Activity measurements of the radionuclides ¹⁸F and ^99mTc for the NMISA, South Africa in the ongoing comparisons BIPM.RI(II)-K4.F-18 and BIPM.RI(II)-K4.Tc-99m

In 2015, comparisons of activity measurements of ¹⁸F and ^99mTc using the Transfer Instrument of the International Reference System (SIRTI) took place at the National Metrology Institute of South Africa (NMISA, South Africa). Ampoules containing about 25 kBq of ¹⁸F and ^99mTc solutions were measured in the SIRTI for more than two half-lives. The NMISA standardized the activity in the ampoules by ionization chamber measurements traceable to 4π(LS)β-γ coincidence measurements. The comparisons, identifiers BIPM.RI(II)-K4.F-18 and BIPM.RI(II)-K4.Tc-99m, are linked to the corresponding BIPM.RI(II)-K1.F-18 and BIPM.RI(II)-K1.Tc-99m comparisons and degrees of equivalence with the respective key comparison reference values have been evaluated. (authors)