| 摘要 |
PURPOSE: To provide a gas sensor having a short response time by carrying out gas detection while irradiating light onto the outer surface of a gas sensitive body. CONSTITUTION: A barium titanate film having a thickness of about 1μm, a gas sensitive thin film 2 is formed on an insulating alumina substrate 1 by spattering. A cathode 3 and an anode 4 are formed from a Pt film, and a predetermined voltage is applied to the thin film 2 which is exposed to a gas to be detected. Gas is adsorbed to the outer surface of the thin film 2 so as to change the conductivity which is detected by an ammeter 6. In this arrangement, light is irradiated onto the outer surface of the film 2 by means of a xenon lamp or the like so as to remarkably improve the responsiveness. In order to adsorb the gas onto the outer surface of the film 2, an energy barrier should be overcome. However, in the case of the light irradiation, the light energy excites the gas so as to allow occurrence of adsorption at a high speed. Thereby it is possible to shorten the response time of the sensor.
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