Claims
- 1. A gas component detection apparatus comprising:
- first and second gas sensing elements each including a metal oxide which exhibits variable electric resistances according to gaseous components and temperatures of gases to be detected;
- a catalyst carried by said first sensing element for promoting oxidation reactions of the gaseous components of the gases,
- a first pair of electrodes inserted into said sensing element for sensing a variation in electric resistance exhibited at that portion of said first sensing element subjected to catalytic action of said catalyst and resulting from the gaseous components and temperatures of the gases,
- a second pair of electrodes inserted into said second sensing element for sensing an electric resistance variation resulting mainly from the gas temperature,
- circuit means adapted to be joined to said sensing elements for producing an output signal, and
- means connecting the electrodes of the sensing elements to the circuit means in a manner whereby the variations in resistance of the sensing elements resulting from the gas temperatures offset one another and said output is representative of variations in resistance of the first sensing element resulting from the gaseous components.
- 2. A gas component detection apparatus as set forth in claim 1, wherein the metal oxide of each of said first and second sensing elements includes a plurality of different metal oxides, said oxides exhibiting substantially the same resistance variation for the same temperature variation.
- 3. A gas component detection apparatus as set forth in claim 1 or 2, wherein said first sensing element has a porous structure, while said second sensing element has a dense structure.
- 4. A gas component detection apparatus as set forth in claim 3, wherein said second sensing element includes chromium oxide as an additional oxide.
- 5. A gas component detection apparatus as set forth in claim 3, wherein said second sensing element includes manganese oxide as an additional oxide.
Priority Claims (1)
Number |
Date |
Country |
Kind |
52-47702 |
Apr 1977 |
JPX |
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation-in-part of the applicants' earlier U.S. patent application, Ser. No. 751,956, filed on Dec. 17, 1976, now Pat. No. 4,099,922 dated July 11, 1978.
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2636178 |
Mar 1977 |
DEX |
Continuation in Parts (1)
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Number |
Date |
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Parent |
751956 |
Dec 1976 |
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