Report on NIM-NMC Bilateral Comparison: SPRT Calibration. Comparison from -190 o C to 420 o C

Transcription

1 Report on NIM-NMC Bilateral Comparison: SPRT Calibration Comparison from -190 o C to 420 o C CCT-K3.2 Prepared by Sun Jianping National Institute of Metrology, China 1 Introduction Several international key comparisons in thermometry have been organized by Consultative Committee for Thermometry [1, 2], and a few laboratories participated in those comparisons because of the limitation of the participant number. From 1997 to 2001, the key comparison, CCT-KC3 piloted by NIST was carried out by a serial of laboratories in North America, Europe and Asia including National Institute of Metrology (NIM), China. In 2009, National Metrology Centre (NMC), Singapore, made an initiation to establish a bilateral comparison with NIM to link the results to the CCT-KC3 and facilitate the NMC CMC submission. This comparison got agreement by NIM and APMP in 2009, and registered in KCDB in 2010 as CCT-K3.2. It involved six fixed points including the triple point of argon, the triple point of mercury, the triple point of water, the melting point of gallium, the freezing point of tin and the freezing point of zinc. 2 Participants China Sun Jianping, Zhang Jintao Singapore Ye Shaochun, Kho Hao Yuan, Wang Li National Institute of Metrology(NIM) National Metrology Centre(NMC) No.18, Bei San Huan Dong Lu 1 Science Park Drive, Beijing Singapore China Phone: Phone: Fax : Fax : sunjp@nim.ac.cn ye_shaochun@nmc.a-star.edu.sg

2 3 Artifacts NMC supplied two traveling SPRTs, the details are shown in Table 1. Table 1. Information list of the SPRTs Serial number Model Manufacturer Length of Sensor Temperature range SA Tinsley 50mm 0 o C to 420 o C Hart Scientific 40mm -190 o C to 0 o C 4 Protocols and technical instructions The two SPRTs will be firstly calibrated by NMC using the ITS-90 fixed points prior to sending them to NIM, and the results will be sent to the independent party. After that, the two SPRTs will be calibrated at NIM using the NIM ITS-90 fixed points, and the results will be sent to the independent party. After the completion of the measurements at NIM, the SPRTs will be returned to NMC and the two SPRTs will be calibrated the second time to close the loop. The results will be sent to the independent party. Through discussion, the agreement was obtained on the APMP-TCT former Chairman, Dr Juntaro Ishii as the independent party. NMC measurements (Pre-submission of artifacts to NIM): 1) The two 25 Ω quartz sheath SPRTs chosen by NMC must meet the ITS-90 purity requirements. 2) Prior to the fixed-point cell measurements, the SPRTs will be stabilized by annealing at a temperature of 480 C. The stability criteria value for an SPRT is calculated from the difference between the R ( K), 0 ma values measured before and after anneal. The stability values obtained must be better than 0.3 mk to qualify the SPRTs for the NMC measurements. The triple point of water (TPW) should be measured after every annealing cycle and documented in the Excel data file listed in Appendix A. 3) After annealing and stabilizing the SPRTs, the measurement sequence to be followed is SPRT 1 : TPW, Zn FP, TPW, Sn FP, TPW, Ga MP, and TPW.

3 SPRT 2 : TPW, Ar TP, TPW, Hg TP, and TPW. All results must be reported for 0 ma. 4) Measurement results (Appendix A) are to be submitted electronically to the independent party at the time of delivery of the artifacts to NIM. In addition to Appendix A, Appendix B, Appendix C (Fixed-point cell uncertainties) and Appendix D are to be submitted electronically as well. 5) On completion of the first set of measurements, NMC will send the artifacts to NIM. NIM measurements: 1) Upon receipt of the SPRTs, NIM will inspect the artifacts for damage. If there is damage, NIM and NMC will discuss and agree on how to proceed. 2) If no damage has been sustained, the SPRTs will be measured at the TPW upon receipt. The as received [R ( K), 0 ma] values will be reported to NMC prior to annealing the SPRTs. Approval by both NIM and NMC is required before proceeding to the next step. 3) Prior to the fixed-point cell measurements, the SPRTs will be stabilized by annealing at a temperature of 480 C. The stability criteria value for an SPRT is calculated from the difference between the R ( K), 0 ma values measured before and after annealing. The stability values obtained must not exceed 0.3 mk to qualify the SPRTs for the NIM measurements. If an SPRT is found to be unstable, NIM will contact the NMC for a replacement. 4) After annealing and stabilizing the SPRTs, the measurement sequence to be followed is SPRT 1 : TPW, Zn FP, TPW, Sn FP, TPW, Ga MP, and TPW. SPRT 2 : TPW, Ar TP, TPW, Hg TP, and TPW. All results must be reported for 0 ma. 5) On completion of the measurements, the results will be sent to the independent party and NMC will collect the artifacts from NIM. NMC (Post-receiving of artifacts from NIM) : 1) In order to close the measurement loop, NMC will repeat the steps outlined in

