Abstract: A digital computer performs a complete eddy current analysis of the tubes of a steam generator from data input to generation of a final report. The computer extracts signatures generated by various structural features and tube defects from the data, breaks down composite signatures into their component parts and classifies each such signature by applying thereto a cascading set of experience based rules. Signatures classified as structural features are examined closely for the presence of colocated tube defects. A post processor correlates the location of the indication identified from the time based eddy current data with the known physical location of the structural features so that the position of the defects can be presented in terms of distances from fixed structures.