Cathodic testing by a trained cathodic specialist must be conducted every ____.

• A. One year
• B. Two years
• C. Three years
• D. Five years

Answer: (C)

Regular verification of a cathodic protection system by a trained specialist is essential to ensure ongoing protection against corrosion. Over time, coating degradation, soil resistivity changes, stray currents, and equipment drift can alter the protective potential. A trained specialist uses reference electrodes and proper procedures to measure potentials and assess the rectifier, anodes, and overall system performance, then interprets whether the protection criteria are still met and makes necessary adjustments.

Three-year intervals strike a practical balance: they’re frequent enough to catch meaningful changes before significant corrosion can occur, yet not so frequent that testing becomes unnecessarily costly or redundant in many environments. Shorter intervals (such as annually) may be warranted in harsher or higher-risk settings; longer intervals (such as five years) risk undetected loss of protection.