DEVICE FOR ULTRASONIC TEST OF MATERIALS AND ARTICLES Russian patent published in 1998 - IPC

FIELD: nondestructive testing by ultrasonic methods. SUBSTANCE: device has generator 1 of sinusoidal signals, former 2 of rectangular pulses, first generator 3 of pseudorandom code sequence, period former 4, first electron key 5, power amplifier 6, radiating converter 7, receiving converter 8, input amplifier 9 and first demodulator 10 connected in series electroacoustically and first demodulator 10, second demodulator 11. Generator 1 forms continuous harmonic oscillations with frequency P_c equal to working frequency of flaw detector. Former 2 of rectangular pulses forms continuous oscillations of "square wave" type that come to inputs of first 3 and second 22 formers of pseudorandom code sequences from harmonic signal. First 18 and second 23 inverters form inverse pseudorandom sequences. Four two-input AND circuits 19, 24, 26 and 28 form decoder creating four sequences of controlling signals arriving to first inputs of electron keys 20, 25, 27 and 29. Harmonic oscillations of same frequency differing by phase shift only come to their second inputs. Each of additional codes is filtered by optimal filters 15 and 16 matched to it. After this "compressed" signals are summed up by first adder 17 and are fed to indicator. EFFECT: improved operational characteristics of device thanks to increase of sensitivity and authenticity of test. 5 dwg, 1 tbl