| 摘要 |
The invention relates to a dual-action alarm sensor with both acoustic and thermal detectors, which is intended to emit an output signal when the place the alarm sensor is to monitor is entered. The alarm sensor comprises a tubular lens housing 1 with a catoptric system where the two detectors 3, 4 are placed in the obstruction of the system with the thermal detector 4 facing away from the listening direction and the acoustic detector 3 placed in front of the thermal detector in the listening direction. In this way, the sound screen is obtained, which the thermal detector in the form of a pyroelectric detector requires because such a detector is piezoelectric (reacts to sound). <IMAGE> |
