Abstract. A key comparison has been made between the air-kerma standards of the VSL, Netherlands and the BIPM in the medium-energy x-ray range. The results show the standards to be in agreement at the level of the combined standard uncertainty when account is taken of the effect of the diaphragm support for the BIPM standard. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database.

Main text. 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 kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).