METHODS FOR ENHANCING REPRODUCIBILITY OF CALIBRATION RESULTS FOR HYDRAULIC PRESSURE TRANSDUCERS

摘要

The effects of the calibration procedure on the results are investigated for quartz Bourdon-type hydraulic pressure transducers. A fully-automated system that uses a pressure balance as the standard device has been developed for the calibrations at pressures from 10 MPa to 100 MPa. The effect of the interval between the calibration cycles and the effect of preliminary pressurization are quantitatively evaluated for two kinds of calibration cycles, stepwise and 0-A-0-type calibration cycles. For the stepwise cycle, the interval between the calibration cycles strongly affects the results in the pressure increasing process. The preliminary pressurization reduces the influence of the interval on the results. However, in turn, the waiting time between the preliminary pressurization and the main calibration cycle exerts a strong influence on the results. For the 0-A-0-type calibration cycle, the effect of the interval on the results is almost half of that for the stepwise cycle. Moreover, with preliminary pressurization, the calibration results are rarely affected by the interval. From the results, possible methods for obtaining reproducible calibration results are discussed.