A novel solid state carbon monoxide sensor

摘要

Carbon monoxide (CO) detection for homes and the workplace has become more important with the increase in concern for indoor air quality. Mostof the current technology is based on the use of a heated filament type sensor. These sensors have slow response times to low levels of carbon monoxide and have long recovery times after exposure. A new carbon monoxide sensor based on the detection of heat from the oxidation of carbon monoxide has been developed. The bridge circuit of the sensor incorporatesa precision thermistor coated with a catalyst developed at NASA-LaRC for satellite CO_2 laser systems. The air oxidation of carbon monoxide to carbon dioxide is catalyzed at room temperature. When this exothermoci reaction takes place, there is an increase in the temperature of the thermistor. The temperature increase is a function of the amount of carbon monoxide being oxidized which is measured by the change in bridge circuit current.