Non-destructive testing techniques having high speed and high detectability are required for testing heat exchanger and boiler tubes in in-service inspections. A rapid non-destructive inspection method is described, developed to detect and locate defects on heat exchanger tubes (θsub(ex) = 25-100 mm), and which is based on non-contact Electro Magnetic Acoustic Transducers (EMATs) acting from a remote position and operating by shear horizontal (SH) guided waves.