BigPatents India

A sheath-type glowplug with an ion current sensor and a method for the operation of said sheath-type glowplug is disclosed, whereby the sheath-type glowplug comprises a housing (3) and a rod-shaped heating element (5) arranged in a concentric bore in said housing (3). The heating element (5) has at least one insulating layer (11), a first supply layer (7) and a second supply layer (9), whereby the first supply layer (7) and the second supply layer (9) are connected by a bridge (8) at the combustion chamber end (6) of the heating element (5). The first and second supply layers (7, 9) and the bridge (8) comprise electrically conducting ceramic material and the insulating layer comprises electrically insulating ceramic material. The heating element (5) comprises at least one electrode for ion current detection (7, 9, 33), whereby said electrode for ion current detection (7, 9, 33) comprises electrically conducting ceramic material.