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

Abstract

A key comparison of the standards for air kerma of the National Physical Laboratory (NPL), United Kingdom and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in November 2017. The comparison result, based on the calibration coefficients for two transfer chambers and expressed as a ratio of the NPL and the BIPM standards for air kerma, is 0.9996 with a combined standard uncertainty of 3.0×10-3. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database.KEY WORDS FOR SEARCHRadiation dosimetry, air kerma, key comparison, Co-60 gamma radiationMain textTo 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 kcdb.bipm.org/.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).