Reversible optical waveguide vapor sensor
US4513087A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 1983 |
| Grant date | Apr 23, 1985 |
| Priority date | — |
| Expiry date | Jan 31, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/175383
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device for detecting small amounts of a chemical such as ammonia, and other ammonia-like molecules such as hydrazine or pyridine, in air and in other gases is disclosed. A capillary tube serves as a multiple total reflective medium for an optical beam from a light-emitting diode. The outer surface of the capillary tube is coated with a dye which, when exposed to the chemical, changes color so that the multiply reflected light is modified. The resultant change in the output light intensity from the capillary tube is photodetected and recorded to sense the presence of the chemical. When the chemical is removed, the dye returns to its original color so that the device can be reused.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.