Smoke detector
US4524351A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1982 |
| Grant date | Jun 18, 1985 |
| Priority date | — |
| Expiry date | Aug 13, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/0062
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a smoke detector of the type in which smoke is detected in a detection chamber based upon a variation of an ionization current flowing therein or a variation of light beam passing therethrough, there is provided a reference signal generating section which produces a reference signal having a predetermined characteristic corresponding to typical smoke flowing into the detection chamber when a fire occurs, and a signal comparison section which compares a detection signal detected in the detection chamber with the reference signal, wherein a smoke sensing signal is produced when the detection signal is determined as a signal due to a fire but is not produced when the detection signal is determined as the signal due to the entry of an insect into the detection chamber or due to cigarette's smoke flowing thereinto.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.