Since 1976, 12 national metrology institutes (NMI) and two other laboratories have submitted 35 samples of known activity of ⁸⁸Y 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.Y-88. The activities ranged from about 400 kBq to 29 MBq. The degrees of equivalence between each equivalent activity measured in the SIR and the key comparison reference value (KCRV) have been calculated and the results are given in the form of a matrix for ten NMIs. A graphical presentation is also given. The results of an APMP regional comparison, comparison identifier APMP.RI(II)-K2.Y-88, completed in 2000 for this radionuclide have been linked to the SIR results through that of the NMIJ. This has enabled six other NMIs to have degrees of equivalence in the KCDB and two others to supersede their earlier result in the SIR.

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 Section II of the Consultative Committee for Ionizing Radiation (CCRI(II)), according to the provisions of the Mutual Recognition Arrangement (MRA).