PROCESS AND APPARATUS FOR SUSTAINING THE CATHODIC PROTECTION OF METAL SURFACES

摘要

For corrosion protection of metallic surfaces in contact with an electrolyte by an external current, using an inert electrode as the external current anode, and a potentiostat, the protective current being periodically switched off and the actual potential (Eact) being measured directly between the external current anode acting in this phase as reference electrode and the surface to be protected and being compared with the protective potential (Eset) set on the potentiostat, and the difference (Eact-Eset) being utilised directly as the control variable for the protective current, it is intended that the protective potential just prevailing at the time is measurable and hence readjustable independently of the protective current which has flowed through. This is achieved when the potential (Eact) is measured after a slight time interval after switching-off and is utilised in the control phase as the control variable for the protective current flowing during the switched-on time.