| 摘要 |
<p>A method and device for nondestructive and noncontact detection of faults in a test piece, or electrically conductive particles in a liquid flow, moving past the device, using eddy currents. The test piece or flow is exposed to periodic alternating electromagnetic fields. A periodic electrical signal is detected by a receiver coil. The receiver coil signal has a carrier oscillation whose amplitude and/or phase is being modulated by a defect in the test piece or by electrically conducting particles and is digitized with an A/D converter stage. A useful signal is produced from the digitized receiver coil signal with a signal processing unit, and the useful signal is evaluated with an evaluation unit for detecting a fault in the test piece or electrically conductive particles. When overdriving of the A/D converter stage by the receiver coil signal is ascertained by monitoring the curve shape of the digitized receiver coil signal, a part of the receiver coil signal truncated by the A/D converter stage is reconstructed using a mathematical approximation in the digitized receiver coil signal.
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