An apparatus and method for directing ultrasonic and magnetostrictively generated mechanical waves from an exterior point to an interior point within a small diameter tube, pipe, or cylindrical structure. The present invention incorporates an external mechanism for generating waves in a cylindrical waveguide tube gun of a size small enough for insertion into the target tube and configured so as to maintain mechanical contact with an inside diameter of the target tube. Standard ultrasonic wave generating devices or magnetostrictive/mechanical wave generating coils are positioned on the waveguide external to the target tube and generate appropriate mechanical waves through the waveguide to a point interior to the target tube. A mechanical interface between the waveguide and the inside diameter surface of the tube is positioned and provided at a point within the target tube to transfer both the interrogating waves and the received return signal waves between the target tube and the waveguide. Appropriate sensor devices for ultrasonic and/or magnetostrictive/mechanical waves are positioned to receive the returned signals and interpret the impedance mismatches that indicate flaws, supports and geometric variations in the tubular wall. Appropriate signal reception, amplification, and filtration elements are positioned to convert the received signal into a signal voltage suitable for display and processing.
Robert L. Spinks;Joseph W. Brophy;Ronald H. Peterson