APMP.T-K3.4: Key comparison of realizations of the ITS-90 over the range C to C

Transcription

1 APMP.T-K3.4: Key comparison of realizations of the ITS-90 over the range C to C Final report Prepared by. Joung (coordinator) and K. S. Gam Korea Research Institute of Standards and Science (KRISS) Republic of Korea A. Achmadi and B. A. Trisna Research Center for Metrology-LIPI (RCM-LIPI) Indonesia April, 016 1

2 Table of content 1. Introduction 3. Participating laboratories 3 3. Artifact 3 4. Measurement procedure 4 5. Summary of raw data submissions 4 6. Link from APMP.T-K3.4 to CCT-K Linkage mechanism Data analysis 9 7. Bilateral differences 1 8. Incomplete submission 16 Appendix 1: Protocol of the APMP.T-K Appendix : Measurement data 3 Appendix 3: Uncertainty of the measurement 5 Appendix 5: Immersion curve 7 Appendix 5: Instrumentation 3

3 1. Introduction The APMP bilateral key comparison APMP.T-K3.4 was initiated by the request of RCM-LIPI (Indonesia) to link their national standards to the average reference values (ARVs) of the CCT-K3. Korea research institute of standards and science (KRISS, Republic of Korea) was requested to provide the linkage to the CCT-K3 for the temperature range from C to C. The protocol of the comparison (Appendix 1) was agreed by both the laboratories in 011, and the comparison was carried out in a participant-pilot-participant sequence from 011 to 013. In the APMP.T-K3.4, two standard platinum resistance thermometers (SPRTs) were chosen as the artifacts, and they were calibrated at the ITS-90 fixed-points in the comparison range. The fixed-points in this comparison included Zn FP ( C), Sn FP (31.98 C), In FP ( C), Ga MP ( C), and Hg TP ( C). The protocol of the APMP.T-K3.4 provided general guidance of the comparison and the measurement sequence to be performed. Actual realization of the fixed-points and measurement with the artifacts were carried out according to the local practice. Participants including the pilot were asked to make all the required corrections such that the resistance ratios were equivalent to the ITS-90 assigned temperature values at 0 ma.. Participating laboratories KRISS (Republic of Korea) ukchul Joung, Kee Sool Gam Korea research institute of standards and science 67 Gajeong-Ro, Yuseong-Gu Daejeon 34113, Korea wukchul.joung@kriss.re.kr RCM-LIPI (Indonesia) Aditya Achmadi, Beni Adi Trisna Research Center for Calibration, Instrumentation and Metrology Indonesian Institute of Sciences Kompleks PUSPIPTEK Gedung 40 Tangerang Selatan, BANTEN- INDONESIA aditya_achmadi@yahoo.com 3. Artifact The artifacts used for this comparison were two SPRTs, and they were provided by RCM-LIPI. The specifications of the artifacts are as follows. 3

4 - Serial number: 136 and 160 (hereafter referred to as artifact 1 and artifact ) - Model: 670SQ - Manufacturer: Isotech - Sheath type: Quartz sheathed - Sensing element length: 35 mm (distance from the tip of the thermometer to the mid-point of the sensing element: around 5 mm) 4. Measurement procedure The SPRTs were first calibrated at RCM-LIPI before being sent to KRISS, the pilot laboratory. After the calibration at KRISS, the artifacts were sent back to RCM-LIPI to repeat the calibration. Transportation of the artifacts was done by hand-carrying. Measurements at fixed-points were performed in order of decreasing temperatures alternating with measurements at the triple point of water. 5. Summary of raw data submissions Raw data from the participating laboratories are given in Appendix. However, for convenience, the reported resistance ratios are duplicated here in Tables 1 and. Table 1. Resistance ratios received from participants in APMP.T-K3.4 (artifact 1). Lab (Zn FP) (Sn FP) (In FP) (Ga MP) (Hg TP) RCM-LIPI pre KRISS RCM-LIPI post Table. Resistance ratios received from participants in APMP.T-K3.4 (artifact ). Lab (Zn FP) (Sn FP) (In FP) (Ga MP) (Hg TP) RCM-LIPI pre KRISS RCM-LIPI post Measurement uncertainties from the participants are also given in Appendix 3, and for convenience, the uncertainties at the fixed-points are presented here in Table 3. Table 3. Uncertainties of the fixed-point resistance ratios in mk at 95 % level of confidence and k =. Lab U(Zn FP) U(Sn FP) U(In FP) U(Ga MP) U(TP) U(Hg TP) RCM-LIPI KRISS

