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. - Highlights: • The SIRTI for activity comparisons of short-lived radionuclides was extended to ¹⁸F. • The three first ¹⁸F SIRTI comparisons took place at the VNIIM, NPL and the ENEA-INMRI. • Relative uncertainties of the NMIs primary measurements ranged from 0.3% to 0.6%. • Relative uncertainties of the SIRTI measurements ranged from 0.06% to 0.14%. • The comparison results agree with the SIR KCRV within 1 or 2 standard uncertainties.