What are the two types of cathodic protection systems?

Cathodic protection systems are essential for preventing corrosion on metal surfaces, particularly those exposed to electrolyte environments such as soil and water. The two types of cathodic protection systems are galvanic and impressed current systems.

Galvanic systems utilize the natural electrochemical potential between two dissimilar metals. In this system, a more reactive metal, often referred to as the sacrificial anode, is connected to the metal that needs protection. This setup allows the sacrificial anode to corrode instead of the protected metal, effectively preventing corrosion.

Impressed current systems, on the other hand, involve an external power source to provide a steady flow of electrical current. This current is supplied to the anodes, which can be made from various materials, including inert titanium or graphite. The impressed current is directed to the metal surface requiring protection, creating a cathodic environment that inhibits corrosion rates.

Understanding these two systems is crucial for effectively implementing cathodic protection in various industrial applications, ensuring both longevity and safety of metal infrastructure. The incorrect options describe different concepts or categories of protection that do not specifically relate to the types of cathodic protection systems used in corrosion prevention.