Ongoing BIPM Key Comparison Research Articles

Bilateral comparison of 1.018 V and 10 V standards between INRIM (Italy) and the BIPM, November to December 2023 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

Main textAs part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1.018 V and 10 V voltage reference standards of the BIPM and the INRIM (Italy), from November to December 2023. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_7 (Z7) and BIPM_9 (Z9), were transported by freight to the INRIM and back to the BIPM. In order to keep the Zeners powered during their transportation phase, two additional external batteries were connected in parallel to the internal battery. At the INRIM and the BIPM, the reference standard for DC voltage is a Programmable Josephson Voltage Standard (PJVS). The output electromotive force (EMF) of each travelling standard was measured by direct comparison with the primary standard. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by the INRIM, at the level of 1.018 V and 10 V, at the INRIM, UINRIM, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 1st of December 2023. U INRIM - U BIPM = -0.04 µV; u c = 0.03 µV, at 1.018 V U INRIM - U BIPM = -0.18 µV; u c = 0.19 µV, at 10 Vwhere uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the realisation of the volt at the BIPM and at the INRIM, and the uncertainty related to the comparison.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1.018 V and 10 V standards between SASO-NMCC (Saudi Arabia) and the BIPM, September to November 2023 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

Main textAs part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1.018 V and 10 V voltage reference standards of the BIPM and the SASO-NMCC (Saudi Arabia), from September to November 2023. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_E (ZE) and BIPM_F (ZF), were transported by freight to the SASO-NMCC and back to the BIPM. In order to keep the Zeners powered during their transportation phase, a voltage stabiliser developed by the BIPM was connected in parallel to the internal battery. At the SASO-NMCC and the BIPM, the reference standard for DC voltage is a Programmable Josephson Voltage Standard (PJVS). The output electromotive force (EMF) of each travelling standard was measured by direct comparison with the primary standard. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by the SASO-NMCC, at the level of 1.018 V and 10 V, at the SASO-NMCC, USASO-NMCC, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 30th of September 2023. U SASO-NMCC - U BIPM = 0.06 µV; uc = 0.05 µV, at 1.018 V U SASO-NMCC - U BIPM = 0.22 µV; uc = 0.12 µV, at 10 Vwhere uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the realisation of the volt at the BIPM and at the SASO-NMCC, and the uncertainty related to the comparison.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 10 pF and 100 pF standards (ongoing BIPM key comparisons BIPM.EM-K14.a and 14.b) between the NMIM (Malaysia) and the BIPM

Main textThis report presents the results of a bilateral comparison between the NMIM, Malaysia, and the BIPM, which was carried out using two 10 pF and two 100 pF travelling standards belonging to the BIPM, following an "A-B-A" pattern. The comparison at 10 pF forms part of the ongoing BIPM key comparison BIPM.EM-K14.a and that at 100 pF of the ongoing BIPM key comparison BIPM.EM-K14.b, where BIPM is the pilot laboratory for both comparisons.The standards were measured during a total time of 19 weeks, from February 2022 to June 2022. The measurand of this comparison was the two terminal-pair capacitance of the travelling capacitors at frequencies of 1000 Hz and 1592 Hz, and a measuring voltage of 15 V (rms) for the 10 pF standards and 10 V for the 100 pF standards.The results from the NMIM and the BIPM agree within a difference smaller than the relative expanded uncertainty of the comparison, which is dominated by the NMIM extrapolation of the BIPM calibrations, and to the use of a digital capacitance bridge to support the surveillance of the standards through periodical intermediate checks.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 Ω and 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.a and 13.b) between the CEM (Spain) and the BIPM

Main textThis report gives the result of a bilateral comparison of resistance between the CEM (Spain) and the BIPM carried out from March 2022 to September 2022. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a period of about one month at the CEM, and finally again at the BIPM. The measurand was the 4 terminal dc resistance at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13b (for 10 kΩ).The results from the CEM and the BIPM were found to be in good agreement, with a difference D smaller than the relative expanded uncertainty U c (95% confidence, k = 2) giving D = 0.056 × 10-6, U c = 0.106 × 10-6 for 1 Ω and D = 0.020 × 10-6, U c = 0.068 × 10-6 for 10 kΩ.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 Ω and 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.a and 13.b) between INRIM (Italy) and the BIPM

Main textThis report gives the result of a bilateral comparison of resistance between INRIM (Italy) and the BIPM carried out from October 2022 to February 2023. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a period of about one month and a half at INRIM, and finally again at the BIPM. The measurand was the 4 terminal dc resistance at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13b (for 10 kΩ).The results from INRIM and the BIPM were found to be in good agreement, with a difference D smaller than the relative expanded uncertainty U c (95% confidence, k = 2) giving D = -0.074 × 10-6, U c = 0.134 × 10-6 for 1 Ω and D = -0.045 × 10-6, U c = 0.174 × 10-6 for 10 kΩ.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1.018 V and 10 V standards between CSIR-NPL (India) and the BIPM, April to June 2022 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

