Multifrequency eddy current testing signal analysis for steam generator tube inspection

In eddy current testing (ECT) of steam generator tubes in nuclear power plants, it is a very important to extract the flaw signal from signals compounded by flaws and supporting structures. To perform such an important task, the multifrequency eddy current testing methods are widely adopted since they have a well-known capability of extracting the flaw signal from the compound signals. This technique is claimed to be very effective to extract the flaw signal from signals including background noise and/or support plate signals. We proposed an use of one of a linear mixing technique using the discrete cosine transform method. We explore the performance of the frequency mixing approach for signal use as qualified data analyst training data. The proposed method is computationally efficient so that it can be implemented in a real time fashion.