As a part of the ongoing BIPM key comparisons BIPM.EM-K10.b, an on-site, direct comparison of the 10 V Josephson array voltage standard of the Bureau International des Poids et Mesures (BIPM) was made with that of the Korea Research Institute of Standards and Science (KRISS), Republic of Korea, in February 2008.

The final result of the comparison is presented as the difference between the value assigned to the transportable 10 V BIPM Josephson Voltage Standard by the KRISS, at the KRISS, to the theoretical value assigned to the BIPM Josephson Voltage Standard:
(U_KRISS − U_BIPM)/U_BIPM = +1.7 × 10⁻¹⁰ and
u_c/U_BIPM = 1.3 × 10⁻¹⁰
where u_c is the relative combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM, the uncertainty of the representation of the volt at KRISS, both based on K_J-90, and the uncertainty related to the comparison.

The results are in very good agreement and show that the primary voltage standards maintained by the KRISS and the BIPM were equivalent, within their stated 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).