Research on Compensation Method of Temperature Drift in Pressure Sensor Using Double Wheatstone-Bridge Method

Abstract

this article deals with the influence of temperature on the output sensitivity of the piezo-resistive pressure sensor. In order to reduce the temperature drift of output for the piezo-resistive pressure sensor, the double Wheatstonce-bridge method is adopted to test the sensor with the ternperature controlled at the range of 300~373 K. Tlre results indicate that the temperature drift of the sensor output can be lowered by over 70% to improve surveying accuracy. Pressure senter is widely applied to many fields of the industry, so its accuracy can directly influence the quality of surveying system. Since the piezo-resistive pressure sensor is mostly made of semiconductor materials, the sensitivity and linearity of silicon sentor will be affected to some extent, among which non- linearity is connected with dopant density, temperature and pressure. In ideal condition, four resistor strips are equal in variables with temperature changing, in this way, electric bridge can keep balance to eliminate the effect of tempereature on the sentor. But it’s not the case in reality, temperature drift of output for the piezo-resistive pressure sensor is unavoidable, so some technical methods should be adopted to control the phenomenon. Temperature drift, playing an important role in affecting the quality and accuracy of sentor, has drawn public concern. Document 2 intrduces how to adjust supply voltage to control temperature drift of output for the piezo-resistive pressure sensor. Document 3 intrduces temperature compensation in the sensitivity of sentor. This article aims at making use of four resistors with negative temperature and Wheatstonce-bridge to reduce temperature drift and improve output accuracy of pressure sentor