Update of the BIPM comparison BIPM.RI(II)-K1.Cr-51 of activity measurements of the radionuclide 51Cr to include the 2012 result of the KRISS (Rep. of Korea), the 2022 result of the POLATOM (Poland), and to link the 2022 EURAMET.RI(II)-K2.Cr-51 comparison

Two new participations in the BIPM.RI(II)-K1.Cr-51 comparison have been added to the previous results and this has produced a revised value for the key comparison reference value (KCRV), calculated using the power-moderated weighted mean. A link has been made to the EURAMET.RI(II)-K2.Cr-51 comparison piloted by the POLATOM in 2022, who sent an ampoule from the EURAMET comparison to the International Reference System (SIR). The LNE-LNHB (France) used the EURAMET comparison to update its degree of equivalence. The degrees of equivalence between each equivalent activity measured in the SIR and the KCRV have been calculated and the results are given in the form of a table for the latest results in the BIPM.RI(II)-K1.Cr-51, and the linked EURAMET.RI(II)-K2.Cr-51. A graphical presentation is also given. 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 https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).