Which parameter does not directly affect cathodic protection performance?

Cathodic protection (CP) is a critical method used to mitigate corrosion in metallic structures, particularly those buried in soil or submerged in water. Multiple factors influence the effectiveness of a cathodic protection system, such as soil resistivity, electrode material, and ambient temperature.

Soil resistivity is fundamental to cathodic protection performance because it dictates how well electrical currents can flow in the soil. High resistivity soils typically require more substantial cathodic protection measures compared to low resistivity soils, which allow for better current distribution.

The choice of electrode material is also crucial since different materials have varying properties, including their corrosion potential and ability to maintain effective polarization levels. Selecting an appropriate electrode material can significantly enhance the system's longevity and efficiency.

Ambient temperature directly influences the electrochemical reactions taking place at the cathode and anode sites, affecting corrosion rates and the overall effectiveness of the cathodic protection.

In contrast, while frequency of moisture changes might play a supportive role in overall corrosion processes, it does not directly impact the fundamental operation of a cathodic protection system. Moisture can affect soil resistivity indirectly and influence corrosion indirectly, but it is not a parameter that drives the performance of the cathodic protection itself. Hence, this