Ultrasonic Testing (UT)

Ultrasonic Testing is a method of NDT that is used to detect internal flaws or to determine the thickness of a material. The technique works by propagating ultrasonic waves into the object or martial to be tested. Reflected ultrasound comes from an interface such as a back wall of an object or an imperfection within the object, our highly trained technicians are able to interpret the signal received using specialist equipment.

Basic methods :

UT – Plate and Pipe 3.1 / 3.2

UT – Nozzle and Nodes 3.8 / 3.9

Advanced Methods :

UT – Phased Array – (PA)

Phased Array technology is the ability to modify electronically the acoustic probe characteristics. Probe modifications are performed by introducing time shifts in the signals sent to and received from individual elements of an array probe. Any Ultrasonic techniques for flaw detection and sizing can be applied using Phased-Array probes.

Phased Array can be used for the following applications; raw material production, aircraft, naval, power generation, petrochemical and anything else that currently applies pulse-echo testing

UT –           Time of f Flight Diffraction

Measuring the amplitude of 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.

In a TOFD system, a pair of ultrasonic probes sits on opposite sides of a weld. One of the probes, the transmitter, emits an ultrasonic pulse that is picked up by the probe on the other side, the receiver. In undamaged pipes, the signals picked up by the receiver probe are from two waves: one that travels along the surface and one that reflects off the far wall. When a crack is present, there is a diffraction of the ultrasonic wave from the tip(s) of the crack. Using the measured time of flight of the pulse, the depth of a crack tips can be calculated automatically by simple trigonometry.

Note day rates vary depending on the type of technique used please contact the office for more information.