Discrimination of carbon dioxide and forane R134a using Figaro-type sensors TGS 832

In this paper, we present the effect of a mixture of carbon dioxide and for ane R134a, (two antagonist gases) in dry synthetic air on the response of a Figaro-type gas sensor, TGS 832. This characterization shows different beh aviour according to the first introduced gas in the mixture and a modificat ion of the sensor response to carbon dioxide. Due to the long time taken to reach the steady-state value, the dynamic slope of the conductance is stud ied as a function of the gas nature and its concentration. We then use disc riminant factorial analysis to validate the choice of the criteria (steady- state and slope values of the conductance) to determine the gas nature (pur e gas or mixture). (C) 1999 Elsevier Science S.A. All rights reserved.