Final report of APMP.AUV.V-S2: supplementary comparison on calibration of laser tachometers using mechanical generators or optical simulators

This is the final report for APMP supplementary comparison APMP.AUV.V-S2 in the area of 'vibration' (quantity of rotational speed). The aim of this comparison was to compare primary measurements of rotational speed in the range from 30 r/min to 99 996 r/min. Six Metrology Institutes from two RMOs, APMP and AFRIMETS, have participated in the comparison with the National Institute of Metrology, P.R. China as the pilot lab. NIM, NMC and NIS used a mechanical generator for calibration, with expanded uncertainties in the order from 10-3 to 10-5. NML, NIMT and KEBS used an optical simulator for calibration, with expanded uncertainties in the order from 10-4 to 10-5. All the participating laboratories provided their calibration results, which were all consistent within their declared expanded uncertainties for the measurement results. Each participant contributed to the SCRVs calculated for five rotational speed comparison values of two laser tachometers, NLYZ-02 and 03, except that NIS's measurement results of NLYZ-03 are invalid. Smaller measurement uncertainties than the order of 10-5 for the calibration of laser tachometers are difficult to achieve for either mechanical generators or optical simulators with the current technology of rotational speed standard devices and laser tachometers. 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 CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).