| 摘要 |
A sensing element (18) for use in an alarm system for protecting an area enclosed by flexible closure device (10). The element includes a plurality of conductors (16), at least one of which is a decoy conductor intended to prevent circumvention of the alarm system by short-circuiting or the like. The decoy conductor can be a dummy conductor carrying no current, or can be connected into an alarm circuit arranged to sense attempts to connect the decoy conductor to another conductor. |
