METHOD OF IMPROVING NOISE IMMUNITY OF ULTRASONIC INSPECTION Russian patent published in 2007 - IPC G01N29/04 

FIELD: ultrasonic inspection.

SUBSTANCE: signal, received by ultrasonic converter, is divided to several time zones. Signals are divided physically by means of, for example, commutating unit. Components of main signal are selected from the main signal, which components are disposed in areas of waiting of signals, reflected from defects. Maximal signal amplitude within zone of waiting of signal, reflected from defects, is determined. Value of the amplitude is compared with admissible one and decision is made on presence or absence of defect on base of results of comparison. Results of the estimation are later used for making decision on necessity of repeat inspection of whole article or of only suspicious part of the article. Amplitude of frequency components are determined are determined in signal spectra, being located in areas of signals waiting, which amplitudes have to be character or non-character for probing pulse spectrum or for received useful signals spectrum. Amplitudes of useful components are compared with amplitudes of frequency components, being non-characteristic for useful signal spectrum. Results of the comparison are used for judging on truth of decision on discontinuity detection. To clean signal off regular component, not only basic cycles of coherent or non-coherent storage of received signals is carried out, but additional cycles as well. Realization, which was cleaned off regular component, is received by subtracting total values of realization, achieved as a result of relatively short and relatively long cycles of storages.

EFFECT: improved noise immunity at ultrasonic inspection.

5 dwg