Dye penetrant inspection (PT, DPI) allows to detect surface defects on any kind of material and product. This method is used mostly for non-ferromagnetic materials, mainly alloy steels and aluminum alloys. The best effects are seen on smooth, non-porous materials, such as rolled, wrought and drawn materials. A thorough cleaning of the examined surface from all kinds of impurities (such as rust or grease) is required before the examination. Testing through even the thinnest layer of paint is impossible. There is a possibility of conducting a tightness test with dye penetrant method. During the examination we always use agents from reputable producers, also for examination in temperatures below 0ºC.
Dye penetrant inspection is one of the most universal NDT method. It is widely used in the examination of elements made of austenitic and ferrous metals, light alloys as well as various ceramic materials and plastics. PT is used for cast, wrought, welded and soldered products. PT inspection is used during production as well as in operation.
PT inspection requires very good surface preparation, experience in application, because it is very easy to make mistakes that disqualify the whole process. Temperatures below 10 ° C and above 55 ° C require special reagents and special preparation of the test object. The necessity of testing under such conditions must be highlighted in the order for testing.