The method that utilizes electrical conductivity to assess contamination levels is the one that specifically involves measuring soluble salts on surfaces, which is effectively done using soluble salt meters. These meters work on the principle that the presence of soluble salts in water can alter its electrical conductivity. By applying a small amount of water to the surface and measuring how well that water conducts electricity, inspectors can determine the level of contaminants, such as salts, that may be present.
This approach is particularly useful in coatings inspection since soluble salts can significantly affect the adhesion and performance of coatings. High levels of salts may lead to issues like corrosion under the coating or premature coating failure, making assessment crucial before applying protective coatings.
In contrast, other methods mentioned do not employ electrical conductivity as a measuring tool. The Bresle Patch test involves applying a patch to capture contamination, which is then analyzed but does not involve conductivity directly. Visual Inspection relies on the inspector’s ability to see and assess contamination visually, lacking the precision of quantifying contamination like soluble salt meters. The Alligatoring Test is used to assess the condition of the coating itself, particularly for patterns of failure, and not for measuring contaminants on a substrate.