Abstract
The buried underground or underwater metallic parts suffer from the chemical or hydrochemical corrosion effect.In this paper the later effect will be studied that is caused by the current generated between the metal parts ( the positive pole ) and the ground( the negative pole)through water or the wet soil.The flowing current will change the iron molecules in to positive ions which react with oh ions and cause the rust (ferric hydroxide)of chemical symbol Fe(OH)3.By the supply of an external DC the generated current will stop from flowing between the metal and ground since the positive pole will be neutralized and then become negative.For designing the cathodic protection it is necessary to measure the created currents and voltage causing corrosion according to the soil environment condition therefore the soil test is the main factor for the design purposes.This work will help in knowing the size of the station generating current and voltage that is locally required directly at the site after taking the measurements by the suggested designed instruments in the paper for this purpose, as shown in the data taken practically.