5 6. Link from APMP.T-K3.4 to CCT-K Linkage mechanism KRISS participated in the CCT-K3 and served as the linking laboratory in the APMP.T-K3.4. The linkage was from the fixed-point resistance ratios of RCM-LIPI to the ARVs of the CCT-K3 through the difference between the fixed-point resistance ratios of KRISS and the ARVs of the CCT-K3. The linkage mechanism is as follows. T RCM LIPI APMP.TK3.4 T RCM LIPI T KRISS T KRISS APMP.T K3.4 CCTK3 ARV CCTK3 APMP.TK3.4 ARV KRISS KRISS CCTK3 CCTK3 APMP.TK3.4 (1) here K3.4 CCT-K3 T RCM LIPI APMP.T ARV is the temperature difference between the K3.4 APMP.T K3.4 fixed-point resistance ratios of RCM-LIPI in the APMP.T-K3.4 and the ARVs of the CCT- K3, T RCM LIPI APMP.T KRISS is the fixed-point temperature difference APMP.T -K3.4 CCTK3 between KRISS and RCM-LIPI measured in the APMP.T-K3.4, T KRISS KRISS is the temperature difference between the CCTK3 CCTK3 fixed-point cells of KRISS in the APMP.T- K3.4 and those in the CCT-K3, T KRISS ARV is the temperature difference between the fixed-point resistance ratios of KRISS in the CCT-K3 and the ARVs of the CCT-K3. The fixed-point temperature difference between KRISS and RCM-LIPI in the APMP.T-K3.4, K3.4 APMP.T K3.4 T RCM LIPI APMP.T KRISS was defined as the average of the measured differences from the two artifacts. T RCM LIPI APMP.T K3.4 T KRISS 1 T RCM LIPI RCM LIPI APMP.T K3.4 APMP.T K3.4 APMP.T K3.4 KRISS KRISS APMP.T K3.4 1 APMP.T K3.4 () 5

6 The temperature difference between KRISS and RCM-LIPI for each artifact was defined by the difference in the resistance ratios at the fixed-point. T RCM LIPI APMP.TK3.4 KRISS RCM LIPI KRISS APMP.TK3.4 i APMP.TK3.4 i APMP.TK3.4 i dr dt (3) Here, the subscript, i refers to the each artifact. The resistance ratio of RCM-LIPI for an artifact was defined as the average of the measurement results before and after the measurement at KRISS. RCM LIPI 1 APMP.TK3.4 i RCM LIPI RCM LIPI APMP.TK3.4 i,pre APMP.TK3.4 i,post (4) Here, the resistance ratios RCM LIPI APMP.T K3.4 i and APMP.T K3.4 i from the 3 repeated measurements. KRISS were the averages The temperature difference between the fixed-point cells of KRISS in the APMP.T-K3.4 and those in the CCT-K3, KRISS KRISS T accounted for any changes in the fixed-point cells APMP.T -K3.4 CCTK3 between these two comparisons. In the APMP.T-K3.4, as the same fixed-point cells were used, this difference vanished but only had uncertainties. As for the temperature difference between the fixed-point resistance ratios of KRISS in the CCT-K3 and the ARVs of the CCT-K3, T KRISS ARV Table 4 reproduces these results. CCTK3 CCTK3, the results from the CCT-K3 was used. Table 4. Temperature difference between the fixed-point resistance ratios of KRISS in the CCT-K3 and the ARVs of the CCT-K3, and corresponding expanded uncertainties at 95 % level of confidence and k =. Temperature difference / mk Zn FP Sn FP In FP Ga MP Hg TP Uncertainty in the temperature difference / mk CCTK3 CCTK3 T KRISS ARV CCTK3 CCTK3 U T KRISS ARV The uncertainty in the temperature difference between the fixed-point resistance ratios of RCM-LIPI and the ARVs of the CCT-K3 was evaluated based on the following equation under the assumption of no correlation between the temperature differences in Eq. (1). The expanded uncertainties were evaluated at 95 % level of confidence and k =. 6

