SNO2 THIN FILM GAS SENSORS FOR FIRE-ALARM SYSTEMS

Abstract This paper presents results of studying of SnO 2 thin films gas sensors (TFGS) sensitivity to the combustion products. The influence of operating temperature and the kind of a combustible material on TFGS sensitivity to the products of combustion and smouldering was considered. The kinetic characteristics of gas sensors as smoke sensors were determined. The specifics of a combustion products influence on gas sensitive characteristics of gas sensors are noted. In comparison on with CO sensors, the smoke sensors have a more wide temperature range of sensitivity γ with some maximums, a greater hysteresis of γ( T ) and a longer time of restoration of initial condition. It was established that gas sensors as smoke sensors have high sensitivity (γ>10) and may be used as sensitive elements in fire-alarm systems. The temperature regimes of their exploitation are discussed also.