AMPP Cathodic Protection Technician (CP2) Practice Exam 2025 – All-in-One Resource to Master CP2 Certification

Soil resistivity is a critical factor that significantly influences the effectiveness of cathodic protection systems. Cathodic protection works by providing an alternative current to the protected structure, which helps to prevent corrosion—a process influenced heavily by the electrical conductivity of the surrounding soil.

Lower soil resistivity enhances the flow of electrical current, allowing for better distribution of the protective charge over the structure's surface. Conversely, high soil resistivity limits the effectiveness of the cathodic protection system, as it restricts current flow, making it more challenging to maintain the desired protective potentials on the structure.

While other factors like atmospheric conditions, structure thickness, and temperature do have roles in cathodic protection systems, they do not impact the fundamental effectiveness of the protection mechanism as directly as soil resistivity. For instance, while temperature can affect corrosion rates, and atmospheric conditions may influence specific localized corrosion activities, these effects are secondary to how well the protection current can be delivered through the soil. Similarly, while structure thickness can determine the amount of corrosion that occurs, it is the surrounding environment's electrical properties—primarily defined by soil resistivity—that ultimately dictate how effectively cathodic protection can operate.