The degree of rust, mill scale etc. can be visibly assessed using Pictorial Surface Standards. Weld beads can be assessed by using a weld comparator and weld gauges measure a range of quality parameters.
Surfaces with soluble salts and ion specific contamination are often invisible to the eye. These soluble salts together with amine blush (amine cured epoxy coatings) can result in premature coating failure.
Elcometer 7061 MarSurf PS1 Surface Roughness Tester is a leight weight and portable measuring solution for a wide variety of surface roughness measurements. Ideally suited for protective coatings applications.