Abstract. In 2006, the Physikalisch-Technische Bundesanstalt (PTB), Germany submitted a sample of known activity of ¹⁸⁶Re to the International Reference System (SIR). The value of the activity submitted was about 166 MBq. This comparison result is the first submission in the ongoing key comparison BIPM.RI(II)-K1.Re-186. The result agrees with that predicted from the efficiency curve for the SIR within a standard uncertainty.

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 the CCRI Section II, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).