Gas monitors
US5973326A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1997 |
| Grant date | Oct 26, 1999 |
| Priority date | — |
| Expiry date | Aug 5, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/031
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A gas monitor includes an infra-red source enclosed within a housing having inner surfaces which are reflective. Radiation emitted from the source reflects off ellipsoidal surfaces and intermediate planar surfaces to be focussed at a sensor, being reflected five times. Radiation is absorbed by gas within the housing and a comparison of the source intensity and detected intensity gives a measure of the gas concentration. Use of ellipsoidal reflective surfaces directs emitted radiation along a plurality of routes having substantially the same path length, hence giving an accurate measure of the gas concentration with a compact device. In another embodiment, off axis parabolas are used to direct the radiation through the gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.