On-site comparison of Quantum Hall Effect resistance standards of the NMC A*STAR and the BIPM: Ongoing key comparison BIPM. EM-K12

The ongoing on-site comparison BIPM.EM-K12 is part of the BIPM programme implemented to verify the international coherence of the primary resistance standards. It allows National Metrology Institutes (NMIs) to validate their implementations of the Quantum Hall Effect (QHE) for dc resistance traceability by comparison to the reference maintained at the BIPM. The realization of the ohm from the QHE-based standard of the NMIs at 100 Ω is compared with that realized by the BIPM from its own transportable quantum Hall resistance standard. This comparison is usually completed by scaling measurements from 100 Ω to 1 Ω and 10 kΩ through the measurement of the resistance ratios 100 Ω/1 Ω and 10 kΩ/100 Ω, respectively. In March 2019, a new BIPM.EM-K12 on-site comparison was carried out at the National Metrology Centre, NMC A*STAR (Singapore). It was the first time the NMC A*STAR participated in this comparison programme. Only the measurement results of the 100 Ω based on the quantum Hall effect and of the 10 kΩ/100 Ω ratio are presented in the report. The reason why the results of the 100 Ω/1 Ω ratio were not included is explained in the introduction of the report. Measurements of the 100 Ω transfer standard in terms of the SI value of the von Klitzing constant, RK, agreed to 1.6 parts in 109 with a relative combined standard uncertainty u c = 3.3 × 10−9. Measurements of 10 kΩ/100 Ω ratio agreed to 2.0 parts in 109 with u c = 2.8 × 10−9. 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).