Fire and smoke sensing system
US4168497A · kind A · utility
0Cited by
4References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 19, 1978 |
| Grant date | Sep 18, 1979 |
| Priority date | — |
| Expiry date | Jan 19, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B17/113
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
At least two sensors are used, providing electrical output signals to indicate alarm conditions, one of the sensors being a bipolar ion sensor having a shielded ion chamber formed to slow or brake atmospheric currents therethrough, and a second sensor which operates essentially in unipolar mode having an ion chamber freely accessible to atmospheric flow therethrough.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.