Smoke detecting apparatus utilizing light signal pulse widths
US5923260A · kind A · utility
16Cited by
4References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1998 |
| Grant date | Jul 13, 1999 |
| Priority date | — |
| Expiry date | Jun 30, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B17/107
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The pulse width of a light reception pulse signal a from a light receiving device is detected, and the smoke density is detected based on a total pulse width of pulse widths per unit time period. Alternatively, the smoke density may be detected based on an integrated value of the light reception pulse signal a from the light receiving device per unit time period. Even if the flow rate of the sucked air is varied, the total light reception pulse width value per unit time period is not varied, so that the smoke density can be accurately detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.