Abstract: A method for improving a sensitivity of a metal detector by reducing an unwanted magnetic field generated by at least one electrically conductive element of the metal detector, the metal detector transmitting a transmit magnetic field into a soil and a possible target within the soil which in response generate a response magnetic field, the method including the step of: redirecting at least a portion of the response magnetic field from entering the at least one electrically conductive element, wherein otherwise the at least one electrically conductive element within an influence of the response magnetic field generates the unwanted magnetic field due to a change in an intensity of the response magnetic field entering the at least one electrically conductive element, the redirecting adapted to reduce or eliminate the unwanted magnetic field generated by the at least one electrically conductive element thereby improving the sensitivity of the metal detector.

Abstract: A metal detector includes means for reducing the induction of eddy currents in conductive elements of a sensor head. The aim of this invention is to remove the effect of small pieces of conductive material, located within or close to the sensor head, being seen as sought targets as the sensor head is moved over magnetic matrix. The means is to surround the conductive material with material with high magnetic permeability and low losses in a time-varying magnetic field, say low-loss ferrite. This will prevent the reflected field from illuminating the conductive material so eddy currents are not generated.

Abstract: A metal detector adapted to generate a transmit search signal and to receive a receive search signal, and to analyse such received search signal, wherein the detector is adapted to allow a selection of operating parameters for each of these functions, said selection being effected by the storage as data in a memory of such selection, characterised in that the detector is adapted to allow such stored data to be modified in accordance with data in an external store, further characterised in that there is a digital data communication transmission program, adapted to effect a transmission of some or all of the stored data through a data transmission means to enable a further metal detector to receive and store for use in such further detector the said data.