Method, sensor and device for detecting trace quantities of gases in a gaseous medium
US4485667A · kind A · utility
7Cited by
3References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1982 |
| Grant date | Dec 4, 1984 |
| Priority date | — |
| Expiry date | Sep 29, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/123
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An enclosure (17) contains two ovens (18, 19) each containing a semiconductor metal oxide (SnO.sub.2 or NiO) sensor (13) previously activated using H.sub.2 S or SO.sub.2. The sensors (13) are heated to different temperatures the lower of which corresponds to a peak on the sensor conductivity curve characteristic of the gas. The signals produced are applied to a comparator (30). For many toxic gases this peak occurs at concentrations below their toxicity threshold in air.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.