| 摘要 |
Electronic detection systems and methods are provided for detecting the unauthorized passage of a person or object past a checkpoint defined, for example, by a doorway to a room or building, an entrance or exit gate for a piece of property, a post or pole supporting the detection equipment or hidden detection means. The detection system includes one or more alarms which operate either in the vicinity of the unauthorized object or person detected and/or remote therefrom such as a central monitor station for monitoring a plurality of checkpoint locations. An alarm deactivating device is employed which may be carried by a person or object and which either generates a code or deactivating signal and broadcasts same to a receiver located at the checkpoint or predeterminately affects or alters a radiation field generated in the vicinity of the checkpoint which code, signal or field change is detected and employed to deactivate and alarm or other circuit.
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