Measuring of Polarization and Ohmic Potentials for the Diagnostics of Corrosion Protection of the Metal Structures

The polarization potential (РР) is regarded as the main criterion of corrosion protection of metal structures in conducting media. However, the potential between the reference electrode and the metal of the protected structure is measured with a voltmeter and contains, in addition to the polarization component, the Ohmic drop of the voltage. But, only the polarization of the surface causes the effect of cathodic protection. Therefore, the Ohmic component should be removed from the measured potential difference for the precise control of the protected structure. To solve the problem of measuring PP is known methods of compensating, relaxation, auxiliary electrodes and calculations, which have disadvantages.