One such NDT method is dye penetrant testing training. Also known as liquid penetrant inspection or penetrant testing, this method is widely applicable to locate surface-connected defects in all non-porous materials like metals, plastics, or ceramics. The principle of Dye penetrant testing is based upon capillary action, where fluid with low surface tension permeates into clean and dry surface-breaking discontinuities. Penetrant is applied to the test component by dipping, spraying, or brushing. After adequate penetration time has been allowed, the inspection takes place under ultraviolet or white light, depending upon the type of dye used.
The liquid or dye penetrant testing is used to identify any cracks, fractures, porosity, incomplete fusion, and flaws in joints.