Gas sensor and gas discriminating method
US5602324A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 25, 1995 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | Apr 25, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/129
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention relates to a gas sensor and a gas discriminating method which are capable of distinctly discriminating two or more kinds of gases. A DC bias and AC signals which are superposed to a junction part, which is formed on a gas sensor having a p-type oxide semiconductor and an n-type oxide semiconductor by means of heterojunction of end surfaces thereof, an impedance characteristic of the junction part is measured, and CO gas and H.sub.2 gas are discriminated in accordance with a dependence on a frequency of the AC signals and on the DC bias of the impedance characteristic. CuO into which an alkali metal element is doped is used as the p-type oxide semiconductor and ZnO is used as the n-type oxide semiconductor. The alkali metal element to be used is an alkali metal element selected from the group of Li, Na and K and the doping quantity is such that 0.2 mole %.ltoreq.M.sub.2 O.ltoreq.5 mole %, where M is Li, Na or K.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.