4 above (Pre-submission of artifacts to NIM) section of this protocol. The measurement period is shown in table 2. After consultations, the chairman of APMP served as the independent party in this comparison. Table 2. Measurement period of this comparison between NIM and NMC Measurement Sequence Description Time Period 1 NMC completed measurements of SPRTs Before Jun, NMC delivered SPRTs to NIM On 24 Jun, NIM completed measurements of SPRTs On 11 Nov, NMC collect SPRT from NIM In Nov, NMC completed measurements of SPRTs In Dec, NMC submitted the final data report to the independent party In Feb, NIM submitted the final data report to the independent party In May, NMC submitted the final data report revised In Jan, Summary of data submission According to the comparison protocol, the measurement results for SPRT stability are shown at the triple point of water in table 3. The results show the maximum change of the resistances of two SPRT(S/N and S/N 4158) at the triple point of water is equivalent to about 0.3mK and 0.1mK respectively, and meet the requirements of the comparison protocol. Table 3. Measurement results for SPRT stability at the triple point of water SPRT. No Date Lab R / 1 ma 2 ma 0 ma ΔR hydr 10-5 / R corrected / 22/06/2010 NMC /07/2010 NIM /11/2010 NMC /11/2010 NMC /11/2010 NIM /11/2010 NMC The measurement data of SPRT at the fixed points are presented in table 4, and the measurement data of SPRT 4158 at the fixed points are presented in table 5. Here

5 the R corrected is expressed as, R R ΔR ΔR ΔR (1) corrected measured self hydr pres Where R measured is the resistance value of SPRT at the fixed points, R self, Rhydr and R pres are the resistance changes due to the self-heating of the SPRT, hydrostatic and gas pressure in the cell of fixed point respectively. Table 4. Measurement data of SPRT at the fixed points from the participants Lab Fixed Point R measured / ΔR self / ΔR hydr / ΔR pres / R corrected / W Zn TPW NMC Sn TPW Ga TPW Zn TPW NIM Sn TPW Ga TPW Zn TPW NMC Sn TPW Ga TPW

6 Table 5. Measurement data of SPRT 4158 at the fixed points from the participants Lab NMC Fixed Point R measured / ΔR self / ΔR hydr / ΔR pres / R corrected Ar TPW Hg TPW / W Ar NIM TPW Hg TPW Ar NMC TPW Hg TPW

7 6 Uncertainty of measurements The uncertainty budgets submitted by the participants are presented in Tables 6 and 7. Tables 6. Uncertainty budget submitted by NIM Uncertainty Components Unc. Contribution/mK (k = 1) Type Zn Sn Ga TPW Hg Ar Fixed point effects Hydrostatic pressure B Residual gas pressure B / / / Impurities B Isotopic composition / / / / / / Strain, crystal defects / / / / / / Static thermal effects B SPRT effects Oxidation B Strain, vacancies, contamination / / / / / / Insulation leakage / / / / / / Resistance measurement Standard resistor stability B Misc. cable effects / / / / / Bridge errors B Self-heating correction B Others Reproducibility A Choice of fixed-point value B Propagation from TPW B Total Combined Uncertainty (k = 2) In NIM s uncertainty budget, the Isotopic composition, Strain and crystal defects the fixed points are not considered, the strain, vacancies, contamination for and insulation leakage for SPRTs, the cable effects in the resistance measurement are neglected, the effect of the impurities on the fixed points was estimated on the basis of the OME method or temperature difference between the freezing point and melting point, the reproducibility was calculated from the multiple realizations of fixed points at NIM. For linking to the CCT-K3, the reference water triple point cell without the isotopic analysis in this comparison was used, and it has the neglectable difference

8 from the other cells including the cell used to participate in the CCT-K7, and the cell with the isotopic analysis in NIM. Here, the average uncertainty of isotopic composition is 0.03mK. At the present definition for the water triple point, the maximum temperature difference among the four NIM cells drops from 0.10mK to 0.02mK after application of the isotope correction [3]. Tables 7. Uncertainty budget submitted by NMC Uncertainty Components Unc. Contribution/mK (k = 1) Type Zn Sn Ga Wtp Hg Ar Fixed point effects Hydrostatic pressure B Residual gas pressure B Impurities B Isotopic composition B Strain, crystal defects Static thermal effects B SPRT effects Oxidation Strain, vacancies, contamination Insulation leakage Resistance measurement Standard resistor stability B Misc. cable effects Bridge errors B Self-heating correction B Others Propagation from TPW B Measurement scatter A Long term drift effects on TPW cell B Total Combined Uncertainty (k = 2) In NMC s uncertainty budget, for the Zn, Sn, Ga and Ar, the isotopic composition is neglected and the Strain, crystal defects are considered for the water triple point, all components for the SPRT effects is neglected, the cable effect in the resistance measurement is considered in the realization of the triple point of mercury, the long

