Patent ID: 6437573
Filing Date: 2002-08-20
Classification: G01V

Abstract:
An inductive sensor head for detecting at least one of a ferrous and non-ferrous electrically conducting object buried in a surrounding medium comprising:a twin pair of co-axially positioned field coils provided with a mutual distance, each of said field coils having a small axial length-to-diameter ratio; and two twin pairs of sense coils with orthogonally arranged axes positioned in a center plane parallel to and at approximately a half distance between the winding planes of said two field coils, each of said two twin pairs of sense coils consisting of two co-axially arranged sense coils having a smaller diameter than a diameter of said field coils and an inductance higher than an inductance of each of said field coils, the common axis thereof being oriented orthogonal to the axis and in a diameter direction of said field coils and in a plane essentially parallel to the winding planes of said field coils, said two twin pairs of sense coils being positioned at an equal distance from the center of each of said field coils and within the same magnetic flux direction emanating from said field coils when excited by an electric current.