Metal detector

A device for detecting metal in an inspection region comprising

• a magnetic field generation unit,
• a magnetic field detection unit,
• a control unit, and
• a monitor,
• wherein:
• the magnetic field generation unit generates a magnetic field in the inspection region at a fixed inspection frequency;
• the magnetic field detection unit detects a change in the magnetic field in the inspection region at the fixed inspection frequency to detect a metal in the inspection region;
• and
• the control unit comprises a transmission signal setting unit, a reception signal processing unit, a noise diagnosis unit, and a capacitor setting unit,
• and wherein:
• the control unit:
• is configured to be able to set a plurality of inspection frequencies;
• sets a frequency range including the inspection frequency for each of the inspection frequencies;
• measures the change in the magnetic field of the inspection region while changing the frequency in each of the set frequency range without fixing the frequency at the inspection frequency;
• displays a plurality of frequency distribution diagrams obtained on the basis of a measurement result of the change in the magnetic field of the inspection region on a monitor as a noise diagnosis result;
• and
• receives setting of the inspection frequency.