Method and exhaust gas sensor for determining a corrected nitrogen oxide content in an exhaust gas of an internal combustion engine

Abstract

The present invention relates to a method and an exhaust gas sensor for determining a corrected nitrogen oxide content in the exhaust gas of an internal combustion engine. The exhaust gas sensor (10) comprises a main body (12), a measuring cavity (40) arranged in the main body (12), in which a measuring electrode (44) is arranged, an exhaust gas electrode (22) exposed to the exhaust gas, which forms an amperometric measuring cell with the measuring electrode (44), and a reference cavity (50) connected to the ambient air, in which a reference electrode (52) is arranged.The method according to the invention comprises applying a measuring current (IP2) to the measuring electrode (44) such that a measuring voltage (V2) developing between the measuring electrode (44) and the reference electrode (52) is maintained at a predetermined first setpoint value, determining a nitrogen oxide content at least partially on the basis of the measuring current (IP2) applied to the measuring electrode (44), determining the electrical impedance of the amperometric measuring cell and determining a corrected nitrogen oxide content at least partially on the basis of the determined nitrogen oxide content and at least partially on the basis of the determined electrical impedance of the amperometric measuring cell.

Description

[0001] The present invention relates to a method for determining a corrected nitrogen oxide content in an exhaust gas of an internal combustion engine, in particular by means of an exhaust gas sensor, for example a nitrogen oxide sensor, as well as an exhaust gas sensor and a vehicle

[0002] Exhaust gas sensors, such as nitrogen oxide sensors, lambda sensors, and oxygen sensors, can be based on the amperometric principle, i.e., an electrochemical method for the quantitative determination of chemical substances. Specifically, an electric current is applied to an electrode of the exhaust gas sensor in such a way that a constant electrochemical potential is established. For example, nitrogen oxide sensors allow the nitrogen oxide concentration to be measured in the exhaust gas of internal combustion engines, such as gasoline or diesel engines. This enables, for example, optimal control and diagnosis of nitrogen oxide catalysts by the engine control system.

[0003] Such exhaust gas sensors comprise a main body formed from a solid electrolyte, in which cavities with associated electrodes are provided. Furthermore, a heating device is arranged in the main body, which is designed to heat the main body to and maintain it at a predetermined operating temperature, for example, approximately 850°C. Due to additional external heat input, such as from the exhaust gas flowing around the exhaust gas sensor, the electrodes may be warmer than in their initial state, which can lead to an increased signal from the exhaust gas sensor, for example, an excessively high nitrogen oxide content.

[0004] Exemplary exhaust gas sensors and control methods for operating such are known from US 2002 / 0 179 594 A1, US 2011 / 0 023 459 A1, US 2023 / 0 194 463 A1, US 2002 / 0 189 942 A1 and US 2020 / 0 088 666 A1.

[0005] The present invention is based on the object of specifying a method and an exhaust gas sensor for determining a corrected nitrogen oxide content in an exhaust gas flowing through an exhaust tract of an internal combustion engine, the accuracy of which is at least partially increased.

[0006] This object is achieved by a method according to claim 1, an exhaust gas sensor according to claim 7, and a vehicle according to claim 9. Advantageous embodiments are specified in the subclaims.

[0007] The present invention is essentially based on the idea of ​​at least partially compensating for heat input acting externally on the exhaust gas sensor, which thus impairs its accuracy, by taking into account the electrical impedance of a measuring cell of the exhaust gas sensor. In particular, the present invention utilizes the knowledge that external heat input affects the electrical impedance of the measuring cell of the exhaust gas sensor. By determining this electrical impedance of the measuring cell of the exhaust gas sensor, the nitrogen oxide content determined based on a measuring current applied to the measuring cell can then be at least partially corrected.

