DEFECT DETECTOR FOR CONDUCTIVE MATERIALS

• US 20170199156A1
• Filed: 01/21/2016
• Published: 07/13/2017
• Est. Priority Date: 01/12/2016
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Villani, JR., Joseph A., Stetson, JR., John B.
• Granted Patent: US 10,088,452 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 27/82 for investigating the presence of flaws

Abstract

A method includes passing a magnetometer along a length of a material. The method also includes measuring, via the magnetometer, a first magnetic field magnitude along a first portion of the length of the material and measuring, via the magnetometer, a second magnetic field magnitude along a second portion of the length of material. The method further includes determining that the material comprises a defect along the second portion of the length of material by determining that the first magnetic field magnitude is different than the second magnetic field magnitude.

Claims

16. A method comprising:

receiving, from a magnetometer, an initial magnetic field magnitude;

moving the magnetometer parallel to a length of a material;

receiving, from the magnetometer, a measured magnetic field magnitude that is different than the initial magnetic field magnitude at a first location along the length of the material; and

determining, based on the measured magnetic field magnitude, that the material comprises a defect at the first location.

17. A method comprising:

measuring, using a magnetometer, a magnetic field of Earth while the magnetometer travels parallel to a length of material;

monitoring for a change in the measured magnetic field of Earth while the magnetometer travels parallel to the length of the material; and

determining that a portion of the length of the material comprises a defect by detecting the change in the measured magnetic field of Earth.

21. The method of claim 17, wherein said inducing the current in the length of material comprises using an induction coil to generate a magnetic field.

18. A method comprising:

inducing a current in a length of material;

determining an expected magnitude of a magnetic field along the length of the material;

measuring, using a magnetometer, a measured magnitude of the magnetic field along at least a portion of the length of the material; and

determining that the length of the material comprises a defect by comparing the expected magnitude of the magnetic field and the measured magnitude of the magnetic field.

19. The method of claim 18, further comprising determining a location of the defect in the length of the material relative to the magnetometer.

20. The method of claim 19, wherein determining the location of the defect in the length of the material relative to the magnetometer comprises calculating

22. A device comprising:

a magnetometer configured to sense a magnetic field magnitude; and

a processor operatively coupled to the magnetometer and configured to;

monitor the magnetic field magnitude sensed by the magnetometer;

determine a change in the magnetic field sensed by the magnetometer; and

determine that a length of a material comprises a defect based at least on the change in the magnetic field.

1. A method comprising:

passing a magnetometer along a length of a material;

measuring, via the magnetometer, a first magnetic field magnitude along a first portion of the length of the material;

measuring, via the magnetometer, a second magnetic field magnitude along a second portion of the length of material; and

determining that the material comprises a defect along the second portion of the length of material by determining that the first magnetic field magnitude is different than the second magnetic field magnitude.

2. The method of claim 1, wherein said determining that the first magnetic field magnitude is different than the second magnetic field magnitude comprises determining that the first magnetic flux material is different than the second magnetic flux material by a first threshold.

3. The method of claim 1, wherein said measuring the first magnetic field magnitude and said measuring the second magnetic field magnitude occurs at a 10,000 Hertz (Hz) bandwidth.

4. The method of claim 1, wherein said measuring the first magnetic field magnitude and said measuring the second magnetic field magnitude occurs at a 50,000 Hertz (Hz) bandwidth.

5. The method of claim 1, wherein said measuring the first magnetic field magnitude and said measuring the second magnetic field magnitude occurs at a sensitivity of 10⁻

9 Tesla.

6. The method of claim 1, wherein said measuring the first magnetic field magnitude comprises measuring the first magnetic field magnitude in three directions.

7. The method of claim 6, wherein each of the three directions are orthogonal to one another.

8. The method of claim 1, wherein said passing the magnetometer along the length of the material comprises maintaining a consistent distance between the magnetometer and the length of the material.

9. The method of claim 8, wherein the consistent distance is a distance between five and ten meters.

10. The method of claim 1, wherein the material is a ferrous material.

11. The method of claim 1, wherein the material is ferromagnetic.

12. The method of claim 1, wherein the material comprises at least one of a railway rail or a pipe.

13. The method of claim 1, wherein the material comprises a component of machinery.

14. The method of claim 1, wherein the defect comprises a break, a crack, a hole, a pit, or a gouge in the length of the material.

15. The method of claim 1, wherein the magnetometer is configured to measure a magnetic field at a plurality of locations simultaneously.

23. The device of claim 22, wherein to monitor the magnetic field magnitude sensed by the magnetometer, the processor is configured to monitor the magnetic field magnitude sensed by the magnetometer while the magnetometer moves along at least a portion of the length of the material.

24. The device of claim 23, wherein the magnetometer moves along at least the portion of the length of the material with a consistent distance between the magnetometer and the length of the material.

25. The device of claim 24, wherein the consistent distance is a distance between five and ten meters.

26. The device of claim 22, wherein to determine that the first magnetic field magnitude is different than the second magnetic field magnitude the processor is configured to determine that the first magnetic flux material is different than the second magnetic flux material by a first threshold.

27. The device of claim 22, wherein the magnetometer is configured to sense the magnetic field magnitude at a 10,000 Hertz (Hz) bandwidth.

28. The device of claim 22, wherein the magnetometer is configured to sense the magnetic field magnitude at a 50,000 Hertz (Hz) bandwidth.

29. The device of claim 22, wherein the magnetometer is configured to sense the magnetic field magnitude with a sensitivity of 10⁻

9 Tesla.

30. The device of claim 22, wherein the magnetometer is configured to sense the magnetic field magnitude in three directions.

31. The device of claim 30, wherein each of the three directions are orthogonal to one another.

32. The device of claim 22, wherein the material comprises at least one of a railway rail or a pipe.

33. The device of claim 22, wherein the material comprises a component of machinery.

34. The device of claim 22, wherein the defect comprises a break, a crack, a hole, a pit, or a gouge in the length of the material.

35. The device of claim 22, wherein the magnetometer is configured to measure a magnetic field at a plurality of locations simultaneously.

30-1. The device of claim 22, wherein the material is a ferrous material.

31-1. The device of claim 22, wherein the material is ferromagnetic.

36. A device comprising:

a magnetometer configured to sense a magnetic field magnitude; and

a processor operatively coupled to the magnetometer and configured to;

receive, from the magnetometer, a first magnetic field magnitude along a first portion of a length of material;

receive, from the magnetometer, a second magnetic field magnitude along a second portion of the length of material; and

determine that the material comprises a defect along the second portion of the length of material by determining that the first magnetic field magnitude is different than the second magnetic field magnitude.

37. A device comprising:

a magnetometer configured to sense a magnetic field magnitude; and

a processor operatively coupled to the magnetometer and configured to;

determine an expected magnitude of a magnetic field along a length of a material;

measure, using a magnetometer, a measured magnitude of the magnetic field along at least a portion of the length of the material; and

determine that the length of the material comprises a defect by comparing the expected magnitude of the magnetic field and the measured magnitude of the magnetic field.

38. The device of claim 37, further comprising a coil configured to induce a current through the length of the material.

39. The device of claim 37, wherein the processor is further configured to determine a location of the defect in the length of the material relative to the magnetometer.

40. The device of claim 39, wherein to determine the location of the defect in the length of the material relative to the magnetometer the processor is further configured to calculate