What is the voltage reading necessary for a successful cathodic test?

A successful cathodic test indicates the effectiveness of the cathodic protection system, which is important in preventing corrosion on buried or submerged metallic structures. A voltage reading of -0.85 volts signifies that the protective current is effectively working to polarize the metal surface, ensuring that it remains at a lower potential compared to the surrounding area. This negative voltage means that the structure is sufficiently protected from corrosion, as it highlights the shift in electrical potential triggered by the cathodic protection system.

This value is based on industry standards used to determine the appropriate levels of cathodic protection. A reading lower than -0.85 volts indicates better protection, while readings higher or around zero could suggest insufficient protection and potential for corrosion. The chosen voltage is widely accepted as a benchmark in evaluating the health and effectiveness of cathodic protection systems.