Capabilities of Penetrant Inspection.
Penetrant inspection is an inexpensive and reliable nondestructive inspection method for detecting discontinuities that
are open to the surface of the item to be inspected. It can be used on metals and other nonporous materials that are not
attacked by penetrant materials. With the proper technique, it will detect a wide variety of discontinuities ranging in
size from readily visible flaws down to the microscopic level, as long as the discontinuities are open to the surface and
are sufficiently free of foreign material.
Basic Penetrant Process.
The basic fundamentals of the penetrant process have not changed from the oil-and-whiting days. The following
provides a simplified description of the fundamentals. More explicit process details are discussed in subsequent
sections. Figure 2-1 illustrates the basic principles of the penetrant inspection process.
Figure 2-1. Basic Penetrant Inspection Process.