Traceability and Quality Control in a Radiation Thermometry

Laboratory

Frank Liebmann – Tom Kolat

NCSLi 2011

2

Outline

Traceability and Quality Control in a Radiation Thermometry Laboratory• Introduction• Traceability

– Traceability Scheme– Uncertainty Budgets

• Quality Control - Blackbody Sources– Cross-Checks – Verification– Cavity Uniformity– Hot Gas Purge

• Quality Control – Transfer Standard Calibrations– Size-of-Source Effect– Alignment– Long Term Stability History– Transfer Standard Warm-up Time

• Quality Control – Flat-Plate Calibrations– Calibrations below Ambient– Calibration Quality Control Steps

• Conclusion

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

3

Outline

Traceability and Quality Control in a Radiation Thermometry Laboratory• Introduction• Traceability

– Traceability Scheme– Uncertainty Budgets

• Quality Control - Blackbody Sources– Cross-Checks – Verification– Cavity Uniformity– Hot Gas Purge

• Quality Control – Transfer Standard Calibrations– Size-of-Source Effect– Alignment– Long Term Stability History– Transfer Standard Warm-up Time

• Quality Control – Flat-Plate Calibrations– Calibrations below Ambient– Calibration Quality Control Steps

• Conclusion

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

4

Introduction

• Fluke Calibration in American Fork, Utah– (formerly known as Hart Scientific)

• 2005: Work began to establish a radiometric calibration program– Flat-plate radiation sources (IR calibrators)– Transfer standard calibration– Blackbody Cavities

• Steps taken for quality control

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

5

Learning Objectives

• Steps taken to assure quality in any calibration program– especially one involving radiation thermometry

• Foster ideas on how to apply these ideas to a calibration laboratory

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

6

Outline

Traceability and Quality Control in a Radiation Thermometry Laboratory• Introduction• Traceability

– Traceability Scheme– Uncertainty Budgets

• Quality Control - Blackbody Sources– Cross-Checks – Verification– Cavity Uniformity– Hot Gas Purge

• Quality Control Measures – Transfer Standard Calibrations– Size-of-Source Effect– Alignment– Long Term Stability History– Transfer Standard Warm-up Time

• Quality Control Measures – Flat-Plate Calibrations– Calibrations below Ambient– Calibration Quality Control Steps

• Conclusion

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

7

Traceability

• Flat-plate sources calibrated radiometrically– RT transfer standard: KT19II.82

• KT19 calibrated in liquid bath blackbodies– Blackbody ε > 0.999– Modeled in STEEP3– Blackbody Z-axis temperature uniformity profiled

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

8

Traceability

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

9

Traceability

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

10

Traceability Scheme

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

11

Uncertainty Budget

• 4 Uncertainty Budgets– 4180, 4181 Calibrations (2 flat-plate models)– KT19 (Radiometric transfer standard)– TRT (cross check with NMI)

• Original UCB followed traditional contact UCB• 2008: BIPM CCT-WG5

– Uncertainty Budgets for Calibration of Radiation Thermometers below the Silver Point

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

12

Uncertainty Budget

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

KT19 Uncertainties

Provisional

Uncertainties Denot. Type -15 0 50 100 200 350 500

Blackbody

Calibration temperature U1 A 0.013 0.010 0.013 0.013 0.013 0.019 0.029

Blackbody emissivity, isothermal U4 B 0.100 0.100 0.100 0.100 0.100 0.143 0.205

Blackbody emissivity, non-isothermal U5 B 0.002 0.001 0.002 0.006 0.014 0.030 0.046

Reflected ambient radiation U6 B 0.052 0.044 0.028 0.021 0.015 0.011 0.010

Cavity bottom heat exchange U7 B 0.001 0.001 0.001 0.002 0.009 0.029 0.071

Convection U8 A 0.006 0.004 0.004 0.012 0.027 0.050 0.073

Cavity bottom uniformity U9 A 0.042 0.022 0.013 0.016 0.018 0.020 0.033

Ambient conditions U10 B 0.020 0.018 0.014 0.006 0.006 0.010 0.010

Radiation Thermometer

Size-of-source effect U11 B 0.025 0.018 0.009 0.005 0.002 0.002 0.002

Non-linearity U12 B 0.020 0.022 0.030 0.040 0.061 0.099 0.141

Reference temperature U13 B 0.006 0.005 0.002 0.002 0.007 0.017 0.026

Ambient temperature U14 A 0.044 0.038 0.015 0.015 0.054 0.123 0.192

Atmospheric absorption U15 B 0.010 0.011 0.015 0.020 0.031 0.049 0.071

Gain ratios U16 B 0.001 0.001 0.002 0.002 0.003 0.005 0.007

Noise U17 A 0.005 0.004 0.003 0.002 0.002 0.003 0.004

Combined standard uncertainty uc k=1 0.068 0.062 0.057 0.058 0.070 0.115 0.173

Combined expanded uncertainty (k=2) U k=2 0.135 0.124 0.113 0.115 0.139 0.231 0.345

