Buried metal object detection method uses lower operating frequencies for suppressing detection of small metal, objects and compensation of operating frequency for suppressing ground interference

摘要

The detection method uses a metal detector with a oscillator circuit (4) and a search coil (2), providing a primary field, with a secondary field generated in dependence on the environment adjacent the metal detector, with detection of the resulting attenuation of the primary field. The detection of small objects is suppressed by using lower operating frequencies and the ground interference is suppressed by compensating the operating frequency. An Independent claim for a metal object detection device is also included.