Gas detection method and gas detector device
US7180595B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2004 |
| Grant date | Feb 20, 2007 |
| Priority date | — |
| Expiry date | Jul 30, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/0691
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A gas detector device comprises at least a VCSEL source (34, 36) and at least a light sensor (54, 56) for detecting a light beam (50, 52) having passed through a sample chamber (48) containing a given gas to be detected. The sensor is a photodiode in a first embodiment and its detection signal is time derivated by an electronic derivator (64) and then provided to two lock-in amplifiers (84, 86) in order to generate a F-detection and a 2F-detection, F being the frequency of a wavelength modulation of the source, and thus to provide two corresponding measuring signals the division of which gives a precise value of the gas concentration. In a second embodiment, the source is a pyroelectric sensor which directly provides a detection signal proportional to the time derivate of the light beam incident on this sensor. In this last case, the electronic derivator is thus eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.