Photoacoustic gas analyzer
US4818882A · kind A · utility
32Cited by
10References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 20, 1987 |
| Grant date | Apr 4, 1989 |
| Priority date | — |
| Expiry date | May 20, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/3129
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A photoacoustic gas analyzer comprising a measuring chamber, a modulated light source, and at least one microphone in connection with the measuring chamber and measuring the changes of pressure caused by the absorption of the light in the chamber. The measuring chamber comprises an inner surface with a reflecting coating. The measuring signal is thereby proportional to the gas concentration and is not provided as the difference between two almost equal values. As a result it is possible to measure small gas concentrations provided the light intensity within the measuring chamber suffices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.