Tests for a Coated System

Testing section by section can be continued in each direction from the temporary CP location until the changes in the observed currents and potentials as the current interrupter switches on and off are no longer large enough to result in accurate data. The limits of the area that can be maintained above the protected criterion of -0.85 V or better can be established at this same time. 

Coated systems polarize very rapidly and the better the coating, the faster the polarization. This means that conditions stabilize within the first few minutes and sometimes in a matter of seconds after the test current is applied. 

Coating resistance determined for this section of pipeline 

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