One of the major problems of cathodic protection systems in industrial plants (like petroleum and oil refining plants) is the leakage of the DC current due to presence of earthing electrodes that conduct both AC and DC current into the earth and thus the amount of the DC current (needed for cathodic protection) would be reduced which lefts the structure unprotected. The polarization cell is an electrochemical component in which nickel or stainless steel electrodes are immersed in 30% KOH solution. Polarization Cell ceases the flow of DC current into the ground when used with cathodically protected structures. Payesh Sanat Novin (PSN) Co. research team has developed the Polarization Cell that effectively blocks the DC current and passes the AC current through earthing electrode.