NDO Methods


[PMI onderzoek] During inspections in the use phase, but also during the construction of new facilities is in practice often doubt about the correctness of material qualities. Questions such as: Are the materials provided with the Specifications (supplies from China and other countries, where “cheap” produce essentially)? Are we sure that materials are not changed? Or obscure ancient drawings, material unknown. In such situations, it is very convenient that a PMI test (Positive Material Identification) can be performed.


[magnetisch onderzoek 2] Magnetic particle testing (MT) is a method by which into NDT magnetizable materials, applying a magnetic field. This network may be detected. Below the surface and surface defects Performed on a bench under UV light magnet magnetic crack detection is known as one of the most sensitive inspection techniques.
After the application of the magnetic field, there will be at the location of a defect is a leakage field arise above the surface. On the surface of iron powder is then applied in a wet or dry form, whereby the leakage field a tear indication emerges on the surface. This indication is reviewed by the inspector on the basis of the required standard.
[magnetisch onderzoek 1] As well in penetrant testing magnetic survey can be conducted under daylight conditions (black ink: often in combination with a yoke) or under UV conditions (higher sensitivity and in combination with, or a yoke or a magnet couch)
Surface defects or defects just below the surface of the material, a number of applications are:

Las research
Tear Research
Components Research


[penetrant onderzoek 2] Penetrant testing (PT) is an NDT method comprising reacting a penetrating liquid on the surface make. Before the start of the inspection, the surface should be cleaned: paint, grease and dirt should be removed and the liquid penetrant can be applied.

The penetrant fluid passes through the capillary action slowly in a surface crack. After removal of the residual liquid penetrant onto the surface, and the application of a contrast powder (developer), the indication will be visible signed off on the surface. The indication can be judged in accordance with the required standard, and as a result; the indication is acceptable or not.

[penetrant onderzoek 1] The penetrant inspections can be conducted under day light or under UV light (higher sensitivity). Penetrant liquids are available in different sensitivities. For each application the best choice should be to be able to perform. Optimal inspection made ​​in penetrant process

Application areas:

Lasonder Search
Turbine blades

Radiographic examination

Radiographic examination (RT) is an NDT method wherein use is made of short-wave (hard) of radiation which has the property that it is where absorption occurs. Through materials If the remaining radiation is a photograph or digital disc reaches the radiation is converted into a visually interpret the image on the image or video display.

With radiographic examination both internal and surface defects can be detected. These defects can be volumetrically such as porosity, slag jobs, for example an inadequate penetration.

The detection of defects such as cracks and bonding errors is certainly also possible, depending on the beam direction.

weld imperfections

Incomplete root penetration
Inclusions of porosities
Binding Errors etc.
Cracks and / or other defects on surface or internal
Forging and casting
Composite materials

Ultrasonic testing

Ultrasonic testing (UT) is an NDT method which use is made of sound. With the aid of sound waves can be included in the materials, which in terms of structure not be too coarse, in addition to the measurement of wall thickness, defects also be detected in the material.

Because these sound waves reflect on defects or geometric shapes, we can (read) detect defects.

The inspector reviewed on a screen the duration of the sound, and the amount of sound that is reflected on the basis of these data can be a judgment on the quality of the product.

Common uses for Ultrasonic testing are:

Las controls
Wall thickness measurements
Corrosion Research
Lamination controls


[visueel onderzoek 2] Visual examination (VT) is an NDT method in which the inspector performs with or without the use of tools for inspection. Visual examination is the oldest and most underrated NDT method.
The visual assessment of welding, structures and components may be done by direct view, or may be carried out with the aid of borescopes, measuring means, a magnifying glass and / or special lighting.
Performing visual inspection requires a lot of experience and product / process knowledge of the product to be examined.

[visueel onderzoek 1] applications:

Cracks on surface
Cracks on surface
Composite materials
Corrosion (discoloration)
Heat exchangers (through bores