Final report on key comparison EURAMET.EM-K11: ac–dc voltage transfer difference at low voltages

Abstract

A regional key comparison EURAMET.EM-K11 'ac–dc voltage transfer difference at low voltages' has been conducted between national metrology institutes (NMIs). The aim of the comparison was to determine the degree of equivalence (DoE) between the participating NMIs and to link them to the participants of the CIPM key comparison CCEM-K11. A total of 21 NMIs participated in the comparison, most of them members of EURAMET (one withdrew after the draft A report) but three NMIs from AFRIMETS, APMP and COOMET also participated. The measurements were carried out in the period July 2005 to April 2008.The travelling standard, an ac–dc transfer standard with amplified low voltage ranges 220 mV and 22 mV, was very stable during the comparison. The ac–dc voltage transfer difference of the travelling standard was measured at 100 mV and 10 mV and at the frequencies 1 kHz, 20 kHz, 100 kHz and 1 MHz. The comparison reference values (CRVs) were calculated as the weighted mean of the results of the NMIs with independent realizations. The DoEs relative to the CRV and between pairs of NMIs have been determined and show good agreement. The DoEs relative to the KCRV of the CCEM-K11 are also good. The vast majority of the calculated deviations are within the limits of the expanded uncertainties.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).