Methods of and apparatus for detecting low concentrations of target gases in the free atmosphere
US6750453B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 2002 |
| Grant date | Jun 15, 2004 |
| Priority date | — |
| Expiry date | Oct 6, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/3513
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A source directs broadband modulated light into a region the free atmosphere in which target gas may be present. A gas correlation radiometer responds to light transmitted through the region. Separate radiometer channels respond to a single beam of light after transmission through the region. A beam splitter separates the beam into two beams, one directed into each of the channels. The two channels separately and simultaneously respond to a respective one of the light beams for separately and simultaneously generating signals that together indicate whether the target gas is in the free atmosphere. A method provides an optimal bandpass of an IR filter that filters the light before transmission to the radiometers. Another method uses a null factor in computing an output that determines the concentration of the target gas in the free atmosphere. Long distance detection embodiments may be borne by vehicles such as trucks or aircraft.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.