[0008] According to a first aspect of the present invention, a method for determining a corrected nitrogen oxide content in an exhaust gas flowing through an exhaust tract of an internal combustion engine is disclosed using an exhaust gas sensor arranged in the exhaust tract. The exhaust gas sensor comprises a main body, a measuring cavity arranged in the main body, which is fluidly connected to the exhaust tract and in which a measuring electrode is arranged, an exhaust gas electrode attached to an outer side of the main body and exposed to the exhaust gas flowing through the exhaust tract, which forms an amperometric measuring cell with the measuring electrode, and a reference cavity arranged in the main body and connected to the ambient air, in which a reference electrode is arranged.The method comprises applying a measuring current to the measuring electrode such that a measuring voltage developing between the measuring electrode and the reference electrode is maintained at a predetermined first setpoint value, determining a nitrogen oxide content at least partially based on the measuring current applied to the measuring electrode, determining the electrical impedance of the amperometric measuring cell, and determining a corrected nitrogen oxide content at least partially based on the determined nitrogen oxide content and at least partially based on the determined electrical impedance of the amperometric measuring cell.

[0009] Thus, according to the invention, the exhaust gas sensor can be operated as usual. In particular, the control of the heating device of the exhaust gas sensor, which is designed to heat and maintain the main body at a predetermined temperature, can continue to operate unchanged. According to the invention, the electrical impedance of the amperometric measuring cell is determined, which is then used to correct the determined nitrogen oxide content.

[0010] According to a preferred embodiment of the method according to the invention, the corrected nitrogen oxide content is determined by means of an allocation table and / or an allocation rule which establishes a relationship between the determined nitrogen oxide content and the determined electrical impedance.

[0011] In an advantageous embodiment, the method according to the invention further comprises predetermining an electrical reference impedance of the amperometric measuring cell. The corrected nitrogen oxide content is determined at least partially based on the predetermined electrical reference impedance of the amperometric measuring cell. Preferably, the electrical reference impedance of the amperometric measuring cell is predetermined by determining the electrical impedance of the amperometric measuring cell in the new state of the exhaust gas sensor and processed with the currently determined electrical impedance of the amperometric measuring cell.

[0012] In a further advantageous embodiment of the method according to the invention, the exhaust gas sensor further comprises a first pump cavity arranged in the main body, which is fluidly connected between the exhaust tract and the measuring cavity and in which a first pump electrode is arranged, and / or a second pump cavity arranged in the main body, which is fluidly connected between the first pump cavity and the measuring cavity and in which a second pump electrode is arranged. The first pump electrode forms an amperometric first pump cell with the exhaust gas electrode, and / or the second pump electrode forms an amperometric second pump cell with the exhaust gas electrode.The method according to the invention according to such an advantageous embodiment further comprises determining the electrical impedance of the amperometric first pump cell and / or the amperometric second pump cell, and determining an impedance ratio between the determined electrical impedance of the amperometric measuring cell and the determined electrical impedance of the amperometric first pump cell and / or the amperometric second pump cell. The determination of the corrected nitrogen oxide content is then based at least partially on the determined impedance ratio.

[0013] Preferably, the determined electrical impedance of the measuring cell increases with increasing exhaust gas temperature.

[0014] According to a further aspect of the present invention, an exhaust gas sensor for determining a corrected nitrogen oxide content in an exhaust gas flowing through an exhaust tract of an internal combustion engine is disclosed.The exhaust gas sensor according to the invention comprises a main body, a measuring cavity arranged in the main body, which is fluidically connected to the exhaust tract and in which a measuring electrode is arranged, an exhaust gas electrode attached to an outer side of the main body and exposed to the exhaust gas flowing through the exhaust tract, which forms an amperometric measuring cell with the measuring electrode, a reference cavity arranged in the main body and connected to the ambient air, in which a reference electrode is arranged, and a control device which is electrically connected to the measuring electrode, the exhaust gas electrode and the reference electrode and is designed to carry out a method for determining a corrected nitrogen oxide content in the exhaust gas flowing through the exhaust tract of an internal combustion engine.

