Sensor element and method for determining gas components in gas mixtures, and use thereof
AssigneeRobert Bosch GmbH
InventorsDirk Liemersdorf, Thomas Classen, Benjamin Sillmann
Life of this patent
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Abstract
A sensor element of a gas sensor for determining gas components in gas mixtures, having at least one electrochemical measuring cell which is formed by a ceramic substrate and electrodes placed thereon. The sensor element includes at least one interior chamber which is sealed in a gas-tight manner, in which at least one first internal electrode is positioned, which forms an electrochemical cell with each of a second and an additional electrode of the sensor element, one of the electrochemical cells being an electrochemical pump cell, and the second or other electrode being exposed to the measuring gas.
Claims14
A sensor element of a gas sensor for determining gas components in an exhaust gas of an internal combustion engine, comprising:
- a ceramic sensor body having at least one interior chamber which is sealed in a gas-tight manner, in which at least one first internal electrode is positioned, wherein the chamber is not in fluid-conducting contact with the exhaust gas;
- a second electrode, which, together with the first electrode in the chamber forms a first electrochemical cell;
- and
- an additional electrode, which, together with the first electrode in the chamber forms a second electrochemical cell;
- wherein the first electrochemical cell is an electrochemical pump cell and the additional electrode is exposed to a gas being measured.
A method for determining gas components in an exhaust gas of an internal combustion engine using a sensor element having at least two electrochemical pump cells which each include at least one first electrode and one second electrode, at least one of the electrodes being positioned in a gas-tight sealed interior chamber of the sensor element, the method comprising:
- accumulating a quantity of oxygen in the gas-tight sealed interior chamber equivalent to a quantity of a gas component to be determined, wherein the chamber is not in fluid-conducting contact with the exhaust gas;
- subsequently removing the accumulated oxygen by applying a pump voltage to the electrodes of at least one of the electrochemical pump cells;
- and
- determining the gas components based on an electrical characteristic of the at least one of the electrochemical pump cells as the removing is performed.
A method of determining nitrogen oxide content in an exhaust gas using a sensor element having at least two electrochemical pump cells which each include at least one first electrode and one second electrode, at least one of the electrodes being positioned in a gas-tight sealed interior chamber of the sensor element, the method comprising:
- accumulating a quantity of oxygen in the gas-tight sealed interior chamber equivalent to a quantity of the nitrogen oxide content to be determined;
- subsequently removing the accumulated oxygen by applying a pump voltage to the electrodes of at least one of the electrochemical pump cells;
- and
- determining the quantity of the nitrogen oxide content based on an electrical characteristic of the at least one of the electrochemical pump cells as the removing is performed.
A method of monitoring a functional reliability of an NOx catalytic converter using a sensor element having at least two electrochemical pump cells which each include at least one first electrode and one second electrode, at least one of the electrodes being positioned in a gas-tight sealed interior chamber of the sensor element, the method comprising:
- accumulating a quantity of oxygen in the gas-tight sealed interior chamber equivalent to a quantity of a gas component to be determined, wherein the chamber is not in fluid-conducting contact with an exhaust gas;
- subsequently removing the accumulated oxygen by applying a pump voltage to the electrodes of at least one of the electrochemical pump cells;
- and
- monitoring the functional reliability of the NOx catalytic converter based on an electrical characteristic of the at least one of the electrochemical pump cells as the removing is performed.
A method of monitoring an SCR exhaust treatment system using a sensor element having at least two electrochemical pump cells which each include at least one first electrode and one second electrode, at least one of the electrodes being positioned in a gas-tight sealed interior chamber of the sensor element, the method comprising:
- accumulating a quantity of oxygen in the gas-tight sealed interior chamber equivalent to a quantity of a gas component to be determined, wherein the chamber is not in fluid-conducting contact with an exhaust gas;
- and
- subsequently removing the accumulated oxygen by applying a pump voltage to the electrodes of at least one of the electrochemical pump cells;
- and
- monitoring the SCR exhaust treatment system based on an electrical characteristic of the at least one of the electrochemical pump cells as the removing is performed.
Dependencies are inferred from the claim text.