23260S

Luminous flux 37060S

Luminous intensity 37010C-37020S

Luminous intensity of retroreflectors 38070M

Mammography x-ray measuring instruments 46010C-46050S

Manometers 29035C

Mass measurements 22010C-22180M

204
MEASUREMENT ASSURANCE PROGRAMS

Dc resistance 5111 OM

Dc voltage 53120M

Dose interpretation of ferrous-ferric dosimeters 48010M-4801 IM

Laser power and energy 42120M, 42140M

42150M

Mass 22180M

Platinum resistance thermometry 33370M-33380M

Retroreflectors, luminous intensity 38070M-38074M

Transmittance, spectral 38080M

Watthour meters 562 lOM

Mercury-in-glass thermometer 31010C-31 180S

Meteorological airspeed instrumentation 19030S

Meters, flow rate 18030C

Meters, laser power and energy 421 IOC, 421 70S

Meters, optical fiber power 421 30C, 42140M,

421 SOS

Meters, phase 551 10S-55141C

Meters, turbine 1801 OC- 1 8020C

Microphones, pressure and free-field response 25010C-25050C

Micropotentiometers, low voltage 5320 IS

Micropotentiometers, rf 53440S-53445S

Microwave antenna parameter measurements 63100S-63400S

Mixed voltage dividers 54410S

Molecular drag gages 30029C-30031C

Neutron dosimeters 441 OOS

Neutron sources 440 1 0C-44020C

Noise temperature measurements, coaxial and waveguide 61410S-61495S

Non-Mercurial barometers and manometers 29035C

Oil gaging and surveying tapes 10030C

Opal glass transmittance standard 37070C

Optical fiber power meters 42130C, 42140M,

421 80S

Optical flats 1301 OS

Optical polygons 14020S

Optical pyrometers 35010C-35040C

Optical reference planes 13010S

Oscillator characterization 77100C-77140S

Penetrameters, x-ray 46040S

Personnel protection instrumentation 44060C

Phase measurements 551 10S-55141C

Phase shifters, rf and microwave 61295S-61297S

Photodiode spectral response 39070C

Photodiodes, windowed and windowless 40510C-40560C

Photographic step tablets See SRMs (p. 2)

Photometers 37090S

Photometric tests 37100S

Photometry 37010C-371 lOS

205
Pickup sensitivity 24010C-24030C,

24050S

Piston gages, controlled clearance 29020C

Piston gages, dead weight 290 IOC

Pitot-static tubes 190 IOC

Platinum resistance thermometers 33010C-33310C

Plug and ring gages 12010C-12020S

Plug gages 11 01 OS

Pneumatic bridge hygrometers 36060C

Polygons, optical 14020S

Power and energy measurements, low frequency 561 10S-56210M

Power meters, optical fiber 42130C-42140M

421 SOS

Power meters, thermoelectric 61 1 lOS-61 155S

Pressure gages and transducers 29030C

Pressure gages, low absolute 30010C-3001 IC

Pressure gages, low differential 30020C-30021C

Pressure gages, special tests 2904OS

Pressure measurements 29010C-29040S,

30010C-30062C

Proving rings 23010C-23260S

Pulse voltage measuring systems 5441 OS

Pulse waveform measurements 65100S-65400S

Pyrometer indicators 32100C

Pyrometers, optical 35010C-35O4OC

Pyrometers, radiation 35070S

Q-standards 52710C-5271 IC

Quartz halogen lamps 39040C-39045C

Radiance standard sources 39010C-39030C,

40020C

Radiance temperature measurements 35010C-35070S

Radiant energy detectors 39070C

Radiation detectors 46010C-4601 IC

Radiation pyrometers 35070S

Radiation thermometry 35010C-35070S

Radioactive sources, alpha emitting 43030C-43050C,

43090S

Radioactive sources, beta emitting 43060S-43070S

Radioactive sources, gamma emitting 43010C-43020C

Radioactive sources, neutron emitting 44010C-44020C

Radiochrometric dosimeters 49020C-49030C

Radiometric detectors 39080S

Radiometric measurements 39010C-39060S,

40010C-40040S,

40510C-40599S

Radiometric sources 39060S

Radionuclides 43010C-43090S

Reference block measurements, ultrasonic 26030S-26070S

206
Reflection coefficients, coax and waveguide terminals 61310S-61350S

Resistance measurements, dc 51 1(X)S-51 163C

Resistance thermometers 33010C-33310C

Resistive voltage dividers 54210C-54214S

Resistors, high frequency 51310S

Resistors, high-precision standard, dc 51 130C-51 154C

Resistors, high voltage 51210C

Resistors, megohm 51 142C-51 154C

Resistors for current measurements 51 160C-51 163C

Retroreflectors, coefficient of luminous intensity 38070M-38074M

Ribbon filament lamps 35050C-35060C

Ring gages 11040S

R-meters 460 1 OC-460 1 1

C

Rods, surveying leveling 10040S

Rotary and indexing tables 1 4030S

Roughness calibration standards 15010C-15020C

Roundness measurements 13020S-13030S

Saturated standards cells 53130C-53131C

Shock measurements 24040S

Sieves, special tests 10060S,

also SRMs (p. 2)

