Abstract
A new type of a temperature-compensated sensor system, which detects dissociation heat caused by ozone decomposition, is suggested. The detection principle is almost identical to that of a catalytic combustion (pellister-type) sensor except that the suggested sensor does not utilize catalytic materials. A sensing device with catalyst and a compensating device without catalyst have been utilized at the same operating temperature in a conventional catalytic combustion sensor to form a bridge configuration. In the proposed sensor system, sensing devices of identical characteristics without any catalysts are adapted for both sensing and compensating devices. However the operating temperatures of the two devices are different. The sensing device is operated well above the decomposition temperature of ozone, whereas the operating temperature of the compensating device is below the decomposition temperature. Signals of the two devices are amplified with the corresponding gains to cancel the temperature dependences of the two devices, when ozone is not present. Ozone decomposes by itself upon contact with the sensing device owing to thermal decomposition and generates the heat. The thermal decomposition does not take place at the compensating device.