Main textAs part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1.018 V and 10 V voltage reference standards of the BIPM and the CSIR National Physical Laboratory (CSIR-NPL), New Delhi (India), was carried out from September 2021 to April 2022. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_4 (Z4) and BIPM_5 (Z5), were transported by freight to the CSIR-NPL and back to the BIPM. In order to keep the Zeners powered during their transportation phase, a voltage stabiliser developed by the BIPM was connected in parallel to the internal battery. At the CSIR-NPL and the BIPM, the reference standard for DC voltage is a Programmable Josephson Voltage Standard (PJVS). The output electromotive force (EMF) of each travelling standard was measured by direct comparison with the primary standard.The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by CSIR-NPL, at the level of 1.018 V and 10 V, at CSIR-NPL, U CSIR-NPL, and those assigned by the BIPM, at the BIPM, U BIPM, at the reference date of the 9th of December 2021. U CSIR-NPL - U BIPM = -2.91 μV; u c = 0.68 μV, at 1.018 V U CSIR-NPL - U BIPM = -4.97 μV; u c = 0.19 μV, at 10 Vwhere u c is the combined standard uncertainty associated with the measured difference, including the uncertainty of the realisation of the volt at the BIPM and at CSIR-NPL, and the uncertainty related to the comparison.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1.018 V and 10 V standards between DEFNAT (Tunisia) and the BIPM, April to June 2022 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

Main textAs part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1.018 V and 10 V voltage reference standards of the BIPM and the Laboratoire de Métrologie Électrique, DEFNAT (Tunisia), was carried out from April to June 2022. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_E (ZE) and BIPM_F (ZF), were transported by freight to DEFNAT to be measured and back to the BIPM for checking the stability of the traveling standards. At DEFNAT, the reference standard for DC voltage is a Josephson Voltage Standard (JVS). The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard.The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by DEFNAT, at the level of 1.018 V and 10 V, at DEFNAT, U DEFNAT, and those assigned by the BIPM, at the BIPM, U BIPM, at the reference date of the 15th of May 2022. U DEFNAT - U BIPM = 0.03 μV; u c = 0.03 μV, at 1.018 V U DEFNAT - U BIPM = 0.44 μV; u c = 0.12 μV, at 10 Vwhere u c is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at DEFNAT, based on K J, and the uncertainty related to the comparison.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 Ω and 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.a and 13.b) between the INMETRO (Brazil) and the BIPM.

Main textThis report gives the result of a bilateral comparison of resistance between the INMETRO (Brazil) and the BIPM carried out from November 2020 to September 2021. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a period of about two months at the INMETRO, and finally again at the BIPM. The measurand was the 4 terminal dc resistance at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13b (for 10 kΩ).The results from the INMETRO and the BIPM were found to be in good agreement, with a difference D smaller than the relative expanded uncertainty Uc (95% confidence, k = 2) giving D = 0.010 × 10-6, Uc = 0.068 x 10-6 for 1 Ω and D = 0.026 x 10-6, Uc = 0.036 x 10-6 for 10 kΩ.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 Ω and 10 kΩ standards (ongoing BIPM key comparison BIPM.EM-K13) between the NPLI (India) and the BIPM

Main textThis report gives the result of a bilateral comparison of resistance between the NPLI (India) and the BIPM carried out from August 2021 to April 2022. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a period of about one month at the NPLI, and finally again at the BIPM. The measurand was the 4 terminal dc resistances at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13b (for 10 kΩ).The results from the NPLI and the BIPM were found to be in good agreement for 1 Ω but not for the 10 kΩ. The difference D is smaller than the relative expanded uncertainty U c (95% confidence, k = 2) giving D = 0.365 × 10-6, U c = 0.870 × 10-6 for 1 Ω. The difference D is higher than the relative expanded uncertainty U c (95% confidence, k = 2) giving D = 0.306 × 10-6, U c = 0.166 × 10-6 for 10 kΩ.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral Comparison of 1.018 V and 10 V Standards between the SMD (Belgium) and the BIPM, October to December 2021 (part of the ongoing BIPM key comparison BIPM.EM-K11)

