Patent ID: 6154023
Filing Date: 2000-11-28
Classification: G01R

Abstract:
A method of non-invasive sensing of current through a conductor located a distance beneath a surface, the method comprising:positioning a first magnetic field sensor configured to sense magnetic fields of the conductor located beneath the surface, wherein the first magnetic field sensor and the conductor are physically separated from each other such that there is no overlap between the first magnetic field sensor and the conductor;positioning a second magnetic field sensor configured to sense magnetic fields of the conductor, at a location distanced from the first magnetic sensor, wherein the second magnetic field sensor and the conductor are physically separated from each other such that there is no overlap between the second magnetic field sensor and the conductor;sensing with the first magnetic field sensor a magnetic field generated by current in the conductor;sensing with the second magnetic field sensor the magnetic field generated by current in the conductor;generating a first signal from the magnetic field sensed by the first magnetic field sensor;generating a second signal from the magnetic field sensed by the second magnetic field sensor;amplifying the first signal by a first amplifier;amplifying the second signal by a second amplifier; andprocessing the amplified first signal and amplified second signal.