7 U T RCM LIPI U U U APMP.TK3.4 T RCM LIPI T KRISS T KRISS APMP.T K3.4 CCTK3 ARV CCTK3 APMP.TK3.4 ARV KRISS KRISS CCTK3 CCTK3 APMP.T K3.4 (5) here K3.4 CCT-K3 U T RCM LIPI APMP.T ARV is the expanded uncertainty in the temperature K3.4 APMP.T K3.4 difference between the fixed-point resistance ratios of RCM-LIPI in the APMP.T-K3.4 and the ARVs of the CCT-K3, U T RCM LIPI APMP.T KRISS is the expanded uncertainty in the fixed-point APMP.T -K3.4 CCTK3 temperature difference between KRISS and RCM-LIPI measured in the APMP.T-K3.4, U T KRISS KRISS is the expanded uncertainty in the temperature CCTK3 CCTK3 difference between the fixed-point cells of KRISS in the APMP.T-K3.4 and those in the CCT-K3, U T KRISS ARV is the expanded uncertainty in the temperature difference between the fixed-point resistance ratios of KRISS in the CCT-K3 and the ARVs of the CCT-K3. The expanded uncertainty in the fixed-point temperature difference between KRISS and RCM-LIPI measured in the APMP.T-K3.4, T RCM LIPI APMP.T KRISS based on the following equations. U was evaluated K3.4 APMP.T K3.4 U U U T RCM LIPI 1 U 4 U APMP.TK3.4 T T T RCM LIPI U RCM LIPI 1 U 4 RCM LIPI KRISS RCM LIPI APMP.TK3.4 APMP.T K3.4 APMP.TK3.4 APMP.TK3.4 KRISS KRISS KRISS APMP.T K3.4 1 APMP.T K3.4 RCM LIPI U KRISS APMP.TK3.4 i APMP.TK3.4 i APMP.TK3.4 i dr dt APMP.TK3.4i RCM LIPI U RCM LIPI APMP.TK3.4 i,pre APMP.T K3.4 i,post (6) (7) (8) 7

8 In this comparison, SPRT cutoff criteria were used to ensure that uncertainty associated with the travel, handling, or stability of either SPRT did not dominate the standard uncertainty of the temperature difference. In this regard, the test for the stability of the travelling artifacts was based on measurements done by RCM-LIPI before and after the travel to KRISS. Eqs. (9) and (10) show the cutoff criteria used in this comparison, and an artifact which met both the two criteria was not included in the calculation. RCM LIPI RCM LIPI 0.95, eff u RCM LIPI d dt u RCM LIPI r R APMP.TK3.4 i,pre APMP.T K3.4 i,pre R APMP.T K3.4 i,post APMP.TK3.4 i,post t (9) u C SPRT, i u T RCM LIPI u C APMP.T K3.4 i 3 SPRT, i (10) here u C SPRT, i RCM LIPIAPMP.TK3.4i,pre RCM LIPIAPMP.TK3.4i d dt 1,post. (11) In the cutoff criteria above, RCM r ur LIPI APMP.T K3.4 i is the combined standard uncertainty from all sources of random uncertainty for each SPRT, and t 0.95, eff is the appropriate quantile of the Student s t distribution with degrees of freedom, eff needed to compute an approximate 95 % level of confidence for the temperature differences observed after travel to and from KRISS for each SPRT. The expanded uncertainty in the temperature difference between the fixed-point cells of KRISS used in the APMP.T-K3.4 and those in the CCT-K3, T KRISS KRISS using the following equation. U was evaluated APMP.T K3.4 CCTK3 U T KRISS U uc K3.4 KRISSCCTK3 TKRISS U TKRISS APMP.T APMP.T K3.4 uc CCTK3 (1) Here, the subscript uc refers to the uncorrelated uncertainty components in the fixed-point resistance ratio measurements. In this comparison, only the uncertainties due to the chemical impurity and to the hydrostatic head correction were assumed to be correlated. This assumption was based on the fact that the reference fixed-point cells at KRISS had been strictly restricted in use except for international comparisons and calibrations of other fixed-point cells. Thus, contamination of the samples since the CCT-K3 was thought to be unlikely. Therefore, as the same fixed-point cells were employed in the APMP.T-K3.4, uncertainty components related with the physical content and the geometry of the fixed- 8

