Patent ID: 7196529

Claim:
A method of analyzing a conductive pipe member for the presence of at least one of an anomaly associated with electrolytic activity, an anomaly the electromagnetic properties of which are non-linear, and an anomaly associated with corrosion products, comprising the steps of: when the pipe member is in the unperturbed state, applying a reference source signal to the first test location to cause the reference source signal to travel along the pipe member through the anomaly; detecting at least one reference return signal caused by the reference source signal traveling through the anomaly; applying a direct current perturbation signal to the pipe member to place the pipe member in a perturbed state, where the electromagnetic characteristics of the pipe member at the anomaly are altered when the pipe member is in the perturbed state; when the pipe member is in the perturbed state, applying a test source signal to a first test location on the pipe member remote from the anomaly to cause the test source signal to travel along the pipe through the anomaly; detecting at least one test return signal caused by the test source signal traveling through the anomaly; and analyzing the at least one test return signal for characteristics associated with the anomaly by comparing the at least one reference return signal with the at least one test return signal.