Abstract
An on-site comparison of the quantum Hall effect (QHE) resistance standards of the PhysikalischTechnische Bundesanstalt (PTB) and of the Bureau International des Poids et Mesures (BIPM) was made in October 1995. Measurements of a 100 Ω standard in terms of RH(2), the quantized resistance corresponding to the quantum number 2, agreed to -5,5 parts in 1010 with a relative combined standard uncertainty uc = 19 × 10-10. Measurements of 10 000 Ω/100 Ω and 100 Ω/1 Ω ratios agreed to -4 parts in 1010 with uc = 19 × 10-10 and 12 parts in 1010 with uc = 26 × 10-10, respectively.