Update of the BIPM comparison BIPM.RI(II)-K1.Gd-153 of activity measurements of the radionuclide ¹⁵³Gd to include the 2020 result of the NIST (United States)

Since 1988, 3 laboratories have submitted 5 samples of ¹⁵³Gd to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)- K1.Gd-153. Recently, the NIST (United States) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. (authors)