Which testing method requires extraction of salts from the surface for analysis?

The Bresle patch test is designed specifically for the extraction of soluble salts from a surface to determine the level of contamination, particularly on surfaces that will be coated. This method involves placing a small adhesive patch on the substrate and then using a solution to flush out the salts, which are collected for analysis.

In corrosion protection and coatings application, it is vital to measure the presence of soluble salts because they can significantly impact the adhesion of coatings and lead to premature failure. The Bresle patch method is recognized for its effectiveness and reliability in providing accurate results regarding salt contamination, enabling inspectors to make informed decisions about surface preparation before applying coatings.

Other testing methods, like soluble salt meters, typically provide an immediate reading of salt levels without a physical extraction, while the sleeve test focuses more on the assessment of surface profiles. Visual inspection lacks the quantitative rigor needed for understanding specific salt contamination levels.