Gas detection method and gas detection device
US7414727B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 2006 |
| Grant date | Aug 19, 2008 |
| Priority date | — |
| Expiry date | Nov 22, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/39
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for etalon suppression in a gas detection device by determining an etalon fringe period during a calibration step without gas in dependency of the DC drive current. A measuring signal which is a function of the gas absorption and substantially independent of an intensity modulation of an initial light signal at an initial frequency (f) is generated by determining a first pre-measuring signal when the laser source is operated at the center of the gas absorption peak, a second pre-measuring signal when the laser source is operated with a DC drive current below the gas absorption peak of the gas to be detected, and a third pre-measuring signal when the laser source is operated with a DC drive current above said gas absorption peak, with a difference between said DC drive currents which corresponds to the etalon fringe period determined in a calibration step before. The final measuring signal is determined as the difference between the first pre-measuring signal and the arithmetic mean of the second pre-measuring signal and the third pre-measuring signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.