9 point cells were assumed to be correlated, which were the uncertainties due to the chemical impurity and to the hydrostatic head correction. The expanded uncertainty in the temperature difference between the fixed-point resistance ratios of KRISS in the CCT-K3 and the ARVs of the CCT-K3 was available in the final report of the CCT-K3, and is reproduced in Table Data analysis Table 5 shows the results of the cutoff criteria analysis. As shown in the table, since no artifacts failed both the criteria, the data from the two artifacts were all used in the following analysis. Hg TP Passed Passed Table 5. Results of the cutoff criteria analysis. Fixedpoint u C SPRT, i / mk Cutoff criterion 1 value Cutoff criterion 1 result Artifact 1 Artifact Artifact 1 Artifact Artifact 1 Artifact Zn FP Passed Passed Sn FP Passed Passed In FP Passed Failed Ga MP Passed Passed Fixedpoint u T RCM LIPI APMP.T K3.4 i Cutoff criterion value / mk / mk Cutoff criterion result Artifact 1 Artifact Artifact 1 Artifact Artifact 1 Artifact Zn FP Passed Failed Sn FP Passed Failed In FP Passed Passed Ga MP Passed Passed Hg TP Passed Passed Table 6 shows the fixed-point temperature differences between RCM-LIPI and KRISS for both the artifacts and corresponding expanded uncertainties. Table 6. Fixed-point temperature differences between RCM-LIPI and KRISS for both the artifacts and corresponding expanded uncertainties (95 % level of confidence and k = ). Temperature difference / mk Zn FP Sn FP In FP Ga MP Hg TP Uncertainty in the temperature difference / mk RCM LIPI APMP.T K3.4 KRISS APMP.T K3.4 1 RCM LIPI APMP.T KRISS T U T K3.4 APMP.T K

10 RCM LIPI APMP.T K3.4 KRISS APMP.T K3.4 RCM LIPI APMP.T KRISS T U T K3.4 APMP.T K3.4 Table 7 and Fig. 1 show the averaged fixed-point temperature difference between RCM-LIPI and KRISS, and the corresponding uncertainty. Table 7. Averaged fixed-point temperature difference between RCM-LIPI and KRISS, and corresponding expanded uncertainty (95 % level of confidence and k = ). Temperature difference / mk Zn FP Sn FP In FP Ga MP Hg TP Uncertainty in the temperature difference / mk K3.4 APMP.T K3.4 T RCM LIPI APMP.T KRISS K3.4 APMP.T K3.4 U T RCM LIPI APMP.T KRISS Fig. 1. Averaged fixed-point temperature difference between RCM-LIPI and KRISS, and corresponding expanded uncertainty (95 % level of confidence and k = ). In order to complete the linkage, it was needed to evaluate the uncertainty in the temperature difference between the fixed-point cells of KRISS used in the APMP.T-K3.4 and those in the CCT-K3, T KRISS APMP.T -K3.4 KRISS CCTK3. As noted above, since the fixed-point cells used in the APMP.T- K3.4 were the same as those in the CCT-K3, the temperature difference did not influence the linkage, but its uncertainty affected the linkage. The uncertainty in that temperature difference accounted for any 10

11 uncorrelated uncertainties in the realization of the fixed-point and in the measurement of the resistance ratio. In this comparison, only the uncertainties due to the chemical impurity and the hydrostatic head correction were assumed to be correlated. Table 8 shows the related uncertainty components in the APMP.T-K3.4 and in the CCT-K3. Table 8. Uncertainty component for KRISS in the APMP.T-K3.4 and CCT-K3. Uncertainty components correlated between the APMP.T-K3.4 and the CCT-K3 are in boldface. Expanded uncertainty was evaluated at 95 % level of confidence and k =. All the uncertainties are in mk. Zn FP Sn FP In FP Ga MP Hg TP Uncertainty APM APM APM APM APM component CCT CCT CCT CCT CCT P P P P P Repeatability Chemical impurity Hydrostatic head Heat flux Gas pressure Slope of plateau Propagated from TP Bridge nonlinearity Bridge repeatability SPRT self-heating R s stability SPRT oxidation Total A Total B Total U correlated U uncorrelated U{ΔT(KRISS)} U{ΔT(KRISS)} designated KRISS KRISS T. APMP.T -K3.4 CCTK3 Based on the above analysis and using the temperature difference between the fixed-point resistance ratios of KRISS in the CCT-K3 and the ARVs of the CCT-K3 in Table 4, the temperature difference 11

12 between the fixed-point resistance ratios of RCM-LIPI in the APMP.T-K3.4 and the ARVs of the CCT-K3 and its uncertainty were calculated. Table 9 and Fig show the result. Table 9. Temperature difference between the fixed-point resistance ratios of RCM-LIPI in the APMP.T- K3.4 and the ARVs of the CCT-K3, and corresponding expanded uncertainty (95 % level of confidence and k = ). Temperature difference / mk Zn FP Sn FP In FP Ga MP Hg TP Uncertainty in the temperature difference / mk K3.4 CCT-K3 T RCM LIPI APMP.T ARV K3.4 CCT-K3 U T RCM LIPI APMP.T ARV Fig.. Temperature difference between the fixed-point resistance ratios of RCM-LIPI in the APMP.T- K3.4 and the ARVs of the CCT-K3, and corresponding expanded uncertainty (95 % level of confidence and k = ). 7. Bilateral differences The bilateral differences from RCM-LIPI in the APMP.T-K3.4 to CCT-K3 participants were calculated based on the following equations. In doing so, it was assumed that the differences between the CCT-K3 participants were uncorrelated. 1

