APMP comparison of activity measurements of I-131 (APMP.RI(II)-K2.I-131)

The international comparison of activity measurements of 131I (APMP.RI(II)-K2.I-131) was carried out within the framework of the Asia-Pacific Metrology Programme (APMP). Seven laboratories took part in the comparison, and five of them undertook absolute measurements. One ampoule containing the same radioactive solution as that used in the APMP comparison was sent to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM) in order to link the APMP comparison to the BIPM.RI(II)-K1.I-131 comparison and to evaluate degrees of equivalence with the key comparison reference value (KCRV). 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, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).