Humidity dependence of a TGS gas sensor array in an air-conditioned atmosphere

In real-life conditions of use, gas identification by a tin oxide gas senso r is quite difficult because of its lack of selectivity and humidity and te mperature dependency. To solve these problems, these kind of sensors are gr ouped in an array, and powerful pattern recognition methods are used. In th is work, a preliminary study is presented to show the influence of relative humidity on the response to a dry refrigerant gas concentration. Afterward s, we present the characterisation of three TGS type gas sensors (TGS 800, TGS 813 and TGS 832) submitted to multiple relative humidity rates in synth etic air. Their responses are presented in terms of dynamic and steady-stat e responses. Simulated models are proposed to approach the sensors' respons es and could be used in pattern recognition methods. (C) 1999 Elsevier Scie nce S.A. All rights reserved.