Expert system for the characterization of defect signals in steam generator tubes

Comparison Of Pec And Sfec Nde Techniques

“…However, for higher spectral resolution and accuracy requirements, the sweep duration is longer, leading to lengthy inspection times. A solution to this problem might be multi-frequency (MUF) EC when the excitation signal contains several frequency components [8]. Implementation of such an excitation becomes increasingly sophisticated with a growing number of desired frequencies.…”

Case-Based Reasoning for Automatic Interpretation of Data from Eddy-Current Inspection

“…The examples are: SOCRATE [8], Dodger [9], EXTRACSION [10], and a hybrid system described in [11 J. What is characteristic is that all four systems have been developed for nuclear power industry.…”

Pre-processing of signals delivered by a new eddy current sensor for non ferromagnetic tubes testing

“…In both cases, the signals analysis is based upon comparison with typical Lissajoux patterns, more or less assisted by expert systems [2] [3]. To go beyond these methods, we must be able to compute, with a good resolution, the conductivity at any point of the pipe.…”

“…It is necessary to upgrade U0 with each new sample for which no flaw signal issuspected. If we know, for a given instant T, U,, ( ) and A,(&), and if E(&+,) is a sample of at instant we can compute U,( T,,.,) with the following algorithm : 1) compute B matrix such :2) compute the rotation matrix R that diagonalize B3) upgrade basis and eigen values :The matrix B being symmetric, we can use a fast diagonalization algorithm, such as Jacobi's algorithm.It is preferable to work with a f h t e horizon, either with a moving window, of fixed length N, and we have -. either with an div a mP* ' to test the variableexponential loosing factor a < 1 : &k and, as soon we have acquired enough samples so << 1, we have to test the variable…”