| 摘要 |
A barrier alarm for positioning adjacent a door opening includes an elongated tubular body having a vibration-sensing relay fitted therewith. The relay is able to distinguish between a smooth, continuous movement such as associated with the swinging arc motion effected by a breeze and the instantaneous vibration effected by being impacted by a rigid object. The power source may be integrated with the body or may be remote. The power source may be a direct current source or may be an alternating current source. The alarm may be audible or visible or both. The alarm may be integrated with the body or may be remotely positioned. The barrier alarm may be provided in an array that is horizontally-positioned with respect to the top portion of the door jamb or may be vertically positioned with respect to the door. A combination of this arrangement may be used.
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