Choosing the right penetrant
by T. Elias, Technical Sales Manager, MR Chemie
The decision as to whether a colored or fluorescent penetrant test should be favored usually depends on several factors. In addition to the probability of detection, the environmental requirements or the cost factor, it also depends on the nature of the workpiece surface, component compatibility and the properties of the test equipment. In addition, test conditions, customer requirements or specifications must be adhered to. There is therefore a lot to consider when choosing a suitable penetrant.
The penetrant types
At MR Chemie, we offer numerous alternatives with our wide range of product families for many applications, whether colored or fluorescent. Without going into too much detail, which is difficult due to the extensive subject matter, I would like to give you a brief overview of our available penetrant types.
Note: A precise description of the required test agent properties for the respective areas of application can be found, for example, in the DIN EN ISO 3452 series of standards.
Typ I
In the Type I variant, i.e. the purely fluorescent penetrants, you will find products in sensitivity classes 0.5 to 3 with approvals according to ISO, AMS, ASME, PMUC, RCC-M and also for the NSF area. The test agents are solvent- or oil-based and some are also available in the container form as Eco-Line products, i.e. label-free.
Type II
Type II, our colored penetrants are available in sensitivity class 2 and, with the exception of NSF approval, with the same approvals as type I penetrants. These test agents are also solvent or oil-based and Eco-Line products are also available with our MR® 313 as a container or a practical compressed air version.
Note: Within the IIAc product family, our MR® 311-R corresponds to a system sensitivity class 1 according to ISO 3452-2.
Type III
Type III penetrants, colored and fluorescent, are available in sensitivity class 2, classified according to the dye penetration test system. In addition to the solvent and oil-based variants, our MR® 67 is also available as a water-based test agent.
For component temperatures above 100°C, our MR 68 H is also available, as is our MR® 312 for component temperatures down to -30°C.
These are approved for applications in accordance with ISO, ASME, PMUC and RCC-M.
Note: The biodegradability of many of our penetrants has been proven in a Zahn-Wellens test!