9 term drift on the triple point of water is given. 7 Results The differences in temperature between NIM and NMC at the fixed points were calculated with the W values provided by the participants as following, T T T ( W W ) / ( dw dt) (2) NMC-NIM_New NMC NIM_New NMC NIM_New r Where, TNMC-NIM_New is the difference in temperature between NIM and NMC at the fixed point, T NMC is the temperature of realization at the fixed point in NMC, T NIM_New is the temperature of realization at the fixed point in NIM, WNMC is the average value of the resistance ratio measured at the fixed points in NMC before and after NIM, WNIM_New is the resistance ratio measured at the fixed points in NIM, W r is the reference resistance ratio. The values of dw / r dt are given in table 8. The uncertainty of TNMC-NIM_New is estimated using the uncertainties provided by the participants is estimated using the uncertainties provided by the participants at all the Table 8 Values of dw / r dt T/ K dw / r dt fixed points in this comparison, and is expressed by, U ( T ) ( U ( W ) U ( W )) / ( dw / dt) U ( T ) (3) NMC-NIM_New NMC NIM_New r drift Where, UT ( ) is caused by the drift of SPRT during the comparison. Figure 1 shows drift the resistance value R WTP of the SPRT at the triple point of water throughout the comparison. The maximum changes of the resistance value of two SPRTs at the triple

10 point of water are 0.52 mk and 0.29 mk. The Tdrift is calculated with respect to the difference between the two NMC measurements at each fixed point before and after NIM measurements divided by the combined uncertainty of the two NMC measurements if the value is less than one then no UT ( drift ) and if the value is greater than one then the difference becomes the UT ( ). Figure 2 gives the change measured drift by NMC in calibration at each fixed point, and all UT ( ) can be ignored. drift Figure 1. Resistance value of the SPRT at the triple point of water throughout the comparison

11 Figure 2. Change measured by NMC for the SPRT at each fixed point before and after NIM measurements The U( T ) and UT ( drift ) are shown in Table 9 and Figure 3. TNMC-NIM_New, NMC-NIM_New Table 9. TNMC-NIM_New and the uncertainty of TNMC-NIM_New Fixed point T NMC-NIM_New /mk U( T ) NMC-NIM_New /mk Zn Sn Ga Hg Ar

12 Figure 3. Difference between NIM and NMC at the fixed points and uncertainty 8 Link from CCT-K3.2 to CCT-K3 8.1 Stability of the NIM s fixed points Owing to their heavy workload through many years, the old temperature primary standard over range from K to K used in CCT-K3 started to show some sign of aging in NIM. In 2009, NIM developed a new primary standard with the new furnace designed for the Zn, Sn and Ga, and the new fixed points filled from the Zn to Ga, and the new apparatus for the argon triple point set up on the basis of the quasi-adiabatic method. The comparisons between the old primary standard and the new primary standard were carried out,and the difference TNew-Old is of each fixed points between the new primary standard and the old. The details of the changes at all of NIM s fixed points in this comparison are shown in Table 10.

13 Table 10. Details of the changes at all of NIM s fixed points in this comparison Details Zn Sn Ga Ar New Old New Old New Old New Old Type S S S S S S O S Purity 6N 6N 6N 6N 7N 7N 6N 6N Uncertainty/mK, k= T New-Old /mk Uncertainty/mK, k= *: S-Sealed, O-Open 8.2 Link from CCT-K3.2 to CCT-K3 The link from CCT-K3.2 to CCT-K3 via NIM is given by, T T T T (4) (NMC-ARV) NMC-NIM_New ARV-NIM_Old New-Old NIM Here, point, T (NMC-ARV)NIM TARV-NIM_Old is the difference in temperature between NMC and ARV at the fixed is the difference in temperature between ARV and NIM at the fixed point [5], TNew-Old is the difference in temperature between new and old fixed points. The uncertainty of T (NMC-ARV)NIM is expressed by, U ( T ) U ( T ) U ( T ) U ( T ) (5) (NMC-ARV) NMC-NIM_New ARV-NIM_Old New-Old NIM The Difference of CCT-K3.2 to CCT-K3 via NIM result and their uncertainty are shown in Table 11 and Figure 4. Table 11 Difference of CCT-K3.2 to CCT-K3 via NIM results and uncertainties (k=2) Fixed point T ARV-NIM_Old /mk U( T ) ARV-NIM_Old /mk T (NMC-ARV)NIM /mk U( T ) (NMC-ARV) NIM /mk Zn Sn Ga Hg Ar

14 Figure 4. Difference of CCT-K3.2 to CCT-K3 via NIM results and uncertainties (k=2) APPENDIX A: SPRT Calibration results APPENDIX B: Testing of SPRT stability APPENDIX C: Measurement Uncertainty APPENDIX D: Instrumentation APPENDIX E: Immersion curves and plateaus of all fixed points APPENDIX F: Bilateral equivalence between CCT-K3.2 and CCT-K3

