SnO/sub 2/ sensors with variable operating temperature for CO detection: selectivity enhancement

SnO/sub 2/ sensors are widely used for the detection of air contaminants such as CO. Nevertheless, their application encounters many problems, first of all the effect of interfering gases. The low selectivity is in fact a well-known problem of these sensors. Moreover, the high operating temperature of metal oxide sensors implies in general high power consumption. In this work we present a study aimed at the selection of an appropriate measurement technique for the detection of CO for indoor applications (100 ppm CO), also in presence of high concentrations of ethanol (1000 ppm C/sub 2/H/sub 5/OH). Moreover, the work aims at developing very low size and power consumption devices, that could be battery operated, to be used for the development of portable CO detectors.