Photoacoustic gas sensor using a method for modulating the illumination wavelength
US11719625B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 2019 |
| Grant date | Aug 8, 2023 |
| Priority date | — |
| Expiry date | Jul 6, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/021
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A photo-acoustic gas sensor using a method for modulating the wavelength of the laser radiation, the modulation being obtained via judicious use of an electric current, called the generation current, which pumps the one or more laser sources, and is configured to cause the one or more laser sources to operate in pulsed mode, and of a current, called the base current, which takes non-zero values between each laser pulse with a lower magnitude than the magnitude of the generation current, the magnitude of base current being modulated so that the one or more laser sources emit, into the cell, light radiation having a wavelength that varies periodically about a central wavelength so as to take, at regular intervals, a value specifically suitable for the excitation of a gas to be detected, whereby an interaction between the light radiation and the gas to be detected contained in the cell induces the generation of acoustic waves at a resonant frequency of the cell.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.