Method and apparatus for detecting a gas concentration with reduced pressure dependency
US9140644B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 2, 2012 |
| Grant date | Sep 22, 2015 |
| Priority date | — |
| Expiry date | Dec 22, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/399
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention relates to a method that makes the measurement of a trace gas concentration invariant or at least less affected to pressure variations in the gas and atmospheric pressure changes. This method neither requires a pressure sensor nor a pressure calibration routine. Furthermore, the method can be applied to other gas species present in the background gas or to the background gas itself that cross-interfere with the target gas of interest. This allows removing any pressure dependency of cross-interference parameters of other gas species and/or the background gas. The new method for accurately measuring a gas concentration is based on optimizing the wavelength modulation amplitude of the laser to minimum pressure dependency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.