Dye Penetrant Test (PT)
The test object is coated with a solution that contains a visible or
fluorescent dye. Excess solution is then removed from the surface of
the object but leaving it in surface breaking defects.
A developer is then applied to draw the Penetrant out of the defects.
With fluorescent dyes, ultraviolet light is used to make the bleed out
fluoresce brightly, thus allowing imperfections to be readily
seen. With visible dyes, vivid color contrasts between the
and developer make "bleed out" easy to see.
This method is only applied to detect the defects so called