UT ultrasound method

It belongs to the most used volume methods – i.e. search for inner defects in metallic and plastic objects. The ultrasound method uses entering of the ultrasound waves into the tested material. The ultrasound waves are transported into the material via ultrasound sensing head. There are many ultrasound sensing heads. They differ mostly according to the angle of entering of ultrasound waves into the material. If there is any non-integrity in the tested material, it comes to back reflection of the ultrasound waves in the sensing head. This reflection („ echo ”) will be analyzed on the display of the device. The ultrasound testing is focused above all on detection of volume inner defects in materials, superficial defects such as cracks and doublings, and on detection of wall thicknesses. The most used application is the detection and the evaluation of defects of welded joints.


EMAT is very similar application of the ultrasound inspection. EMAT (ElectroMagnetic Acoustic Transducer). The method EMAT is used in ferromagnetic materials and it functions on the principle of generation of Lorenz force in magnetic field that is created by the EMAT sensing head. The ultrasound wave that enters into the material is generated on the basis of appropriate orientation of this field. The advantage of this testing is the fact that EMAT does not need any binding medium (oil, grease or water) for transport of the ultrasound wave into the material as compared to the classical ultrasound. This method is most frequently used for continuous scanning of the wall thickness, but currently it is also able to perform the testing with angle sensing head.