Determination of the unit of resistance and the von Klitzing constant Rk based on a calculable capacitor

The calculable cross capacitor according to Thompson and Lampard allows the unit of capacitance, the farad, and thus the unit of resistance, the ohm, and the von Klitzing constant R (k) to be determined in SI units with high accuracy. The underlying electrostatic theorem and the design criteria of a cross capacitor are described, and the influence of imperfections of the electrode system are discussed. The main components of the measuring chain from the farad to the ohm are illustrated.