Thin film metal oxide gas sensor array for gas detection

Abstract

This paper presents how an array of sensors with various sensitivities can be used for reliable detection and recognition of gases. An array of six different thin film metal oxide gas sensors has been constructed and tested. The selected sensors are based on indium, zinc, tin and titanium thin film oxides deposited by reactive magnetron sputtering. Sensors operate inside a measuring chamber at elevated temperatures of 250 – 300°C. The sensors responses upon hydrogen and ammonia exposure (0 – 3000 ppm) at relative humidity (0 – 75%Rh) are studied. The results show that exploiting the cross sensitivity and different sensing performance of the sensors allows to increase the reliability of gas sensing at relatively low operating temperatures.