Main textAs part of the ongoing BIPM key comparison BIPM.EM-K11, a comparison of the 1.018 V and 10 V voltage reference standards of the BIPM and the Service Métrologie - Metrologische Dienst (SMD), Brussels, Belgium, was carried out from October to December 2021. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_B (ZB) and BIPM_6 (Z6), were transported to SMD and back to BIPM by road. At SMD, the reference standard for DC voltage is a Josephson Voltage Standard (JVS). The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard.The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by SMD, at the level of 1.018 V and 10 V, at SMD, USMD, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 17th of November 2021. U SMD - U BIPM = -0.03 μV; u c = 0.13 μV, at 1.018 V U SMD - U BIPM = 0.02 μV; u c = 0.28 μV, at 10 Vwhere u c is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at SMD, based on KJ, and the uncertainty related to the comparison.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 Ω and 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.a and 13.b) between the EMI (United Arab Emirates) and the BIPM

Main textThis report gives the result of a bilateral comparison of resistance between the EMI (United Arab Emirates) and the BIPM carried out in 2020. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a period of about one month at the EMI, and finally again at the BIPM. The measurand was the 4 terminal dc resistance at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13b (for 10 kΩ).The results from the EMI and the BIPM were found to be in good agreement, with a difference D smaller than the relative expanded uncertainty Uc (95% confidence, k = 2) giving D = -0.057 × 10-6, Uc = 0.400 × 10-6 for 1 Ω and D = 0.017 × 10-6, Uc = 0.194 × 10-6 for 10 kΩ.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 Ω and 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.a and 13.b) between the NSAI-NML (Ireland) and the BIPM.

Main textThis report gives the result of a bilateral comparison of resistance between the NSAI-NML (Ireland) and the BIPM carried out from November 2020 to March 2021. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a period of about one month at the NSAI-NML, and finally again at the BIPM. The measurand was the 4 terminal dc resistance at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13b (for 10 kΩ).The results from the NSAI-NML and the BIPM were found to be in good agreement, with a difference D smaller than the relative expanded uncertainty U c (95% confidence, k = 2) giving D = - 0.081 × 10-6, U c = 0.180 × 10-6 for 1 Ω and D = 0.069 × 10-6, U c = 0.424 × 10-6 for 10 kΩ.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 10 V standards between the NSAI-NML (Ireland) and the BIPM

Main textAs part of the ongoing BIPM key comparison BIPM.EM-K11, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland - National Metrology Laboratory (NSAI - NML), Dublin, Ireland, was carried out in November and December 2020. The objective for NSAI-NML in participating in this comparison was to demonstrate the international equivalence of its DC voltage measurement results and to support their calibration and measurement capabilities (CMCs) published in the Key Comparison Database of the BIPM (KCDB).Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_8 (Z8) and BIPM_9 (Z9), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the group standard.At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson Voltage Standard, developed at the BIPM. The output EMF of each travelling standard was measured against the Josephson Voltage Standard (JVS). Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure.The comparison result is presented as the difference between the value assigned to a 10 V standard by NSAI-NML, at NSAI-NML, U NSAI-NML, and that assigned by the BIPM, at the BIPM, U BIPM, on the reference date of 2020/11/14, as U NSAI-NML - U BIPM = -2.99 µV; u c = 1.71 µVwhere u c is the combined standard uncertainty associated with the measured difference, including the uncertainty of the realization of the volt at NSAI-NML, and the uncertainty related to the comparison.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 Ω and 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.a and 13.b) between the NMC A*STAR (Singapore) and the BIPM

This report gives the result of a bilateral comparison of resistance between the NMC A*STAR (Singapore) and the BIPM carried out in 2018-2019. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about two months, then for a period of about one month at the NMC A*STAR, and finally again at the BIPM. The measurand was the 4 terminal dc resistance at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13b (for 10 kΩ).The results from the NMC A*STAR and the BIPM were found to be in good agreement, with a difference smaller than the relative expanded uncertainty (95% confidence, k = 2) of 0.064 × 10−6 for 1 Ω and 0.036 × 10−6 for 10 kΩ.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 10 pF and 100 pF standards (ongoing BIPM key comparisons BIPM.EM-K14.a and 14.b) between the SASO (Saudi Arabia) and the BIPM

This report presents the results of a bilateral comparison between the SASO, Saudi Arabia, and the BIPM, which was carried out using two 10 pF and two 100 pF travelling standards belonging to the BIPM following an "A-B-A" pattern. The comparison at 10 pF forms part of the ongoing BIPM key comparison BIPM.EM-K14.a and that at 100 pF of the ongoing BIPM key comparison BIPM.EM-K14.b, where BIPM is the pilot laboratory for both comparisons.The standards were measured during a total time of 21 weeks, from October 2019 to February 2020. The measurand of this comparison was the two terminal-pair capacitance of the travelling capacitors at a frequency of 1000 Hz, and a measuring rms voltage of 10 V.The results from the SASO and the BIPM agree within a difference smaller than the relative expanded uncertainty of the comparison, which is dominated by the contribution of the calibration of the SASO reference capacitors.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 Ω and 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.a and 13.b) between the NIM (The People's Republic of China) and the BIPM

