Abstract: A guided wave electromagnetic acoustic transducer for detecting defects in moving metallic products such as rods, tubes and the like and which has coils energized by pulse of a few cycles of a high frequency alternating voltage which produces an alternating field in the product, the coils being alternately wound and connected in series and measuring dynamic acoustic stress that is a function of the radial distance from the center of the product being tested and produces a reading that is different than that showing a surface defect in the product.

Abstract: This invention relates to a Electromagnetic Acoustic Transducer which has the ability to detect flaws in assorted metallic objects, such as pipes, rods, bars and the like, including those objects which are already installed and cannot be removed without a major undertaking. The Transducer also has an embodiment which includes hinged arms for surrounding the circular objects that have already been installed such as piping. The system employs Lamb waves to move along the surface of metallic objects to affect a bounced return to thereby allow detection of flaws on the surface or in the interior of said objects.