High-Temperature Self-Compensating Absolute Micro-Pressure Sensor and Its Testing Method

In this study, we designed an absolute pressure micro-pressure sensor, with its testing method based on the requirements of high-temperature resistance, self-compensation, and micro-pressure test. The substrate of the sensor is made of raw porcelain through high-temperature sintering, and the functional layer is integrated into the surface of the substrate by silver paste through a screen-printing process. Therefore, the sensor has high temperature resistance. The ceramic base of the sensor is prepared based on the principle of film stress and strain measurement of micro pressure by filling carbon film in raw porcelain layer and using a high-temperature sintering process to obtain an air-tight cavity structure. In the preparation of the functional layer, a unique differential capacitance structure is constructed on the surface of the substrate using the screen-printing process. This hardware temperature self-compensation structure enables the high-precision measurement of the sensor. Finally, the high temperature and absolute pressure micro-pressure sensor are combined with a
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–
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conversion circuit to complete the test on the high-temperature-micro pressure composite test platform. The experimental results show the sensor can measure the absolute pressure from 3 to 100 kpa in the temperature range of 23 °C to 300 °C, and the repeatability error of the pressure test is less than 3.3% at 300 °C.