The measurements of the international comparison of ac-dc current transfer standards identified as EURAMET.EM-K12 started in June 2012 and were completed in December 2014. Twenty NMIs in the EURAMET region and one NMI in the AFRIMET region took part: BEV (Austria), CMI (Czech Republic), PTB (Germany), METAS (Switzerland), JV (Norway), UME (Turkey), GUM (Poland), IPQ (Portugal), CEM (Spain), INRIM (Italy), SP (Sweden), DANIAmet-MI-Trescal (Denmark), BIM (Bulgaria), MKEH (Hungary), SIQ (Slovenia), LNE (France), NSAI NML (Ireland), VSL (The Netherlands), NPL (United Kingdom), Metrosert (Estonia), NIS (Egypt). The comparison was proposed to link the National Metrology Institutes organised in EURAMET to the key comparison CCEM-K12. The ac-dc current transfer difference of each travelling standard had been measured at its nominal current 10 mA and 5 A at the following frequencies: 10 Hz, 55 Hz, 1 kHz, 10 kHz, 20 kHz, 50 kHz, 100 kHz. The test points were selected to link the results with the equivalent CCEM Key Comparison (CCEM-K12), through five NMIs participating in both EURAMET and CCEM key comparisons (PTB, JV, NPL, SP and BEV). The report shows the degree of equivalence in the EURAMET region and also the degree of equivalence with the corresponding CCEM reference value. 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).

Current transformers (CTs) are precision devices that scale high currents down to values that can be easily handled by measurement equipment. To support CT applications in revenue metering, a comparison on AC current transformer calibration systems was performed among 15 European national metrology institutes using a precision CT as the travelling device. The first comparison results for the transformation ratios (4, 5, 6, 8, 10) kA/5 A of the travelling CT at nominal burden of 5 VA and 15 VA indicate good agreement between the participating laboratories. The main differences are found for phase displacement, at least partly caused by the instability of the traveling standard.

Ten years ago the international community started the expansion of the measurement range for ac-dc current transfer from 20 A to a present level of 100 A at frequencies up to 100 kHz with uncertainties of around 100 μA/A. At BEV coaxial current shunts based on resistive foils as well as low inductance tee connectors suitable to compare the shunts were fabricated [1]. This paper describes progress in the theory and practice of these shunts and tees within the last decade.

This report presents the results of a trilateral comparison of measurements on a Zener voltage standard within the framework of EUROMET. The participants are the national metrology institutes of Romania (INM), Turkey (UME) and Austria (BEV); BEV acted as the pilot laboratory. The comparison was performed in order to link the National Institute of Metrology Bucharest (INM) to the BIPM key comparisons. 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 (MRA).

Fifteen National Metrology Institutes have participated in DC voltage ratio comparison CCEM-K8. The method followed to normalize the participants' results, the calculation of the key comparison reference values and the comparison results are reported for the two mandatory ratios of the comparison, 1000 V/10 V and 100 V/10 V.

To expand the measurement capability up to 100 A at 100 kHz a construction for current shunts and Tee-connectors has been made, calculated and manufactured up to 40 A until now

The purpose of this work was (a) to develop an experimental set-up which is capable to record the time dependent temperature fluctuations of single junction thermal converters due to low-frequency ac currents by using an IR photo detector and (b) a characterisation of the local and temporal temperature behaviour of shunts for the ac current measurements with a thermocamera

This report presents the results of a comparison of measurements on four electronic DC reference standards performed by national metrology institutes in the EUROMET region and BIPM. The results of the comparison, in terms of degrees of equivalence, show that there is a good agreement between the measurement results of the participants. The results also show that the time-dependent fluctuations in the output voltages of the travelling standards provide one of the main sources of uncertainty. 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 EUROMET, comparison identifier EUROMET.EM.BIPM-K11, according to the provisions of the Mutual Recognition Arrangement (MRA).

A comparisons of the 10 V Josephson array voltage standard (JAVS) of the Slovak Institute of Metrology (SMU, Bratislava, Slovakia) was carried out in the framework of two EUROMET projects no. 496 and 497. The Zener diode-based transfer standards have been used for all comparisons, the results of which are presented in this contribution.

A program for the measurement procedure was developed which calculates the voltage of the Josephson Array Voltage Standard with the actual readings of the microwave frequency. The results on low noise measurements with standard cells show, that different conditions of the microwave frequency are taken into account by the program.