Abstract. The main objective of the EUROMET project 702 was to compare the extent of comparability among eleven participating European national metrology institutes (INRIM (IT), OMH (HU), PTB (DE), BEV (AT), IPQ (PT), LNE (FR), MIKES (FI), GUM (PL), SMU (SK), UME (TR) and VNIIM (RU)) in performing calibrations of high-resolution hydrometers for liquid density determination in the range between 600 kg m^-3 and 1300 kg m^-3. By means of two groups of four similar transfer standards of excellent metrological characteristics, the participating laboratories were initially divided into two groups (petals) linked by the three density laboratories of INRIM, OMH and PTB.

The results of the participating laboratories have been analyzed in this report and a good agreement was found between the results provided by most of the participants. These results allowed also determination of the degrees of equivalence of each NMI participating with the EUROMET_key comparison reference values (EU_KCRV); they will provide a basis for the review of the Calibration Measurement Capabilities (CMC) entries on hydrometer calibration, and they allowed the degree of equivalence between pairs of NMIs to be established.

The Istitituto Nazionale di Ricerca Metrologica (INRIM), Italy, formerly IMGC-CNR, coordinated the project.

Main text. 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 kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).