Impedance Bridge Ratio Transformer Calibration by Reference-Step Conductance Build-Up

A reference-step conductance build-up method suitable for automation has been developed for calibrating the ratio dial transformer of a wide-range impedance bridge. The uncertainties over the range 40 Hz to 20 kHz are estimated not to exceed 0.2 muV/V referred to the divider input voltage. At 100 kHz, the uncertainties do not exceed 2muA7V