Improved setup for bridge standard calibration up to 5 kHz

Abstract

This paper presents an improved calibration setup for static bridge standards with carrier frequency supply voltage in the frequency range between 225 Hz and 5 kHz. In the past the small bridge differential voltage in the mV/V range was calibrated in two subsequent voltage ratio calibrations. However, this procedure was time consuming and only works reliably if both voltages are stable over time. For this purpose a new setup was developed which is able to measure the differential voltage of the bridge standard in one single measurement. This improves the calibration time to approx. one third with reduced uncertainty.