CIPM MRA COMPARISON REPORTS

This report contains the comparison results of ten national metrology institutes (NMIs) that participated in the CCEM-K5.2017 key comparison of 50-60 Hz active power. In the comparison, two travelling standards were sent around and measured at ten test points, for five different power factors at both 120 V – 5 A and 240 V – 5 A. The total measurement period spanned from March 2018 until August 2022, and was affected by customs issues, the outbreak of the covid pandemic, and the request for re-measurements by VSL and NIST. The comparison results were generally good, but in some cases the NMI results were slightly inconsistent with the key comparison reference value. This is likely caused by underestimated systematic effects that have resulted in underestimated uncertainties reported by the participants.

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