In Ultrasonic Testing, very short ultrasonic pulse-waves with center frequencies ranging from 0.1-15 MHz and occasionally up to 50 MHz are launched into materials to detect internal flaws or to characterize materials. It is also commonly used to determine the thickness of the test object - monitoring pipework corrosion being a good example.
There are a few types of welding where radiographic examination cannot be performed or is restricted, typically due to the geometry of the test part or inaccessibility to it. UT technique is then used to inspect these welds.
An ultrasonic wave is transmitted into the material to be tested and its reflection is analysed for flaws. This is akin to radar “ping” where the radar signal is reflected by any object in its path. A well-trained UT technician is able to spot a minute flaw in the weld by analysing the UT wave on the display. OAG prides itself in training (in-house) its technician to ASNT Level II standard, and equips them with field experiences prior to training them according to the CSWIP/PCN standards.