Humidity compensation based on power-law response for MOS sensors to VOCs

Abstract

• Convert temperature and relative humidity into one variable, namely absolute humidity to compensate the sensors. • Based on the law of power law response, a compensation model is established and the parameters can be calibrated. • The performance of this model is verified in experimental systems and application of electronic nose, respectively. The compensation model for humidity is proposed for Metal oxide semiconductor (MOS) sensors to respond to volatile organic compounds (VOCs) vapor. There are four frequently-used sensors were investigated for the detection of three typical VOCs, namely, acetone, ethanol and methanol. In this study, water vapor was treated as a reactant involved in the response, then a model is proposed based on the power law response. As the resistance of sensor and humidity enter the model, the detected gas concentration will be output. The effect of model is well verified on the experimental system. Even the model was applied to electronic nose to improve the recognition results. It indicates that our method is of great value to system that needs to remove the interference of water vapor.