Absolute determination of the farad and the ohm, and measurement of the quantized Hall resistance RH(2) at LCIE

A calculable five-electrode cylindrical capacitor is used at Laboratoire Central des Industries Electriques (LCIE) for the absolute determination of the farad. The ac measurements linking the calculable standard to the resistors of a quadrature bridge are made at two different frequencies: ω = 2500 rad /s and ω = 5000 rad/s. The resistors of the quadrature bridge are linked to Ω
LCIE
and to the quantized Hall resistance R
H
(2) thanks to a resistance ratio measurement bridge using a cryogenic dc current comparator. The total one-standard-deviation (1σ) uncertainty on the measurement of R
H
(2) is 2.2 × 10
⁻⁷
.