Methods and apparatus for testing a component

• US 20060109001A1
• Filed: 11/19/2004
• Published: 05/25/2006
• Est. Priority Date: 11/19/2004
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: McKnight, William Stewart, Suh, Ui Won, Ertel, John William, Gambrell, Gigi Olive
• Granted Patent: US 8,013,599 B2
• Time in Patent Office: Days
• US Class Current: 324/232
• CPC Class Codes: G01B 7/28 for measuring contours or curvatures
• CPC Class Codes: G01N 27/9006 Details, e.g. in the structure or functioning of sensors
• CPC Class Codes: G01N 27/902 by moving the sensors

Abstract

A method for inspecting a component having a surface profile that includes a local minima and a local maxima. The method includes positioning an eddy current probe proximate to a surface of the component to generate a first position indication, positioning the eddy current probe proximate to the surface of the component to generate a second position indication that is different than the first position indication, and interpolating between the first and second position indications to determine a profile of a portion of the surface of the component.

Claims

1. A method for inspecting a component having a surface profile that includes a local minima and a local maxima, said method comprising:

positioning an eddy current probe proximate to a surface of the component to generate a first position indication;

positioning the eddy current probe proximate to the surface of the component to generate a second position indication that is different than the first position indication; and

interpolating between the first and second position indications to determine a profile of a portion of the surface of the component.

2. A method in accordance with claim 1 wherein positioning the eddy current probe proximate to surface of the component to generate a first position indication comprises positioning the eddy current probe normal to the surface of the surface of the component, and wherein positioning the eddy current probe proximate to surface of the component to generate a second position indication comprises positioning the eddy current probe normal to the surface of the surface of the component.

3. A method in accordance with claim 1 wherein interpolating the first and second position indications further comprises interpolating between the first and second position indications to generate at least one position indication between the first and second position indications.

4. A method in accordance with claim 2 wherein at least one of said first and second positions include at least one of a local minima and a local maxima.

5. A method in accordance with claim 1 further comprising generating a scan plan of a component to be inspected using the determined profile.

6. A method in accordance with claim 5 further comprising:

coupling a differential probe to an eddy current inspection system;

moving the eddy current probe along a first scan line in a scan direction; and

indexing the eddy current probe to a second scan line that is different than the first scan line such that the eddy current probe is maintained in a substantially normal alignment with the surface of the component to generate a plurality of scan data.

7. A method in accordance with claim 6 wherein indexing the eddy current probe to a second scan line further comprises indexing the eddy current probe to a second scan line utilizing the using the determined profile.

8. A method in accordance with claim 6 further comprising utilizing the scan data to generate at least one two-dimensional image of the component being inspected.

9. A method in accordance with claim 8 further comprising dividing the two-dimensional image into a plurality of sub-images that each have approximately the same shape.

10. A method in accordance with claim 9 further comprising selecting a filter based on the third image generated and filtering the third image to generate a final image.

11. A differential eddy current probe for inspecting a component, said eddy current probe comprising:

a body portion comprising an outer surface and having a width, and a length that is longer than said width;

a tip portion extending from said body portion, said tip portion comprising an end and an outer tip, said end extending between said body portion and said outer tip, said tip portion having a width and a length, said tip portion width gradually decreases from said tip portion end to said outer tip, said tip portion length gradually decreases from said tip portion end to said outer tip; and

at least one differential pair of coils mounted within said tip portion, each of said at least one pair of coils comprises a substantially cylindrical shape, at least a portion of each of said at least one pair of coils is positioned adjacent to said tip portion outer tip for generating a magnetic field that is substantially perpendicular to a surface of the component being inspected.

12. An eddy current probe in accordance with claim 11 wherein said body portion and said tip portion are formed unitarily together.

13. An eddy current inspection system comprising:

a differential eddy current probe; and

a computer coupled to said eddy current probe, said computer configured to

position said eddy current probe proximate to a surface of a component to generate a first position indication;

position said eddy current probe proximate to said component surface to generate a second position indication that is different than said first position indication; and

interpolate between said first and second position indications to determine a profile of a portion of said component surface.

14. A system in accordance with claim 13 wherein said computer is further configured to:

position said eddy current probe normal to said component surface of the component to generate said first position indication; and

position said eddy current probe normal to said component surface of the component to generate said second position indication.

15. A system in accordance with claim 13 wherein said computer is further configured to interpolate between said first and second position indications to generate at least one position indication that is between said first and second position indications.

16. A system in accordance with claim 13 wherein said computer is further configured to generate a scan plan of said component using the determined profile.

17. A system in accordance with claim 13 wherein said computer is further configured to:

move said eddy current probe along a first scan line in a scan direction; and

index said eddy current probe to a second scan line that is different than the first scan line such that said eddy current probe is maintained in a substantially normal alignment with said component surface to generate a plurality of scan data.

18. A system in accordance with claim 17 wherein said computer is further configured to index said eddy current probe to a second scan line using the determined profile.

19. A system in accordance with claim 17 wherein said computer is further configured to analyze said scan data to generate at least one two-dimensional image of the component being inspected.

20. A system in accordance with claim 19 wherein said computer is further configured to:

select a filter based on said third image generated; and

filter said third image to generate a final image.