Reproducibility of calibration results by 0-A-0 pressurization procedures for hydraulic pressure transducers

This paper focuses on 0-A-0 pressurization for the calibration of electromechanical pressure gauges in order to obtain reproducible results by various procedures. In 0-A-0 pressurization, pressure is released to atmospheric pressure after finishing each measurement at each calibration pressure, and the output reading at atmospheric pressure is used for offset correction. Pressure gauges are calibrated under various pressure sequence and time interval conditions in the pressure range of 10 MPa to 100 MPa using a fully automated calibration system that uses a pressure balance as the standard device. Results for a quartz Bourdon-type pressure transducer are mainly reported. The hysteresis obtained by 0-A-0 pressurization is found to be nearly one-tenth of that obtained by stepwise pressurization. The effect of the previously applied pressure is less than 10 parts per million even for a random pressure sequence. Key points for calibration procedures are proposed from the calibration results for different time intervals. When the appropriate procedure is used, 0-A-0 pressurization largely reduces the effect of pressurization history, thus yielding highly reproducible calibration results.