Method and device for examining an exhaust gas sensor
First Claim
1. A method for testing an exhaust gas sensor having a first chamber, a second chamber, a first diffusion barrier separating the first and second chambers, and a second diffusion barrier forming a gas inlet of the first chamber, the first chamber having first main pump electrode, the second chamber having a measuring electrode and an auxiliary pump electrode, and a second main pump electrode and a reference electrode being disposed outside of the first and second chambers, said method comprising:
- sensing a first voltage as a predefined voltage between the auxiliary pump electrode and the reference electrode;
determining a set point diagnostic value as a function of the sensed first voltage multiplied by a predefined factor and adding a predefined shift value to the resulting value, wherein the predefined shift value is determined as a function of a calibration of the exhaust gas sensor;
sensing a measuring current between the measuring electrode and the second main pump electrode, the measuring current being set as a pump current by adjusting a second voltage between the measuring electrode and the reference electrode to the predefined voltage, and determining an actual diagnostic value as a function of the sensed measuring current; and
detecting a fault in the exhaust gas sensor as a function of the set point diagnostic value and the actual diagnostic value.
1 Assignment
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Accused Products
Abstract
A first voltage (V1) is detected between an auxiliary pump electrode and a reference electrode of an exhaust gas sensor, and a target diagnosis value (SDIAG) is determined as a function of the detected first voltage (V1). A measured current (Im) is detected between a measurement electrode and a second main pump electrode of the exhaust gas sensor, said measured current being set up as the pump current by regulating a second voltage between the measurement electrode and the reference electrode to a pre-defined voltage. An actual diagnosis value (IDIAG) is determined as a function of the detected measured current (Im). An error (ERR) of the exhaust gas sensor is recognized depending on the target diagnosis value (SDIAG) and the actual diagnosis value (IDIAG).
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Citations
11 Claims
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1. A method for testing an exhaust gas sensor having a first chamber, a second chamber, a first diffusion barrier separating the first and second chambers, and a second diffusion barrier forming a gas inlet of the first chamber, the first chamber having first main pump electrode, the second chamber having a measuring electrode and an auxiliary pump electrode, and a second main pump electrode and a reference electrode being disposed outside of the first and second chambers, said method comprising:
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sensing a first voltage as a predefined voltage between the auxiliary pump electrode and the reference electrode; determining a set point diagnostic value as a function of the sensed first voltage multiplied by a predefined factor and adding a predefined shift value to the resulting value, wherein the predefined shift value is determined as a function of a calibration of the exhaust gas sensor; sensing a measuring current between the measuring electrode and the second main pump electrode, the measuring current being set as a pump current by adjusting a second voltage between the measuring electrode and the reference electrode to the predefined voltage, and determining an actual diagnostic value as a function of the sensed measuring current; and detecting a fault in the exhaust gas sensor as a function of the set point diagnostic value and the actual diagnostic value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A device for testing an exhaust gas sensor,
the exhaust gas sensor having a first chamber, a second chamber, a first diffusion barrier separating the first and second chambers, and a second diffusion barrier forming a gas inlet of the first chamber, the first chamber having a first main pump electrode and the second chamber has a measuring electrode and an auxiliary pump electrode, and a second main electrode and a reference electrode being disposed outside of the first and second chambers, the device being configured to: -
sense a first voltage as a predefined voltage between the auxiliary pump electrode and the reference electrode and determine a set point diagnostic value as a function of the sensed first voltage multiplied by a predefined factor and the resulting value being added to a predefined shift value, wherein the predefined shift value is determined as a function of a calibration of the exhaust gas sensor, sense a measuring current between the measuring electrode and the second main pump electrode, the measuring current being set as a pump current by adjusting a second voltage between the measuring electrode and the reference electrode to the predefined voltage, and determine an actual diagnostic value as a function of the sensed measuring current, and detect a fault in the exhaust gas sensor as a function of the set point diagnostic value and the actual diagnostic value. - View Dependent Claims (9, 10)
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11. A method for testing an exhaust gas sensor having a first chamber, a second chamber, a first diffusion barrier separating the first and second chambers, and a second diffusion barrier forming a gas inlet of the first chamber, the first chamber having first main pump electrode, the second chamber having a measuring electrode and an auxiliary pump electrode, and a second main pump electrode and a reference electrode being disposed outside of the first and second chambers, said method comprising:
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sensing a first voltage as a predefined voltage between the auxiliary pump electrode and the reference electrode; determining a set point diagnostic value based at least in part on a first current between the measuring electrode and the second main pump electrode at the first voltage; sensing a measuring current between the measuring electrode and the second main pump electrode, the measuring current being set as a pump current by adjusting a second voltage between the measuring electrode and the reference electrode to the predefined voltage; determining an actual diagnostic value as a function of the sensed measuring current; and detecting a fault in the exhaust gas sensor as a function of the set point diagnostic value and the actual diagnostic value.
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Specification