Comparison of 18F activity measurements at the VNIIM, NPL and the ENEA-INMRI using the SIRTI of the BIPM

In 2014, the first three comparisons of activity measurements of 18F were carried out at the VNIIM, NPL and the ENEA-INMRI using the BIPM's Transfer Instrument of the International Reference System. The transfer instrument and the NMIs primary measurement methods are briefly described. The degrees of equivalence with the key comparison reference value defined in the frame of the corresponding SIR comparison have been evaluated. World-wide consistency of activity measurements of 18F is demonstrated.