| 摘要 |
<p>A wear indicator for an igniter (10) having a center electrode (14), an annular ground electrode (22) surrounding the center electrode (14), and a spark gap (23) between the electrodes (14, 22) extending along a surface (27) of a ceramic material. An annular wear indicating groove (42) 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 (14) at a location which becomes exposed to indicate when the semiconductor material is sufficiently eroded to necessitate replacement of the igniter.</p> |