13 T RCM LIPI APMP.TK3.4 T RCM LIPI T KRISS T KRISS APMP.T K3.4 CCTK3 Lab CCTK3 APMP.TK3.4 Lab KRISS CCTK3 KRISS CCTK3 APMP.TK3.4 (13) U T RCM LIPI U U U APMP.TK3.4 T RCM LIPI T KRISS T KRISS APMP.T K3.4 CCTK3 Lab CCTK3 APMP.TK3.4 Lab KRISS CCTK3 KRISS CCTK3 APMP.T K3.4 (14) here -K3.4 CCTK3 T RCM- LIPI APMP.T Lab is the fixed-point temperature difference CCTK3 CCTK3 between RCM-LIPI in the APMP.T-K3.4 and a participant of the CCT-K3, T KRISS Lab is the fixed-point temperature difference -K3.4 CCTK3 between KRISS and a participant of the CCT- K3, U T RCM- LIPI APMP.T Lab is the expanded uncertainty in the fixed-point CCTK3 CCTK3 temperature difference between RCM-LIPI in the APMP.T-K3.4 and a participant of the CCT-K3, U T KRISS Lab is the expanded uncertainty in the fixed-point temperature difference between KRISS and a participant of the CCT-K3. The bilateral differences between KRISS and participants of the CCT-K3 and the corresponding uncertainties are reproduced in Table 10. Table 10. Bilateral differences between KRISS and participants of the CCT-K3 and corresponding expanded uncertainties (95 % level of confidence and k = ). T KRISS Lab / mk Fixed-point CCTK3 CCTK3 CCTK3 CCTK3 U T KRISS Lab / mk BIPM BNM IMGC MSL NIM NIST NML Zn FP ΔT U Sn FP ΔT U

14 In FP ΔT U Ga MP ΔT U Hg TP ΔT U Fixed-point T KRISS Lab / mk CCTK3 CCTK3 CCTK3 CCTK3 U T KRISS Lab / mk NPL NRC NRLM PTB SMU VNIIM VSL Zn FP ΔT U Sn FP ΔT U In FP ΔT U Ga MP ΔT U Hg TP ΔT U Based on the above equations and the bilateral differences between KRISS and participants of the CCT- K3, the bilateral differences between RCM-LIPI in the APMP.T-K3.4 and participants of the CCT-K3 were calculated, and the result is shown in Table 11. Table 11. Bilateral differences between RCM-LIPI and participants of the CCT-K3 and corresponding expanded uncertainties (95 % level of confidence and k = ). T RCM- LIPI APMP.T Lab / mk Fixed-point -K3.4 -K3.4 CCTK3 CCTK3 U T RCM- LIPI APMP.T Lab / mk BIPM BNM IMGC MSL NIM NIST NML Zn FP ΔT U Sn FP ΔT U In FP ΔT U Ga MP ΔT U

15 ΔT Hg TP U Fixed-point T RCM- LIPI APMP.T Lab / mk -K3.4 -K3.4 CCTK3 CCTK3 U T RCM- LIPI APMP.T Lab / mk NPL NRC NRLM PTB SMU VNIIM VSL Zn FP Sn FP In FP Ga MP Hg TP ΔT U ΔT U ΔT U ΔT U ΔT U

16 8. Incomplete submission Laboratories failing to submit data for APMP.T-K3.4 report draft A: (1) RCM-LIPI: Instrumentation list Appendix 1: Protocol of the APMP.T-K3.4 Appendix : Measurement data Appendix 3: Uncertainty of the measurement Appendix 4: Immersion curve Appendix 5: Instrumentation 16

