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

An indirect comparison of the standards for air kerma of the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), Australia, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in May 2010. The comparison result, based on the calibration coefficients for two transfer standards and expressed as a ratio of the ARPANSA and the BIPM standards for air kerma, is 1.0009 with a combined standard uncertainty of 3.1 * 10-3. The degrees of equivalence between the ARPANSA and the other participants in the key comparison have been calculated and the results are presented in the form of a matrix. A graphical presentation is also given. (authors)