A comparison of the 10 V Josephson array voltage standard of the Bureau International des Poids et Mesures (BIPM) was made with that of the Laboratoire National de Métrologie et d'Essais (LNE), France, in December 2007. The results are in very good agreement and the estimated combined relative standard uncertainty is 1.1 parts in 10¹¹.

This comparison is the first to follow the new version of the technical protocols for BIPM.EM-K10a & b (Options A and B¹), which were reviewed by the experts designated during the 23rd CCEM (2007) to be members of the CCEM Support Group for BIPM direct on-site Josephson comparisons. The difference with the previous version of the protocol is the insertion of the following rule: "When a significant improvement is obtained during the comparison both the initial and the final results are added to the KCDB with a note, but only the final result appears on the graph of results."

This article describes the technical details of the experiments which were carried out to achieve the final result of the comparison.

¹ Option A is the scheme where the BIPM measures the JVS of the participant with its measurement setup. Option B is the other way around.

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).