Electrical and Magnetic Methods of Nondestructive Testing

This textbook is intended to help satisfy an urgent requirement for up-to-date texts at graduate and senior undergraduate level on the subjects in Nondestructive Testing (NDT). The subject matter is confined here to electrical and magnetic methods, with emphasis on the widely-used eddy current and magnetic flux leakage methods (including particle inspection) but proper attention is paid to other techniques, such as microwave and AC field applications, which are rapidly growing in importance. Theoretical analyses relating to the various methods are discussed and the depths of presentation are often governed by whether or not the information is readily available elsewhere. Thus, for example, a considerable amount of space is devoted to eddy current theory at what the author considers to be a reasonable standard and not, as usually experienced, in either a too elementary manner or at a level appreciated only by a post-graduate theoretical physicist. The inclusion of the introductory chapter is intended to acquaint the reader with some of the philosophy of NDT and to compare, briefly, the relative performances of the more important methods of testing.
Chapter 2 provides a summary of the basic electrical and magnetic theory relating to the subject. It is mainly intended for reference rather than for tutorial purposes, although some of the more important aspects of the theory are treated at greater length. The remainder of the chapters discuss the various techniques and applications. An appendix contains information on SI units, British and American Standards relevant to electrical and magnetic testing, a brief introduction to the Bessel and other functions appertaining to eddy current theory and some programmes in BASIC for calculating, with a personal computer, the impedance components of eddy current coils used for testing defect-free metal samples.