METHOD OF ULTRASONIC TESTING OF PRODUCTS MADE OF COARSE-GRAINED MATERIALS AND ULTRASONIC TESTING UNIT FOR INSPECTION OF PRODUCTS MADE OF COARSE-GRAINED MATERIALS Russian patent published in 1995 - IPC

FIELD: nondestructive test of materials quality. SUBSTANCE: product receives pulses at three definite frequencies, whose values are selected in the extreme points of standard envelope spectra, and the class of defect is judged from the relation of amplitudes. The testing unit is provided with a defect class indicator, solver and additional amplitude meter. EFFECT: determination of the true class of defect and its view on the background of noise caused by material structure. 3 cl, 4 dwg