CIPM MRA COMPARISON REPORTS

A new indirect comparison of the standards for air kerma of the Budapest Főváros Kormányhivatala (BFKH), Hungary, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the ¹³⁷Cs radiation beam using the radiation protection facility of the International Atomic Energy Agency (IAEA) in Seibersdorf, Austria, in August 2025. The comparison result, based on the calibration coefficients for one transfer chamber and expressed as a ratio of the BFKH and the BIPM standards for air kerma, is 1.0039 with a combined standard uncertainty of 3.1 parts in 10³. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database, to update the 2009 comparison result.

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).