| 摘要 |
<P>PROBLEM TO BE SOLVED: To highly accurately detect only an intruder really closely approaching to a protection fence. <P>SOLUTION: A protection fence 10 is formed by linking conductive panels 1 such as a net fence. A monitoring signal output device 31 applies a monitoring signal of a prescribed frequency to the conductive panels 1 via an inductor 315. An approach detecting device 32 detects a potential change in the conductive panels 1, and detects an approach of a human body to the conductive panels 1 based on a level fluctuation of the monitoring signal in the detection signal representing the detected potential change. The frequency of the monitoring signal is made to accord with a frequency of a peak time appearing in transmission characteristics in a frequency range from an output point of the monitoring signal to the inductor 315 to an input point of the approach detecting device 32 when no human body approaches to the conductive panels 1. <P>COPYRIGHT: (C)2012,JPO&INPIT |
