How is the level of cathodic protection primarily determined?

The level of cathodic protection is primarily determined by potential measurements because these measurements reflect the electrochemical environment of the metal surface being protected. Cathodic protection works by either sacrificial anodes or impressed current systems to shift the metal potential to a less electropositive value, thereby reducing the corrosion rate.

By measuring the potential of the metal in relation to a stable reference electrode, one can assess the effectiveness of the cathodic protection system and ensure the metal is sufficiently protected from corrosion. The ideal potential range for protection is typically defined by certain criteria that indicate sufficient polarization of the metal surface. Monitoring these potential values allows for adjustments in the cathodic protection system to maintain effective protection levels.

In contrast, pH levels and conductivity measurements provide important information about the environment in which the material is located and may influence corrosion processes but do not directly indicate the level of cathodic protection. Continuity measurements identify the integrity of the electrical connection within the protection system but do not quantify the effectiveness of the protection itself. Therefore, potential measurements are the best indicator of how well the cathodic protection is functioning.