Apparatus for measuring terrain conductivity
First Claim
1. A conductivity meter for measuring conductivity of terrain, including:
- a first transmitter coil;
a signal generator connected to the first transmitter coil to supply a time-varying current thereto for inducing eddy currents in the terrain;
a first receiver coil horizontally spaced from the first transmitter coil;
a temperature sensing device for measuring temperature; and
a signal processor, including a memory storing a plurality of temperature dependent correction values, for isolating from a signal received by the first receiver coil a secondary signal representative of a secondary magnetic field generated in the terrain by the eddy currents, and determining an apparent terrain conductivity based on the isolated secondary signal and a selected temperature dependent correction value selected from the stored temperature dependent correction values according to a measured temperature received from the temperature sensing device.
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Accused Products
Abstract
A conductivity meter for measuring conductivity of terrain, including a first transmitter coil, a signal generator connected to the first transmitter coil to supply a time-varying current thereto for inducing eddy currents in the terrain, a first receiver coil horizontally spaced from the first transmitter coil, a temperature sensing device for measuring temperature, and a signal processor, including a memory storing a plurality of temperature dependent correction values, for isolating from a signal received by the first receiver coil a secondary signal representative of a secondary magnetic field generated in the terrain by the eddy currents, and determining an apparent terrain conductivity based on the isolated secondary signal and a selected temperature dependent correction value selected from the stored temperature dependent correction values according to a measured temperature received from the temperature sensing device.
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Citations
22 Claims
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1. A conductivity meter for measuring conductivity of terrain, including:
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a first transmitter coil;
a signal generator connected to the first transmitter coil to supply a time-varying current thereto for inducing eddy currents in the terrain;
a first receiver coil horizontally spaced from the first transmitter coil;
a temperature sensing device for measuring temperature; and
a signal processor, including a memory storing a plurality of temperature dependent correction values, for isolating from a signal received by the first receiver coil a secondary signal representative of a secondary magnetic field generated in the terrain by the eddy currents, and determining an apparent terrain conductivity based on the isolated secondary signal and a selected temperature dependent correction value selected from the stored temperature dependent correction values according to a measured temperature received from the temperature sensing device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of measuring terrain conductivity, comprising:
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generating an AC signal and applying it to a transmitter coil positioned over the terrain whose conductivity is being measured;
receiving signals from the transmitter coil by means of a receiver coil horizontally spaced from the transmitter coil;
isolating from the received signals a signal representative of a secondary magnetic field generated in the terrain by eddy currents resulting from a primary magnetic field generated by the transmitter coil;
measuring a temperature of the receiver coil and selecting based thereon a correction value from a plurality of pre-determined temperature dependent correction values; and
calculating an apparent conductivity according to the selected correction value a magnitude of the isolated signal.
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18. A conductivity meter for measuring conductivity of terrain, including:
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a transmitter coil;
a signal generator connected to the first transmitter coil to supply a time-varying current thereto for inducing current in the terrain;
a plurality of receiver coils horizontally spaced from the transmitter coil different distances; and
a signal processor configured to isolate, for each receiver coil, an associated secondary signal representative of a secondary magnetic field generated in the terrain by the induced current and received by the receiver coil, and determine, for each isolated secondary signal an apparent conductivity based on the isolated secondary signal. - View Dependent Claims (19)
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20. A conductivity meter for measuring conductivity of terrain, including:
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a first transmitter coil and a second transmitter coil located proximate to each other and having perpendicular dipoles;
a signal generator connected to the first transmitter coil and the second transmitter coil to supply a time-varying current thereto for generating perpendicular primary magnetic fields inducing currents in the terrain;
a first receiver coil coplanar with and horizontally spaced from the first transmitter coil;
a second receiver coil coplanar with and horizontally spaced from the second transmitter coil in the same direction and substantially the same distance that the first receiver coil is spaced from the first transmitter coil, the first transmitter and first receiver coils having parallel dipoles and the second transmitter and second receiver coils having parallel dipoles; and
a signal processor configured to isolate, for the first receiver coil, a secondary signal representative of a secondary magnetic field generated in the terrain by the current induced therein by a primary filed generated by the first transmitter coil, and to isolate for the second receiver coil, a secondary signal representative of a secondary magnetic field generated in the terrain by the current induced therein by a primary field generated by the second transmitter coil, the signal processor being configured to determine, for each isolated secondary signal an apparent conductivity based on the isolated secondary signal. - View Dependent Claims (21, 22)
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Specification