Multi-sensors exhaust gas emission monitoring system for industrial applications

The measurement systems commonly used for exhaust-gas composition analysis in industrial applications are usually expensive. Moreover, they need frequent calibration procedures to guarantee the measurement accuracy. The portable gas analyzer proposed in this paper takes into account a tradeoff between calibration time and device cost while maintaining an accuracy comparable with the standard instruments. The instrument is composed by a sensor array, based on both electrochemical and chemoresistive low-cost sensors, a measurement chamber, a custom front end electronics, and a PC-based acquisition and processing system. Specific processing algorithms have been designed to compensate problems such as sensor drift, sensor cross sensitivity to different gases, and dependence of the sensor response on temperature and humidity.