Dc Voltage Standards 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).

Development of Automatic Calibration System for Solid-State DC Voltage Standards and Its Validation

Development of Automatic Calibration System for Solid-State DC Voltage Standards and Its Validation

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).

Quasi-continuous dc voltage standard using sinusoidal and pulse-driven Josephson junction arrays

Josephson voltage standards (JVSs) provide a primary realization of the volt, the unit of electromotive force. They generate direct current (dc) voltages up to 10 V and show agreement better than 1 nV V−1 at 10 V. For JVSs based on Josephson junction arrays (JJAs) that are driven by sinusoidal radiofrequency (RF) power, commonly referred to as continuous wave-driven JJAs (CWD JJAs), the minimum voltage that can be generated is limited to the voltage across one Josephson junction (JJ) for practical devices. To achieve this resolution, they may require a perfect JJA chip. JVSs based on a pulse-driven (PD) JJA require high performance electronics (i.e. high bandwidth, low distortion and jitter, pulse shaping filters and large memory) to achieve their minimum and maximum voltage. We have combined two CWD JJAs and two PD JJAs driven by two microwave inputs to one chip to generate quasi-continuous dc voltages up to the sum of the full-scale voltages of both JJAs that are robust to the imperfections of the JJs and have relaxed requirements on the RF electronics driving the JJA, compared to the existing CWD JVSs and PD JVSs, respectively. By use of the JJA chip at the National Measurement Institute Australia, we demonstrate its feasibility to generate voltages up to 1 V. Preliminary evaluation of the system shows that the voltage uncertainty can be 11 nV (k = 2) or better and the theoretical resolution is better than 1 nV from 0 V to 1 V. The main requirement is that all the JJs must have quantum locking ranges with respect to the power and frequency of the RF bias and for the PD JJAs to have a constant voltage over a range of dc bias current. Although this development is not a replacement for existing state-of-the-art JVSs, we anticipate that it will be an alternative fit-for-purpose solution for metrological applications under non-ideal operating conditions or when the components of the state-of-the-art solutions are not available.

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 1.018 V and 10 V standards between the BIM (Bulgaria) and the BIPM (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 Bulgarian Institute of Metrology, BIM, was carried out in April 2019. The objective for BIM in participating in this comparison was to demonstrate the international equivalence of its DC voltage measurement results and to support the calibration and measurement capabilities (CMCs) published in the Key Comparison Database of the BIPM (KCDB).Two BIPM Zener diode-based travelling standards (Fluke 732B) were shipped to Sofia in March 2019.At the BIPM, the reference standard for DC voltage is a primary voltage standard based on the Josephson effect, developed by the BIPM. The output electromotive force (EMF) of each travelling standard was measured against the Josephson Voltage Standard (JVS) before and after the measurements at BIM. At the BIM, the reference standard is a commercial JVS.The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by BIM, at the level of 1.018 V and 10 V, at BIM, UBIM, and those assigned by the BIPM, at the BIPM, UBIM, at the reference dates of the 26th of March 2019. UBIM - UBIM = - 0.01 µV; uc = 0.02 µV, at 1.018 V UBIM - UBIM = + 0.30 µV; uc = 0.09 µV, at 10 Vwhere uc is the combined standard uncertainty associated with the measured difference.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).

Quantum-Derived Voltage Waveform Synthesis With Pulse-Driven High-Transition-Temperature Josephson Junctions

Microwave-driven Josephson junction arrays are the basis for dc and ac voltage standards, whose accuracy derives from quantized voltage pulses. These pulses are also used to synthesize voltage-noise reference signals that are used in noise thermometry systems. This article describes our recent demonstration of voltage synthesis in a high-transition-temperature YBa 2 Cu 3 O 7-δ junction circuit.

Supplementary comparison EURAMET EM-S41 bilateral comparison of DC voltage reference standards (1,018 V and 10 V) (EURAMET.EM-S41)

This report describes a bilateral comparison of DC voltage standards organised within the frame of the EU-Indonesia Trade Support Program II n° APE12-06b between LNE, France and KIMLIPI, Indonesia. This bilateral comparison registered in the KCDB as EURAMET.EM-S41 was piloted by LNE. LNE participated in EUROMET comparison N° 429, designated EUROMET.EM.BIPM-K11 thus providing the link between KIM-LIPI results and CCEM-K11. This report includes the measurement results from the participants and information about their calibration methods for measurements of 1,018 V and 10 V.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 V and 10 V standards between the NMISA (South Africa) and the BIPM April to June 2017 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

