The dye penetration test reveals the tiniest defect on the surface of metallic and low-porosity materials. It is applied when a particularly thorough and in-depth modus operandi is called for – e.g. in steel, bridge or container construction.
In the course of the penetration test, a coloured test liquid uses the capillary forces of fine ruptures in the surface and pores of the material to protrude in any irregularity of the inspected object. The ensuing application of a developer layer visualises the cavities, ruptures and other imperfections.