Penetration testing PT
Penetration testing is used to detect surface defects of materials, such as cracks, dissections, lappings or non-welds. This method is based on the capillary effect, that is on a liquid penetrating and filling up tight and non-accessible areas. The penetration liquids are intended to infiltrate surface apertures. After a specified time, excess substance is removed from the surface, and the penetrating liquid remains only in apertures. It is then possible to detect and locate existing defects by using appropriate developers and fluorescent additives. Penetration testing is used for accepting goods or during production, inspections and maintenance. It can be performed on the entire surface of the material or locally. This method cannot be used to inspect porous materials.