Incoherent cavity ringdown spectroscopy gas analyzer coupled with periodic chemical scrubbing
US8654334B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 2012 |
| Grant date | Feb 18, 2014 |
| Priority date | — |
| Expiry date | May 6, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/33
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An incoherent cavity ringdown spectroscopy (iCRDS) gas analyzer is provided with a gas flow path to introduce a sample gas into an enclosed volume bounded by a pair of mirrors defining an optical cavity. A pulsed broadband incoherent light source with a wavelength band that coincides with an absorption band of a specified gas species to be detected (e.g., NO2 or SO3) directs pulses of light into the optical cavity, while a photodetector is positioned to detect light exiting the cavity. A scrubber in an alternate flow path into the enclosed volume periodically scrubs the sample gas of the specified gas species. A processor determines the concentration of the specified gas species from the ringdown decay time of the photodetector measurement signals, with the periodic scrubbing of the sample gas providing a calibration reference from its slower decay time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.