Time of Flight Diffraction (TOFD) has been the fastest growing ultrasonic inspection technique of recent years, offering rapid, cost-effective testing of steel structures and welds. However, interpretation of the scanned image is difficult, requiring highly specialist skills, and critics say the results can lack consistency.

Now researchers from the university’s Department of Electrical Engineering and Electronics are developing a way to use software to provide automatic processing and interpretation of these images, with sponsorship from Phoenix, a specialist in the design and manufacture of non-destructive testing systems.

Dr Waleed Al-Nuaimy, the lecturer in charge of the three-year project, said: “TOFD is a unique automated technique which allows rapid inspection but interpreting the results is time-consuming and requires a high level of skill. A typical TOFD inspection can generate many signal indications and the operator must check and interpret them one by one.

“A computer, by comparison, can interpret the information from multiple images at the same time and operate to a more rigorous standard. The technique we are working on will use advanced algorithms, not only to highlight and detect flaws, but also to size them and define their geometry.”

Karl Quirk, managing director of Phoenix Inspection Systems, commented: “Automatic analysis of results will reduce the margin for error, improve consistency and speed up reporting. Though nothing will ever take the place of the technician’s input and scrutiny, it would make TOFD easier to use and encourage a more widespread acceptance of this highly efficient testing technique.”