Sensor for determining a concentration of particles in a gas flow

A device for determining a concentration of particles in a gas flow, the device comprising:

• a carrier;
• and
• a sensor that is situated on a surface of the carrier and that includes an electrode structure that includes at least two measuring electrodes;
• wherein:
• the device is configured for exposure of the sensor to the gas flow;
• the at least two measuring electrodes are of different polarities and are formed as an interdigital comb structure that includes finger electrodes;
• the finger electrodes are distributed in first areas and in second areas;
• with respect to respective pairs of immediately adjacent ones of the finger electrodes in the first areas, the finger electrodes of the respective pair are at a first distance from each other;
• with respect to respective pairs of immediately adjacent ones of the finger electrodes in the second areas, the finger electrodes of the respective pair are at a second distance from each other;
• the first distance exceeds the second distance;
• and
• the first areas and the second areas at least partially adjoin each other alternately,
• wherein the finger electrodes in the first areas and the finger electrodes in the second areas have a same width,
• wherein the second areas having a lesser distance of the finger electrodes in relation to a mean distance is used for signal formation in the present sensor, so as to increase a sensitivity of the sensor, and wherein the first areas having a greater distance of the finger electrodes in relation to a mean distance is provided in the interdigital comb structure, to provide for an attraction of particles from more distant layers above the sensor element, which then accumulate in the second areas having the lesser distance so as to contribute to the signal formation and avoid early saturation of the sensor,
• wherein the first areas and the second areas in the interdigital comb structure each alternately adjoin one another at least over regions on a surface of the sensor element,
• wherein the mean distance corresponds to a mean value or median of distances between the finger electrodes in a Y direction, and wherein the mean distance is determined from all distances used or from extreme values, including a greatest distance and a smallest distance in the electrode structure, and
• wherein the Y-direction is generally perpendicular to a direction of the gas flow in the plane of the electrode structure, and wherein a X-direction is generally parallel to the direction of the gas flow above the sensor element, and wherein a Z-direction is perpendicular to a surface of the sensor element and to the X-direction and the Y-direction.