Comparison of the standards for air kerma of the KRISS and the BIPM for 60Co gamma radiation

A direct comparison of the standards for air kerma of the Korea Research Institute of Standards and Science (KRISS), Korea, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in 2010. The result, expressed as a ratio of the KRISS and the BIPM standards for air kerma, is 0.9995 with a combined standard uncertainty of 1.6 * 10-3. The degrees of equivalence between the KRISS and the other participants in the key comparison, designated as BIPM.RI(I)-K1, have been calculated and the results are presented in the form of a matrix. A graphical presentation is also given. (authors)