Abstract. In 2006 and 2007, the National Metrology Institute of Japan (NMIJ) and the Laboratoire national de métrologie et d'essais–Laboratoire national Henri Becquerel (LNE–LNHB) submitted samples of known activity of ⁵⁷Co to the International Reference System (SIR). The values of the activity submitted were about 1.7 MBq and 3.7 MBq respectively. The new key comparison results have replaced the previous results for Japan and France. These new results have enabled a re-evaluation of the key comparison reference value. The matrix of degrees of equivalence in the key comparison database that now contains twelve results, identifier BIPM.RI(II)-K1.Co-57, has been updated with the new results.

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 CCRI Section II, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).