15 References [1] Mangum B.W., Strouse G.F., Guthrie W.F., Pello R., Stock M., Renaot E., Hermier Y., Bonnier G., Marcarino P., Gam K.S., Kang K.H., Kim Y.-G., Nicholas J.V., White D.R., Dransfield T.D., Duan Y., Qu Y., Connolly J., Rusby R.L., Gray J., Sutton G.J.M, Head D.I., Hill K.D., Steele A., Nara K., Tegeler E., Noatsch U., Heyer D., Fellmuth B., Thiele-Krivoj B., Duris S., Pokhodun A.I., Moiseeva N.P., Ivanova A.G., de Groot M.J., Dubbeldam J.F., Metrologia 39:179(2002). [2] Nubbemeyer H.G., Fischer J., Metrologia 39, Tech.Suppl., (2002). [3] X. K. Yan, J. T. Zhang, Y. L. Wang, C. F. Ma, Y. N. Duan, Int. J. Thermophys. 29:104(2008). [4] [5] Minutes of the Working Group 8 of the Comité Consultatif de Thermométrie, December 2003,CCT-WG8 documents, restricted access. (

16 APPENDIX A: SPRT Calibration results Laboratory: Contact thermometry Lab, National Institute of Metrology, China Contact Person: Sun Jianping Contact Address: No.18, Bei San Huan Dong Lu, Beijing, China Manufacturer / SPRT serial no (0 o C to 420 o C): Tinsly Length of Sensor: About 470mm Manufacturer / SPRT serial no (-190 o C to 0 o C): Hart 4158 Length of Sensor: About 470mm SPRT calibration results: Fixed Point R measured Self Heating Hydrostatic Pressure R corrected ( ) ( ) ( ) ( ) ( ) Zn TPW Sn TPW Ga TPW W *: R corrected = R measured Self Heating Hydrostatic Pressure SPRT 4158 calibration results: Fixed Point R measured ( ) Self Heating ( ) Hydrostatic ( ) Pressure ( ) R corrected ( ) W Ar TPW Hg TPW *: R corrected = R measured Self Heating Hydrostatic Pressure Laboratory: NMC.. Contact Person: YE Shaochun..

17 Contact Address: 1 Science Park Drive, Singapore ye_shaochun@nmc.a-star.edu.sg... Manufacturer / SPRT serial no (0 o C to 420 o C) : Tinsley / Length of Sensor: 50mm... Manufacturer / SPRT serial no (-190 o C to 0 o C): Hart Scientific / Length of Sensor: 40mm... SPRT calibration results: Before NIM Fixed Point R measured ( ) Self Heating Hydrostatic Pressure ( ) (x10-5 ) (x10-5 ) R corrected ( ) * W Zn TPW Sn TPW Ga TPW Ar TPW Hg TPW *: R corrected = R measured Self Heating Hydrostatic Pressure After NIM Fixed Self Heating Hydrostatic Pressure R measured ( ) Point ( ) (x10-5 ) (x10-5 ) R corrected ( ) W Zn TPW Sn TPW Ga TPW Ar TPW Hg TPW *: R corrected = R measured Self Heating Hydrostatic Pressure

18 APPENDIX B: Testing of SPRT stability Laboratory: Contact thermometry Lab, National Institute of Metrology, China Contact Person: Sun Jianping Contact Address: No.18, Bei San Huan Dong Lu, Beijing, China Manufacturer / Type of Resistance Bridge (AC / DC): MI /DC 6015T Manufacturer / Reference Resistor serial no.: China /814 Manufacturer / National Reference cell of water triple point cell serial no. : China/NIM Manufacturer / SPRT serial no: Hart 4158/ Tinsly Length of Sensor: About 470mm Result sheet : Testing of SPRT 4158 stability Date Cell Measured Value ( ) 1 ma 2 ma 0 ma Hydrostatic ( ) R corrected ( ) TPW nat.ref Remarks: Meeting the requirement of the Bilateral Comparison Protocol about the SPRT stability. Result sheet : Testing of SPRT stability Date Cell Measured Value ( ) 1 ma 2 ma 0 ma Hydrostatic ( ) R corrected ( ) TPW nat.ref Remarks: Meeting the requirement of the Bilateral Comparison Protocol about the SPRT stability. Laboratory: NMC.. Contact Person: YE Shaochun.. Contact Address: 1 Science Park Drive, Singapore ye_shaochun@nmc.a-star.edu.sg... Manufacturer / Type of Resistance Bridge (AC / DC): DC M16010A. Manufacturer / Reference Resistor serial no. : Tinsley / 10 Ω

19 Manufacturer / National Reference TPW cell serial no. : Hart Scientific. Manufacturer / SPRT serial no (0 o C To 420 o C) : Tinsley / Length of Sensor: 50mm... Manufacturer / SPRT serial no (-190 o C To 0 o C): Hart Scientific / Length of Sensor: 40mm... Result sheet : Testing of SPRT (253126) stability Date Cell Measured Value ( ) 1 ma 2 ma 0 ma Hydrostatic (x10-5 ) R corrected ( ) 22/6/2010 TPW nat.ref /11/2010 TPW nat.ref Remarks : = mK Result sheet : Testing of SPRT ( ) stability Date Cell Measured Value ( ) 1 ma 2 ma 0 ma Hydrostatic (x10-5 ) R corrected ( ) 4/11/2010 TPW nat.ref /11/2010 TPW nat.ref Remarks : = mK

