| 摘要 |
A fence alarm system, (10) comprising a plurality of fence alarms (12, 13, 14) is described, wherein each fence alarm (12, 13, 14) has a plurality of laterally spaced electrically conductive fence elements (12.1, 13.1, 14.1) which are connected in series with each other. Each of the fence alarms (12.1, 13.1, 14.1) includes two electrically isolated cross members (12.201, 12.202, 14.201, 14.202) which together define fence alarm panels (18, 20, 22). The fence alarm panels (18, 20, 22) are supported by support posts (24, 26, 28). A sensing arrangement is electrically connected to the fence elements (12.1, 13.1, 14.1) and is calibrated to a nominal electrical value such as a resistive value. The sensing arrangement is able to sense a predefined deviation from the nominal electrical value caused by a deviation in an electrical property of the fence elements (12.1, 13.1, 14.1). An additional trip wire (36) is also provided. |
