A QHE-based system for calibrating impedance standards

Coaxial transformer bridges applied to a newly formed system for calibrating impedance standards are described. In this system, an R-R bridge characterizes reference quantum Hall devices as well as directly links them to 12906.4 (Omega) or 10000 (Omega) standard resistors. These resistors, in turn, serve as reference standards in capacitance calibrations made by a multifrequency quadrature R-C bridge and a C-C bridge. Finally, by means of a multifrequency double-balance L bridge, 1and 10-nF capacitors calibrated in this manner are linked to inductance standards whose values range from 1 to 100 mH.