Dye penetrant testing is a non-destructive test method that counts as a surface process. The process is based on the principles of capillary action. The penetration process serves as visual evidence of open material separation to the surface (e.g. pores and cracks) of a non-porous test subject (mainly metal, but also plastic and ceramic). The test subjects must be carefully cleaned, leaving no residue, so that it is possible for the penetrating medium to penetrate flaws without hindrance.
A type-tested penetration-medium system consists of three components: the penetration medium, the intermediate cleaner and the developer. After cleaning without leaving any residue, as a rule the test object is dried, as water in the flaws can also make penetration more difficult or impossible.
Depending on the type of penetration medium – water-soluble, solvent-soluble or post-emulsifiable – the intermediate cleaning takes place after the penetration time specified in the test instructions. This work step must be carried out with great care so that the penetration medium is not washed out of the flaws.
After a further drying process, which must be conducted within a certain temperature range, the developer is applied. Now the reversal of the penetration process follows, with the penetration medium being sucked up by the developer. On the one hand, the developer improves the visibility. On the other, there is also a colour contrast. As a rule, this is red-white (therefore often called the 'Red-White test'). There are, however, also fluorescing penetration medium systems where the evaluation is carried out under UV light.
From its inception, Klaus Gross GmbH & Co. KG has been in the business of non-destructive material testing, which allows us to look back over a treasure-trove of 30 years of experience. This experience, combined with a high degree of flexibility and highly motivated staff, has characterised us from the beginning.
We can carry out any process we offer either at our premises or at the client's location. This applies to HT, PT, MT, RT, UT or VT tests; on request, we can provide a complete evaluation and documentation directly on the spot. We can ensure this as we use only personnel qualified at Level 2 in our operation. For test supervision, there is also a Level 3 tester in house.
For many years, our range of activities has included the inspection of drilling rods. In this respect, we have trained some of our employees in the NS2™ standard, which ensures the highest level of quality.
See the sub-menu points for a quick overview of the testing processes we carry out. Our skilled personnel are available for questions at any time.