Uncertainty (°C)

13

Outline

Traceability and Quality Control in a Radiation Thermometry Laboratory• Introduction• Traceability

– Traceability Scheme– Uncertainty Budgets

• Quality Control - Blackbody Sources– Cross-Checks – Verification– Cavity Uniformity– Hot Gas Purge

• Quality Control – Transfer Standard Calibrations– Size-of-Source Effect– Alignment– Long Term Stability History– Transfer Standard Warm-up Time

• Quality Control – Flat-Plate Calibrations– Calibrations below Ambient– Calibration Quality Control Steps

• Conclusion

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

14

Quality Control - Blackbody Sources

• Cross check with a national laboratory• Determination of cavity bottom uniformity• Use of a hot-gas purge

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

15

Cross-Checks – Verification

BlackbodyNominal

Temperature(°C)

Temperature Difference

(K)

NISTUncertainty

(K)

AMFUncertainty

(K)

NormalEquivalence

LT -15 0.074 0.34 0.128 0.20LT 0 0.014 0.3 0.133 0.04LT 50 -0.051 0.12 0.170 -0.25LT 100 -0.125 0.11 0.218 -0.51MT 100 -0.058 0.11 0.218 -0.24MT 200 -0.155 0.12 0.335 -0.44HT 200 -0.114 0.12 0.335 -0.32HT 300 -0.144 0.13 0.226 -0.55HT 350 -0.222 0.13 0.260 -0.76HT 420 -0.253 0.14 0.317 -0.73HT 500 -0.320 0.16 0.392 -0.76

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

16

Cavity Uniformity

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

17

Hot Gas Purge

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

18

Outline

Traceability and Quality Control in a Radiation Thermometry Laboratory• Introduction• Traceability

– Traceability Scheme– Uncertainty Budgets

• Quality Control - Blackbody Sources– Cross-Checks – Verification– Cavity Uniformity– Hot Gas Purge

• Quality Control – Transfer Standard Calibrations– Size-of-Source Effect– Alignment– Long Term Stability History– Transfer Standard Warm-up Time

• Quality Control – Flat-Plate Calibrations– Calibrations below Ambient– Calibration Quality Control Steps

• Conclusion

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

19

Quality Control – Transfer Standard

• Size-of-Source Effect• Alignment• Long Term Stability History• Transfer Standard Warm-up Time

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

20

Size-of-Source Effect

• 35 mm diameter aperture used• Diameter based on testing

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

21

Alignment

• Three steps– Angular alignment (laser, aligns tripod head)– Z-axis alignment– X-Y alignment

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

22

Long Term Stability History

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

23

Transfer Standard Warm-up Time

• Time constant ~ 15 minutes

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

24

Outline

Traceability and Quality Control in a Radiation Thermometry Laboratory• Introduction• Traceability

– Traceability Scheme– Uncertainty Budgets

• Quality Control - Blackbody Sources– Cross-Checks – Verification– Cavity Uniformity– Hot Gas Purge

• Quality Control – Transfer Standard Calibrations– Size-of-Source Effect– Alignment– Long Term Stability History– Transfer Standard Warm-up Time

• Quality Control – Flat-Plate Calibrations– Calibrations below Ambient– Calibration Quality Control Steps

• Conclusion

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

25

Quality Control – Flat Plate

• Models 4180 and 4181• Reflected radiation ~ room temperature• Scatter temperature controlled• Calibration points below ambient

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

26

Calibrations below Ambient

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

27

Calibration Geometry

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

28

Particulates (Dust)

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

29

Outline

Traceability and Quality Control in a Radiation Thermometry Laboratory• Introduction• Traceability

– Traceability Scheme– Uncertainty Budgets

• Quality Control - Blackbody Sources– Cross-Checks – Verification– Cavity Uniformity– Hot Gas Purge

• Quality Control – Transfer Standard Calibrations– Size-of-Source Effect– Alignment– Long Term Stability History– Transfer Standard Warm-up Time

• Quality Control – Flat-Plate Calibrations– Calibrations below Ambient– Calibration Quality Control Steps

• Conclusion

© 2011 Fluke Calibration NCSL - Liebmann – RT QC

30

Conclusion

• Establishment of quality in radiation thermometry calibration• Blackbody cavities• Transfer standards• Flat-Plate calibrations

© 2011 Fluke Calibration NCSL - Liebmann – RT QC