“…Driven by electrophoresis, soot particles deposit on the sensor surface and a current, I , occurs after a certain percolation time and continuously increases with more and more soot deposited on the sensor. This time span or the electrical current (respectively the resistance) at a certain time can be a measure for the amount of soot in the exhaust [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. Some authors call this type of sensors “accumulating (or collecting) soot sensors” [ 7 ], since the occurring sensor current is a measure for the accumulated amount of soot on the sensor.…”