As 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 National Metrology Institute of South Africa, NMISA (South Africa), was carried out from April to June 2017. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_A (ZA) and BIPM_B (ZB), were transported by freight to NMISA and back to BIPM. In order to keep the Zeners powered during their transportation phase, a voltage stabilizer developed by BIPM was connected in parallel to the internal battery. It consists of a set of two batteries, electrically protected from surcharge-discharge, easy to recharge and is designed to power two transfer standards for ten consecutive days. At NMISA, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard.At the BIPM, the travelling standards were calibrated, before and after the measurements at NMISA, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and atmospheric pressure.The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by NMISA, at the level of 1.018 V and 10 V, at NMISA, U NMISA, and those assigned by the BIPM, at the BIPM, U BIPM, at the reference dates of the 19th and 18th of May 2017, respectively. U NMISA − U BIPM = + 0.07 μV; u c = 0.02 μV, at 1.018 V U NMISA − U BIPM = + 0.001 μV; u c = 0.34 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 NMISA, based on K J-90, and the uncertainty related to 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 1.018 V and 10 V standards between the KEBS (Kenya) and the BIPM, January to March 2018, (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

As 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 Kenya Bureau of Standards, was carried out from January to February 2017. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_A (Z8) and BIPM_B (ZB), were hand carried to KEBS and back to BIPM by M. Gibosn Aguko. Since the total duration of the travels from one institute to the other was not exceeding the capabilities of the self-powering of the Zeners (36 hours), the transfer standards did not need any additional battery connected in parallel to the internal battery. At KEBS, the reference standard for DC voltage is a 732B Zener standard traceable to a primary voltage by means of a calibration service requested once a year from a National Measurement Institute (UME, Turkey) operating a Josephson Voltage Standard (JVS) two times per year. The output EMF (Electromotive Force) of each travelling standard was measured against the Zener voltage standard by means of an accurate multimeter.At the BIPM, the travelling standards were calibrated, before and after the measurements at KEBS, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and atmospheric pressure.Since KEBS did not record the temperature of the internal voltage reference during its measurement session, no correction for the Zener temperature dependence was applied. However, as a consequence the related uncertainty was adjusted.The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by KEBS, at the level of 1.018 V and 10 V, at KEBS, U KEBS, and those assigned by the BIPM, at the BIPM, U BIPM, at the reference dates of the 2 February 2018. U KEBS - U BIPM = + 0.11 µV; u c = 0.34 µV, at 1.018 V U KEBS - U BIPM = + 0.25 µV; u c = 1.55 µV, at 10 V where 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 KEBS, based on KJ-90, and the uncertainty related to the comparison. KEBS' uncertainties appear to be over estimated and would require revision.KEY WORDS FOR SEARCHJosephson voltage standard; Zener diode; KEBS; BIPM; comparison; Kenya; electricity and magnetism; CIPM MRAMain 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).

High performance selectable-value transportable high dc voltage standard

Abstract At National Institute of Metrological Research (INRIM), a selectable-value transportable high dc voltage standard (THVS) operating in the range from 10 V to 100 V in steps of 10 V, was developed. This standard was built to cover the lack of high level dc voltage standards at values higher than 10 V to employ mainly as transportable standard for inter-laboratory comparisons (ILCs) or eventually as laboratory (local) high level dc voltage standard. An electronic technique was used to improve the THVS accuracy of the high values. The THVS shows lower noise, better short- term stability and accuracy than top level dc voltage and multifunction calibrators (MFCs) and satisfactory suitability to be transported. The project is extensible to 1000 V.

Bilateral comparison of 1 V and 10 V standards between the DEFNAT (Tunisia) and the BIPM February to March 2016 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the Laboratoire de Métrologie Electrique, DEFNAT (Tunisia), was carried out from February to March 2016. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_C (ZC) and BIPM_6 (Z6), were transported by freight to DEFNAT and back to BIPM. In order to keep the Zeners powered during their transportation phase, a BIPM in-house voltage stabiliser was connected in parallel to the internal battery. The voltage stabiliser consists of a set of two batteries, electrically protected from surcharge-discharge, easy to recharge and is designed to power two transfer standards for 10 consecutive days. At DEFNAT, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard.At the BIPM, the travelling standards were calibrated, before and after the measurements at DEFNAT, with the Josephson Voltage Standard. 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 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 26th of February 2016. U DEFNAT - U BIPM = + 0.07 μV; u c = 0.04 μV, at 1.018 V U DEFNAT - U BIPM = + 0.38 μV; u c = 0.10 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 NSAI-NML, based on KJ-90, and the uncertainty related to 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 10 V standards between the NSAI - NML (Ireland) and the BIPM, February 2016 (part of the ongoing BIPM key comparison BIPM.EM-K11.b)

As part of the ongoing BIPM key comparison BIPM.EM-K11.b, 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 January and February 2016. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_7 (Z7) 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. 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 final result of the comparison is presented as the difference between the values assigned to DC voltage standards by NSAI - NML, at the level of 10 V, at NSAI - NML, U NML, and those assigned by the BIPM, at the BIPM, U BIPM, at the reference date of the 31 of January 2016. U NML - U BIPM = + 0.22 μV; u c = 1.35 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 NSAI-NML, based on KJ-90, and the uncertainty related to 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).

