Abstract: A method for operating a selective catalytic reduction (SCR) system having a urea solution supply and an ultrasound based urea concentration sensor, the measurement signal of the urea concentration sensor being representative of a propagation time of an ultrasonic pulse along a predefined path length in a fluid of the urea solution supply includes: heating at least the fluid in a detection region of the urea concentration sensor from a predefined first temperature to a predefined second temperature; during the heating, detecting the measurement signal at at least a third and fourth temperature, and in each case determining a raw concentration characteristic value as a function of the respective measurement signal, which raw concentration characteristic value is representative of the propagation time of the ultrasonic pulse; and determining a concentration characteristic value, representative of a concentration of urea in the fluid, as a function of the raw concentration characteristic values.

Abstract: A soot sensor for the detection of soot particles in an exhaust gas flow, having interdigitally engaged measurement electrodes applied on a substrate. An electrical resistance between the measurement electrodes is a measure of soot load of the exhaust gas flow. The measurement electrodes are divided into two regions, a first region in which no soot particles can be deposited and a second region where soot particles are deposited from the exhaust gas flow. The first region and the second region are exposed simultaneously to the other conditions prevailing in the exhaust gas flow.

Abstract: A method and arrangement for determining a concentration of a constituent of a fluid mixture in a fluid chamber includes: emitting an ultrasonic pulse into the fluid mixture, receiving a reflection of the ultrasonic pulse as a measurement signal after the ultrasonic pulse has been reflected at at least two impedance jumps, determining the concentration of the constituent of the fluid mixture on the basis of the measurement signal.

Abstract: A method for performing on-board functional diagnostics on a soot sensor of a vehicle and/or for detecting further components in the soot in a motor vehicle having an internal combustion engine. The soot sensor is electrically connected to an evaluation circuit with is permanently installed in the motor vehicle. In order to specify a method for performing functional diagnostics on a soot sensor and/or for detecting further components in the soot, with which method it is possible to detect a faulty soot sensor and/or further components in the soot in a cost-effective way, the evaluation circuit measures the temperature coefficient of the soot sensor and detects the defectiveness of the soot sensor and/or the presence of further components in the soot on the basis of the temperature coefficient of the soot sensor.

Abstract: A method for operating a soot sensor that has an interdigital electrode structure, to which a measurement voltage is applied. Soot particles from an exhaust gas flow are deposited onto the interdigital electrode structure and the measurement current is evaluated as a measure of the soot load of the soot sensor. The interdigital electrode structure is burned clean at or above a predetermined soot load, which is detected by means of an upper current threshold. The method includes burning the interdigital electrode structure clean by heating up the soot sensor after the upper current threshold has been reached; monitoring the measurement current while the interdigital electrode structure is being burned clean; and stopping the burning clean when the value of the measurement current has reached a lower current threshold.

Abstract: A method for operating a soot sensor in the exhaust gas tract of an internal combustion engine. The soot sensor includes an inter-digital electrode structure to which a measurement voltage is applied. Soot particles from the exhaust gas flow deposit themselves on the inter-digital electrode structure and an measuring current is evaluated as a measurement for the soot concentration of the soot sensor. A heating element for burning clean the inter-digital electrode structure is provided. The method for operating the soot sensor has good measurement results and the shortest possible idle time. To this end, a point in time for burning clean the soot sensor is determined in accordance with the operational state of the internal combustion engine and then, the burning clean of the inter-digital electrode structure starts by heating the soot sensor by the heating element.

Abstract: A method for on-vehicle functional diagnosis of a soot sensor and/or for detecting further components in the soot in a motor vehicle having an internal combustion engine, the soot sensor connected electrically to an evaluation circuit. To specify a method for functional diagnosis of a soot sensor and/or for detecting further components in the soot, by which it is possible to detect a faulty soot sensor and/or further components in the soot in an economical manner, the evaluation circuit measures a temperature coefficient of the soot sensor and detects the faultiness of the soot sensor and/or the presence of further components in the soot from the temperature coefficient of the soot sensor.

Abstract: A magnetized nut for fastening a compressor wheel of an exhaust turbocharger to a turbo shaft. The nut has a base body made of a non-magnetic material forming a hollow space for accommodating a magnetic material, and a method for the production of the magnetized nut. In order to provide a magnetized nut that is produced in a simple and cost-effective manner and ensures as equal a distribution of mass as possible with regard to the rotational axis of the nut, the magnetic material is introduced into the hollow space using injection molding.

Abstract: An arrangement and method for determining a characteristic variable of a fluid having a movably suspended measuring element, a restraining element, an advancing element and a control device. The control device is designed to actuate the restraining element and/or the advancing element in order to move the measuring element between the first measuring point and the second measuring point, to determine a time period which the measuring element requires in order to be moved between the first measuring point and the second measuring point, and to determine a characteristic variable of the fluid on the basis of the determined time period, a predetermined force and a known geometry.

