cesky nemecky anglicky

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Visual test / VT

Visual test is a basic method for detection and assessment of surface defects.
There are two of them, the first is direct and the other is indirect. The direct method is carried out by naked eye or with simple visual aids, for example a magnifying glass. When the indirect method is applied it is important to use special optical instruments such as endoscopes, boroscopes or cameras. A sufficient amount of light is required in both test methods. Visual test is usually carried out before other non-destructive tests.


Magnetic particle test / MT, MPI

Magnetic particle test is applied to detection of surface and just undersurface incompactness in ferromagnetic materials. Certain part of the product is magnetized by permanent magnet or electromagnet. Ferromagnetic powder is promptly applied at the same time with magnetization. In the place of defect the stray flax of magnetic field appears and applied magnetic powder makes the incompact places visible. According to test sensitivity requirements it is possible to choose between monochrome and fluorescent method and following assessment conduct in either specified achromatic light or in ultraviolet light.



Liquid penetrant test / PT


Liquid penetrant test is applied to defect detection of various sizes and shapes related to material surface. In contrast to magnetic particle test, penetration test can be used not only for ferromagnetic material but also for other materials. Chromatic or fluorescent liquid penetrant is applied to the surface of test component and gradually penetrates surface incompactness. Surplus of penetrant is removed and consequently the chemical substance is applied onto surface of the component. This chemical substance helps capillary action of detection liquid caused by incompactness and also makes assessment of eventual indications possible. This is all done in either specified achromatic light or ultraviolet light.


Ultrasonic test / UT


Ultrasonic test is mainly applied to inner defect detection in both metallic and non-metallic material as well as material thickness test. Impuls-reflective method with classic A scan is very frequently used in common ultrasonic practice. It is possible to operate the scan manually or automatically. This method enables to locate the position and shape of the finding very precisely, provided both calibration and setting of ultrasonic equipment for the tested object are done properly. The most essential advantage of this ultrasonic test is that there is no waste created during the test and, moreover, it is extremely enviromentaly friendly.

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Measurement test by ultrasound

The principle of this method lies in measuring the pass time of ultrasonic signal in tested material. Material constant is essential for measuring the speed of ultrasonic waves in tested material. Special ultrasonic thickness equpments with easy operation or digital ultrasonic equipments are used for this type of measuring. It is, however, necessary to choose a convenient probe type according to size and material structure. Therefore, direct, twin and simple probes generating longitudinal ultrasonic waves ranging between 2MHz and 10MHz are most frequently used. This method enables to test and measure both various metallic and non-metallic material.



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