METHOD OF DETECTION OF FLAWS IN WELDS IN PROCESS OF WELDING AND THEIR LOCATION BY ACOUSTIC SIGNALS Russian patent published in 2000 - IPC

FIELD: nondestructive inspection of quality of welds. SUBSTANCE: wave form of broadband acoustic signal by which its peak and medium amplitudes are determined is recorded by wide- band acoustic-emission and receiving converters. Ratio of peak and medium amplitudes is computed and characteristic of signal spectrum that represents degree of its high frequency is found. Threshold values of parameter of ratio of peak and medium amplitudes and parameter of signal high frequency are set, two signals additional to value of peak amplitude of filtration threshold are formed from them for welding process and for weld cooling off. If one of converters records in process of welding signal exceeding all three filtration thresholds characteristic of welding process then thresholds for this converter and converters adjacent to it are automatically decreased for specified time period to values of filtration thresholds characteristic of process of weld cooling off. Acoustic signals are continued to be recorded and after their processing one makes conclusion on quality of weld. EFFECT: enhanced authenticity and objectivity of evaluation of quality of weld right in process of welding. 1 dwg