SINGLE MODE ULTRASONIC INSPECTION METHOD AND APPARATUS

摘要

An ultrasonic inspection apparatus is adapted for utilizing both pitch/catch and pulse/echo information obtained utilizing a single mode of wave propagation. The apparatus includes an ultrasonic signal transmitting assembly, a signal receiving assembly, a positioning mechanism, and an arrangement for recording the information received by the signal receiving assembly. The transmitting assembly includes at least one source transducer for transmitting shear mode ultrasonic search signals into the mass of an object to be inspected. The signal receiving assembly receives shear mode ultrasonic catch signals that are produced as the ultrasonic search signals encounter discontinuities in the mass of the object to be inspected and are directed toward and detected by at least one catch transducer. The signal receiving assembly also receives shear mode ultrasonic echo signals that are directed back to a first source transducer. The position determining mechanism is adapted for controlling the position of each source transducer and each catch transducer and for keeping track of the exact position of each transducer as the transducers send and/or receive ultrasonic signals so that signals from common discontinuities may be grouped together or correlated. The recording device records the ultrasonic signals received by the signal receiving assembly in a form that enables the signals to be analyzed to help characterize the acoustic discontinuities in the mass of the object being inspected.