Novel and low-cost temperature compensation technique for piezoresistive pressure sensors

Abstract

This paper proposes a low-cost technique to compensate for the temperature dependence of piezoresistive pressure sensors configured in a Wheatstone bridge. The sensor is treated as a resistive circuit and three equivalent resistances are measured by setting appropriately the bridge terminals. One of these equivalent resistances depends on temperature but not on pressure and, hence, it can be used to compensate for the temperature dependence of the output parameter. In such a way, neither data of a previous temperature calibration nor additional components are required to compensate for the temperature dependence. The proposed technique is applied to a commercial pressure sensor, which is measured by means of a direct sensor-tomicrocontroller interface circuit. Experimental results show that temperature effects on the pressure measurement decrease more than ten times when the proposed technique is applied.