Among the processes that accelerate the loss of performance of reinforced concrete structures, considering their frequent occurrence and severity, corrosion of reinforcement can be seen as one of the most important. A worrying factor is that most buildings in the main Brazilian urban centers are between 40 and 50 years old, a time when repairs and maintenance become more routine. Therefore, the problems related to the corrosion of the reinforcements tend to accentuate in the coming years and the identification of corrosion will play an important role. Thus, this research has the purpose of analyzing the application of the diagnosis through potential corrosion techniques. For this, full-scale reinforced concrete beams were analyzed. Corrosion was stimulated by the Modified Immersion Accelerated Corrosion - CAIM method, at three levels of mass loss: 5%, 10%, and 15%. The diagnostic technique through the corrosion potential was applied, in which it was observed that there is uncertainty in the corrosion evaluation for the mass loss levels of 5 and 10%, resulting in a corrosion uncertainty interval, but at 15%, the potential technique proved to be satisfactory.