Evaluation of chloride permeability characteristics of concrete. The test is performed to monitor the amount of electrical current passing through concrete cores or cylinders. A potential difference is maintained across the ends of the specimen, one of which is the negative end and is immersed in a sodium chloride solution, the other (positive end) in a sodium hydroxide solution. The total charge passed, in Coulombs, that is related to the resistance of the specimen to chloride ion penetration, is measured.