G.i. Earthing Electrode

F15:3043-1987 Clause 9.2.& 98.3 says. The material selected for Earthing  electrode, should exhibit a galvanicpotential with respect to the ground as nearly equal to that exhibited by the structure of unprotected condition, the material used be such that it resists the corrosion. Tests in a wide variety of solids have shown that copper is entirely EARTHING satisfactory and taking the life of copper Earthing as max. 12 years, the average loss ] 7 is weight of copper, buried for 12 years is 0.2 percent per year and average loss in weight of galvanized steel, a little inferior to copper, 0.5 percent per year.