Sonde array for use with buried line locators

• US 8,106,660 B1
• Filed: 05/14/2010
• Issued: 01/31/2012
• Est. Priority Date: 10/04/2003
• Status: Active Grant

• Current Assignee: Seescan, Inc.
• Original Assignee: Seektech Inc.
• Inventors: Merewether, Ray, Olsson, Mark S.
• Primary Examiner(s): Aurora, Reena
• Application Number:
  US12/780,311
• Time in Patent Office: 627 Days
• Field of Search: 324/67, 324/326, 343/728, 343/788, 343/867
• US Class Current: 324/326
• CPC Class Codes: G01V 3/08 operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices with electromagnetic waves G01V3/12
• CPC Class Codes: G01V 3/081 the magnetic field is produced by the objects or geological structures characterised by the method of magnetic field measurement G01R33/00
• CPC Class Codes: G01V 3/10 using induction coils
• CPC Class Codes: G01V 3/104 using several coupled or uncoupled coils G01V3/101 takes precedence
• CPC Class Codes: G01V 3/15 specially adapted for use during transport, e.g. by a person, vehicle or boat
• CPC Class Codes: G01V 3/165 operating with magnetic or electric fields produced or modified by the object or by the detecting device with electromagnetic waves G01V3/17

Abstract

A sonde array that is useful in locating buried utilities includes at least three substantially mutually orthogonal antennas. Each antenna includes a substantially cylindrical ferromagnetic core, an insulating layer surrounding the core, and a length of a conductor wrapped around the insulating layer to form a coil. The coils of the antennas are substantially identical.

Claims

1. A sonde array useful in locating buried utilities, comprising:

At least three substantially mutually orthogonal antennas, each antenna including;

a substantially cylindrical ferromagnetic core;

an insulating layer surrounding the core; and

a length of a conductor wrapped around the insulating layer to form a coil;

wherein the antennas have a substantially identical configuration, and are arranged in three sets of pairs that extend along X, Y, and Z axes.

2. The sonde array of claim 1 wherein the insulating layer comprises a bobbin.

3. The sonde array of claim 1 wherein the core is made of ferrite.

4. The sonde array of claim 1 wherein the length of conductor is made of copper wire.

5. The sonde array of claim 1 wherein the coils of each set of antennas are wired in phase and in series.

6. The sonde array of claim 1 wherein the antennas of each pair are positioned on opposite sides of a member made of a magnetic material.

7. The sonde array of claim 6 wherein the member made of magnetic material magnetically couples the cores of each pair of antennas.

8. The sonde array of claim 6 wherein the member is formed as a block.

9. The sonde array of claim 8 wherein the block is enclosed in a central hub.

10. The sonde array of claim 1, further comprising a push cable coupled to the sonde for deployment in a pipe or conduit.

11. The sonde array of claim 1, wherein each of the mutually orthogonal antennas have an identical configuration.

12. The sonde array of claim 1, further comprising an electrical power source coupled to the sonde array for providing current to generate a magnetic field signal from the sonde array.

13. The sonde array of claim 12, wherein the electrical power source comprises a power amplifier configured to switch the current from coil-to-coil.

14. The sonde array of claim 13, wherein the current is switched at substantially a phase zero-crossing point.

15. The sonde array of claim 13, wherein the electrical power source is configured to provide the current at a single drive frequency.

16. The sonde array of claim 13, wherein the electrical power source is configured to provide the current at a plurality of drive frequencies to different coils.

17. The sonde array of claim 16, wherein the plurality of drive frequencies vary by an integer number of cycles.

18. A sonde array useful in locating buried utilities, comprising:

six sondes of identical configuration, each sonde including;

a cylindrical bobbin;

a molded core form;

a central ferrite core extending within the bobbin; and

a copper wire coil wound around the bobbin;

wherein the sondes are arranged and connected as three separate sets, each being wired in-phase, in series electrically as they appear on one coil; and

a center block of magnetic material coupling each pair of cores together.

19. The sonde array of claim 18, further including a central hub coupled to the block and each of the bobbins.