CIPM MRA COMPARISON REPORTS

A supplementary comparison of air kerma standards of five participating laboratories was carried out in ²⁴¹Am and ⁶⁰Co radiation beams at radiation protection level, from June 2024 to January 2025. Three of the participating laboratories are secondary standards laboratories (DSA, STUK, and SSM) and NPL and CIEMAT are primary standards laboratories, with NPL providing the reference values for the comparison. The comparison results are published in the BIPM key comparison database (KCDB) under the reference EURAMET.RI(I)-S19. The comparison was made indirectly using two ionization chambers as transfer instruments. The results are analysed and presented in terms of ratios of the calibration coefficients provided by the participants with respect to the comparison reference values.

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).