Robert Boschgmbh

Helge Schichlein

Bernd Schumann

Lothar Diehl

Sabine Thiemann-Handler

Berndt Cramer

Thorsten Ochs

Jens Schneider

Thomas Wahl

Frank Stanglmeier

Jens Wagner

Torsten Handler

Claudius Bevot

Andy Tiefenbach

Eckart Reihlen

Thomas Seiler

Goetz Reinhardt

Bjoern Alexander Schuetz

The invention relates to a circuit assembly for operating a probe () for determining the oxygen concentration in a gas mixture, in particular a Lambda probe for determining the oxygen concentration in the exhaust gas of internal combustion engines, comprising two electrodes () which act as an outer and an inner pump electrode and form a pump cell, two electrodes which act as a Nernst electrode () and a reference electrode () and form a Nernst cell, and a pump current controller (), which controls a pump current that is applied to the pump cell such that a predeterminable Nernst voltage (U) that can be tapped at the Nernst cell is controlled to a predeterminable value, characterized in that the predeterminable value of the Nernst voltage can be varied.

Circuit assembly for operating a gas probe

A method for operating at least one sensor element for detecting at least one property of a gas in a measured-gas space is described. The method comprises at least the following steps: at least one first step, in the first step at least one parameter being ascertained; at least one second step, in the second step the parameter being compared with at least one comparison value, in accordance with that comparison at least one feature being allocated to the sensor element or to at least one part of the sensor element. An apparatus for carrying out the method is also described.

Method for operating a gas sensor element and device for carrying out said method

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 device for operating a gas sensor having both at least one pump cell and a measuring cell is provided. A constant current source is provided that makes available a pump current which acts upon an outer electrode of the pump cell. The constant current source provides at least two different amounts of the pump current and/or allows for an alternating operation having ON phases and OFF phases, the duration of the ON phases/OFF phases being specifiable. The device may be largely implemented in digital circuitry and adapted to different requirements.

Device for operating a gas sensor

A ceramic gas sensor for measuring a gas component in a gas mixture, which includes a sensor element, which has at least one first electrode exposed to the gas mixture to be determined, and at least one further electrode. Only one shared electrical contact is provided for the first electrode and for the additional electrode, an electrical resistor, which is situated inside the gas sensor, being preconnected to the first electrode and/or the additional electrode.

Gas sensor for measuring a gas component in a gas mixture

A sensor element of a gas sensor, which is used for determining the concentration of ammonia and, optionally, at least one further component of a gas mixture, in particular in exhaust gases of combustion engines. The sensor element includes at least one first auxiliary electrode and at least one measuring electrode positioned downstream in the flow direction of the gas mixture, which are in direct contact with the gas mixture, a signal generated by the measuring electrode being used at least intermittently for determining the concentration of ammonia. A potential, at which ammonia contained in the gas mixture is oxidized, is applied at least intermittently to the first auxiliary electrode or the measuring electrode.

Sensor element and method for determining ammonia

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Stuttgart, Germany

Helge Schichlein