System and Method for Detection of Fiber Optic Cable Using Static and Induced Charge

• US 20060018619A1
• Filed: 06/16/2005
• Published: 01/26/2006
• Est. Priority Date: 06/18/2004
• Status: Active Grant

• Current Assignee: Southwest Research Institute
• Original Assignee: Southwest Research Institute
• Inventors: Helffrich, Jerome A., Thwing, Clinton J., Light, Glenn M.
• Granted Patent: US 7,155,107 B2
• Time in Patent Office: Days
• US Class Current: 385/134
• CPC Class Codes: G02B 6/562 locatable, e.g. using magnetic means

Abstract

The system and method provides means for detecting fiber optic cable embedded within a structure such as a wall of a building. It relies upon detecting an electrical field generated by movement of static and induced electrical charged fiber optic cable contained within the building wall. The invention is particularly useful when only one side of a wall structure is accessible and there is no access to the fiber optic cable. The process comprises the steps of locating wall studs, making a small hole in the wall material between the wall studs at approximately mid height, inserting a field emitter in the small hole for generating an electrical charge on a fiber cable, inserting an air nozzle in the small hole to create fiber cable movement, and detecting an electric field generated by the movement of an electrically charged fiber cable.

Claims

1. A method for detecting fiber optic cable embedded within a structure, the structure including internal support members and at least one wall having an internal surface affixed to the support members and an opposite accessible external surface, the method comprising the steps of:

inserting a tip of an electrostatic field emitter through the wall from the accessible wall surface to a location between the support members affixed to the internal surface;

activating the tip of the electrostatic field emitter with a high voltage for a sufficient time to induce an electrostatic charge on any fiber optic cable located between the support members;

injecting high pressure air through an air nozzle inserted into the structure from the accessible wall surface at the location between the support members for causing movement of any fiber optic cable located between the support members; and

detecting the presence of any fiber optic cable by positioning an electric field detector near the accessible wall surface for measuring an electric field generated by the movement of any electrostatically charged fiber cable located between the support members.

2. The method of claim 1, further comprising the step of identifying locations of the support members of the structure from the accessible surface, the support members containing no fiber optic cable.

3. The method of claim 1, further comprising the step of removing the tip of the electrostatic field emitter from the wall and inserting the air nozzle through the wall from the accessible wall surface to the location between the support members.

4. The method of claim 1, further comprising the step of providing user access to at least one surface of the structure.

5. The method of claim 1, wherein the step of inserting a tip of an electrostatic field emitter further comprises the step of producing a small diameter hole in the wall halfway between the support members and at approximately midwall height, and inserting the tip of the electrostatic field emitter through the hole.

6. The method of claim 5, wherein the step of producing a small diameter hole and inserting the tip of the electrostatic field emitter further comprises the step of removing the tip of the electrostatic field emitter from the wall and inserting the air nozzle through the hole.

7. The method of claim 1, wherein the step of activating the tip of the electrostatic field emitter further comprises the step of activating the tip of the electrostatic field emitter for generating ions.

8. The method of claim 1, wherein the step of injecting high pressure air through an air nozzle further comprises the step of injecting high pressure air through an air nozzle into the structure and manipulating the nozzle to provide a directional airflow in multiple directions within the structure for causing fiber optic cable movement.

9. The method of claim 1, further comprising the step of identifying the location of the fiber optic cable by positioning the electric field detector for maximum electric field strength.

10. A system for detecting fiber optic cables embedded within a wall structure, the structure including internal support members and at least one wall having an internal surface affixed to the support members and an opposite accessible external surface, the system comprising:

a tip of an electrostatic field emitter inserted through the wall from the accessible wall surface to a location between the support members affixed to the internal surface;

the tip of the electrostatic field emitter activated with a high voltage for a sufficient time to induce an electrostatic charge on any fiber optic cable located between the support members;

high pressure air being injected through an air nozzle inserted into the structure from the accessible wall surface at the location between the support members for causing movement of any fiber optic cable located between the support members; and

an electric field detector positioned near the accessible wall surface for detecting the presence of any fiber optic cable by measuring an electric field generated by the movement of any electrostatically charged fiber cable located between the support members.

11. The system of claim 10, further comprising identified locations of the support members of the structure from the accessible surface, the support members containing no fiber optic cable.

12. The system of claim 10, further comprising the tip of the electrostatic field emitter removed from the wall and the air nozzle inserted through the wall from the accessible wall surface to the location between the support members.

13. The system of claim 10, further comprising a user access to at least one surface of the structure.

14. The system of claim 10, wherein a tip of an electrostatic field emitter inserted through the wall further comprises a small diameter hole in the wall halfway between the support members and at approximately midwall height for inserting the tip of the electrostatic field emitter through the hole.

15. The system of claim 14, wherein small diameter hole for inserting the tip of the electrostatic field emitter further comprises the tip of the electrostatic field emitter being replaced in the wall by insertion of the air nozzle through the hole.

16. The system of claim 10, wherein the tip of the electrostatic field emitter activated further comprises the tip of the electrostatic field emitter activated for generating ions.

17. The system of claim 10, wherein the high pressure air injected through an air nozzle further comprises the high pressure air injected through an air nozzle into the structure and the nozzle manipulated to provide a directional airflow in multiple directions within the structure for causing fiber optic cable movement.

18. The system of claim 10, further comprising the electric field detector positioned for maximum electric field strength to identify the location of the fiber optic cable.

19. A method for detecting fiber optic cable embedded within a structure, comprising the steps of:

inserting a charging device within a structure to fill a space within the structure with ions that attach to a fiber optic cable within the structure;

replacing the charging device with a directional air nozzle within the structure for causing movement to the fiber optic cables within the structure; and

using a charge detection device, detecting an electric field generated by movement of the electrically charged fiber optic cable within the structure.

20. The method of claim 19, wherein the step of using a charge detection device further comprises:

positioning a horizontal wire above a ground plane for detecting an electric field generated by movement of the electrically charged fiber optic cable within the structure;

connecting the horizontal wire to an input of an electrometer amplifier; and

connecting an output of the electrometer amplifier to an indicating device for displaying the strength of the electric field generated by movement of the electrically charged fiber optic cable.

21. The method of claim 20, wherein the horizontal is a patch electrode.

22. The method of claim 19, wherein the step of inserting a charging device comprises the step of:

inserting a hardened metallic tip of a high voltage probe within the wall structure;

encasing a non-inserted part of the high voltage probe in an insulating material; and

electrically connecting the hardened metallic tip to a high voltage source.

23. A system for detecting fiber optic cable embedded within a structure, comprising:

a charging device inserted within a structure to fill a space within the structure with ions that attach to a fiber optic cable within the structure;

the charging device being replaced with a directional air nozzle within the structure for causing movement to the fiber optic cables within the structure; and

a charge detection device for detecting an electric field generated by movement of the electrically charged fiber optic cable within the structure.

24. The system of claim 23, wherein the charge detection device further comprises:

a horizontal wire positioned above a ground plane for detecting an electric field generated by movement of the electrically charged fiber optic cable within the structure;

the horizontal wire connected to an input of an electrometer amplifier; and

an output of the electrometer amplifier connected to an indicating device for displaying the strength of the electric field generated by movement of the electrically charged fiber optic cable.

25. The system of claim 24, wherein the horizontal wire is a patch electrode.

26. The method of claim 23, wherein the charging device comprises:

a hardened metallic tip of a high voltage probe inserted within the wall structure;

a non-inserted part of the high voltage probe encases in an insulating material; and

the hardened metallic tip electrically connected to a high voltage source.