Fiber optic system with self test used in fire detection
US4623788A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1983 |
| Grant date | Nov 18, 1986 |
| Priority date | — |
| Expiry date | Dec 2, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/145
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A fire detection system incorporating fiber optics and having a selectively energizable light source for applying light pulses to a fiber optics path and a one way light transmitting element, such as a dichroic mirror, at the remote end of the fiber optics path for reflecting the pulses back to the detection portion of the system, thus providing a Built In Test Equipment (BITE) test capability in the system. Instead of a dichroic mirror, a bandpass filter may be used as the light transmitting member. The bandpass filter is selected to transmit light with wavelengths in the range from about 1.3 to 1.5 microns, in which case the light source is a light emitting diode (LED) emitting light at a wavelength of approximately 0.9 microns. The fiber optics path includes a branch which is coupled to the light source. This branch may comprise one fiber of a multi-fiber bundle or it may be an auxiliary fiber of a commercially available fiber optics combiner. An overall system incorporates a plurality of these individual fire detection arrangements in conjunction with a BITE control stage and associated fire alarm. Any detected fire activates the fire alarm. However, the same fire detection sig…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.