METHOD OF ACOUSTO-OPTICAL WELDED SEAM QUALITY CONTROL DURING WELDING AND DEVICE TO THIS END Russian patent published in 2010 - IPC G01N29/14 

FIELD: instrument making.

SUBSTANCE: invention relates to welded seam quality control equipment. Proposed method comprises receiving acoustic signals originating in welding zone with the help of wideband acoustic transducers displaced relative to each other and welded seam K, amplifying received acoustic signals and filtering them according to preset peak amplitude and high-frequency content of acoustic signal spectrum. It comprises also analog-to-digital conversion, recording the time of acoustic emission signal arrival to acoustic transducers and computing acoustic signal source coordinates. Results of acoustic-emission control allow plotting acoustic emission signal localization pattern and selecting active areas that feature increased amount of aforesaid signals. Note here that continuous signals are recorded in control process; their amplitude is averaged for preset time interval for obtained averaged values to be used to adjust the data conversion channel selection threshold for reception of acoustic signals in welding zone. Digital form of acoustic emission signal is used to cluster signal groups for every piezo antenna consisting of three acoustic transducers. Then, groups of clustered signal groups are isolated and localized. If critical number of cluster signals satisfying excess amplitude and frequency selection conditions is exceeded, welded seam should be rejected.

EFFECT: higher validity of flaw detection and accuracy of pinpointing defects in welded seam during welding and cooling.

2 cl, 3 dwg