Assessment of corrosion in the field is complex because of the wide variety of applications, process conditions, and fluid phases that exist in industrial plants where corrosion occurs. A wide range of direct and indirect measurement techniques is available, but each technique has its strengths and weaknesses. In some applications certain techniques cannot be used. Some techniques can be used online, while others are done off-line. Commonly more than one technique is used so the weaknesses of one are compensated for by the strengths of another. In other cases, a combination of different techniques can be synergistic, such as process sampling along with detection of corrosion upset.

RPA offers the various techniques for corrosion assessment with respect to their benefits and limitations across the wide spectrum of industries in which they are used.