Multi-functional sensor
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsJiro Terada, Tsuneharu Nitta
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Abstract
A multi-functional sensor capable of sensing the humidity and the concentration of reducing gases in the surrounding atmosphere with a single sensing element of p-type metal-oxide ceramic semiconductor is provided. When the ambient temperature is lower than 150.degree. C., the sensor can detect humidity in terms of variations in ion conduction due to the physical absorption of water by the sensing element, but when the ambient temperature or the temperature of the sensing element is at temperatures between 200.degree. and 600.degree. C., the sensor can detect the presence or concentration of reducing gases in the surrounding atmosphere in terms of variations in electron conduction due to the chemical absorption of gases by the sensing element.
Claims6
A multi-functional sensor capable of detecting humidity and a gas or gases comprising
- (a) a sensing element consisting essentially of a p-type metal-oxide ceramic semiconductor,
- (b) means attached to said sensing element for detecting or measuring humidity in terms of variations in ion conduction due to the physical absorption of water, temperature lower than 150.degree. C., and
- (c) means attached to said sensing element for detecting or measuring a gas or gases in terms of variations in electron conduction due to the chemical absorption of said gas or gases at temperature between 200.degree. C. and 600.degree. C.
Dependencies are inferred from the claim text.