Temperature drift and compensation techniques for the thermal conductivity Gas sensor

The thermal conductivity gas sensor will have a large temperature drift when the environment temperature changes. In order to reduce the influence on measuring accuracy brought by temperature drift this paper makes heat transfer mechanism theoretical analyses on the thermal conductivity gas sensor and takes it as a basis to analyze the reason for the temperature drift. At last, we put forward an easy way to achieve sensor temperature drift compensation based on analog circuit. This method is based on the voltage temperature coefficient between sensitive element and reference element. Series connect a proper compensation resistor to make the voltage temperature coefficient between sensitive element and reference element same so as to realize temperature drift compensation. In this paper, we determined the relationship between the voltage temperature coefficient of the sensitive and reference element and the compensation resistor value to build a temperature compensation model of the thermal conductivity gas sensor. This temperature drift compensation method prove to be correct and effective through the experimental research and theoretical analysis which can reduce the influence on measuring accuracy brought by temperature drift of thermal conductivity gas sensor effectively and provide a new design idea and implementation method for the this kind of sensor.