Ultrasonic time of flight testing (TOFD)

The time-of-flight diffraction method (TOFD) is based on two acoustic converters (probes) operating separately. TOFD detects and records both diffraction signals and reflected signals from the defect boundary, and the location and dimensions of the defect are determined.

The most significant differences from the standard echo pulse (UT) method are:

• the possibility of achieving greater accuracy for measurements, usually ± 1 mm and for re-testing ± 0.3 mm;
• almost complete independence of the probability of detecting a defect from its angular position;
• calibration is based on the passage time of diffraction signals and does not depend on the amplitude of the signal;
• high control performance, since scanning is carried out along the same line with control of the entire seam volume
• ability to replace the Radiographic testing (RT) method with TOFD.

TUV NORD Baltik invites anyone wishing to undergo The time-diffraction method (TOFD) and qualify in one or more industrial and production sectors to one of the qualification levels.

NOTE to learn TOFD, we strongly recommend studying UT-ll.