This report gives the result of a bilateral comparison of resistance between the NIM (The People's Republic of China) and the BIPM carried out at the end of 2018, beginning of 2019. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a period of one month at the NIM, and finally again at the BIPM. The measurand was the 4 terminal dc resistance at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13.b (for 10 kΩ).The results from the NIM and the BIPM were found to be in good agreement, with a difference smaller than the relative expanded uncertainties (95% confidence, k = 2) for both 1 Ω and 10 kΩ standards. Relative differences are + 0.010 × 10−6 for 1 Ω and − 0.001 × 10−6 for 10 kΩ with a relative expanded uncertainty of 0.034 × 10−6 for 1 Ω and 0.032 × 10−6 for 10 kΩ.KEY WORDS FOR SEARCHResistance; ohm; NIM; The People's Republic of China; BIPM; CIPM MRA; comparison; K13; electricityMain textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 10 pF and 100 pF standards (ongoing BIPM key comparisons BIPM.EM-K14.a and 14.b) between the SMD (Belgium) and the BIPM.

This report presents the results of a bilateral comparison between the SMD, Belgium, and the BIPM, which was carried out using two 10 pF and two 100 pF travelling standards belonging to the BIPM following an "A-B-A" pattern. The comparison at 10 pF forms part of the ongoing BIPM key comparison BIPM.EM-K14.a and that at 100 pF of the ongoing BIPM key comparison BIPM.EM-K14.b, where BIPM is the pilot laboratory for both of these comparisons.The standards were measured during a total time of 18 weeks, from August 2018 to December 2018. The measurand of this comparison was the two terminal-pair capacitance of the travelling capacitors at a frequency of 1000 Hz, and a measuring rms voltage of 15 V.The results from the SMD and the BIPM were found to be in good agreement, within a difference smaller than the relative expanded uncertainty of the comparison.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 Ω and 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.a and 13.b) between the NPLI (India) and the BIPM

This report gives the result of a bilateral comparison of resistance between the NPLI (India) and the BIPM carried out in 2012-2013. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements. The standards were measured first at the BIPM for a period of about three months, then for a period of about two months at the NPLI, and finally again at the BIPM. The measurand was the 4 terminal dc resistance at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13.b (for 10 kΩ).The results from the NPLI and the BIPM were found to be in agreement, with a difference smaller than the relative expanded uncertainty (95 % confidence, k = 2) of 0.52 × 10-6 for 1 Ω and 0.28 × 10-6 for 10 kΩ.KEY WORDS FOR SEARCHResistance; ohm; CIPM MRA; comparison; K13; electricityMain textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 10 pF and 100 pF standards (ongoing BIPM key comparisons BIPM.EM-K14.a and 14.b) between the NIMT (Thailand) and the BIPM

This report presents the results of a bilateral comparison of 10 pF and 100 pF capacitance standards between the NIMT (Thailand) and the BIPM carried out in 2018. The comparison at 10 pF forms part of the ongoing BIPM key comparison BIPM.EM-K14.a and that at 100 pF of the ongoing BIPM key comparison BIPM.EM-K14.b. The BIPM is the pilot laboratory for both of these comparisons.Two 10 pF and one 100 pF travelling standards belonging to the NIMT were used in this comparison carried out with an 'A-B-A' pattern of measurements. The standards were measured first at NIMT for a period of about one month, then for a similar period at the BIPM, and finally again at NIMT. The measurand was the two terminal-pair capacitance at a frequency of either 1000 Hz or 1592 Hz, for a measuring rms voltage of 15 V at 10 pF and 10 V at 100 pF.The results from the NIMT and the BIPM at both 1000 Hz and 1592 Hz were found to be in good agreement, with a difference smaller than the relative expanded uncertainty of the comparison.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Bilateral comparison of 1 Ω and 10 kΩ standards (ongoing BIPM key comparisons BIPM.EM-K13.a and 13.b) between the NMISA (South Africa) and the BIPM

This report gives the result of a bilateral comparison of resistance between the NMISA (South Africa) and the BIPM carried out in 2017. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a period of about two months at the NMISA, and finally again at the BIPM. The measurand was the 4 terminal dc resistance at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13b (for 10 kΩ).The results from the NMISA and the BIPM were found to be in good agreement, with a difference 1.02 time larger for 1 Ω and smaller than the relative expanded uncertainties (95% confidence, k = 2) for 10 kΩ. Differences are 0.12 × 10-6 for 1 Ω and 0.60 × 10-6 for 10 kΩ.KEY WORDS FOR SEARCHResistance; ohm; NMISA; South Africa; BIPM; CIPM MRA; comparison; electricityMain textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).