radionuclide metrology-ESIR

ESIR – Extension of SIR

A pilot study has been carried out to test the system in condition of a key comparison of standard solution of 60Co. Compared to the reference SIR, the study shown the capability of ESIR to provide accurate and precise degrees of equivalence – a least when the solution is known not containing additional impurities. The CCRI(II) validates the fact that the service can open in 2024 and a protocol is under definition (link to the protocol).


Radionuclides covered 14C, 35S, 45Ca, 55Fe, 63Ni, 89Sr, 90Sr, 99Tc, 147Pm, 241Am, 241Pu
BIPM comparator Planned to be opened in 2024
Level Radionuclide dependent
Quantity Bq/g
Uncertainty Aiming for 0.5 % (k = 2)
Comparison service identifier BIPM.RI(II)-K5
Underpins equivalence for... Radionuclides set out in the MMM
Validity Results remain valid for 15 years
Key comparison reference value Power-moderated weighted mean of results


Guidance document MMM

60Co Pilot Study

60Co Pilot Study

The international reference system for activity measurements of g-ray emitting nuclides

Coulon R. and Al., The international reference system for beta-particle emitting radionuclides: Validation through the pilot study CCRI(II)-P1.Co-60, Appl. Rad. Isot., 200, 2023

How to participate - ESIR

How to participate


ESIR reporting form


Protocol for BIPM.RI(II)-K5 comparisons

Ionizing Radiation - contact Radionuclides



BIPM Ionizing Radiation Department - Radionuclide Metrology