Electromagnetic either prospectively device and an electromagnetic either prospectively method

摘要

Electromagnetic either prospectively device, which comprises:a transmission unit (46, 48) for generating a periodically variable magnetic field to a target either prospectively;a detection unit (2, 2a), which contains a squid (20) for detecting a magnetic field, which, according to the prospectively object is generated; anda data processing unit (3, 3a) for collecting a detection result is obtained from the detection unit,the detection means includesa feedback coil (21) for generating a magnetic field for canceling a magnetic field, which in the squid occurs, anda feedback circuit (221, 222, 223, 224) for supplying a current, which corresponds to a voltage, which is generated by the squid, for the feedback coil, andthe data processing unit is operative toa plurality of time data units, each having a length of at least a period of the variable magnetic field, of said detection of the magnetic field, which, by way of a certain time period occurs, to extract,to determine whether or not a deviation from a reference value in order to..