Performance of the binary compensation unit for cryogenic current comparators

The binary compensation unit for PTB's resistance measurement bridge based on a cryogenic current comparator (CCC) is successfully operated for about three years now. In this contribution we focus on the stability of the compensation unit as investigated in a series of calibrations in 20-weeks intervals. As an example of the versatility, we present experimental data from the calibration of a 100 Ω normal resistor against the quantum Hall resistance (QHR) for different numbers-of-turns and compensation settings. The consistency of these results is a proof of the quality of this module.