METHOD FOR INCREASING INTERFERENCE PROTECTION OF ULTRASONIC TESTING AND A DEVICE FOR CARRYING OUT SAID METHOD

摘要

The inventive method is directed at increasing the interference protection of ultrasonic testing and consists in dividing a signal received by an ultrasound converter into several time zones, in separating the signal from the components thereof situated in waiting zones of signal reflected from defects, in individually processing signals received from different time zones by emitting signals from zones of action of sounding pulses and base echo waiting areas to broadband amplifiers, in filtering reflected from defect signals, which are coming from the signal waiting zones, in determining a maximum signal amplitude of a signal in the waiting zones of signals reflected from a defect, in comparing said amplitude value with a maximum permissible value and in concluding about the presence / absence of a defect according to said comparison results. The certainty of determination of the presence / absence of defects is evaluated by comparing, in the waiting zones of the signals which are reflected from a defect, the amplitudes of frequency components intrinsic to the spectrum of sounding pulses or to the spectrum of received useful signals with the amplitude of the frequency components which are not intrinsic to the spectrum of sounding pulses or to the spectrum of received useful signals. Synchronised interferences are removed from the received signals by means of main and auxiliary received-signal accumulation cycles and the thus synchronised interference-free received signal is obtained by subtracting sum signals which are obtained by means of the main and auxiliary accumulation cycles. A device for carrying out said method is also disclosed.