Nondestructive flaw testing of rails in track by induction methods is described and compared with ultrasonic methods. Relative strengths and weaknesses of induction testing are listed. Results taken from concurrent induction and ultrasonic testing are given which demonstrate the complementary nature of the two methods.
Charles S. Fitzgerald,
"Inspection for rail defects by magnetic induction", Proc. SPIE 2458, Nondestructive Evaluation of Aging Railroads, (30 June 1995); doi: 10.1117/12.212672; https://doi.org/10.1117/12.212672