BIPM comparison BIPM.RI(II)-K1.I-131 of activity measurements of the radionuclide 131I for the NMIJ (Japan), the NIST (USA) and the LNE-LNHB (France), with linked results for the APMP.RI(II)-K2.I-131 comparison

Three new participations in the BIPM.RI(II)-K1.I-131 comparison have been added to the previous results and this has produced a revised value for the key comparison reference value (KCRV), calculated using the power-moderated weighted mean. A link has been made to the APMP.RI(II)-K2.I-131 comparison held in 2009 through the NMIJ who participated in both comparisons. Three national metrology institutes (NMIs) used the Asia Pacific Metrology Programme (APMP) comparison to update their degree of equivalence. The degrees of equivalence between each equivalent activity measured in the International Reference System (SIR) and the KCRV have been calculated and the results are given in the form of a table for twelve NMIs in the BIPM.RI(II)-K1.I-131 comparison and five other participants in the APMP.RI(II)-K2.I-131 comparison. A graphical presentation is also given. (authors)