17 Appendix 1: Protocol of the APMP.T-K3.4 Bilateral Comparison from the Hg TP to the Zn FP between KRISS and KIM-LIPI Objective: This comparison is designed to compare the realization of the ITS-90 through the calibration of SPRTs. The range of temperature covered in this comparison is from the triple point of Hg ( K) to the freezing point of Zn ( K). The transfer standards used will be long-stem SPRTs. NMI Participants: Pilot: KRISS, ukchul Joung, Participating lab: KIM-LIPI, Beni Adi Trisna, Projected Timeline: Protocol Agreement June 30, 011 Transfer Standards Sent to KRISS September 30, 011 Transfer Standards Returned to KIM-LIPI December 31, 011 Transfer Standards Re-Measured by KIM-LIPI March 31, 01 Draft A Report Completed April 30, 01 Participants will supply the following information: ITS-90 calibrated SPRTs o o o NMI participant will select their own SPRTs based on their own criteria for suitability and will convey the selection criteria to the Pilot Laboratory SPRTs must be calibrated by NMI participant before measurements are made by the pilot and then again on return from the pilot SPRTs are to be measured at every available fixed-point cell over the range of the comparison including the In FP and Ga MP Calibration results supplied in FP with all corrections applied by the NMI such that the FP values are equivalent to the ITS-90 assigned temperature values for 0 ma. Uncertainties, u FP SPRTi, may be specific to each SPRT or a nominal uncertainty may be given for both SPRTs. The calibration results should be based on 3 repeated measurements at each fixed point. 17

18 o Appendix A gives a reporting worksheet The measurement equation used to compute each calibration result with an indication of which inputs vary randomly for each realized equilibrium and which inputs are systematic across all equilibria for each fixed point within this comparison o Any quantities in the measurement equation that are a mixture of random and systematic effects for each SPRT should be broken into constituent parts that are either purely random or purely systematic within this comparison. An example of an SPRT measurement is given in Appendix B. Uncertainty budget compliant with CCT G3 that includes degrees of freedom associated each component o A suggested fixed-point cell uncertainty budget is given in Appendix C Sources of uncertainty may be added or deleted as needed An NMI may choose to supply their own uncertainty budget (CMC and G3 compliant) that includes degrees of freedom for each source of uncertainty Please identify which components of the uncertainty budget are associated with random effects in FP and which are associated with systematic effects in FP within this comparison. Heat Flux (Immersion) profile for each fixed-point cell used o [R(FP), 0 ma] and corresponding [immersion depth (sensor midpoint), cm] Reporting the calibration results: The participating NMIs should report FP to the independent party within weeks after completing the measurement without informing the results to the other participating laboratory. After receiving all results from the participating laboratories (two results from KIM-LIPI, one from KRISS), the independent party will forward the results to the pilot laboratory. After reporting FP to the independent party, the participating NMI (KIM-LIPI) should send all the results and required information to KRISS (ukchul Joung, wukchul.joung@kriss.re.kr). If you have questions about any aspect of the protocol or are not sure how to report something that is requested, please contact ukchul Joung prior to submitting your report. After reviewing a ll submitted reports, we will contact you if there is anything that is unclear to us or if any addi tional information is needed to complete the analysis of the data. Method of Analysis: 18

19 The fixed-point realization temperature differences between KRISS and KIM-LIPI will be calculated using the following equations: T KIM LIPI 1 T T KIM LIPI,SPRT1 KIM LIPI, SPRT where T KIM FP FP KIM LIPI,SPRT i i LIPI,SPRT i SPRT. i d r dt KRISS,SPRT C C SPRT is a term used to account for uncertainty associated with the travel, handling, or stability of each i SPRT and is taken to have a value of C and a standard uncertainty, u SPRT i C SPRTi, of u C SPRTi FPKIM LIPI,SPRT FP i,postkriss d dt 1 KIM LIPI,SPRT i,pre KRISS. r An SPRT cutoff criterion for use in calculating values of T KIM LIPI will be used to ensure that uncertainty associated with the travel, handling, or stability of either SPRT does not dominate the standard uncertainty of T, u KIM LIPI T KIMLIPI. The cutoff criterion will be based on the statistical agreement between each SPRT s resistance ratios before and after its travel to KRISS and the magnitude of u C SPRTi. The mathematical definition for the cutoff criterion will be: and u C FPKIM LIPI,SPRT FP d d i,postkriss KIM LIPI,SPRT i,pre KRISS r T FP u FP u R SPRTi KIM LIPI,SPRT i,postkriss u T uc KIM LIPI 3 SPRTi In the cutoff criterion above, R R FP KIM LIPI,SPRT i KIM LIPI,SPRT i,pre KRISS t 0.95, eff Resultsfrom SPRTi willnot be used u is the combined standard uncertainty from all sources of random uncertainty for each SPRT and t is the appropriate quantile of the Student s t 0.95, eff distribution with eff degrees of freedom needed to compute an approximate 95 % confidence interval for the temperature difference observed after travel to and from KRISS for each SPRT. 19

