| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a metal detection system. <P>SOLUTION: Operation of a metal detection system is monitored, the metal detection system including a balance coil system 2 provided with: a transmission coil 21 connected with a transmission device 1; and first and second reception coils 22 and 23 which provide, to a reception device 3, output signals s22 and s23 which are canceled mutually when the metal detection system is in a balanced state. A modulated monitoring signal s300 is supplied to a monitoring coil 24 inductively connected with at least one reception coil 22, 23 and the output signals s22 and s23 are demodulated in a demodulation device 34 which provides a demodulated monitoring signal s30, and compared with a reference s3 in phase and/or amplitude. In the case where a measurement deviation exceeds a specific threshold value, a caution is raised. <P>COPYRIGHT: (C)2012,JPO&INPIT |
