Activity measurements of the radionuclide 99m Tc for the NIM, China in the ongoing comparison BIPM.RI(II)-K4.Tc-99m

In 2012, the fourth comparison of activity measurements of 99m Tc using the Transfer Instrument of the International Reference System (SIRTI) took place at the Chinese National Institute of Metrology (NIM). An ampoule containing about 70 kBq of 99m Tc traceable to the NIM primary standard was measured in the SIRTI for more than three half-lives. The comparison, identifier BIPM.RI(II)-K4.Tc-99m, is linked to the BIPM.RI(II)-K1.Tc-99m comparison and the degrees of equivalence with the key comparison reference value and between the present NIM result, the other K4 participant and the six participants in the K1 comparison have been evaluated.