Final report of APMP comparison of mass standards APMP.M.M-K5 (Sub-) multiples mass key comparison

Main text This report describes a key comparison of mass standards APMP.M.M-K5, conducted between 19 participating members of the Asia-Pacific Metrology Programme (APMP). The APMP.M.M-K5 comparison was launched during the 13th meeting of the Technical Committee for Mass and Related Quantities APMP-TCM (2012).Two sets of stainless steel weights with five nominal mass values: 2 kg, 200 g, 50 g, 1 g, and 200 mg were used as travelling standards. These nominal values were chosen as they followed the nominal values of CCM.M-K5. The aim of the comparison is to verify the consistency of 2 kg, 200 g, 50 g, 1 g and 200 mg stainless steel mass standards among members of APMP-TCM. The program was piloted by the National Institute of Metrology, P.R. China (NIM). All the participants have provided their support and help to successfully organize and run the comparison. The nominated 19 participants have been divided into five petals and the corresponding five sets of transfer standards have been circulated within the groups simultaneously. The pilot laboratory measured the volumes and the magnetic properties of the standards before the circulation and had reported these values to the participants. The pilot laboratory has also verified the stability of all travelling standards for more than one year. The set of five weights was circulated among all the participating laboratories in August 2015 and received back from the last participant in August 2016. The final report of this comparison is being given in this document. To reach the main text of this paper, click on Final Report . Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/ . The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).