Final report on EURAMET key comparison EURAMET.M.D-K2.2 (1523)

The key comparison EURAMET.M.D-K2.2 (1523)on the density of liquids determined by oscillation type density meters was organized and carried out within the framework of the EMPIR project 17RPT02 "rhoLiq". Density measurements of liquids are mainly performed by laboratories calibrating or checking liquid density measuring instruments such as oscillation-type density meters. Another aim of this comparison was to establish traceability for liquid density measurements at emerging National Metrology Institutes (NMIs) to enable them to provide high-level measurement and calibration services for national stakeholders, e.g. food, chemical, pharmaceutical and petroleum industries. The results of this comparison can be used to claim calibration and measurement capabilities (CMCs).Most European emerging NMIs in this project had not yet participated in comparisons or obtained unsatisfactory results, or the uncertainty had an unfit magnitude for purpose.BEV (Austria) piloted this comparison, supported by PTB (Germany).Samples of deuterated water, tetrachloroethylene and oil of high viscosity were measured in the temperature range from 5 °C to 20 °C at atmospheric pressure by hydrostatic weighing for this comparison.The coronavirus pandemic caused delays in the proposed initial schedule of this key comparison. Measurements were performed in 2021. The reference values of the key comparison were linked to CCM.D-K2 for PTB and EURAMET.M.D-K2 for BEV.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).