20 APPENDIX C: Measurement Uncertainty Laboratory: Contact thermometry Lab, National Institute of Metrology, China Contact Person: Sun Jianping Contact Address: No.18, Bei San Huan Dong Lu, Beijing, China Zn Fixed point S/N: NIM-FP-Zn Uncertainty Components Contribution/mK (k = 1) Fixed point effects Hydrostatic pressure 0.05 Residual gas pressure 0.05 Impurities 0.30 Isotopic composition / Strain, crystal defects / Static thermal effects 0.15 SPRT effects Oxidation 0.01 Strain, vacancies, contamination / Insulation leakage / Resistance measurement Standard resistor stability 0.08 Misc. cable effects / Bridge errors 0.01 Self-heating correction 0.01 Others Reproducibility of Zn fixed point 0.20 Choice of fixed-point value as derived from 0.08 Uncertainty propagated from the TPW 0.35 Total Combined Uncertainty (k = 2) 1.1

21 Sn Fixed point S/N: NIM-FP-Sn Uncertainty Components Contribution (k = 1) Fixed point effects Hydrostatic pressure 0.05 Residual gas pressure 0.05 Impurities 0.15 Isotopic composition / Strain, crystal defects / Static thermal effects 0.08 SPRT effects Oxidation 0.01 Strain, vacancies, contamination / Insulation leakage / Resistance measurement Standard resistor stability 0.06 Misc. cable effects Bridge errors 0.01 Self-heating correction 0.01 Others Reproducibility of Zn fixed point 0.2 Choice of fixed-point value as derived from 0.12 Uncertainty propagated from the TPW 0.23 Total Combined Uncertainty (k = 2) 0.8

22 Ga Fixed point S/N: MIN-MP-Ga Uncertainty Components Contribution (k = 1) Fixed point effects Hydrostatic pressure 0.05 Residual gas pressure 0.02 Impurities 0.21 Isotopic composition / Strain, crystal defects / Static thermal effects 0.06 SPRT effects Oxidation 0.01 Strain, vacancies, contamination / Insulation leakage / Resistance measurement Standard resistor stability 0.03 Misc. cable effects Bridge errors 0.01 Self-heating correction 0.01 Others Reproducibility of Zn fixed point 0.10 Choice of fixed-point value as derived from 0.05 Uncertainty propagated from the TPW 0.14 Total Combined Uncertainty (k = 2) 0.58

23 TPW Fixed point S/N : NIM Uncertainty Components Contribution (k = 1) Fixed point effects Hydrostatic pressure 0.04 Residual gas pressure / Impurities 0.02 Isotopic composition 0.03 Strain, crystal defects / Static thermal effects 0.03 SPRT effects Oxidation 0.01 Strain, vacancies, contamination / Insulation leakage / Resistance measurement Standard resistor stability 0.01 Misc. cable effects / Bridge errors 0.01 Self-heating correction 0.03 Others Reproducibility of fixed point 0.02 Total Combined Uncertainty (k = 2) 0.16

24 Hg Fixed point S/N : NIM-Hg Uncertainty Components Contribution (k = 1) Fixed point effects Hydrostatic pressure 0.04 Residual gas pressure / Impurities 0.10 Isotopic composition / Strain, crystal defects / Static thermal effects 0.08 SPRT effects Oxidation 0.01 Strain, vacancies, contamination / Insulation leakage / Resistance measurement Standard resistor stability 0.01 Misc. cable effects / Bridge errors 0.01 Self-heating correction 0.02 Others Reproducibility of Zn fixed point 0.10 Choice of fixed-point value as derived from 0.06 Uncertainty propagated from the TPW 0.08 Total Combined Uncertainty (k = 2) 0.40

25 Ar Fixed point S/N: NIM-Ar Uncertainty Components Contribution (k = 1) Fixed point effects Hydrostatic pressure 0.02 Residual gas pressure / Impurities 0.05 Isotopic composition / Strain, crystal defects / Static thermal effects 0.11 SPRT effects Oxidation 0.01 Strain, vacancies, contamination / Insulation leakage / Resistance measurement Standard resistor stability 0.01 Misc. cable effects Bridge errors 0.01 Self-heating correction 0.02 Others Reproducibility of Zn fixed point 0.1 Choice of fixed-point value as derived from 0.11 Uncertainty propagated from the TPW 0.05 Total Combined Uncertainty (k = 2) 0.40

26 Laboratory: NMC.. Contact Person: YE Shaochun.. Contact Address: 1 Science Park Drive, Singapore ye_shaochun@nmc.a-star.edu.sg... Zn Fixed point S/N : Zn Uncertainty Components Contribution (k=1) (mk) Fixed point effects Hydrostatic pressure Residual gas pressure Impurities Isotopic composition 0 Strain, crystal defects 0 Static thermal effects SPRT effects Oxidation 0 Strain, vacancies, contamination 0 Insulation leakage 0 Resistance measurement Standard resistor stability Misc. cable effects 0 Bridge errors Self-heating correction Others Propagation from TPW Measurement scatter Total Combined Uncertainty (k = 2) 2.15 Remark The above uncertainty components are based on NMC uncertainty budget table calculations.