20 Appendix A: Measurement Reporting orksheet Participating NMI Before sending SPRTs to pilot laboratory Zn Sn In Ga Hg SPRT 1, mk u FP SPRT1 Number of equilibria realized SPRT u FP SPRT, mk Number of equilibria realized Final R(TP) On return to participating laboratory Zn Sn In Ga Hg SPRT 1, mk u FP SPRT1 Number of equilibria realized SPRT u FP SPRT, mk Number of equilibria realized Final R(TP) Fixed-point cell information s/n Zn Sn In Ga Hg Immersion depth, cm Pressure, kpa Resistance ratio bridge model Reference resistor model Resistor enclosure stability, mk 0

21 Measurement system Appendix B: Example of an SPRT measurement T meas. (FP) = T 90 (FP) + pressure correction + immersion correction (FP) = calc.(fp) + (T meas. T 90 ) / dr/dt Before sending SPRTS to pilot laboratory pressure immersion correction, mk u correction, mk correction, mk u correction, mk Zn Sn In Ga Hg After sending SPRTS to pilot laboratory pressure immersion correction, mk u correction, mk correction, mk u correction, mk Zn Sn In Ga Hg 1

22 Appendix C: Suggested Fixed-Point Cell Uncertainty Budget Participating NMI Type A Phase transition realization repeatability Hg Ga In Sn Zn Systematic mk df mk df mk df mk df mk df or random Total A Type B Chemical impurities Hydrostatic-head Propagated TP SPRT self-heating Heat flux Moisture Gas pressure Slope of plateau Total B Combined standard uncertainty Expanded uncertainty (k = level, using effective df)

23 Appendix : Measurement data Participating NMI Before sending SPRTs to pilot laboratory RCM-LIPI Artifact 1 Artifact Fixed-point Zn FP Sn FP In FP Ga MP Hg TP R FP / Ω Number of R FP / Ω Number of R TP / Ω equilibria R TP / Ω realized U / mk U / mk equilibria realized Final R(TP) Ω Ω 3

24 On return to participating laboratory Artifact 1 Artifact Fixed-point Zn FP Sn FP In FP Ga MP Hg TP R FP / Ω Number of R FP / Ω Number of R TP / Ω equilibria R TP / Ω realized U / mk U / mk equilibria realized Final R(TP) Ω Ω 4

25 Participating NMI KRISS Artifact 1 Artifact Fixed-point Zn FP Sn FP In FP Ga MP Hg TP R FP / Ω Number of R FP / Ω Number of R TP / Ω equilibria R TP / Ω realized U / mk U / mk equilibria realized Final R(TP) Ω Ω 5

26 Appendix 3: Uncertainty of the measurement Participating NMI RCM-LIPI Type A Hg TP TP Ga MP In FP Sn FP Zn FP Systematic or random Phase transition realization repeatability random Total A Type B Chemical impurities systematic Hydrostatic-head systematic Heat flux systematic Gas pressure systematic Slope of plateau systematic Propagated from TP systematic Isotopic variation systematic Bridge nonlinearity systematic Bridge repeatability random SPRT self-heating systematic R s stability systematic SPRT oxidation systematic Total B Combined standard uncertainty / mk Expanded uncertainty / mk (95 % level of confidence, k = )

27 Participating NMI KRISS Type A Hg TP TP Ga MP In FP Sn FP Zn FP Systematic or random Phase transition realization repeatability random Total A Type B Chemical impurities systematic Hydrostatic-head systematic Heat flux systematic Gas pressure systematic Slope of plateau systematic Propagated from TP systematic Isotopic variation systematic Bridge nonlinearity systematic Bridge repeatability random SPRT self-heating systematic R s stability systematic SPRT oxidation systematic Total B Combined standard uncertainty / mk Expanded uncertainty / mk (95 % level of confidence, k = )

