Method of, and apparatus for, detecting reducing gases in a gas mixture
US4627269A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1985 |
| Grant date | Dec 9, 1986 |
| Priority date | — |
| Expiry date | Mar 18, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/124
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Reducing gases can be detected in a gas mixture to be investigated, particularly in air, with high sensitivity and precision by means of a gas detector. The gas detector comprises a gas sensor which is arranged within a measuring chamber. The temperature of the gas sensor can be continuously increased according to a predetermined pattern from a starting value to an upper threshold value and can be subsequently decreased again to the starting value according to the same or according to a different pattern. There are provided at least two such heating cycles. Simultaneously therewith the gas mixture to be investigated, which is present in the measuring chamber, is periodically exchanged against a pure reference gas which is contained in a reference chamber. A selected property, such as the electrical conductivity of the gas sensor is thereby periodically changed. The temporal variation of this periodically varying electric conductivity can be detected in an evaluation circuit arrangement and/or evaluated for determining the concentration and/or the nature of the reducing gases which are present in the gas mixture to be investigated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.