Abstract
This study focuses on the effects of the calibration protocol on the results for hydraulic pressure transducers. Using a fully-automated calibration system that uses a pressure balance as the standard device, quartz Bourdon-type hydraulic pressure transducers were calibrated at pressures from 10 MPa to 100 MPa. Two kinds of calibration procedures, stepwise and 0-A-0-type procedures, were applied to pressure increasing and decreasing cycles. For the stepwise procedure, the interval between the calibration cycles exerts a strong influence on the results in the pressure increasing process. The preliminary pressurization immediately before the cycle can reduce the effects of the interval. However, in turn, the waiting time between the preliminary pressurization and the main calibration cycle considerably affects the results. Results with the 0-A-0-type procedure differ from those with the stepwise procedure. In particular, hysteresis becomes much smaller because the effect of previously applied pressure is reduced by the pressure release to zero pressure. From the results, possible measures for obtaining reproducible calibration results are presented.