Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the BFKH, Hungary and the BIPM in ⁶⁰Co gamma radiation

Main text A new key comparison of the standards for air kerma of the Budapest Főváros Kormányhivatala (BFKH), Hungary and the Bureau International des Poids et Mesures (BIPM) was carried out in the 60 Co radiation beam of the BIPM in October 2021. The comparison result, based on the calibration coefficients for a transfer chamber and expressed as a ratio of the BFKH and the BIPM standards for air kerma, is 1.0029 with a combined standard uncertainty of 2.2 parts in 10 3 . The result agrees within the uncertainties with the comparison carried out in 2016. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. 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).