Final report on COOMET.M.M-K5: Key comparison in the field of multiples and submultiples of the kilogram (COOMET 258/RU/02)

This report summarizes the results of a comparison of mass standards conducted between four participating members of the Euro-Asian Cooperation of National metrological Institutes (COOMET). The COOMET key comparisons are usually carried out on those schemes that were proposed and implemented by the Consultative Committee for Mass and Related Quantities of the CIPM. Measurement comparisons bring to the laboratories confidence in the measurement standards and lead to their international acceptance. This comparison arose from discussions at the 9th meeting of TC 1.6 'Mass and Related Quantities' on 21-23 April 2004, SMU, Slovakia. The comparison is internally identified as COOMET 258/RU/02 and corresponds to the KCDB identifier COOMET.M.M-K5, as attributed by the BIPM. The purpose of the key comparison COOMET.M.M-K5 'Comparison in the field of multiples and submultiples of the kilogram' is to compare the results of measurements obtained by the participants. Two weights sets with five nominal mass values 2 kg, 200 g, 50 g, 1 g and 200 mg (OIML Class E1) were used as transfer standards. These nominal values were chosen to follow the second phase of the CCM key comparison CCM.M-K5. The All-Russian D I Mendeleyev Research Institute for Metrology, VNIIM, was the pilot laboratory as well as the linking laboratory to CCM.M-K5. The comparison was carried out from May 2015 to July 2008. In 2007, measurements were carried out by Kazakhstan Institute of Metrology (RSE 'KazInMetr') on their own initiative. The computation of the degrees of equivalence shows a generally good agreement between participants.