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US 5,311,128 AGranted
Eddy current imaging system using spatial derivatives for flow detection
AssigneeAbb Amdata Inc.
InventorsJohn P. Lareau, David S. Leonard
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AssigneeAbb Amdata Inc.
InventorsJohn P. Lareau, David S. Leonard
Estimating the term…
An eddy current imaging system includes an eddy current sensing coil positioned proximate a workpiece for scanning the workpiece to produce a signal indicative of the integrity of the workpiece for regions in an x,y array of data. Such a signal may be a complex impedance signal representative of the amplitude and/or the phase of the signal. Two data processing techniques are disclosed for enhancing the display of a flay in the workpiece. The first includes the step of calculating a spatial derivative of the amplitude and/or phase indicative signal from the coil and providing an image of the spatial derivative to produce a C scan of the spatial derivative. The second includes the steps of determining the regions of maximum ascent and/or descent of the signal for regions in the scan and calculating an impedance plane trajectory from the data array of path points for displaying a reconstructed optimum signal independent of path pattern.
A method for contrast imaging a workpiece with eddy current imaging means including an eddy current sensing coil positioned proximate said workpiece by traversing said workpiece in an arbitrary pattern independently of velocity or direction, thus to scan said workpiece and produce a signal indicative of the impedance of said workpiece proximate said eddy current sensing coil and the location of said sensing coil, said method including:
A method of displaying a contrast image of a flaw in a workpiece which is scanned in an arbitrary pattern independently of velocity or direction by an eddy current coil to produce a quadrature impedance amplitude indicative signal, comprising the steps of:
The method for contrast imaging a workpiece with eddy current imaging means including an eddy current sensing coil positioned proximate said workpiece and traversing said workpiece in a pattern, thus to scan said workpiece ad produce a signal indicative of the impedance of said workpiece proximate said eddy current sensing coil for each scanned position of interest, said method including:
A method for contrast imaging a workpiece, comprising the steps of;
A method for contrast imaging a workpiece with eddy current imaging means including an eddy current sensing coil positioned proximate said workpiece by traversing said workpiece in an arbitrary pattern independently of velocity or direction, thus to scan said workpiece and produce a signal indicative of the impedance of said workpiece proximate said eddy current sensing coil and the location of sensing coil, said method including:
A method of displaying a contrast image of a flaw in a workpiece which is scanned in an arbitrary pattern independently of velocity or direction by an eddy current coil to produce an in phase indicative signal, comprising the steps;
Dependencies are inferred from the claim text.