EFFECT OF CH4, SO2 AND NO ON THE CO RESPONSE OF AN SNO2-BASED THICK-FILM GAS SENSOR IN COMBUSTION GASES

SnO//2-based thick film gas sensors were constructed, and their sensitivities to CO, CH//4, SO//2 and NO in the concentration range 0 to 1000 ppm were studied. The composition of the carrier gas was chosen so as to simulate the composition of the exhaust gases of a combustion process. The selectivities of the sensors to CO were studied by determining the response when one of the gases CH//4, SO//2 or NO was the interfering gas. Preliminary studies were also carried out with actual exhaust gases formed in a pilot combustion process by comparing the CO response of the sensors to that given by an infrared analyser.