Quasi-static absolute calibration method of piezoelectric sensors for pressure measurement

There exit electrostatic leakage and drift during static calibration with piezoelectric pressure-measuring sensors. In allusion to this phenomenon, the quasi-static absolute calibration method of piezoelectric sensor for pressure measurement is presented, which is base on a semi-sinusoidal pressure generator. Six holes were designed around the oil cylinder of the half-sine pressure generator, four of which were installed with standard sensors providing measured pressure values and the other two for the sensors to be calibrated. First of all, the measured pressure consistency of the four standard sensors was monitored. The data pairs, the initial height of drop hammer and the pressure measured, were selected to compute the absolute calibration model subsequently. Finally the absolute calibration with sensors to be calibrated was carried into execution with the model above. The verification experiment of model precision shows that it meets the precision demand of notional shooting range for the pressure sensor calibration. The relative deviation is in the range of ±1% within 100MPa∼500MPa pressure segment, and in the range of ±3% in 40MPa∼100MPa segment.