27 Sn Fixed point S/N : Sn Uncertainty Components Contribution (k=1) (mk) Fixed point effects Hydrostatic pressure Residual gas pressure Impurities Isotopic composition 0 Strain, crystal defects 0 Static thermal effects SPRT effects Oxidation 0 Strain, vacancies, contamination 0 Insulation leakage 0 Resistance measurement Standard resistor stability Misc. cable effects 0 Bridge errors Self-heating correction Others Propagation from TPW Measurement scatter Total Combined Uncertainty (k = 2) 1.53

28 Ga Fixed point S/N : Ga Uncertainty Components Contribution (k=1) (mk) Fixed point effects Hydrostatic pressure Residual gas pressure Impurities Isotopic composition 0 Strain, crystal defects 0 Static thermal effects SPRT effects Oxidation 0 Strain, vacancies, contamination 0 Insulation leakage 0 Resistance measurement Standard resistor stability Misc. cable effects 0 Bridge errors Self-heating correction Others Propagation from TPW Measurement scatter Total Combined Uncertainty (k = 2) 0.65

29 TPW Fixed point S/N : 5901D-Q-1027 Uncertainty Components Contribution (k=1) (mk) Fixed point effects Hydrostatic pressure Residual gas pressure Impurities Isotopic composition Strain, crystal defects 0 Static thermal effects SPRT effects Oxidation 0 Strain, vacancies, contamination 0 Insulation leakage 0 Resistance measurement Standard resistor stability Misc. cable effects 0 Bridge errors Self-heating correction Others Measurement scatter Long term drift effects on TPW cell Total Combined Uncertainty (k = 2) 0.46

30 Hg Fixed point S/N : Hg 9301 Uncertainty Components Contribution (k=1) (mk) Fixed point effects Hydrostatic pressure Residual gas pressure Impurities Isotopic composition 0 Strain, crystal defects 0 Static thermal effects SPRT effects Oxidation 0 Strain, vacancies, contamination 0 Insulation leakage 0 Resistance measurement Standard resistor stability Misc. cable effects 0 Bridge errors Self-heating correction Others Propagation from TPW Measurement scatter Total Combined Uncertainty (k = 2) 0.65

31 Ar Fixed point S/N : Ar 9301 Uncertainty Components Contribution (k=1) (mk) Fixed point effects Hydrostatic pressure Residual gas pressure Impurities Isotopic composition 0 Strain, crystal defects 0 Static thermal effects SPRT effects Oxidation 0 Strain, vacancies, contamination 0 Insulation leakage 0 Resistance measurement Standard resistor stability Misc. cable effects 0 Bridge errors Self-heating correction Others Propagation from TPW Measurement scatter Total Combined Uncertainty (k = 2) 0.77

32 APPENDIX D: Instrumentation Laboratory: Contact thermometry Lab, National Institute of Metrology, China Contact Person: Sun Jianping Contact Address: No.18, Bei San Huan Dong Lu, Beijing, China Zn Fixed point cell Cell Zn Cell manufacturer / Model / Serial no. NIM, NIM-FP-Zn(2009) Open/closed? closed Pressure in cell hPa Crucible Crucible material Graphite Crucible manufacturer China Crucible length 279mm Metal sample Sample source China Sample purity % Sample weight 1.3kg Thermometer well Well material Quartz Well ID (mm) 8.0 mm Immersion depth of SPRT 170mm Furnace/Bath Manufacturer NIM Control type PID How many zones? 3-zone Furnace heater AC/DC? AC Heat pipe liner? NO ITS-90 Realisation Techniques Freeze/Melt? Freeze Method of forming solid/liquid interface freeze Heat transfering fluid? No Duration of freeze/melt >15h Cell used as FP/MP/TP? FP Induced Sn Fixed point cell Cell Cell manufacturer / Model / Serial no. Sn NIM, NIM-FP-Sn(2009)

33 Open/closed? Closed Pressure in cell hPa Crucible Crucible material Graphite Crucible manufacturer China Crucible length 279mm Metal sample Sample source China Sample purity % Sample weight 1.4kg Thermometer well Well material Quartz Well ID (mm) 8.0 mm Immersion depth of SPRT 170mm Furnace/Bath Manufacturer NIM Control type PID How many zones? 3-zone Furnace heater AC/DC? AC Heat pipe liner? NO ITS-90 Realisation Techniques Freeze/Melt? Freeze Method of forming solid/liquid interface freeze Heat transfering fluid? No Duration of freeze/melt >15h Cell used as FP/MP/TP? FP Induced Ga Fixed point cell Cell Ga Cell manufacturer / Model / Serial no. NIM, NIM-MP-Ga(2009) Open/closed? closed Pressure in cell hPa Crucible Crucible material Teflon Crucible manufacturer China Crucible length 220mm Metal sample Sample source China Sample purity % Sample weight 0.5kg

