Update of the BIPM comparison BIPM.RI(II)-K1.Ho-166m of activity measurements of the radionuclide 166mHo to include the 2017 results of the NMISA (South Africa) and update of the KCRV

Abstract

Since 1989, 6 national metrology institutes (NMI) have submitted 7 samples of known activity of 166mHo to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ho-166m. The values of the activity submitted were between about 70 kBq and 470 kBq. The key comparison reference value (KCRV) has been re-evaluated using the power-moderated weighted mean to include the PTB and NMISA results dated 2013 and 2017, respectively. There are now five valid results in the KCDB for the BIPM.RI(II)-K1.Ho-166m comparison and the degrees of equivalence between the equivalent activity measured in the SIR and the KCRV have been calculated. The degrees of equivalence for linked regional key comparisons (APMP and EURAMET) were updated.Main textTo 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).