Identification of toxic gases with a sensor array using temperature modulation

This paper describes a procedure to improve the sensor selectivity using a sensor array which is built with four sensors (Figaro and MiCS sensors). The heating temperature of each sensor is modulated between 200/spl deg/C and 450/spl deg/C by a triangular signal with a frequency of 25 mHz. Principal component analysis is used to discriminate among three reducing gases (carbon monoxide, acetylene and hydrogen sulfide). New data of unknown gas are tested and the identification results demonstrate the potentiality of this method.