Abstract: An apparatus and method extends the useful life of a low tension igniter plug by advancing a homogeneous semiconductor element as it is consumed over time by sparks between a central conductor and an outer metal shell of the plug. An insulator surrounds at least a portion of the central conductor, with the outer metal shell having a discharge end spaced to provide a spark gap with a tip of the central conductor. The homogeneous semiconductor element surrounds the tip of the central conductor and is axially positioned between the insulator and the discharge end of the outer metal shell so that it is in contact with the outer metal shell at the spark gap.

Abstract: A wear indicator for an igniter of the type having a center electrode, an annular ground electrode surrounding the center electrode, and a spark gap between the electrodes extending along a surface of a ceramic material. An annular wear indicating groove is formed in the ground electrode to indicate when the ground electrode is sufficiently eroded to necessitate replacement of the igniter. For a low voltage igniter the ceramic material at the spark gap is a semiconductor material which also is subject to erosion during use. A wear indicating groove also may be formed on the center electrode at a location which becomes exposed to indicate when the semiconductor material is sufficiently eroded to necessitate replacement of the igniter.