A Method of Representing and Comparing Eddy Current Lissajous Patterns

The commercially available systems for EC inspection usually use only the phase and amplitude information. After the detection (with amplitude and phase thresholds), the defects are sized using calibration curves and the phase information. Such a system is not foolproof, usually because ofincorrect or spurious defect detection. Therefore, in practice the classification made by the system is usually checked afterwards by a human operator. The operator can quickly determine whether the computer classification is correct just looking at the shape ofthe curve.