Patent application number | Description | Published |
20080296156 | SENSOR ELEMENT FOR DETERMINING A PHYSICAL PROPERTY OF A MEASURING GAS - 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. %. | 12-04-2008 |
20090107839 | GAS SENSOR - 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. | 04-30-2009 |
20090152112 | GAS SENSOR - 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. | 06-18-2009 |
20090152130 | Gas sensor and method for detecting particles in a gas flow - A gas sensor 10 for detecting particles in a gas stream has a first electrochemical pump cell 14, which has a measuring chamber 16 in which a first electrode 18 is disposed to pump particles between the first measuring chamber 16 and the gas stream. Furthermore, a second electrochemical pump cell 20 is provided, which has a second measuring chamber 22 in which a second electrode 24 is disposed so as to pump particles. According to the invention, the second measuring chamber 22 is connected to the gas stream via an absorber medium 34 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 34, and to desorb the absorbed particles in a second operating mode, and to detect the quantity of the desorbed particles. Thus, the gas sensor 10 is able to take even low concentrations into account, and short-term measuring errors do not have such a serious effect. | 06-18-2009 |
20100000864 | GAS SENSOR WITH PUMP CELL AND ADDITIONAL OUTER ELECTRODE - The invention relates to a gas sensor, especially a lambda probe, for determining the oxygen concentration in the exhaust gas of an internal combustion engine that is operated with a fuel/air mixture. Said gas sensor comprises a pump cell arranged in or on a sensor element, said pump cell having a first electrode and a second electrode that are separated from the exhaust gas by at least one layer, and an electronic circuit for producing a voltage applied between the first electrode and the second electrode and for measuring and evaluating a pump current thereby produced in order to make it possible to draw conclusions therefrom on the composition of the fuel/air mixture. The invention is characterized in that an additional outer electrode is arranged on the sensor element. Said additional electrode is exposed to the exhaust gas and supplied with a negative current. | 01-07-2010 |
20100126883 | SENSOR ELEMENT HAVING SUPPRESSED RICH GAS REACTION - A sensor element for determining at least one physical property of a gas mixture is provided. The sensor element has at least one first electrode and at least one second electrode, and at least one solid electrolyte that connects the at least two electrodes. The at least one first electrode is connected via at least one diffusion-resistance element to the at least one gas chamber and/or to at least one reference chamber. The at least one second electrode is connected via at least one flow-resistance element to the at least one gas chamber. The at least one flow-resistance element and the at least one diffusion-resistance element are designed in such a way that the limit current of the at least one first electrode is smaller than the limit current of the at least one second electrode. | 05-27-2010 |
20110108419 | HEATED BISTABLE SENSOR HAVING SIMPLIFIED ELECTRICAL CONTACTING - A sensor element for determining a physical property of a gas in a measuring gas chamber includes at least two electrodes, at least one solid-state electrolyte connecting the electrodes, and at least one heating element having at least two heating contacts. A first heating contact and a first electrode are contacted via a common connecting line, and a second heating contact and a second electrode are connected to a common ground line. | 05-12-2011 |
20120167656 | Method and Diagnostic Device for Diagnosing a Heatable Exhaust Gas Sensor of an Internal Combustion Engine - 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. | 07-05-2012 |
20130167511 | METHOD FOR CORRECTING THE PUMP CURRENT OF A SENSOR ELEMENT - 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. | 07-04-2013 |
20140238102 | METHOD FOR ADJUSTING A GAS SENSOR - 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 | 08-28-2014 |