[0015] In an advantageous embodiment, the exhaust gas sensor according to the invention further comprises a first pump cavity arranged in the main body, which is fluidly connected between the exhaust tract and the measuring cavity and in which a first pump electrode is arranged, and / or a second pump cavity arranged in the main body, which is fluidly connected between the first pump cavity and the measuring cavity and in which a second pump electrode is arranged. The first pump electrode forms an amperometric first pump cell with the exhaust gas electrode, and / or the second pump electrode forms an amperometric second pump cell with the exhaust gas electrode.

[0016] According to yet another aspect of the present invention, a vehicle having an exhaust gas sensor according to the invention is disclosed.

[0017] According to the invention, the determined electrical impedance of the measuring cell can be used to determine the average temperature of the main body in the area of ​​the measuring electrode, which in turn can compensate for the falsified measured values ​​of the exhaust gas sensor.

[0018] Further features and objects of the invention will become apparent to those skilled in the art by practicing the present teachings and viewing the accompanying drawings in which: Fig. 1 shows a schematic sectional view through an exhaust gas sensor for an internal combustion engine of a vehicle, shown as an example in the form of a nitrogen oxide sensor, Fig. 2 shows an exemplary diagram in which the relationship between the electrical impedance of the measuring cell of the exhaust gas sensor of the Fig. 1 and the measuring current applied to it, and Fig. 3 shows an exemplary flow diagram of a method according to the invention for determining a corrected nitrogen oxide value.

[0019] Within the scope of the present disclosure, amperometric sensors, such as nitrogen oxide sensors, lambda sensors, and oxygen sensors, are characterized in that their measuring principle is based on amperometry, i.e., an electrochemical method for the quantitative determination of chemical substances. In particular, an electric current is adjusted at a working electrode in such a way that a temporally constant electrochemical potential is established.

[0020] Furthermore, in the context of the present disclosure, the term "control" encompasses the control-related terms "control" and "regulation." Those skilled in the art will recognize when control-related control and when control-related regulation are to be applied.

[0021] The Fig. 1 shows an exemplary nitrogen oxide sensor 10, which exemplifies an exhaust gas sensor. Consequently, the present invention is also intended to be used in all sensors for internal combustion engines for vehicles that have a heating device, such as lambda sensors and oxygen sensors. In particular, the present invention is applicable to exhaust gas sensors that have a ceramic base with at least one pair of electrodes attached thereto, and in which the electrical resistance of the heating device can be determined to control the temperature of the main body of the exhaust gas sensor to a constant value.

[0022] With reference to the Fig. 1 shows a schematic sectional view of the exemplary nitrogen oxide sensor 10, which is designed to be arranged in an exhaust tract of an internal combustion engine (not shown) and to quantitatively detect the nitrogen oxide content or the oxygen content in the exhaust gas of the internal combustion engine.

[0023] The nitrogen oxide sensor 10 has a main body 12 made of a solid electrolyte, which is preferably formed from a mixed crystal of zirconium oxide and yttrium oxide and / or by a mixed crystal of zirconium oxide and calcium oxide.

[0024] Additionally, a solid solution of hafnium oxide, a solid solution of perovskite-based oxides, or a solid solution of trivalent metal oxide, such as aluminum oxide (Al2O3), can be used. The main body 12 forms a sensor element of the exhaust gas sensor 10. The main body 12 is therefore also referred to as the sensor element 12 below.

[0025] Within the main body 12 of the exemplary nitrogen oxide sensor 10, a first pump cavity 20, a second pump cavity 30, and a measuring cavity 40 are provided. The first pump cavity 20 is connected to the exterior of the main body 12 via a connecting path 15. In particular, exhaust gas can flow into the first pump cavity 20 through the connecting path 15. The second pump cavity 30 is connected to the first pump cavity 20 via a first diffusion path 25.

[0026] The measuring cavity 40 is connected to the second pump cavity 30 via a second diffusion path 35.

