A sheathed element glow plug having an ionic current sensor and a method of operating
such a sheathed element glow plug are provided. The sheathed element glow plug
includes a housing and a rod-shaped heating element arranged in a concentric bore
in the housing. The heating element has at least one insulation layer, a first
feeder layer, and a second feeder layer, the first feeder layer and the second
feeder layer being connected by a web on the combustion chamber-side end of the
heating element, the first and second feeder layers and the web being made of an
electrically conducting ceramic material, and the insulation layer being made of
an electrically insulating ceramic material. The heating element has at least one
ionic current detection electrode made of an electrically conducting ceramic material.
