METHOD FOR CARRYING OUT ARTICLE QUALITY CONTROL Russian patent published in 1995 - IPC

FIELD: quality control; non-destructive control. SUBSTANCE: method involves mounting ultrasonic transducer on an article under control, emitting ultrasonic oscillation pulses, receiving a series of echo pulses reflected from the opposed article surface, scanning with ultrasonic signals the body of the article under control. In scanning an article, the ultrasonic transducer is rotated about its own axis in the course of emittence and reception processes. The presence of defect is determined by analyzing the received pulse parameters. The ultrasonic oscillation pulses are emitted by means of resonance generators periodically changing basic frequency within the limits of each electric excitation pulse of ultrasonic resonance generator in the range of frequencies including the main resonance frequency of the generator and its odd harmonics. A series of pulses having the same reflection number is selected from the received echo signals. The envelope of the selected series is built to make conclusion related to the presence of material structure defect in the article under control using the information about the envelope shape and kind of changes due to rotating the ultrasonic transducer about its axis and scanning the body of the article under control with ultrasonic signal. EFFECT: enhanced reliability of quality control process; effective detection of spacious defects of article material structure. 2 dwg