| 摘要 |
An eddy current imaging system (15) includes an eddy current sensing coil (17) positioned proximate a workpiece for scanning the workpiece to produce a signal (21, 22) indicative of the integrity of the workpiece for regions in an x, y array of data. Such a signal (21, 22) 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 flaw in the workpiece. The first includes the step (30) of calculating a spatial derivative of the amplitude and/or phase indicative signal from the coil (17) and providing an image of the spatial derivative to produce a C scan of the spatial derivative. The second includes the steps (35, 36) 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. |
