AC Bridge Pressure Sensor With Temperature Compensation for High Temperature and Pressure Composite Environment

In this article, a high-temperature resistant ac bridge pressure sensor is designed for the application of high temperature and pressure combined environment. The temperature drift error compensation of the pressure sensor is realized by designing and arranging the structure of temperature-sensitive and pressure-sensitive capacitors connected with the bridge. In particular, the sensor alumina ceramic substrate is prepared by the lamination postsintering process of green tapes, and the silver paste is tightly integrated on the alumina ceramic surface by the inkjet printing postsintering process. Among them, the high-temperature and pressure-sensitive compact cavity is formed by the creative carbon film filling process before the multilayer green tapes lamination. Finally, three sets of high temperature and temperature-pressure composite test platforms were built and the comprehensive performance of the sensor was tested. The results show that the sensor can work at a high temperature of not less than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$700~^{\circ }$ </tex-math></inline-formula>C and can complete the combined high temperature and high pressure test at a high temperature of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$23~^{\circ }$ </tex-math></inline-formula>C–<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$400~^{\circ }$ </tex-math></inline-formula>C, in which the test error at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$400~^{\circ }$ </tex-math></inline-formula>C is less than 3.3%.