Abstract: A particle sensor arranged in an exhaust duct such that particles from the exhaust-gas flow accumulate on and/or between at least two sensor electrodes when a voltage greater than a limit voltage is applied between the two sensor electrodes and substantially no particles accumulate if the voltage is lower than the limit voltage. During a first time period, a first voltage greater than the limit voltage is applied between the sensor electrodes. During a second time period, a second voltage, lower than the limit voltage, is applied between the sensor electrodes, and/or the particle sensor is heated to a predefined temperature, such that substantially no particles accumulate on and/or between the at least two sensor electrodes. Following the second time period, a third voltage greater than the limit voltage is applied between the sensor electrodes.

Abstract: A method and device for measuring the soot load in the exhaust gas systems of diesel engines using a sensor which is mounted downstream of a particulate filter and comprises a sensor element, to measure the operability of the particulate filter. According to the method, the soot load of the sensor element is measured resistively or capacitively using electrodes. The measuring voltage of the sensor element is controlled depending on at least one actual operating parameter of the diesel engine.

Abstract: A soot sensor for the detection of soot particles in an exhaust gas flow, having interdigitally engaged measurement electrodes applied on a substrate. An electrical resistance between the measurement electrodes is a measure of soot load of the exhaust gas flow. The measurement electrodes are divided into two regions, a first region in which no soot particles can be deposited and a second region where soot particles are deposited from the exhaust gas flow. The first region and the second region are exposed simultaneously to the other conditions prevailing in the exhaust gas flow.

Abstract: A method for performing on-board functional diagnostics on a soot sensor of a vehicle and/or for detecting further components in the soot in a motor vehicle having an internal combustion engine. The soot sensor is electrically connected to an evaluation circuit with is permanently installed in the motor vehicle. In order to specify a method for performing functional diagnostics on a soot sensor and/or for detecting further components in the soot, with which method it is possible to detect a faulty soot sensor and/or further components in the soot in a cost-effective way, the evaluation circuit measures the temperature coefficient of the soot sensor and detects the defectiveness of the soot sensor and/or the presence of further components in the soot on the basis of the temperature coefficient of the soot sensor.

Abstract: A method for on-vehicle functional diagnosis of a soot sensor and/or for detecting further components in the soot in a motor vehicle having an internal combustion engine, the soot sensor connected electrically to an evaluation circuit. To specify a method for functional diagnosis of a soot sensor and/or for detecting further components in the soot, by which it is possible to detect a faulty soot sensor and/or further components in the soot in an economical manner, the evaluation circuit measures a temperature coefficient of the soot sensor and detects the faultiness of the soot sensor and/or the presence of further components in the soot from the temperature coefficient of the soot sensor.

Abstract: A method for the on-board functional diagnosis of a soot sensor and detection of further constituents in the soot in a motor vehicle having an internal combustion engine. The soot sensor is connected electrically to an evaluation circuit in the motor vehicle. A faulty soot sensor and/or further constituents in the soot can be detected in an inexpensive way. The evaluation circuit measures the voltage coefficient of the soot sensor and detects the defectiveness of the soot sensor and/or the presence of further constituents in the soot using the voltage coefficient of the soot sensor.

Abstract: A method and device for determining a fuel portion in a motor oil of a motor vehicle. The motor oil is brought between at least two electrodes forming a capacitor. The capacitance of the capacitor is determined while the motor oil is located between the electrodes, and the fuel portion in the motor oil is determined from the capacitance of the capacitor.

Abstract: An arrangement and method for determining a characteristic variable of a fluid having a movably suspended measuring element, a restraining element, an advancing element and a control device. The control device is designed to actuate the restraining element and/or the advancing element in order to move the measuring element between the first measuring point and the second measuring point, to determine a time period which the measuring element requires in order to be moved between the first measuring point and the second measuring point, and to determine a characteristic variable of the fluid on the basis of the determined time period, a predetermined force and a known geometry.

Abstract: A magnetized nut for fastening a compressor wheel of an exhaust turbocharger to a turbo shaft. The nut has a base body made of a non-magnetic material forming a hollow space for accommodating a magnetic material, and a method for the production of the magnetized nut. In order to provide a magnetized nut that is produced in a simple and cost-effective manner and ensures as equal a distribution of mass as possible with regard to the rotational axis of the nut, the magnetic material is introduced into the hollow space using injection molding.

Abstract: An element which generates a magnetic field for fastening a compressor wheel to a turboshaft of an exhaust-gas turbocharger, has a basic body and a thread. In order to specify an element which generates a magnetic field for fastening a compressor wheel to a turboshaft, which element generates as high a magnetic field strength as possible and nevertheless can absorb without damage the forces and the tightening torques which occur during fastening of the compressor wheel to the turboshaft, the entire basic body includes a magnetic material and a sleeve is arranged in the basic body, which sleeve includes a non-magnetic material and has the thread which can be screwed to a mating thread of the turboshaft.

Abstract: Presented is an apparatus that includes a vehicle component that includes an outer wall that includes an internal face and at least one electro-acoustic transducer disposed on the internal face of the outer wall of the vehicle component. The at least one electro-acoustic transducer includes a pot-type housing and a piezo-electric ceramic body disposed inside the pot-type housing. The pot-type housing includes a base area affixed to the internal face of the outer wall of the vehicle component.