34 Thermometer well Well material Glass Well ID (mm) 8.0 mm Immersion depth of SPRT 150mm Furnace/Bath Manufacturer NIM Control type PID How many zones? 1-zone Furnace heater AC/DC? AC Heat pipe liner? No ITS-90 Realisation Techniques Freeze/Melt? Melt Method of forming solid/liquid interface Double-interface method Heat transfering fluid? No Duration of freeze/melt >70h Cell used as FP/MP/TP? MP Hg Fixed point cell Cell Hg Cell manufacturer / Model / Serial no. NIM, NIM-Hg(1996) Open/closed? Closed Pressure in cell / Crucible Crucible material Glass Crucible manufacturer China Crucible length 252mm Metal sample Sample source China Sample purity % Sample weight 1.0kg Thermometer well Well material Glass Well ID (mm) 8.0 mm Immersion depth of SPRT 190mm Furnace/Bath Manufacturer China Control type PID How many zones? 1-zone Furnace heater AC/DC? AC Heat pipe liner? No

35 ITS-90 Realisation Techniques Freeze/Melt? Melt Method of forming solid/liquid interface Melting method Heat transfering fluid? Alcohol Duration of freeze/melt >10h Cell used as FP/MP/TP? TP Ar Fixed point cell Cell Ar Cell manufacturer / Model / Serial no. NIM, NIM-Ar(2008) Open/closed? Open Pressure in cell / Crucible Crucible material Stainless steel Crucible manufacturer China Crucible length 160 mm Metal sample Sample source American Sample purity % Sample weight 300g Thermometer well Well material Stainless steel Well ID (mm) 9.0mm Immersion depth of SPRT 80mm Furnace/Bath Manufacturer NIM Control type PID How many zones? 1 Furnace heater AC/DC? AC Heat pipe liner? No ITS-90 Realisation Techniques Freeze/Melt? Melt Method of forming solid/liquid interface Quasi-Adiabatic method Heat transfering fluid? Liquid nitrogen Duration of freeze/melt >15h Cell used as FP/MP/TP? TP

36 TPW fixed point cell Cell TPW Cell manufacturer NIM, NIM-1-130(2008) Water source and purity China, % Well diameter Φ8mm Immersion depth 215mm Heat transfer liquid: water / alcohol / others Alcohol Cell maintained in: Ice bath / Water bath Alcohol bath Ice mantle: Method of preparation Cooling with liquid nitrogen Annealing time before use 7 days Bridge and Reference Resistor Bridge Manufacturer / Model / Serial no. MI/6015T/ AC/DC DC If AC, give Frequency / Bandwidth / Gain / Quad gain / Read manually or off IEEE-488 / Normal measuring current / Self-heating current / If DC, give Gain / Period of reversal 4s Reference resistor Type Standard resistance Manufacturer / Model / Serial no. China, Bz20, 814 Temperature of the ref resistor Temperature coefficient of the ref resistor α= ,β=

37 Laboratory: NMC.. Contact Person: YE Shaochun.. Contact Address: 1 Science Park Drive, Singapore ye_shaochun@nmc.a-star.edu.sg... Zn Fixed point cell Cell Zn Cell manufacturer / Model / Serial no. Hart Scientific/ 5906 / Zn Open/closed? closed Pressure in cell kpa Crucible Crucible material High purity metal /graphite, argon Crucible manufacturer Hart Scientific Crucible length Surface to bottom: 195 mm Metal sample Sample source Hart Scientific Sample purity % Sample weight Not available Thermometer well Well material Quartz Well ID (mm) 8.0 mm Immersion depth of SPRT Furnace/Bath Furnace Manufacturer Hart Scientific Control type PID Controller How many zones? 3 zones Furnace heater AC/DC? AC Heat pipe liner? No ITS-90 Realisation Techniques Freeze/Melt? Freeze Method of forming solid/liquid interface Insert rod Heat transfering fluid? Air Duration of freeze/melt At least 6 hours Cell used as FP/MP/TP? FP Sn Fixed point cell Cell Sn Cell manufacturer / Model / Serial no. Hart Scientific / 5905 / Sn Open/closed? Closed Pressure in cell kpa

38 Crucible Crucible material High purity metal /graphite, argon Crucible manufacturer Hart Scientific Crucible length immersion depth: 195mm Metal sample Sample source Hart Scientific Sample purity % Sample weight Not Available Thermometer well Well material Quartz Well ID (mm) 8.0 mm Immersion depth of SPRT Furnace/Bath Furnace Manufacturer Hart Scientific Control type PID Controller How many zones? 3 zones Furnace heater AC/DC? AC Heat pipe liner? No ITS-90 Realisation Techniques Freeze/Melt? Freeze Method of forming solid/liquid interface Insert rod Heat transfering fluid? Air Duration of freeze/melt At least 6 hours Cell used as FP/MP/TP? FP Ga Fixed point cell Cell Ga Cell manufacturer / Model / Serial no. Hart Scientific / 5943 / Ga Open/closed? Closed Pressure in cell kpa Crucible Crucible material Teflon Crucible manufacturer Hart Scientific Crucible length 168 mm Metal sample Sample source Hart Scientific Sample purity % Sample weight Not Available Thermometer well Well material Quartz Well ID (mm) 8.2 ± 0.25 mm

