Remote Field Electromagnetic Technique has been increasingly used in the NDT of Carbon Steel and high ferritic (duplex) material with excellent results. Up to this time, most of the applications have been made by the use of a single channel circumferential pick-up coil. The detection and sizing of oriented flaws such as small pitting has been very difficult using the single channel circumferential coils. The RFET methods in conjuction with multi-channel (8 or 16 channel ) techniques has opened up many different possibilities of detecting and sizing these oriented pit flaws. The sensor array which is part of the pick-up coil system, consists of probes which have diameters in the range of 1-2mm. The electronics for the multi-channel system is based on the Digital Signal Processing chips (DSP). The real-time display is achieved by the use of the DSP technology in conjunction with several signal processing algorithms and signal pattern displays. This system has been used in the field for different size tubes with excellent results. The test results for 0.75"m 1.00", and 2.0" diameter Carbon Steel and 1.00" diameter duplex tubes are presented in this paper.
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.Vol. 5, pages 67 - 68 Publisher:Ashgate Publishing Company
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