What is the required overlap for each pass of the transducer during an ultrasonic examination of a weld?

In ultrasonic testing (UT), especially when examining welds, the concept of overlap is crucial to ensure comprehensive coverage and reliability of the inspection results. The required overlap for each pass of the transducer generally refers to the percentage of the previous scanning area that must be covered with each subsequent pass to ensure no areas are left unexamined.

A 10% overlap is typically considered effective for ultrasonic examinations. This allows for sufficient overlap to compensate for factors such as beam divergence, variations in material properties, or transducer response, which could potentially affect the detection of flaws. By maintaining this overlap, inspectors can enhance the probability of detecting discontinuities that could compromise the integrity of the weld.

While other percentages might be used in different contexts or specific applications, 10% is recognized in many standards as a balanced approach that provides adequate coverage without being excessive. This makes the process efficient while ensuring thoroughness in the inspection.