Magnetic Sensors Assessment in Velocity Induced Eddy Current Testing
; Rocha, T.
Ribeiro, A. L.
Magnetic Sensors Assessment in Velocity Induced Eddy Current Testing, Proc IEEE Instrumentation and Measurement Technology Conf., Montevideo, Uruguay, Vol. 00, pp. 00 - 00, May, 2014.
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This paper presents a development on a new nondestructive testing method with eddy currents induced by velocity. In this method a permanent magnet that is attached to a moving carriage creates eddy currents in the conductive material to be inspected. By measuring the opposing magnetic field generated by the eddy currents it is possible to obtain information regarding the presence of defects. Different magnetic field sensors, differential pick-up coils, giant magneto resistors (GMR) and Hall sensors have been used and compared. Before presenting the measured results a preview of the electrical and magnetic fields in the sample was studied in order to position the probes that include the permanent magnet to create the eddy currents and the magnetic sensor to measure the resultant magnetic field density. The best probe’s position is the one that presents the highest sensibility to the defects’ presence.