[0027] Also formed in the main body 12 is a reference cavity 50 that communicates directly with the exterior of the main body 12. A reference electrode 52 is arranged within the reference cavity 50. In particular, the reference cavity 50 communicates with the ambient air, i.e., not with the exhaust gas, and is designed to form an oxygen reference for the various electrodes arranged in the nitrogen oxide sensor 10.

[0028] An exhaust gas electrode 22 is arranged on an outer side of the main body 12. In particular, during a measuring operation of the nitrogen oxide sensor 10, by applying a reference current to the exhaust gas electrode 22, the oxygen present in the exhaust gas can be ionized and diffuse through the main body 12 as oxygen ions to the reference electrode 52, where it can be converted back into oxygen molecules to form an oxygen reference.

[0029] A first pumping electrode 24 is arranged within the first pumping cavity 20. In particular, during the measuring operation of the nitrogen oxide sensor 10, by applying a first pumping current IP0 to the first pumping electrode 24, the oxygen present in the exhaust gas can be ionized within the first pumping cavity 20 and migrate or pass through the main body 12 as oxygen ions. Due to the oxygen ions discharged from the first pumping cavity 20, a first electrode voltage or first Nernst voltage V0 is indirectly formed between the first pumping electrode 24 and the reference electrode 52. More precisely, the first electrode voltage or first Nernst voltage V0 is formed directly from the residual oxygen still present in the first pumping cavity 20.

[0030] A second pump electrode 34 is arranged within the second pump cavity 30. During the measuring operation of the nitrogen oxide sensor 10, by applying a second pump current IP1 to the second pump electrode 34, the oxygen present in the gas mixture within the second pump cavity 30 can be ionized and migrate or pass through the main body 12 as oxygen ions. Due to the oxygen ions discharged from the second pump cavity 30, a second electrode voltage or second Nernst voltage V1 is indirectly formed between the second pump electrode 34 and the reference electrode 52. More precisely, the second electrode voltage or second Nernst voltage V1 is formed directly from the residual oxygen still present in the second pump cavity 30.

[0031] A measuring electrode 44 is arranged within the measuring cavity 40. This measuring electrode is designed to ionize the oxygen and / or nitrogen oxides present within the measuring cavity 40 upon application of a measuring current IP2 during the measuring operation of the nitrogen oxide sensor 10, so that the oxygen ions can migrate or pass through the main body 12. Due to the oxygen ions discharged or pumped out of the measuring cavity 40, a third electrode voltage or third Nernst voltage V2 forms between the measuring electrode 44 and the reference electrode 52, which is kept at a constant value by applying the measuring current IP2 to the measuring electrode 44. More precisely, the third electrode voltage or third Nernst voltage V2 is formed directly from the residual oxygen still present in the measuring cavity 40 or the residual oxygen bound with nitrogen. The applied measuring current IP2 is then an indication of the nitrogen oxide content within the exhaust gas.

[0032] Thus, the Fig. The nitrogen oxide sensor 10 shown in Figure 1, which is an example of a sensor based on the amperometric measuring principle, has three relevant electrode pairs, namely a first electrode pair consisting of the first pump electrode 24 and the exhaust gas electrode 22, a second electrode pair consisting of the second pump electrode 34 and the exhaust gas electrode 22 and a third electrode pair consisting of the measuring electrode 44 and the exhaust gas electrode 22. The first electrode pair also forms an amperometric first pump cell, the second electrode pair forms an amperometric second pump cell and the third electrode pair forms an amperometric measuring cell

[0033] The pumping currents IP0 and IP1 applied to the first and second pumping electrodes 24, 34 are set such that preferably only the oxygen is ionized, but not the nitrogen oxides. In particular, the first pumping electrode 24 is designed to pump almost all of the oxygen out of the exhaust gas during normal operation of the nitrogen oxide sensor 10 or to allow a predetermined oxygen slip from the first pumping cavity 20 into the second pumping cavity 30. The second pumping electrode 34 is designed to ionize and discharge the oxygen not yet pumped out of the first pumping cavity 20, so that almost only nitrogen oxides are present in the measuring cavity 40. The measuring electrode 44 is designed to ionize the nitrogen oxides, wherein the measuring current IP2 applied to the measuring electrode 44 is a measure of the nitrogen oxide content in the exhaust gas.

