Robert Boschgmbh

Thomas Seiler

Lothar Diehl

Goetz Reinhardt

Hartwig Lehle

Ulrich Eisele

Jens Schneider

Torsten Handler

Jens Wagner

Detlef Heimann

Holger Reinshagen

Walter Strassner

Frank Meier

Helge Schichlein

Henrico Runge

Juergen Ruth

Christoph Peters

Marcus Scheffel

Bjoern Alexander Schuetz

Gerhard Lemke

Peter Brida

Stefan Klein

Moritz Waldorf

Christian Ohly

Joachim Graeber

Karsten Glashoff

Cyril Verdier

Jochen Betten

In a method for adjusting a gas sensor having a hollow chamber connected to a measuring gas chamber and having an electrochemical pump cell electrochemically pumping the gas component into or out of the hollow chamber, at least two pumping-in phases are provided in which the gas component is pumped into the hollow chamber by the electrochemical pump cell, and at least two pumping-out phases are provided in which the gas component is pumped out of the hollow chamber by the electrochemical pump cell. On the basis of at least one feature of the pump current during the pumping-out phases (M), at least one piece of information for adjusting the gas sensor is generated. A parameter regarding the pumping-in is predefined differently in the at least two pumping-in phases.

Method for adjusting a gas sensor

A method for diagnosing a sensor element for detecting at least one fraction of a gas component of a gas in a measuring gas chamber, in particular a sensor element for detecting oxygen in an exhaust gas of an internal combustion engine. The sensor element includes at least one first electrode, to which the gas may be applied, and at least one second electrode, the first electrode and the second electrode being connected via at least one solid electrolyte. A diagnostic signal is applied between the first electrode and the second electrode, a response signal being detected between the first electrode and the second electrode.

Method and device for diagnosing electrodes in sensor elements

A method for operating a sensor element, in particular a lambda sensor, for determining the concentration of a gas component of a gas mixture, in which the gas component is removed from a measuring gas chamber by applying a pump voltage and the concentration of the gas component in the gas mixture is inferred therefrom. Oscillations of the pump current caused by dynamic pressure variations are taken into consideration for a correction of the sensor signal in that a frequency analysis of the pump current is carried out.

Method for correcting the pump current of a sensor element

A method is described for diagnosing a heatable exhaust gas sensor of an internal combustion engine, in which a predefined chronologically varying or constant voltage or a predefined chronologically varying or constant current is generated with the aid of a voltage source, the voltage or the current is applied to terminals of the exhaust gas sensor, a current or applied voltage, which flows through the voltage source when the voltage or the current is applied, is detected, and the current or the voltage is analyzed to diagnose the exhaust gas sensor. To diagnose the exhaust gas sensor, which permits a reliable and accurate diagnosis of the exhaust gas sensor and allows a statement about the type of a possibly existing error on the exhaust gas sensor, the method is executed independently of a control and/or regulating unit of the internal combustion engine, an operating temperature of the exhaust gas sensor being regulated to a predefined temperature value with the aid of a regulating element, which is separate from the control and/or regulating unit.

Method and diagnostic device for diagnosing a heatable exhaust gas sensor of an internal combustion engine

Disclosed is a gas sensor, particularly a lambda probe, for determining the oxygen concentration in the exhaust gas of an internal combustion engine that is operated using a fuel-air mixture. Said gas sensor comprises a pump cell with an outer electrode that is exposed to the exhaust gas, an inner electrode located in a measuring chamber which is separated from the exhaust gas by means of a first diffusion barrier, and an electronic circuit for generating a voltage applied between the outer electrode and the inner electrode as well as for measuring and evaluating a pump current that is generated in said process in order to draw a conclusion therefrom about the composition of the fuel-air mixture. The inventive gas sensor is characterized in that the outer electrode is arranged in an independent measuring volume which is separated by means of an additional, second diffusion barrier whose coefficient of diffusion is different from that of the first diffusion barrier while the circuit is configured so as to preferably repeatedly reverse the polarity of the voltage.

Gas sensor

A gas sensor for detecting particles in a gas stream has a first electrochemical pump cell, which has a measuring chamber in which a first electrode is disposed to pump particles between the first measuring chamber and the gas stream. Furthermore, a second electrochemical pump cell is provided, which has a second measuring chamber in which a second electrode is disposed so as to pump particles. The second measuring chamber is connected to the gas stream via an absorber medium for absorption of the particles to be detected. This makes it possible to absorb the particles to be detected in a first operating mode using the absorber medium, and to desorb the absorbed particles in a second operating mode, and to detect the quantity of the desorbed particles. Thus, the gas sensor is able to take even low concentrations into account, and short-term measuring errors do not have such a serious effect.

Gas sensor and method for detecting particles in a gas flow

The invention relates to a gas sensor for determining the oxygen concentration in a gas mixture, especially in the exhaust gas of internal combustion engines. Said gas sensor comprises a pump cell having an outer pump electrode, exposed to the gas mixture, and an inner pump electrode, exposed to the gas mixture via a diffusion barrier, and a solid electrolyte body interposed between the outer pump electrode and the inner pump electrode. The gas sensor also has a reference electrode, exposed to a reference gas, and a sensor heating device. The outer pump electrode is connected to a circuit arrangement via a pump current line, the inner pump electrode via a measuring line, the reference electrode via a reference current line and the sensor heating device via two heating lines. The invention is characterized in that the pump current line and one heating line are electrically interconnected and grounded, the pump current can be supplied via the measuring line and the Nernst voltage can be tapped between the measuring line and the reference pump current line and the reference pump current flows from the reference electrode to the outer pump electrode.

A sensor element is provided for determining a physical property of a measuring gas, especially of the concentration of at least one gas component in the measuring gas, which has at least one ceramic layer, a diffusion barrier adjoining the at least one ceramic layer and at least one electrode that is exposed to the measuring gas diffusing through the diffusion barrier. In order to reduce the production variations with respect to the static pressure dependence and the limiting current of the diffusion barrier), the proportions of silicon in the diffusion barrier and in the at least one ceramic layer are approximately equal and differ by not more than 1 wt. %.

Sensor element for determining a physical property of a measuring gas

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Stuttgart, Germany

Thomas Seiler