Bilateral comparison of 1 Omega and 10 k Omega 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 SEARCH Resistance; ohm; NMISA; South Africa; BIPM; CIPM MRA; comparison; electricity 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).