Underground utility line locator and method for use
First Claim
1. A system for locating an underground utility line, wherein the utility line emits an electromagnetic field, the system comprising:
- one and only one top antenna supported on the frame proximate the top of the frame, in which the top antenna detects the electromagnetic field on only one axis;
one and only one bottom antenna supported proximate the bottom of the frame and separated from the top antenna by a known distance, in which the bottom antenna detects the electromagnetic field on only one axis;
a null antenna supported on the frame and disposed at an orientation orthogonal to the top antenna and the bottom antenna;
wherein the top antenna and the bottom antenna define a locating plane;
an inclinometer supported on the frame to measure a tilt angle of the frame within the locating plane; and
a processor supported on the frame to determine a direct distance between the frame and the underground utility line using a signal strength of the electromagnetic field received at the top antenna compared to a signal strength received at the bottom antenna with the null antenna pointed substantially at the utility line;
wherein the processor determines a horizontal distance between the frame and a point on the ground above the utility line using the direct distance and the tilt angle of the frame.
1 Assignment
0 Petitions
Accused Products
Abstract
A locator for determining the location of a buried utility line from an offset position. The locator has a top peak antenna, a bottom peak antenna, and a null antenna. The locator is tilted until the null antenna is pointed directly at the utility line with the top and bottom peak antennas disposed in a locating plane that is substantially vertical and perpendicular to the line. The tilt angle of the locator and the direct distance between the locator and the utility is measured. The tilt angle and direct distance are used by the processor to determine the vertical and horizontal distances between the locator and the utility.
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Citations
33 Claims
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1. A system for locating an underground utility line, wherein the utility line emits an electromagnetic field, the system comprising:
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one and only one top antenna supported on the frame proximate the top of the frame, in which the top antenna detects the electromagnetic field on only one axis; one and only one bottom antenna supported proximate the bottom of the frame and separated from the top antenna by a known distance, in which the bottom antenna detects the electromagnetic field on only one axis; a null antenna supported on the frame and disposed at an orientation orthogonal to the top antenna and the bottom antenna; wherein the top antenna and the bottom antenna define a locating plane; an inclinometer supported on the frame to measure a tilt angle of the frame within the locating plane; and a processor supported on the frame to determine a direct distance between the frame and the underground utility line using a signal strength of the electromagnetic field received at the top antenna compared to a signal strength received at the bottom antenna with the null antenna pointed substantially at the utility line; wherein the processor determines a horizontal distance between the frame and a point on the ground above the utility line using the direct distance and the tilt angle of the frame. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 29)
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12. A method for determining the location of an underground utility line using a hand-held locator, the method comprising:
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positioning the locator at a point that is laterally displaced from the utility line; pointing a bottom of the locator toward the utility line by tilting the locator until a minimum signal is measured at a null antenna; measuring a tilt angle of the locator; measuring a signal strength of an electromagnetic field transmitted from the utility line at one and only one top antenna and at one and only one bottom antenna, wherein the top antenna and the bottom antenna are separated by a known distance, and wherein the top antenna and the bottom antenna each detect the electromagnetic field on only one axis; processing the measured signal strength of the top antenna and the bottom antenna to determine a direct distance between the locator and the utility line; determining a horizontal distance to the utility line based on the tilt angle of the locator and the direct distance; and displaying the horizontal distance. - View Dependent Claims (13, 14, 15, 16, 30)
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17. A system for determining the location of a utility line that emits an electromagnetic field, the utility line being disposed at least partially under a surface obstruction that prevents placing the locator directly above the utility line, the system comprising:
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a locator comprising; a frame having a top and a bottom; a display; one and only one top antenna disposed proximate the top of the frame, in which the top antenna detects the electromagnetic field on only one axis; one and only one bottom antenna disposed proximate the bottom of the frame and separated from the top antenna a known distance, in which the bottom antenna detects the electromagnetic field on only one axis; a null antenna supported on the frame orthogonal to the bottom antenna; an inclinometer supported by the frame to detect a tilt angle of the frame; a processor to determine a direct distance between the locator and the underground utility line using a signal strength of the electromagnetic field received at the top antenna compared to a signal strength received at the bottom antenna with the null antenna pointed substantially at the utility line; wherein the processor uses the direct distance and the tilt angle of the frame to calculate a shortest horizontal distance between the locator and a point on the ground above the utility line and within a plane defined by the top antenna and the bottom antenna; and wherein the processor sends a display signal to the display to show the direct distance and the shortest horizontal distance. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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- 25. A locator for determining the depth of and location on the surface above a utility line while the locator is not directly above the utility line and a null antenna is pointed at the line, in which the locator comprises one and only one top antenna and one and only one bottom antenna, and in which the top antenna and the bottom antenna each detect an electromagnetic field emitted from the utility line on only one axis.
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32. A system for locating an underground utility line, wherein the utility line emits an electromagnetic field, the system comprising:
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one and only one top antenna supported on the frame proximate the top of the frame, in which the top antenna is a peak antenna; a bottom antenna supported proximate the bottom of the frame and separated from the top antenna by a known distance, in which the bottom antenna is a peak antenna; a null antenna supported on the frame and disposed at an orientation orthogonal to the top antenna and the bottom antenna; wherein the top antenna and the bottom antenna define a locating plane; an inclinometer supported on the frame to measure a tilt angle of the frame within the locating plane; and a processor supported on the frame to determine a direct distance between the frame and the underground utility line using a signal strength of the electromagnetic field received at the top antenna compared to a signal strength received at the bottom antenna with the null antenna pointed substantially at the utility line; wherein the processor determines a horizontal distance between the frame and a point on the ground above the utility line using the direct distance and the tilt angle of the frame.
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33. A method for determining the location of an underground utility line using a hand-held locator, the method comprising:
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positioning the locator at a point that is laterally displaced from the utility line; pointing a bottom of the locator toward the utility line by tilting the locator until a maximum signal is measured at one and only one top antenna or at a bottom antenna, in which the top and the bottom antennas are separated by a known distance and are each peak antennas; measuring a tilt angle of the locator; measuring a signal strength of an electromagnetic field transmitted from the utility line at the top and at the bottom antenna; processing the measured signal strength of the top antenna and the bottom antenna to determine a direct distance between the locator and the utility line; determining a horizontal distance to the utility line based on the tilt angle of the locator and the direct distance; and displaying the horizontal distance.
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Specification