Apparatus and method for detecting magnetically detectable plastic pipe and other sources of magnetic fields from a distance using a vertically aligned gradiometer on a horizontal support
First Claim
1. A hand-held apparatus for manipulation by an operator for detecting magnetically detectable plastic pipe and other sources of magnetic fields from a distance comprisinga horizontally oriented support member having a handle extending at an acute angle therefrom,a magnetic field gradiometer supported at the distal end of said support member a substantial distance ahead of the operator in a substantially vertical position,said gradiometer comprising a hollow tube of non-magnetic material having flux-gate magnetometer sensors supported therein at a selected linear spacing, anda differential amplifier connected to said flux-gate magnetometer sensors to subtract the signal produced and zero out the effect of the earth'"'"'s magnetic field in a magnetically neutral environment, and detect a magnetic field gradient when placed in proximity to a magnetic field,a microprocessor supported on said support member operatively connected to said gradiometer for processing signals therefrom, andan electronic read-out module supported on said handle spaced from said gradiometer and operable to receive signals from said microprocessor and convert them into a visual and audible display to be sensed by the operator or user,the size and weight distribution of said apparatus and the angles at which the components are assembled cooperate to assure that when the apparatus is hand held by said handle said gradiometer is balanced in a vertical position at a substantial distance ahead of the operator or user.
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Accused Products
Abstract
An apparatus is disclosed for manipulation by an operator or user for detecting magnetically detectable plastic pipe and other sources of magnetic fields from a distance having a horizontally oriented support member with a handle extending at an acute angle therefrom. A magnetic field gradiometer comprising a hollow non-magnetic tube with two flux-gate magnetometers therein is supported at the distal end of the support member a substantial distance ahead of the operator in a substantially vertical position. A microprocessor is supported on the support member operatively connected through a differential amplifier to the gradiometer for processing signals therefrom. An electronic read-out module is supported on the handle spaced from the gradiometer and operable to receive signals from the microprocessor and convert them into an audible or visual display to be sensed by the operator or user. The size and weight distribution of the apparatus and the angles at which the components are assembled assure that when the apparatus is hand held by the handle the gradiometer is balanced in a vertical position at a substantial distance ahead of the operator or user. An alternate embodiment, i.e., a magnetic field mapper, is shown having a plurality of gradiometers supported in parallel on supporting wheels and having the visual and audio display in the form of a laptop or notebook type computer supported on the handle for the wheeled apparatus. A hand held embodiment of the mapper is also disclosed.
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Citations
18 Claims
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1. A hand-held apparatus for manipulation by an operator for detecting magnetically detectable plastic pipe and other sources of magnetic fields from a distance comprising
a horizontally oriented support member having a handle extending at an acute angle therefrom, a magnetic field gradiometer supported at the distal end of said support member a substantial distance ahead of the operator in a substantially vertical position, said gradiometer comprising a hollow tube of non-magnetic material having flux-gate magnetometer sensors supported therein at a selected linear spacing, and a differential amplifier connected to said flux-gate magnetometer sensors to subtract the signal produced and zero out the effect of the earth'"'"'s magnetic field in a magnetically neutral environment, and detect a magnetic field gradient when placed in proximity to a magnetic field, a microprocessor supported on said support member operatively connected to said gradiometer for processing signals therefrom, and an electronic read-out module supported on said handle spaced from said gradiometer and operable to receive signals from said microprocessor and convert them into a visual and audible display to be sensed by the operator or user, the size and weight distribution of said apparatus and the angles at which the components are assembled cooperate to assure that when the apparatus is hand held by said handle said gradiometer is balanced in a vertical position at a substantial distance ahead of the operator or user.
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4. An apparatus for manipulation by an operator for detecting magnetically detectable plastic pipe and other sources of magnetic fields from a distance comprising
a horizontally oriented support member, a first hollow tube of non-magnetic material constructed to be held by said support member in a horizontal position, a plurality of flux-gate magnetometer sensors, and at least one reference flux-gate magnetometer sensor, supported on said hollow tube at selected linear spacing a substantial distance ahead of the operator in a substantially vertical position, a second hollow tube of non-magnetic material integral with an extending at a right angle to said first tube and including a flux-gate magnetometer sensor spaced vertically above said first named magnetometer sensors, at least one microprocessor operatively connected to said sensors for processing signals therefrom, an electronic read-out module supported on said support member spaced from said gradiometers and operable to receive signals from said microprocessor and convert them into a sensory display to be sensed by the operator, a plurality of differential amplifiers connected one to each of said flux-gate magnetometer sensors and to said vertically spaced sensor to subtract the signals produced and zero out the effect of the earth'"'"'s magnetic field in a magnetically neutral environment, and detect a magnetic field gradient when placed in proximity to a magnetic field, and a flux-gate compass supported in said second hollow tube to measure and record movement of said support member from side to side.
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7. A magnetic field detecting apparatus for manipulation by an operator for detecting magnetically detectable plastic pipe and other sources of magnetic fields from a distance comprising
a plurality of horizontally oriented, substantially parallel, support members, a pair of wheels operatively supporting said support members for wheeling said apparatus along the surface of the ground, a plurality of magnetic field gradiometers, one of each being supported at the distal end of respective ones of said support members a substantial distance ahead of the operator in a substantially vertical position, said gradiometers are each enlarged at their upper ends and are split and openable, circuit boards for each gradiometer positioned in said enlarged upper ends, a plurality of microprocessors operatively connected one to each of said gradiometers for processing signals therefrom, and an electronic read-out module supported on said support member spaced from said gradiometers and operable to receive signals from said microprocessors and convert them into a sensory display to be sensed by the operator, said read-out module comprising a laptop or notebook size computer providing a contour map of magnetic field intensity versus distance traveled on the screen thereof.
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11. A method of detecting magnetically detectable plastic pipe having a characteristic signature thereon from a distance comprising providing a magnetic field detection apparatus comprising
a horizontally oriented support member, a magnetic field gradiometer supported at the distal end of said support member a substantial distance ahead of the operator in a substantially vertical position, a microprocessor supported on said support member operatively connected to said gradiometer for processing signals therefrom, and an electronic read-out module supported on said support member spaced from said gradiometer and operable to receive signals from said microprocessor and convert them into a sensory display to be sensed by the operator or user, moving said apparatus over a selected area with said gradiometer held a substantial distance ahead of the operator in a substantially vertical position until a magnetic field is detected, then moving said apparatus around the area to determine whether the field has a signature resembling that of said plastic pipe, determining orientation of said pipe by locating alternating polarity with a zero in between and making a traverse along the length of said pipe, during said traverse, detecting several positive and negative maxima and minima of magnetic signal separated by null values, and measuring the pitch of said magnetic signal, and processing said signal by said microprocessor and producing a read-out on said display module.
Specification