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.
展开▼
