• A liquid with high surface wetting characteristics is applied to the
surface of the part and allowed time to seep into surface
breaking defects.
• The excess liquid is removed from the surface of the part.
• A developer (powder) is applied to pull the trapped • A developer (powder) is applied to pull the trapped
penetrant out the defect and spread it on the surface
where it can be seen.
• Visual inspection is the final step in the process. The
penetrant used is often loaded with a fluorescent dye and
the inspection is done under UV light to increase test
sensitivity