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

A first key comparison of the standards for air kerma of the Laboratory for Nuclear Calibrations (LNK) from the Studiecentrum voor Kernenergie - Centre d'Etude de l'Energie Nucleaire (SCK-CEN), Belgium and of the Bureau International des Poids et Mesures (BIPM) was carried out in the ⁶⁰Co radiation beam of the BIPM in September 2016. The comparison result, evaluated as a ratio of the SCK-CEN and the BIPM standards for air kerma, is 1.0021 with a combined standard uncertainty of 2.6 x 10^-3. The results for an indirect comparison made at the same time are consistent with the direct results at the level of 7 parts in 10⁴. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. (authors)