Penetrant methods

Penetrant methods are non-destructive Material testing methods. They are mainly used to identify material defects that are open towards the surface such as pores, cracks and creases.

The workpiece's surface is first cleaned and then a penetrant, in most cases a liquid, that can penetrate into the defects is applied. Due to its capillary action, the penetrant can also penetrate into hairline cracks. After a specific exposure time, it is rinsed from the surface but remains on the defects and can be made visible using a developer. Methods such as Met-L-Check and UV-Apenol use UV light and fluorescent liquids.

Penetrant methods can be used to test all types of materials and are easy to perform in situ. Automatic detection systems are also available for use in mass production.