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Ultrasonic Testing, UT

Testing method for materials where ultrasonic waves are transmitted and bounces back to a receiver that reads and detects internal defects.

Beskrivning
Illustration of Ultrasonic Testing, UT

The process

A coupling agent which usually consists of oil is applied to the material [1] to better transfer ultrasonic waves to the material. An ultrasonic transducer [2], which is coupled to a diagnostic machine, acts as both transmitter and receiver. This sends out ultrasonic waves passing through the material and then bounces back to the ultrasonic transducer. If it bounces too quickly, this means that a defect [3] is present. It is also possible to read the ultrasonic waves by placing a separate receiver on the other side of the material.

Advantages and disadvantages
In comparison with alternative methods
Internal defects can be detected and their sizes can be determined
thick samples do not take longer to process than the thin specimens
Need access to only one side of the specimen
Volumetric defects can be detected
crack-like defects can be detected
A wide range of material thicknesses can be examined
Requires a lot of experience
Spurious readings and the possibility to read the signals wrong
Abrasive surfaces may affect the test results