[0034] Furthermore, a heating device 60 is arranged within the main body 12, which is designed to heat the main body 12 to a predetermined operating temperature and to maintain it at this temperature, for example at approximately 850°C.

[0035] The operating method for determining the nitrogen oxide content in the exhaust gas of the internal combustion engine using the disclosed nitrogen oxide sensor 10 is already known from the prior art, to which reference is made here. The control principle for the nitrogen oxide sensor 10 of the Fig. 1 is characterized in that the respective electrode voltages or Nernst voltages V0, V1, V2 are kept at a constant level by applying and adjusting the pump currents IP0, IP1 and the measuring current IP2.

[0036] The Fig. 2 shows an exemplary diagram in which the relationship between the electrical impedance ZP2 of the measuring cell of the exhaust gas sensor 10 of the Fig. 1 and the applied measuring current IP2. From the diagram of the Fig. 2 shows that there is a direct relationship between the electrical impedance ZP2 of the measuring cell and the applied measuring current IP2, whereby the electrical impedance ZP2 of the measuring cell is essentially directly proportional to the temperature of the exhaust gas flowing through the exhaust tract. The curve 200 of the Fig. 2 is recorded during an increase in exhaust gas. However, this increase in exhaust gas also affects the actual temperature of the main body 12, which leads to a falsification of the measurement result of the nitrogen oxide content and an increase in the measurement inaccuracy of the exhaust gas sensor 10.

[0037] According to the invention, the dependence of the measurement accuracy of the exhaust gas sensor 10 on the fluctuating exhaust gas temperature is to be at least partially compensated. Fig. 3 an exemplary method according to the invention for determining a corrected nitrogen oxide value.

[0038] The procedure of Fig. 3 starts at step 300 and then goes to step 310, at which the measuring current IP2 is applied to the measuring electrode 44 such that the third electrode voltage or third Nernst voltage V2 is kept at a predetermined setpoint.

[0039] In a subsequent step 320, the nitrogen oxide content in the exhaust gas flowing through the exhaust tract is determined based on the measuring current IP2 applied to the measuring electrode 44 - as is essentially known from the prior art.

[0040] In a subsequent step 330, which can also occur simultaneously with step 310 or with step 320, the electrical impedance of the amperometric measuring cell is determined. In particular, in step 330, a short current pulse of predetermined strength can be applied to the measuring cell, and the resulting pump voltage can be measured. From this, the electrical impedance or electrical resistance of the measuring cell can be determined.

[0041] In a further step 340, the nitrogen oxide content determined in step 320 is processed with the electrical impedance of the amperometric measuring cell determined in step 330 in such a way that a corrected nitrogen oxide content in the exhaust gas is determined before the method is terminated in step 350.

[0042] It has been found that the electrical impedance ZP2 of the measuring cell also increases with the temperature of the main body, which is heated partly by the heating device 60 and partly at least partially by the passing exhaust gas. Thus, the measurement accuracy of the exhaust gas sensor 10 can be at least partially increased by taking into account the determined electrical impedance ZP2 of the measuring cell.

[0043] Preferably, before step 330 of determining the electrical impedance ZP2 of the measuring cell, an electrical reference impedance ZP2_0 of the amperometric measuring cell can be predetermined. The electrical reference impedance ZP2_0 of the amperometric measuring cell can be predetermined by determining the electrical impedance of the amperometric measuring cell in the new state of the exhaust gas sensor 10.

[0044] In such a preferred embodiment of the method, the predetermined electrical reference impedance ZP2_0 of the amperometric measuring cell can be taken into account when determining the electrical impedance ZP2 of the measuring cell. This allows any aging effects of the measuring electrode 44 or contamination of the exhaust gas sensor 10 to be at least partially compensated.

