An ultrasonic inspection system for inspecting objects, such as pipe, is disclosed which includes an ultrasonic inspection probe or search unit, and the usual ultrasonic transducers and electronics associated with the probe. The system also includes novel apparatus for continuously tracking and recording operation with respect to a reference point or area, on the object being inspected. For this purpose, the inspection probe includes one or more sources of radiant energy which are periodically actuated as the probe is moved about the object being inspected, and a plurality of receiving devices or microphones located at a fixed relationship with respect to the area being inspected or to a known reference point on the area, such as a weld. The location of the probe can be determined and recorded from information obtained by receipt of the signals from the source of radiant energy by two or more of the receiving devices. In order to permit the yaw of the inspection probe with respect to the centerline of the pipe to also be determined, and more accurately locate the inspection transducer of the probe at least two sources of radiant energy may be utilized at the inspection probe and the respective sources may be actuated at different time intervals to avoid interference between the tracking signals from the respective sources.
Jerry L. Jackson;Theodore L. Allen;Wayne T. Flach;William D. Jolly;Steve A. Cerwin