ultrasonic flaw detection of edges in automatic testing through object extension

ultrasonic flaw detection of edges in automatic testing through object extension

edge flaw detection is a complicated task in ultrasonic testing for both ends of a tube or the edge of pieces. that's why a majority of globally known automatic testing system manufacturers exclude this feature from their products. as a rule of thumb, a span of 10 to 20 cm from each end of objects is defined as an outlier and the user needs to find an alternative testing solution. the main reason for this situation is the geometrical limitations that a probe holder suffers in covering the body of pieces to be tested. because an array of different probes are included in a casing larger than the probe itself to scan the piece, all probes can't disseminate their signals on the piece's edges at zero testing time (the starting time of a test from one end of a piece). this is an inevitable issue in the manual approach too when the wave projection and scan direction are the same. to resolve the problem, the full-immersion method can be applied where both the object and probes are submerged in a liquid. although, the need for sinking parts in a couplant makes it slow and costly for sizable parts like pipes and cylinders. this paper proposes a new contact technique for ultrasonic edges based on the extension of the objects’ ends that offers a higher speed and less complexity compared to the full-immersion method.