METHOD AND DEVICE USED TO DETECT CORROSION IN CATHODICALLY-PROTECTED BURIED STEEL, PARTICULARLY IN CONCRETE REINFORCEMENTS, OR TO DETERMINE IF SAID CORROSION IS PASSIVE

摘要

The invention relates to a method for detecting corrosion in buried steel which, after containment of a carrier direct current, consists in: modulating an alternating current; determining the phase difference between the intensity of the alternating current and the alternating potential applied in order to ascertain whether or not the cathodic protection is effective, on the condition that the frequency interval of the alternating current is between 0.01 and 100 Hz. The measurement method consists in: (i) generating an alternating current which is applied between the buried steel and a counterelectrode located on the surface of the ground and (ii) using a standard electronic system, measuring the value of the applied voltage u and current i. Said values are subsequently processed electronically using a suitable device in order to determine phase angle n, the value of which indicates the effectiveness of the cathodic protection.