Patent ID: 8421471
Filing Date: 2013-04-16
Classification: G01N,G01R

Abstract:
1. A device for nondestructive and noncontact detection of faults in a test piece which is moving relative to the device, comprising: a transmitter coil arrangement with at least one transmitter coil for exposing the test piece to a plurality of periodic alternating electromagnetic fields; a receiver coil arrangement with at least one receiver coil for detecting a periodic electrical signal which has a carrier oscillation such that at least one of an amplitude and a phase is modulated by a fault in the test piece when a fault is detected by the receiver coil arrangement; a signal processing unit for producing a useful signal from a receiver coil signal; an evaluation unit for evaluating the useful signal for purposes of detection of the fault in the test piece; and a self-test unit which automatically or upon an external request undertakes systematic quantitative checking of the signal processing functions of at least one of the signal processing unit, the transmitter coil arrangement, and the receiver coil arrangement, and upon external request undertakes calibration of the signal processing unit with a calibration standard to replace at least one of the transmitter coil arrangement and/or of the receiver coil arrangement.