US005828213A [ii] Patent Number: [45] Date of Patent:
[54] METHOD AND APPARATUS FOR MAGNETICALLY SAMPLING THE UNIFORMITY OF AN ELONGATE OBJECT
[76] Inventor: Jack R. Hickman, 2120 Danny Park, Metairie, La. 70001
[21] Appl. No.: 733,944
[22] Filed: Oct. 21, 1996
[51] Int. CI.6 G01N 27/82; G01R 33/12
[52] U.S. CI 324/235; 324/232; 324/242;
324/262
[58] Field of Search 324/220-221,
324/228, 232, 235, 240-243, 262
[56] References Cited
U.S. PATENT DOCUMENTS
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4,827,215 5/1989 van der Walt 324/240
4,864,233 9/1989 Harrison 324/240 X
4,929,897 5/1990 Van Der Walt 324/242 X
5,293,117 3/1994 Hwang 324/232 X
5,402,066 3/1995 Hickman, Jr. et al 324/242
5,414,353 5/1995 Weischedel 324/232
FOREIGN PATENT DOCUMENTS 0093566 4/1983 European Pat. Off. .
Primary Examiner—Gerard R. Strecker
Attorney, Agent, or Firm—Randall C. Brown; Rick Matos;
Akin, Gump, Strauss, Hauer & Feld, L.L.P.
[57] ABSTRACT
Apparatus for performing nondestructive magnetically testing and inspection ol elongate objects. The apparatus concentrically surrounds the elongate object to be tested and includes means for inducing a magnetic field in the elongate object and a partial lerrous return path for the magnetic flux emanating from a pair ol magnet arrays. The partial lerrous return path is engaged with a sensor for detecting variations or flaws in the elongate object.
31 Claims, 10 Drawing Sheets
