RMO Supplementary Comparison EURAMET.EM-S46 High voltage comparison of DC ratio

Main text Different methods were used for the 20000:1 high DC voltage ratio (scale factor) calibration up to 200 kV by the participating laboratories. The traceability was based either on calibration of divider resistance values at 1 kV, or on voltage-ratio based devices used at 1 kV, 10 kV or 50 kV. Voltage-ratio based devices were traceable either to a Josephson voltage standard or to a self-calibrating ratio standard. After removal of one outlier, the expanded uncertainty (k=2) of the reference value at 1 kV was 1.7·10 -6 , increasing up to 3.2·10 -6 on higher voltages. Comparison on voltages above 1 kV was based on the low voltage calibration, and on the previously determined voltage coefficient of the divider design. 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 CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).