39 Immersion depth of SPRT Furnace/Bath Manufacturer Control type How many zones? Furnace heater AC/DC? Heat pipe liner? ITS-90 Realisation Techniques Freeze/Melt? Method of forming solid/liquid interface Heat transfering fluid? Duration of freeze/melt Cell used as FP/MP/TP? Furnace Hart Scientific PID Controller single DC No Melt Heater rod Air / Water / Silicone oil At least 6 hours MP Hg Fixed point cell Cell Cell manufacturer / Model / Serial no. NIM / 9301 Open/closed? Closed Pressure in cell NA Crucible Crucible material Stainless Steel Crucible manufacturer NIM Crucible length 163 mm Metal sample Sample source NIM Sample purity % Sample weight Not Available Thermometer well Well material Quartz Well ID (mm) 8.2 ± 0.25 mm Immersion depth of SPRT Furnace/Bath Bath Manufacturer Heto Control type PID Controller How many zones? NA Furnace heater AC/DC? AC Heat pipe liner? No ITS-90 Realisation Techniques Freeze/Melt? Melt Method of forming solid/liquid interface Insert rod Hg

40 Heat transfering fluid? Alcohol Duration of freeze/melt At least 6 hours Cell used as FP/MP/TP? TP Ar Fixed point cell Cell Ar Cell manufacturer / Model / Serial no. NIM / 9301 Open/closed? Closed Pressure in cell NA Crucible Crucible material Stainless Steel Crucible manufacturer NIM Crucible length Approx. 225 mm Metal sample Sample source NIM Sample purity % Sample weight Not Available Thermometer well Well material Stainless Steel Well ID (mm) Approx ± 0.2 mm Immersion depth of SPRT Furnace/Bath Dewar container Manufacturer NIM Control type Manually valve control How many zones? NA Furnace heater AC/DC? NA Heat pipe liner? NA ITS-90 Realisation Techniques Freeze/Melt? Melt Method of forming solid/liquid interface Pressure constant valve Heat transfering fluid? Liquid nitrogen Duration of freeze/melt 3 hours Cell used as FP/MP/TP? TP TPW fixed point cell Cell Cell manufacturer Water source and purity Well diameter Immersion depth Heat transfer liquid: water / alcohol / others TPW Hart Scientific Ocean / model 5901D-Q 12 mm (ID), 60 mm (OD) Effective: 222 mm, 265 mm / 252 mm Water

41 Cell maintained in: Ice bath / Water bath Ice mantle: Method of preparation Annealing time before use Water bath Dry ice A week / 2 weeks Bridge and Reference Resistor Bridge Measurement International / 6010A / Manufacturer / Model / Serial no AC/DC DC If AC, give Frequency - Bandwidth - Gain - Quad gain - Read manually or off IEEE Normal measuring current - Self-heating current - If DC, give Gain NA Period of reversal 8 seconds Reference resistor Type 10 ohm (AC/DC 5685A) Manufacturer / Model / Serial no. Tinsley / 5685A / Temperature of the ref resistor ± 0.15 C Temperature coefficient of the ref resistor ppm/ C

42 APPENDIX E: Immersion curves and plateaus of all fixed points Laboratory: Contact thermometry Lab, National Institute of Metrology, China Contact Person: Sun Jianping Contact Address: No.18, Bei San Huan Dong Lu, Beijing, China Immersion curve for the zinc freezing point Immersion curve for the tin freezing point Immersion curve for the gallium melting point Immersion curve for the mercury triple point Immersion curve for the triple point of argon

43 Plateau curve of the freezing point of Zinc Plateau curve of the freezing point of tin Plateau curve of the melting point of Gallium Plateau curve of the triple point mercury Plateau curve of the triple point argon

44 Laboratory: National Metrology Centre (NMC), A*STAR, Singapore Contact Person: YE Shaochun Contact Address: 1 Science Park Drive, Singapore ye_shaochun@nmc.a-star.edu Immersion curve for the zinc freezing point Immersion curve for the tin freezing point Immersion curve for the gallium melting point Immersion curve for the mercury triple point Immersion curve for the triple point of argon

45 Plateau curve of the freezing point of Zinc Plateau curve of the freezing point of tin Plateau curve of the melting point of Gallium Plateau curve of the triple point mercury Plateau curve of the triple point argon

46 APPENDIX F: Bilateral equivalence between CCT-K3.2 and CCT-K3 Fixed point Ar NMI* => BIPM BNM IMGC KRISS MSL NIM NIST NML NPL NRC NRLM PTB SMU VNIIM VSL dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. dir. inc. T/mK NMI U/mK NMC Hg T/mK NMI U/mK NMC Ga T/mK NMI U/mK NMC Sn T/mK NMI U/mK NMC Zn T/mK NMI U/mK NMC *: NMI refer to the CCT-K3 participants