The DCVG method is directly connected to the cathodic protection of pipelines. The impressed cathodic protection current getting into the insulation defects causes a drop of voltage in the soil. This potential grade can be detected between the two electrodes placed on the ground with a sensitive mV meter therefore the location of the coating defect can be determined with a precision of 10 cm. The size of the insulation defect is characterized by a relative number, the so-called % IR number.

This method is also effective in the case of pipelines without cathodic protection by using temporary anodes and CP stations.

At the laying of new pipelines it is recommended to carry out a DCVG examination immediately after the pipelaying so that the contractor could repair the possible insulation defects still under guarantee.

The DCVG method is also suitable for the insulation inspection of underground storage tanks.