Bilateral Comparison of 1.018 V and 10 V Standards between EMI (United Arab Emirates) and the BIPM, January to March 2025 (part of the ongoing BIPM key comparison BIPM.EM-K11.a and b)

Main text As part of the ongoing BIPM key comparison BIPM.EM-K11, a comparison of the 1.018 V and 10 V voltage reference standards of the BIPM and the Emirates Metrology Institute (EMI), United Arab Emirates, was carried out from January to March 2025. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_A (ZA) and BIPM_D (ZD), were transported by freight to EMI and back to BIPM. In order to keep the Zeners powered during the transportation, a voltage stabilizer developed by the BIPM was connected in parallel to the internal battery. At EMI, the reference standard for DC voltage is a 732B Zener standard traceable to a primary voltage standard by means of a calibration service requested from a National Metrology Institute (NPL, United Kingdom). The output electromotive force (EMF) of each travelling standard was measured against the Zener voltage standard by means of an accurate multimeter, which is used as a null detector. At the BIPM, the output EMF of each travelling standard was calibrated before and after the measurements at EMI against a Programmable Josephson Voltage (PJVS). Results of all measurements were corrected by the BIPM for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by EMI, at the level of 1.018 V and 10 V, at EMI, U EMI , and those assigned by the BIPM, at the BIPM, U BIPM , at the reference date 2 February 2025. U EMI - U BIPM = -0.31 µV; u c = 0.37 µV, at 1.018 V U EMI - U BIPM = -1.20 µV; u c = 1.54 µV, at 10 V where u c is the combined standard uncertainty associated with the measured difference, including the uncertainty of the realization of the volt at EMI, at the BIPM, and the uncertainty related to the comparison. 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).