Enhancement of gas selectivity by additives and pattern recognition in SnO/sub 2/ sensors

Using gas chromatography (GC), the effect of additives on the decomposition reactions of both reducing gases (CH/sub 3/OH, C/sub 2/H/sub 5/OH, etc) and an oxidizing gas (CH/sub 3/CN) was analyzed for the selection of proper additives. The effect of additives was further investigated in terms of the sensing characteristics. Based on these studies, two sensors, PdCl/sub 2/-added SnO/sub 2/ and La/sub 2/O/sub 3/-added SnO/sub 2/, showing discriminative sensing behaviors to CH/sub 3/CN were selected. By combining the signal patterns obtained from the two sensors, selectivity of the SnO/sub 2/ sensors for CH/sub 3/CN was highly enhanced.