Abstract. In 2005, the Physikalisch-Technische Bundesanstalt (PTB), Germany, submitted an ampoule with about 79 MBq activity of ⁹⁹Tc^m to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), to update their value in the key comparison database for the BIPM.RI(II)-K1.Tc-99m comparison. A graphical presentation is also given of the results for all six NMI participants.

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 CIPM Mutual Recognition Arrangement (MRA).