An AC Josephson Voltage Standard up to the Kilohertz Range Tested in a Calibration Laboratory

This paper describes the development of an automated ac quantum voltmeter toward a turnkey system, which can be used for calibration of common dc and ac voltage standards. The setup was tested in an accredited commercial calibration laboratory to characterize Fluke 5700A calibrators and voltage standards. The measured voltage in dependence on various parameters is presented in the range of dc to 2 kHz with amplitudes up to 10 V. The uncertainty components are discussed, and the system relevant Type B uncertainty for ac voltage calibrations is 0.15 μV/V. The contribution of the leakage current is investigated in detail and found to be notable for frequencies above 1 kHz due to parasitic capacitances. The combined measurement uncertainty for calibration ac voltages is less than 0.62 μV/V (k = 1 and 40 Hz-1 kHz) and is limited by the noise of the calibrator. Comparison measurements at Physikalisch-Technische Bundesanstalt have been done and confirm the system reproducibility.

Coherence investigations of DC voltage group standard

Abstract A method of checking coherence of comparison results of primary DC voltage group standards is described in the paper. Usefulness of the proposed method was proved by coherence investigation of DC voltage group standard kept in the Central Military Calibration Laboratory (CWOM, Warsaw, Poland). Results obtained for the group of five Fluke DC voltage standards prove very good coherence of voltage differences results and confirmed accuracy of DC voltage unit in the CWOM at the level of 10-6

交流電圧標準を導く薄膜型サーマルコンバータの開発

Thermal voltage converters have been widely used in the electric standard field as a major method to derive AC voltage standards from DC voltage standards. However, there are only a limited number of organizations that are capable of fabricating thermal voltage converters. Furthermore, establishing AC-DC voltage standards has been constrained by the lack of high-quality thermal converters. High-quality thermal converters are used only by national metrology institutes (NMIs) because the conventional thermal converters are too fragile for many calibration laboratories. The National Institute of Advanced Industrial Science and Technology (AIST) has developed new thin-film multi-junction thermal converters(TFMJTCs) to realize a reliable high-performance thermal converter. Development of a durable TFMJTC with a heater on an aluminum nitride (AlN) substrate is expected to make significant contribution to Japanese calibration laboratories.

Bilateral Comparison of 10 V Standards between the NSAI - NML (Ireland) and the BIPM, March 2015 (part of the ongoing BIPM key comparison BIPM.EM-K11.b)

As part of the ongoing BIPM key comparison BIPM.EM-K11.b, 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 February and March 2015. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_6 (Z6) and BIPM_C (ZC), 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. 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 final resultof the comparison is presented as the difference between the values assigned to DC voltage standards by NSAI - NML, at the level of 10 V,at NSAI - NML, UNML, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 24 February 2015.UNML − UBIPM = - 0.82 mV; uc = 1.35 mV , at 10 Vwhere uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML, based on KJ-90, and the uncertainty related to the comparison.Main text.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 V and 10 V Standards between the NIS (Egypt) and the BIPM, August to September 2014 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the National Institute for Standards (NIS), Giza, Egypt, was carried out from August to September 2014. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_B (ZB) and BIPM_C (ZC), were transported as hand luggage on board an airplane to NIS and back to BIPM. At NIS, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at NIS, with the Josephson Voltage Standard. 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 final result of the comparison is presented as the difference between the values assigned to DC voltage standards by NIS, at the level of 1.018 V and 10 V, at NIS, UNIS, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 7 September 2014. UNIS - UBIPM = 0.09 µV; uc = 0.08 µV, at 1 VUNIS - UBIPM = 0.22 µV; uc = 0.14 µV, at 10 Vwhere uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NIS, based on KJ-90, and the uncertainty related to the comparison.This is a satisfactory result. The comparison result shows that the voltage standards maintained by NIS and the BIPM were equivalent, within their stated standard uncertainties, on the mean date of the comparison.Main text.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 V and 10 V standards between the DMDM (Serbia) and the BIPM, January to March 2014 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the Directorate of Measures and Precious Metals (DMDM), Beograd, Serbia, was carried out from January to March 2014. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_6 (Z6) and BIPM_A (ZA), were transported by freight to DMDM. At DMDM, the reference standard for DC voltage is a Josephson Voltage Standard. The output electromotive force of each travelling standard was measured by direct comparison with the primary standard.At the BIPM, the travelling standards were calibrated, before and after the measurements at DMDM, with the Josephson Voltage Standard. 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 final result of the comparison is presented as the difference between the values assigned to DC voltage standards by DMDM, at the level of 1.018 V and 10 V, at DMDM, UDMDM, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 13 February 2014.UDMDM − UBIPM = 0.094 µV; uc = 0.072 µV, at 1 VUDMDM − UBIPM = 0.39 µV; uc = 0.12 µV, at 10 Vwhere uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at DMDM, based on KJ-90, and the uncertainty related to the comparison.The results at the 10 V level are not covered by the uncertainties with a coverage factor of 2. After the distribution of the Draft A, the DMDM discovered that the pressure gauge was defective. Some considerations on the correction to apply on the comparison result and the corresponding uncertainties are presented in the report.Nevertheless, the above results fully cover the CMCs of DMDM which are significantly larger. No corrections for temperature and pressure are applied in calibrations for customers' secondary standards.Main text.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).