Spectral irradiance 3904OC-39050C,

400 IOC, 40030C

Spectral irradiance, lamps 39040C-39050C

Spectral radiance 39010C-39030C,

40020C

Spectral radiance, lamps 39010C-39030C

Spectral response, laser 42164S

Spectral response, photodiode 3908 IS

Spectral transmittance filters 38010C-3804OC

Spectrophotometric measurements 38010C-38080M,

also SRMs (p. 2) Spectroradiometric detectors 39071S-39090S

Spectroradiometric sources 39010C-39060S

Spherical diameter standards, balls 1 1030S

Stage micrometer 10020C

Standard voltage cells 53130C-53150C

Steel ultrasound reference blocks 26040S, 26060S,

26070S

Step gages, length 11060S

Step height measurements, surface 15030C

Step tablet density, photographic See SRMs (p. 2) Sucker rods 120 IOC

Surface roughness standards 15020C,

also SRMs (p. 2) Surveying and oil gaging tapes 10030C

Surveying leveling rods 10040S

Tapes 10030C

207
Thermal voltage and current converters (100 Hz-1 GHz) 53405S-53445S

Thermal voltage converters (to 1 MHz) 53350C-53352C

Thermistor mounts 611 lOS-61 155S

Thermocouples and thermocouple materials 32010C-32150S

Thermometers, Beckmaim 31180S

Thermometers, calorimetric type 31170S

Thermometers, cryogenic type 33140C-33141C

Thermometers, germanium resistance 33140C-33141C

Thermometers, laboratory 31010C-31260S

Thermometers, platinum resistance 33010C-33310C

Thermometers, rhodium-iron resistance 33140C-33141C

Thermometric fixed-point devices 33360S,

also SRMs (p. 2)

Thermometry, radiation 35010C-35070S

Thread measuring wires 11020C

Threaded plug and ring gages 12020S

Time and frequency measurement services 76100S-761 lOS

Time domain 77120C

Titanium ultrasound reference blocks 26040S, 26060S,

26070S

Transducer measurements, acoustic emission 26200C

Transducer measurements, ultrasonic 26100C

Transducers, low pressure 30010C-30021C

Transformers, voltage and current 54510C-54600S

Transmittance, Measurement Assurance Program 38080M

Transmittance filters, spectral 38010C-38040C

Transmitting diffusers 37080S

Turbine flow meters 18010C-18020C

Two-dimensional gages 1 2030S

Ultrasonic reference block measurements 26030S-26070S

Ultrasonic system power, calorimetric 26100C

Ultrasonic transducer measurements 26100C

Ultrasonic transducer power, radiation pressure 26100C

Ultraviolet detectors 40510C-40599S

Ultraviolet sources 40010C-40040S

Unsaturated standard cells 53150C

Vacuum gages 30029C-30038C,

30050S

Vacuum measurements 30010C-30050S

Vacuum ultraviolet radiometric measurements 40010C-40040S

Var, varhour meters 56200C-56202C

Very-high-frequency omnidirectional measurements 55210C-55230S

Vibration and shock measurements 24010C-24060S

Voltage, ac 53201

S

Voltage, dc 531 10S-53190S

Voltage, rf dc 53405S-53445S

Voltage and current transformers 54510C-54600S

Voltage dividers, capacitive 54310S-5431 IS

208
Voltage dividers, inductive 541 10S-54131C

Voltage dividers, mixed 5441 OS

Voltage dividers, resistive 54210C-54214S

Voltage reference standards, solid state 53160C-53161C

Voltmeters, high accuracy, ac 53200S

Volume standards 17010C-17020S

VOR measurements 551 1 OS

Watt, watthour meters 561 10S-56210M

Wattmeters, high power 61 1 60S, 61 1 90S

Waveform measurements, pulse 65100S-65400S

Waveguide attenuators 61230S

Waveguide terminations and reflection coefficients 61320S-61350S

Waveguide thermistor mounts 61 144S-61 155S

Wavelength standards 38050C

Wedges 14040S

Weights (mass standards) 22010C-22180M

Wires for thread and gear measurements 1 1020C

X-ray and photographic step tablets See SRMs (p. 2) X-ray dosimeters 46010C-46050S

X-ray penetrameters 46040S

X-ray step tablets See SRMs (p. 2)

209 « U. S. GOVERNMENT PRINTING OFFICE: 1 998-433-23S/B2675

III[HSUII[m[flT S[IIVIC[S

Traceabilily and Accuracy

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