DYE PENETRANT INSPECTION (DPI)

The penetrant testing method is a development of the original oil and chalk test that has been used for many years in the detection of defects which outcrop at the surface of a component.

It can be utilised for both ferrous and non-ferrous materials but is particularly useful when components manufactured from non-ferrous materials and austenitic steels are to be examined and the more discriminating magnetic particle test cannot be employed.

The detecting medium may be either a red dye that is visible under normal lighting conditions or a fluorescent dye which requires the use of an ultraviolet lamp.

It is particularly useful in the laboratory as a cost effective method of testing small machined components in large batch quantities.