Patent ID: 7145328

Claim:
Metal detector comprising transmitting coils, receiving coils and an electronic processing circuit ( 30 ) adapted to detect variations in signals received by the receiving coils in relation to a reference value, characterised in that it also includes a test module comprising selection means ( 40 ) for detecting a test request, and control means ( 50 ), used when a test request by the selection means ( 40 ) is detected, for comparing the signals from the receiving coils, at the time of subsequent passing of a standard reference object through the detector, with a predetermined response, wherein the control means ( 50 ) comprise a display module ( 52 ), a recording module ( 54 ), a comparison module ( 56 ), an output module ( 58 ) and a central processing unit ( 59 ) which controls the assembly, and the display module ( 52 ) is adapted to give signals indicating the height at which the standard reference object must be moved.