PR-208-806-R01 Field Testing a Method to Determine the Rest Potential of Cathodically Protected Pipelines

Describes the development of 'the E-i method' for determining the resting potential of a cathodically protected pipeline. The revised method relies upon a linear-regression fit of a line to on and instant-off potentials and an extrapolation of that line to a potential where the on potential was equal to the off potential and the IR drop in the on potential was zero, which is uniquely the resting potential.