Heat exchange and temperature calculation in thick-film semiconductor gas sensor systems

The precise knowledge of the operating temperature is a very important topic in the field of gas sensing. Experimental evidence suggests in fact that not only the temperature of the film but also that of the air in the immediate contact with the sensing layer is crucial to determine the sensor's behavior. In this paper we analyze the main factors which contribute to heat exchange inside the test chamber; a system of three equations is proposed to calculate the temperature in the various zones of the system, in particular that of the gas adjacent to the sensor. The model, applied to the system operating in flow, was in good agreement with the experimental data.