Electricity: measuring and testing – Fault detecting in electric circuits and of electric components – For fault location
Reexamination Certificate
2001-06-12
2004-04-13
Le, N. (Department: 2858)
Electricity: measuring and testing
Fault detecting in electric circuits and of electric components
For fault location
C324S238000, C324S242000
Reexamination Certificate
active
06720775
ABSTRACT:
BACKGROUND OF INVENTION
The present invention generally relates to nondestructive evaluation of metallic structures and, more particularly, is concerned with a pulsed eddy current two-dimensional sensor array probe and system for electrically conducting component inspection.
The presence of surface cracks and subsurface flaws in metallic structures, such as aircraft skin structures, have the potential to lead to catastrophic failure. Various inspection methods have been used heretofore for crack and flaw detection with varying degrees of success.
One prior art inspection method uses eddy current probes which can give an indication of depth to ascertain crack and flaw severity. The probes requires close contact with the part and have limited resolution and inspection speed. Also, complicated contour following is needed to inspect curvatures of some parts. Lift off between the probes and the part is a major concern. Full coverage with eddy current probes is very time consuming, which leads to spot checking which may miss critical crack and defect areas.
Consequently, a need still exists for an innovation which will provides a solution to the aforementioned problem without introducing any new problems in place thereof.
SUMMARY OF INVENTION
The present invention provides a pulsed eddy current two-dimensional sensor array probe, system and data visualization for electrically conducting component inspection designed to satisfy the aforementioned need. The probe uses a two-dimensional array of magnetic field sensors for inspection of electrically conducting components without requiring mechanical scanning. A coil (solenoid) is used to transmit an electromagnetic pulse of a fixed duration into a component. The induced eddy current penetrates the structure and serves to produce a pattern of electromagnetic transient field above a defect. The two-dimensional array of sensors is located in a plane within the drive coil. Static scanning is employed to collect time evolution response of the magnetic field from all the sensors. This is performed by electronically switching the sensors while the probe is placed in a stationary position on the conducting structure. The response from the sensors is processed to determine the material thickness with a two-dimensional map representing a full field of view.
In one embodiment of the present invention, a pulsed eddy current two-dimensional sensor array probe for electrically conducting component inspection is provided which comprises a drive coil disposed adjacent to a structure under inspection, a pulse generator connected to the drive coil and operable to energize in a pulsed manner the drive coil to transmit transient electromagnetic flux into the structure under inspection, and an array of sensors arranged in a two-dimensional array and substantially surrounded by the drive coil and operable to sense and generate output signals from the transient electromagnetic flux in the structure under inspection.
In another embodiment of the present invention, a pulsed eddy current two-dimensional sensor array system for electrically conducting component inspection is provided which comprises a pulsed eddy current two-dimensional sensor array probe for transmitting in a pulsed manner a transient electromagnetic flux into a structure under test and for sensing and generating output signals from the transient electromagnetic flux in the structure under inspection, and a data acquisition apparatus for receiving and processing the output signals and outputting the processed signals in the form of a two-dimensional image made up of pixels that correspond to the array of sensors. The two-dimensional image is formed by a given gray level to the amplitude of an informative parameter that is computed for each individual sensor in the two-dimensional array. Each element (pixel) of the image is located according to the spatial position of the sensor in the array.
REFERENCES:
patent: 3875502 (1975-04-01), Neumaier
patent: 4292589 (1981-09-01), Bonner
patent: 4495466 (1985-01-01), Lakin
patent: 5056049 (1991-10-01), O'Neill
patent: 5391988 (1995-02-01), Kitagawa
patent: 5434506 (1995-07-01), Flora
patent: 5491409 (1996-02-01), Flora et al.
patent: 5659248 (1997-08-01), Hendengren et al.
patent: 6037768 (2000-03-01), Moulder et al.
patent: 6124712 (2000-09-01), Chaiken
patent: 6150809 (2000-11-01), Tiernan et al.
patent: 6259826 (2001-07-01), Pollard et al.
patent: 6344741 (2002-02-01), Giguere et al.
patent: 6366085 (2002-04-01), Yeshurun et al.
patent: 0533440 (1995-02-01), None
patent: 0512796 (1997-08-01), None
R. Rempt, Scanning with Magnetoresistive Sensors for Subsurface Corrosion, D.O. Thompson & D.E. Chimenti (Eds.), Review of Progress in QNDE, vol. 21B, AIP, N.Y., 2002, pp. 1771-1778.
Y.A. Plotnikov, S.C. Nath, and C.W. Rose, Defect Characterization in Multi-Layered Conductive Components with Pulsed Eddy Current, D. O. Thompson and D.E. Chimenti (Eds.), Review of Progress in QNDE, vol. 21B, AIP, N.Y., 2002, pp. 1976-1983.
European Search Report, Application Number EP 02 25 4028, The Hague, Oct. 24, 2003.
Batzinger Thomas James
Herd Kenneth Gordon
Nath Shridhar Champaknath
Plotnikov Yuri Alexeyevich
Rose Curtis Wayne
Clarke Penny A.
General Electric Company
Le N.
Patnode Patrick K.
Teresinski John
LandOfFree
Pulsed eddy current two-dimensional sensor array inspection... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pulsed eddy current two-dimensional sensor array inspection..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pulsed eddy current two-dimensional sensor array inspection... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3231400