| 摘要 |
This invention relates to a security fence including at least one tensioned wire connected to a detector for sensing movement of the wire. The detector comprises a movable element which sealingly separates two chambers in such a manner that any movement of the sealing element produces a change in volume of at least one of the chambers, which one chamber is connected to a pressure-sensitive switch actuator. Preferably, the said detector comprises an air cylinder with a piston which constitutes the said sealing element and is connected to the said wire. |
