Measuring the concentration of gaseous hydrogen fluoride
US4535241A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 17, 1982 |
| Grant date | Aug 13, 1985 |
| Priority date | — |
| Expiry date | Nov 17, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/1704
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Method and apparatus for quantitatively determining the concentration of gaseous hydrogen fluoride in a medium containing gaseous hydrogen fluoride. The apparatus has one or two lasers (1) (2) which provides a beam (11) having two frequencies, a first frequency which is absorbed by gaseous hydrogen fluoride and a second frequency which is substantially unabsorbed by low pressure gaseous hydrogen fluoride and less absorbed than the first frequency by high pressure gaseous hyrogen fluoride or gaseous hydrogen fluoride plus other gases or vapors. Detectors (12) (15) detect the beam transmitted through the medium and calculator (18) determines the concentration from the outputs of the detectors (12) (15). The preferred lasers (1) (2) are infra red helium-neon lasers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.