NON-DESTRUCTIVE TESTING: TOFD

TOFD NON-DESTRUCTIVE TESTING

Our staff are qualified under ISO 9712 and SNT TC 1A in the TOFD ultrasonic method of non-destructive testing, which is normally used on welds and forged metals of large sizes.

TOFD ultrasonic testing can detect small marks even in great thicknesses, to very precise heights and lengths. Under the ASME code, it can also be used in place of radiographic testing.

TOFD stands for time of flight diffraction and is based on the phenomenon of waves diffracting. It measures the flight time of diffracted waves from the tip of a crack. The TOFD technique uses the flight time of diffracted echoes in a different way to the traditional pulse echo technique, which uses the breadth of the reflection.

The TOFD technique is recognised as a test that can achieve a very high probability of detection of defects and a low false coverage rate compared with other techniques.

Computerised instrumentation for TOFD testing allows for complete recording of all data and therefore repeatability of inspections over the years, not only during construction but also during service.