The penetrant test (PT) is a sensitive method for detecting minute discontinuities that are visible on the weld’s surface.

The penetrant test is especially useful on nonmagnetic materials where a magnetic particle test isn’t possible. Surface defects in weldments made of aluminium, titanium, magnesium and austenitic stainless steel are often exposed using penetrant checks. Since dye penetrant tests are portable, they can be performed anywhere and in any place. Without the use of special equipment, the effects can be observed in normal light.  Test requires an ultraviolet light (black light) to observe the test results. It may be necessary to enclose the viewing area in order to properly read the test results