Thin-film SnO2 sensor arrays controlled by variation of contact potential -: a suitable tool for chemometric gas mixture analysis in the TLV range

The selectivity of SnO2 thin-film gas sensors can be modulated by changing the contact areas of the contact electrodes. The investigated SnO2 arrays have been structured with two mask steps only. Gas mixture analysis in the German threshold limit value (TLV) range has been performed with an integrated thin-film sensor array using principal component regression (PCR) analysis. As an example, NO2, CO, CH4 and H2O mixtures in air have beer, analyzed. In this case additional doping materials, catalysts, temperature gradients, etc., to enhance selectivity are not necessary. (C) 1997 Elsevier Science S.A.