Measuring system for enhanced cathodic corrosion protection

Buried metallic artifacts in soil or seawater are exposed to high risk of corrosion due to the contact with the surrounding aggressive environment. The protection of a wide range of iron-based artifacts is carried out by means of cathodic protection (CP)systems. CP is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell, through the connection of the metal to be protected with another more easily corroded ”sacrificial metal” acting as the anode of the electrochemical cell. Cathodic protection is an efficient solution, however the sacrificial anodes need to be replaced regularly. This paper describes the design and development of a measuring system able to continuously monitor the object protection state maintaining it in safe conditions. The proposed system embeds a controller which is able to adjust the sacrificial anode current, thus increasing its life while keeping its protecting effect. The device is powered by a small lithium battery whose duration can be easily extended to several years making it longer than the sacrificial anodes duration. The proposed device is designed to be employed underwater for the protection of the metallic parts of a surveillance system developed for the protection and fruition of an underwater archeological site in the South of Italy.