| 摘要 |
An intrusion detection sensor is mounted to a wall outside a vault, strong room, safe or protected area to detect both airborne indications of activity in the vicinity of the vault and also structure-borne indications of forced entry attempts. In one embodiment, one or more transducing elements are used to detect airborne and structurally-conducted signals, with the outputs thereof processed for producing an alarm indication when either type of signal exceeds an alarm threshold. Two detection channels are provided with one responsive to high band audio for detecting sounds and vibrations, whether airborne or structure-borne, indicating movement or activity immediately outside the vault or protected area, and the other responsive to airborne or structure-borne impulses and intermittent high level vibrations indicative of attempts at forced entry. Integration parameters for the impulse channel are oriented towards relatively long "memory" so that spaced hammer blows or vibrations will build up towards the alarm threshold. In one embodiment, a vibration block anchored to the wall transmits wall-carried impulses or vibrations to the same transducing element which is utilized to sense airborne indications of an intrusion. In another embodiment only structure-borne vibrations are detected with the use of a single transducing element and a vibration block.
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