Tire inner liner anomaly probe grounding apparatus and method

An apparatus and method for high voltage discharge testing of a tire is disclosed. In particular embodiments, a high voltage probe is maintained against the surface of a tire. The high voltage probe is energized and relative motion is provided between the surface of the tire and the high voltage probe. At the presence of an anomaly that penetrates the insulating material of the tire surface, an electrical discharge will occur between the conductive spring electrode and a reference electrode. The reference electrode is positioned adjacent the bead portion of the tire such that the electrical discharge will travel from the high voltage probe through the anomaly in the surface of the tire to one or more carcass plies in the tire. The carcass plies will carry the electrical discharge to the bead portion of the tire, where the electrical discharge will pass to the reference electrode.