Determining enclosure breach electromechanically

Determination of transgression of the safety of a structure, the method comprising: providing said structure (105) a sensor (120) comprising a first conductive element and a second conductive element substantially parallel to said first conductive element, said first and second elements constitute an electromagnetic transmission line; directing said sensor (120) with at least one signal of constant frequency such that a standing wave pattern on the sensor (120) is induced by reflection of said at least one signal constant frequency from a termination point sensor; measuring at least one characteristic of the sensor (120) caused by the standing wave pattern of voltage; and determine that a security breach has occurred in the structure (105) when the at least one measured characteristic differs from a predetermined value by a predetermined amount.