Romain Coulon, Carine Michotte, Sammy Courte, Manuel Nonis, W M van Wyngaardt, Michael L Smith, Angus H H Bowan, Christine M B Keevers, Emily L Clark, Melek Zarifi, Anuradha Ravindra, D B Kulkarni, Ritu Sharma, Marco Capogni, Pierino De Felice, Mauro Capone, Pierluigi Carconi, Aldo Fazio, Christophe Bobin, Paulo A Lima da Cruz, Carlos J da Silva, Ronaldo Lins da Silva, Anderson Leiras, Johnny de Almeida Rangel, Monica Aguiar Leobino da Silva, Akira Iwahara, Denis E Bergeron, Jeffrey T Cessna, Ryan P Fitzgerald, Lizbeth Laureano-Perez, Leticia Pibida, Milton W Van Rooy, Joline Lubbe, Martin J van Staden, Robert Shearman, John Keightley, Andy Pearce, Natasha Ramirez, Emma Bendall, Sean Collins, Tomasz Ziemek, Edyta Lech, Pawel Saganowski, Marek Czudek, Anna Listkowska, Ole Nähle, Karsten Kossert, Marcell P Takács, Matej Krivošík, and Ivana Bonková
Main text Since 1976, 30 laboratories have submitted 85 samples of 60Co to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)- K1.Co-60. Recently, the PTB (Germany), the NIST (United States), the SMU (Slovakia), the BARC (India), the LNE-LNHB (France), the POLATOM (Poland), the ENEA-INMRI (Italy), the NPL (United Kingdom), the LNMRI-IRD (Brazil), the NMISA (South Africa) and the ANSTO (Australia) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical representation 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).