Detector probe for mapping discontinuities in electromagnetic paths

Claim 2

Apparatus for detection of discontinuities in electromagnetic paths comprising: magnetic toroidal core means having an air gap and responsive to sensed electromagnetic energy to provide magnetic lines of flux therein; electrical conductor coil means wound around a portion of said core means and spaced substantially equidistant from said air gap, said coil responsive to said magnetic lines of flux present in said core means to provide an electrical output which is indicative of the strength of said electromagnetic energy; electromagnetic shielding means comprising first shielding means for providing shielding for said coil means and for said magnetic core means except in the vicinity of said air gap, and second shielding means comprising an electrically conductive wire mesh shroud fitted over said first shielding means and over the portion of said core means around which said coil means is wrapped to provide additional shielding of said apparatus from ambient electromagnetic fields whereby said electrical output is generated only in response to said magnetic lines of flux in said core.

Claim 3

The invention of claim 1 wherein said first shielding means comprises electrical conductor means spirally wrapped about said core means and said coil means with a single direction of lay, each wrap of said conductor means insulated one from the other and wrapped to provide an overlap of a prior wrap by each succeeding wrap and commencing in the vicinity of one side of said air gap and continuing to the vicinity of the other side of said air gap.

Claim 4

The invention of claim 2 wherein said shroud is electrically connected to said electrical conductor means at a selected point and to electrical ground, said mesh electrically insulated from said core and said coil.

Claim 5

Apparatus for detection of discontinuities in electromagnetIc paths comprising: a ferrite core substantially circular in shape with an air gap, said core being sensitive to electromagnetic energy to generate magnetic lines of flux therein; a coil wound around said core substantially equidistant from each side of said air gap, said coil having output leads at each end formed to lay along said core a selected distance before departing from said core, said coil being responsive to magnetic lines of flux in said core to generate an electrical output for said apparatus; strands of electrically conductive material wrapped around said core means and said coil means, including said coil output leads formed to lay along said core, with a single direction of lay commencing in the vicinity of one side of said air gap and continuous to the vicinity of the other side of said air gap, said material providing an electromagnetic shield for said core and said coil; said strand material spirally wrapped with subsequent turns overlapping but insulated from prior turns; and an electrically conductive meshed shroud fitted over but insulated from said core, said coil, and said coil output leads to provide additional shielding, said mesh material electrically connected to a selected point of said strand material, said strands of electrically conductive material and said meshed shroud providing an electromagnetic shield for said core and said coil whereby said coil generates said output only in response to said magnetic lines of flux in said core.

Claim 6

Apparatus for detection of discontinuities in electromagnetIc paths comprising: a ferrite core substantially circular in shape with an air gap, said core being sensitive to electromagnetic energy to generate magnetic lines of flux therein; a coil wound around said core substantially equidistant from each side of said air gap, said coil having output leads at each end formed to lay along said core a selected distance before departing from said core, said coil being responsive to magnetic lines of flux in said core to generate an electrical output for said apparatus; strands of electrically conductive material wrapped around said core means and said coil means, including said coil output leads formed to lay along said core, with a single direction of lay commencing in the vicinity of one side of said air gap and continuous to the vicinity of the other side of said air gap, said material providing an electromagnetic shield for said core and said coil; said strand material spirally wrapped with subsequent turns overlapping but insulated from prior turns; and an electrically conductive meshed shroud fitted over but insulated from said core, said coil, and said coil output leads to provide additional shielding, said mesh material electrically connected to a selected point of said strand material, said strands of electrically conductive material and said meshed shroud providing an electromagnetic shield for said core and said coil whereby said coil generates said output only in response to said magnetic lines of flux in said core.

Claim 7

Apparatus for detection of discontinuities of electromagnetic paths comprising: a ferrite core having an air gap; a sensing coil wound about a portion of said core; means for shielding said coil from both external ambient fields and from fields in said gap, said means comprising a first electrically conductive shield wound about said core and coil and having end portions respectively adjacent to and spaced from opposite sides of said air gap, said shield having a portion interposed between said coil and said gap; and a shielded cable connected to said coil, said cable comprising first and second inner conductors connected to respective ends of said sensing coil, and an outer conductor formed of a mesh shield, said mesh shield surrounding said inner conductors and at least the ends of the sensing coil connected thereto.

Claim 8

Apparatus for detection of discontinuities of electromagnetic paths comprising: a ferrite core having an air gap; a sensing coil wound about a portion of said core; means for shielding said coil from both external ambient fields and from fields in said gap, said means comprising a first electrically conductive shield wound about said core and coil and having end portions respectively adjacent to and spaced from opposite sides of said air gap, said shield having a portion interposed between said coil and said gap; and a shielded cable connected to said coil, said cable comprising first and second inner conductors connected to respective ends of said sensing coil, and an outer conductor formed of a mesh shield, said mesh shield surrounding said inner conductors and at least the ends of the sensing coil connected thereto.

Claim 9

The apparatus set forth in claim 5 including electrical insulation means positioned between said first shield and said mesh shield and means for electrically connecting said first shield to said mesh shield.