Penetrant testing PT
These tests are the oldest method of non-destructive testing. Penetration research is based mainly on the use of the phenomenon of capillarity, i.e. the penetration of liquid into capillaries. The surface tension of the liquid, the wettability of the material and the width of the gap play an important role. In welding, they are used to detect welding incompatibilities, in particular to reveal material discontinuities coming out onto the surface of the welded joint. Penetration tests are suitable for detecting incompatibilities such as cracks, pores, glues, and adhesions that are open and come to the surface. Penetration tests can be carried out on a variety of metal and non-metal materials, except for porous materials. They are performed after VT examination and removal of unacceptable incompatibilities.