In 2004, the National Metrology Institute of Japan (NMIJ) and the Institute for Reference Materials and Measurements (IRMM, Geel) each submitted one sample of known activity of ¹³⁷Cs to the International Reference System (SIR). The NMIJ submission replaces their 1994 SIR measurement and the IRMM is their first measurement in the SIR. The values of the activity submitted were about 2.7 MBq and 0.98 MBq. The key comparison reference value (KCRV) and the degrees of equivalence have been recalculated to include these latest values. The results are given in the form of a matrix that now contains 13 results, comparison identifier BIPM.RI(II)-K1.Cs-137, to which the five remaining eligible results from the CCRI(II)-K2.Cs-137 held in 1982 are linked.

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).