Time of Flight Diffraction (ToFD)

Measuring the amplitude of the reflected signal is a relatively unreliable method of sizing defects because the amplitude strongly depends on the orientation of the crack. Instead of amplitude, TOFD uses the time of flight of an ultrasonic pulse to determine the position and size of a reflector.

What we do

ToFD is an ultrasonic technique originally developed for crack detection. Unlike conventional Pulse Echo, the transmitter receiver in arrangement in ToFD floods the region between the probes with ultrasound. Crack tips are identified by diffraction but it is also very effective for the detection and sizing of Weld Root Erosion or Corrosion (WRE or WRC)

The nature of the reflection of the ultrasound from eroded/corroded areas in the TFD pitch-catch arrangement makes it ideal for the detection of Weld Root Erosion/Corrosion. This approach has a proven track record as an accurate method for the detection and monitoring of corrosion and erosion damage in the weld and heat affected zones.

Our service system

Sonatest VEO/VEO + & Prisma

Our commitment

Is to provide a precise and thorough inspection according to the client’s requirement at all times

Most popular Questions

What is Tofd inspection?

TOFD offers rapid weld inspection with excellent flaw detection and sizing capacities. The diffraction technique provides critical sizing capability with relative indifference to bevel angle or flaw orientation. TOFD can be utilized on its own or in conjunction with other NDT techniques.

What does TOFD stand for?

Time-of-flight diffraction (TOFD) method of ultrasonic testing is a sensitive and accurate method for the nondestructive testing of welds for defects. TOFD originated from tip diffraction techniques which were first published by Silk and Liddington in 1975 which paved the way for TOFD.