CIPM MRA COMPARISON REPORTS

The EURAMET.L-K3.n01 key comparison on angle measurements, piloted by INRIM, was initiated following a decision of the EURAMET Technical Committee for Length (TC-L) in 2018. The comparison was registered in 2021, with artefact circulation taking place from June 2021 to September 2023. Participating laboratories measured the deviation of the pitch angles from the nominal values of a 12-sided optical polygon to demonstrate their measurement capabilities and support Calibration and Measurement Capabilities (CMCs) in this field. The stability of the artefacts was maintained throughout the comparison, and no significant correlations were identified between participants. The comparison results showed generally good agreement among the laboratories in Group 1, with 10 of 156 reported results exhibiting |En| values greater than 1, compared with 22 of 120 results in Group 2. Overall, the comparison demonstrated a satisfactory degree of equivalence for most participants and provided evidence supporting existing and future CMC claims in the calibration of angle standards.

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 CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).