Research on Sectional Nominal Mathematical Model of Piezoelectric Pressure Measurement System Based on Quasi-Static Calibration

Quasi-static calibration is an important method to obtain the working characteristics of piezoelectric pressure measurement system. However, the straight working line equation, which is obtained by fitting the amplitude of quasi-static pressure pulses, cannot reflect the different response characteristics of piezoelectric pressure measurement systems to quasi-static pressure pulses with different amplitude. In this article, a second-order differential equation with constant coefficients is used to describe the mathematical model of the piezoelectric pressure measurement system. The method to obtain the nominal sectional mathematical model of the piezoelectric pressure measurement system is given. Quasi-static calibration tests show that the response characteristics of piezoelectric pressure measurement system to quasistatic pressure pulses with different amplitude are obviously different. The static sensitivity of the piezoelectric pressure measurement system to quasistatic pressure pulses with different amplitude increases with the increase of pressure amplitude. Compared with the straight working line equation of piezoelectric pressure measurement system, sectional nominal second-order differential equation with constant coefficients can effectively reduce dynamic test errors.