Final report on the on-going comparison BIPM.EM-K12: Comparison of quantum Hall effect resistance standards of the PTB and the BIPM

Abstract

An on-site comparison of the quantum Hall effect (QHE) resistance standards of the Physikalisch-Technische Bundesanstalt (PTB) and of the Bureau International des Poids et Mesures (BIPM) was made in November 2013. Measurements of a 100 Ω standard in terms of the conventional value of the von Klitzing constant, RK-90, agreed to 5 parts in 1010 with a relative combined standard uncertainty uc = 22 × 10−10. Measurements of 10000 Ω/100 Ω and 100 Ω/1 Ω ratios agreed to 7 parts in 1010 with uc = 19 × 10−10 and to 8 parts in 1010 with uc = 40 × 10−10, respectively. An investigation of the Peltier effect present in 1 Ω standards was carried out during this comparison and is also reported, as it was found to be the limiting factor in these measurements.