Design and implementation of a kind of high precision temperature compensating system for silicon-on-sapphire pressure sensor

Abstract

In order to reduce the temperature effects on the testing accuracy of the silicon-on-sapphire high-temperature large-range pressure sensor, a miniaturized portable silicon-on-sapphire pressure sensor temperature compensation system is designed and implemented after solving the following three issues: temperature compensation structure design, temperature compensation circuit fabrication, and temperature compensation algorithm implementation. The simulation results indicated that the temperature of the test circuit part of the package structure is close to 30 °C at an ambient temperature of 30 °C, with the sensor sensitive element at 250 °C working temperature and 28 MPa ultimate pressure. Regarding to the problem of large sensor drift in high-temperature environments, a temperature compensation algorithm combining least squares and Lagrange interpolation is designed based on the input and output characteristics of the sensor. The algorithm improves the computational efficiency while also increasing the hysteresis error and nonlinear deviation of the sensor to 0.028%. The test results of the NIM (National Institute of Metrology, China) show that the measurement accuracy of the sensor is higher than 1‰ FS within −20 °C to 140 °C and higher than 3‰ FS within 140 °C to 250 °C.