Abstract
Cathodic protection by means of an automatic potential controller of motor-driven transformer and rectifier type was applied to steel pipe circulating sea water. This controller regulated automatically the current applied to the pipe to maintain the protective potential within ±5mV under the conditions such as the velocity and the resistivity of sea water changed with time.
But as the result of the experiment, it was pointed out that the reliability of automatic potential control was affected by the location of the reference electrode and the value of the set potential.
