Pressure change intrusion detector
US4928085A · kind A · utility
14Cited by
8References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 30, 1989 |
| Grant date | May 22, 1990 |
| Priority date | — |
| Expiry date | May 30, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B13/1681
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Apparatus utilizing change in pressure condition in an area to be protected to indicate intrusion or change in conditions of the area by using a pressure detection device to detect pressure waves at low and infrasonic frequencies which includes a pressure transducer sensitive to change in pressure to provide an output signal. In some instances an amplifier is provided to amplify the output signal, a signal conditioning circuit is provided to delay a portion of the signal, and a detector device is provided to detect the signal with a comparator provided to compare the signal with the delayed signal and actuate an alarm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.