Continuous optical path monitoring of optical flame and radiation detectors
US5914489A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1997 |
| Grant date | Jun 22, 1999 |
| Priority date | — |
| Expiry date | Jul 24, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/145
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Apparatus for the optical detection of flames or explosions, having an optical structure to perform continuous optical path monitoring of the optical window receiving the optical radiation, to ensure against the buildup of radiation absorbing or scattering materials. A light source internal to the housing illuminates a straight optically transmissive quartz or sapphire rod that protrudes through the housing beyond the optical window. The protruding tip of the light rod is beveled and metallized on the bevel to provide internal reflection of the light from the source, the angle of the bevel being such that the reflected light on exiting the light rod illuminates the optical window and the optical detector behind it, thereby providing a test for the cleanliness of the optical window. This optical technique for checking the cleanliness of the optical viewing element can be utilized by other optical instruments including imaging arrays, surveillance cameras and weapons.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.