28 Appendix 4: Immersion curve Appendix 4.1: Zn FP 8

29 Appendix 4.: Sn FP 9

30 Appendix 4.3: In FP 30

31 Appendix 4.4: Ga MP 31

32 Appendix 4.5: Hg TP 3

33 Appendix 5: Instrumentation Appendix 5.1: Resistance measuring device Laboratory RCM-LIPI KRISS Bridge manufacturer MI ASL AC/DC DC, 6010C AC, F900 If AC, give Frequency 30 Hz Bandwidth 0.1 Hz Gain 10 4 Quad gain 10 Output IEEE-488 Normal measuring current 1 ma Self-heating current ma Unity reading Zero reading Compliment check error If DC, give Gain Period of reversal 4 s Output IEEE-488 Reference resistor Type DC, standard resistor 10 Ω AC/DC Manufacturer Tinsley Tinsley Temperature 3 C 5 C Temperature coefficient / C / C Linearity of bridge

34 Appendix 5.: Triple point of water cell Laboratory RCM-LIPI KRISS Cell manufacturer PTB KRISS ater source and purity Distilled deionized water ell diameter 15 mm 11 mm Immersion depth 60 mm 60 mm Heat transfer liquid: water? Alcohol ater Cell maintained in: ice bath/water bath? ater bath mixed with alcohol Ice bath Ice mantle: Method of preparation Dry ice Dry ice Annealing time before use 1 week weeks 34

35 Appendix 5.3: Other fixed-point cell Laboratory RCM-LIPI Fixed-point Zn FP Sn FP In FP Ga MP Hg TP Cell Cell manufacturer Hart Hart Hart Hart Scientific Scientific Scientific Scientific Open/closed? Open Open Open Closed Closed Pressure in cell kpa kpa kpa MP TP Crucible Crucible material Austenitic Graphite Graphite Graphite PTFE Stainless Steel Crucible manufacturer Hart Hart Hart Hart Hart Scientific Scientific Scientific Scientific Scientific Crucible length 50 mm 50 mm 50 mm 168 mm 13 mm Metal sample Sample source Hart Hart Hart Hart Hart Scientific Scientific Scientific Scientific Scientific Sample purity % % % % % Sample weight 1 kg 1 kg 1 kg Thermometer well ell material Austenitic Graphite Graphite Graphite PTFE Stainless Steel ell ID (mm) 8 mm 8 mm 8 mm 7 mm 7 mm Immersion depth of SPRT 170 mm 170 mm 170 mm 143 mm 188 mm Furnace/Bath Furnace Furnace Furnace Furnace Bath Manufacturer Hart Hart Hart Hart Hart Scientific Scientific Scientific Scientific Scientific Control type PID PID PID PID PID How many zones? 3 Zone 3 Zone 3 Zone Furnace heater AC/DC? AC AC AC Heat pipe liner? No No No ITS-90 realization Thermoelectric Heater AC Freeze/melt? Freeze Freeze Freeze Melt Melt Technique Induced Induced Induced Induced Heater Freeze Freeze Freeze melt Heat transfer fluid Air Air Air Air Halocarbon Duration of freeze/melt 16 hours 16 hours 6 hours 10 hours 18 hours Cell used as FP/MP/TP? FP FP FP MP TP 35

36 Laboratory KRISS Fixed-point Zn FP Sn FP In FP Ga MP Hg TP Cell Cell manufacturer KRISS KRISS KRISS KRISS Isotech Open/closed? Open Open Closed Open Closed Pressure in cell Pa Pa Pa Pa TP Crucible Crucible material Graphite Graphite Pyrex Teflon Stainless steel Crucible manufacturer Ultra carbon Ultra carbon NA NA Isotech Crucible length 55 mm 55 mm 180 mm 310 mm 30 mm Metal sample Sample source Johnson Johnson Johnson Rhone- Matthey Matthey Matthey Poulenc Unknown Sample purity % % % % % Sample weight 1.0 kg 1.0 kg 0.7 kg 0.8 kg 3.0 kg Thermometer well ell material Graphite Graphite Pyrex Teflon Stainless Steel ell ID 11 mm 11 mm 10 mm 1 mm 9.5 mm Immersion depth of SPRT 140 mm 140 mm 115 mm 180 mm 155 mm Furnace/Bath Furnace Furnace Furnace Bath Refrigerator Manufacturer Isotech Isotech Isotech Hart Isotech Control type PID PID PID PID PID How many zones? NA NA Furnace heater AC/DC? AC AC AC NA NA Heat pipe liner? No No No NA NA ITS-90 realization Freeze/melt? Freeze Freeze Freeze Melt Melt Outside Technique Induced nucleation, Induced Induced Heater freeze induced freeze melt freeze Heat transfer fluid Air Air Air ater Ethanol Duration of freeze/melt 15 hours 8 hours 0 hours 50 hours 15 hours Cell used as FP/MP/TP? FP FP FP MP TP 36

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