Penetrant (ndt testing)

Dye penetrant inspection (DPI), also called liquid penetrant inspection (LPI) or penetrant testing (PT), is a widely applied & low-cost inspection method used to locate surface-breaking defects in all non-porous materials (metals, plastics, or ceramics). The penetrant may be applied to all non-ferrous materials & ferrous materials, although for ferrous components magnetic particle inspection is often used instead for its sub-surface detection capability.
NDT part penetrant
NDT part penetrant

NDT application