Testing and adjustment of scattered-light smoke detectors
US5497144A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1994 |
| Grant date | Mar 5, 1996 |
| Priority date | — |
| Expiry date | Jan 27, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/145
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
For testing or/and adjusting a scattered-light smoke detector as to sensitivity to smoke, a transparent body with included scattering centers is introduced into the measurement volume of the detector. Aluminum oxide powder particles can serve as scattering centers. The distribution of light scattering centers is preferably uniform, and their concentration chosen to simulate a smoke density corresponding to the alarm threshold of the smoke detector. Thus, scattered-light smoke detectors are readily calibrated to a desired output signal as a function of smoke density. With a different density of scattering centers, the technique can be used for testing scattered-light smoke detectors in the field. If the scattering centers are distributed outside a measurement volume of an uncontaminated detector, the technique can be used for testing as to contamination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.