Response Optimization of a Chemical Gas Sensor Array Using Temperature Modulation

Abstract

This paper consists in the design and implementation of a simple conditioning circuit to optimize the electronic nose performance, where a temperature modulation method was applied to the heating resistor, in order to study the sensor’s response and determine whether they are able to make the discrimination when are exposed to different Volatile Organic Compounds (VOC’s). This study was based on determining the efficiency of the gas sensors to be used in order to perform an Electronic Nose, improving the sensitivity, selectivity and repeatability of the measuring system and selecting the type of modulation (e.g. Pulse Width Modulation) for the analytes detection (i.e, Moscatel wine samples (2% of Alcohol) and Ethyl-Alcohol (70%)). The results demonstrated that using temperature modulation technique to the heater of sensors, it is possible to achieve a good discrimination of VOC's in fast and easy form, through a chemical sensors array. A discrimination model based on Principal Component Analysis (PCA) was implemented to each sensor, and data responses obtained gave a variance of 94.5% and 100% accuracy.