Optical fire-detector
US4156816A · kind A · utility
11Cited by
3References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 4, 1977 |
| Grant date | May 29, 1979 |
| Priority date | — |
| Expiry date | Aug 4, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B17/103
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The invention relates to an optical fire-detector in which a radiation-emitting means is arranged to emit a beam of radiation and which has modulator means for the modulation of the beam of radiation in a phase-inverted relationship within a first and a second wavelength band, and a radiation-detecting means is arranged to receive the beam of radiation after it has passed through an intermediate air medium and includes first means for an individual measurement of intensity in the two wavelength bands and second means for the detection of such variations in the measured intensities which are representative for a fire.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.