non destructive services
ultrasonic inspection
Ultrasonic Inspection (UT) is used to detect cracks and internal defects and to measure wall thickness. Sound waves move through the inspected material they normally follow a straight line but when they hit a defect the sound waves are reflected. The UT Technician can read the characteristics of the defect on the screen of the UT set. By using ultrasonic inspection it is possible to determine wall thickness and to trace defects in the material. UT is carried out using probes at various angles, different material types and specific applications require specialized probes. This type of testing method gives immediate results because the path taken by the sound wave is displayed immediately on the screen of the UT set.
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. The technique is also commonly used to determine the thickness of the test object, for example, to monitor pipework corrosion.
Ultrasonic testing is often performed on steel and other metals and alloys, though it can also be used on concrete, plastic and composites. It is a form of non-destructive testing used in many industries including aerospace, power generation, construction, automotive and other transportation sectors.
how it works
In ultrasonic testing, an ultrasound transducer (probe) connected to a diagnostic machine is passed over the object being inspected. The transducer is typically separated from the test object by a couplant (such as oil) or by water, as in immersion testing.
There are two methods of receiving the ultrasound waveform, reflection and attenuation. In reflection (or pulse-echo) mode, the transducer performs both the sending and the receiving of the pulsed waves as the "sound" is reflected back to the device. Reflected ultrasound comes from an interface, such as the back wall of the object or from an imperfection within the object. The diagnostic machine displays these results in the form of a signal with an amplitude representing the intensity of the reflection and the distance, representing the arrival time of the reflection. In attenuation (or through-transmission) mode, a transmitter sends ultrasound through one surface, and a separate receiver detects the amount that has reached it on another surface after traveling through the medium. Imperfections or other conditions in the space between the transmitter and receiver reduce the amount of sound transmitted, thus revealing their presence.
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news at wis
WIS have implemented and are now accredited to the following: EN ISO 9001:2015, EN ISO 14001:2015 and EN ISO 45001:2018.
WIS have attended courses and examinations at QSA-Global in Houston, Texas and now have technicians trained and qualified in Servicing & Maintenance of the QSA-Global equipment. WIS also have technicians trained and qualified in Source Retrieval, this entailed the actual retrieval of a live source, which other companies providing this service do not carry out. WIS intend to roll out these services to NDT Contractors nationwide.