Patent ID: 8653838

Claim:
A soot sensor configured to detect soot particles in an exhaust gas flow, comprising: a substrate; a measurement electrode structure comprising interdigitally engaged electrodes applied to the substrate, wherein an electrical resistance between the interdigitally engaged electrodes is measured as a measure of the soot load of the exhaust gas flow, the measurement electrodes comprising: a first region where the soot particles cannot be deposited; and a second region where the soot particles are deposited from the exhaust gas flow; and a cover layer arranged on the interdigitally engaged electrodes in the first region, the cover layer: (i) being arranged with respect to the first region so that soot particles cannot be deposited between the part of the interdigitally engaged electrodes in the first region, and (ii) having a defined resistance so that a parasitic current of the interdigitally engaged electrodes in the second region is detected by a comparison between resistance values of the first region and resistance values of the second region, wherein the first region and the second region are simultaneously exposed to prevailing conditions in the exhaust gas flow.