Since 1981, nine national metrology institutes (NMIs) have submitted 16 samples of known activity of ¹⁵²Eu to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM). The activities ranged from about 160 kBq to 18 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. A graphical presentation is also given. The results of a CCRI(II) comparison held in 1999 for this radionuclide are linked to the BIPM comparison for 22 participants through individual measurements of the comparison ampoules in the SIR. This has enabled eight NMIs to update their earlier SIR results and another 12 NMIs, an international laboratory and the BIPM to have degrees of equivalence in the key comparison database (KCDB), comparison identifier CCRI(II)-K2.Eu-152.

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)), comparison identifier BIPM.RI(II)-K1.Eu-152, according to the provisions of the Mutual Recognition Arrangement (MRA).