Penetrate Inspection is a widely used and low cost inspection method. It is used to locate cracks in all non porous materials such as metals and plastics. This method involves applying a visible or fluorescent dye to the surface of the item being tested. This dye could be a solvent or water washable. After the application in the form of immersion or a spray, the dye enters any discontinuities via capillary action. It is known as the dwell time and usually will require a minimum of 20 minutes.
:
