Trilateral Comparison Among Digital and Josephson Impedance Bridges

In this work, we present the results of an onsite trilateral comparison between a dual Josephson impedance bridge developed by METAS and the electronic fully-digital impedance bridges developed by CMI and INRIM-POLITO. The target accuracies of the bridges are at the 10
⁻⁸
level for the former and at the 10
⁻⁷
for the latter. Here we report the results of the calibration of a 10nF capacitance standard against a 12.9kΩ calculable resistance standard at 1233Hz, conditions suitable for the primary direct realization of the impedance units ohm and farad from AC quantum Hall resistance standards or from AC/DC calculable transfer resistance standards calibrated against DC quantum Hall resistance standards.