[0045] For example, the electrical impedance ZP2 of the measuring cell of exhaust gas sensor 10 in its new state at a first exhaust gas temperature is approximately 1,000 ohms. If the exhaust gas heats up from the first temperature to a higher second temperature, the electrical impedance ZP2 of the measuring cell also increases, for example, to approximately 1,200 ohms. According to the invention, the difference of approximately 200 ohms in the electrical impedance ZP2 of the measuring cell can be used to determine the corrected nitrogen oxide content.

[0046] However, if the exhaust gas sensor 10 has already been in operation for a long time, such as 5,000 hours, aging effects may lead to an increased electrical impedance ZP2 of the measuring cell at the first exhaust gas temperature, for example, 1,500 ohms (instead of the previous 1,000 ohms). At the second exhaust gas temperature, the electrical impedance ZP2 of the measuring cell may be approximately 1,700 ohms. By taking into account the electrical reference impedance ZP2_0 of the measuring cell, the difference of 200 ohms instead of 700 ohms can then be used to determine the corrected nitrogen oxide content.

[0047] In an exemplary embodiment, the electrical reference impedance ZP2_0 of the measuring cell can be determined by the electrical impedance ZP2 in the new state of the exhaust gas sensor plus the multiplication of a predetermined impedance value by the number of operating hours.

[0048] Alternatively or additionally, the electrical impedances ZP0 and ZP1 of the first and / or second pump cell can also be determined. By forming a ratio of the electrical impedance ZP2 of the measuring cell to the electrical impedance ZP0, ZP1 of the first and / or second pump cell, an aging correction can also be performed, since the first pump electrode 24 and the second pump electrode 34 are subject to the same aging as the measuring cell 44. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2002 / 0 179 594 A1

[0004] US 2011 / 0 023 459 A1

[0004] US 2023 / 0 194 463 A1

[0004] US 2002 / 0 189 942 A1

[0004] US 2020 / 0 088 666 A1

[0004]

Claims

[1] Method for determining a corrected nitrogen oxide content in an exhaust gas flowing through an exhaust tract of an internal combustion engine by means of an exhaust gas sensor (10) arranged in the exhaust tract, which has a main body (12), a measuring cavity (40) arranged in the main body (12), which is fluidically connected to the exhaust tract (10) and in which a measuring electrode (44) is arranged, an exhaust gas electrode (22) attached to an outer side of the main body (12) and exposed to the exhaust gas flowing through the exhaust tract (10), which forms an amperometric measuring cell with the measuring electrode (44), and a reference cavity (50) arranged in the main body (12) and connected to the ambient air, in which a reference electrode (52) is arranged, the method comprising: - applying a measuring current (IP2) to the measuring electrode (44) such that a measuring voltage (V2) formed between the measuring electrode (44) and the reference electrode (52) is maintained at a predetermined first setpoint value, - determining a nitrogen oxide content at least partly on the basis of the measuring current (IP2) applied to the measuring electrode (44), - Determine the electrical impedance of the amperometric measuring cell, and - determining a corrected nitrogen oxide content based at least partly on the determined nitrogen oxide content and at least partly on the determined electrical impedance of the amperometric measuring cell. [2] Method according to claim 1, wherein the determination of the corrected nitrogen oxide content is carried out by means of an allocation table and / or an allocation rule which establishes a relationship between the determined nitrogen oxide content and the determined electrical impedance. [3] Method according to one of the preceding claims, further comprising: - Predetermining an electrical reference impedance of the amperometric measuring cell, wherein the determination of the corrected nitrogen oxide content is carried out at least partly on the basis of the predetermined electrical reference impedance of the amperometric measuring cell. [4] Method according to claim 3, wherein the electrical reference impedance of the amperometric measuring cell is predetermined by determining the electrical impedance of the amperometric measuring cell in the new state of the exhaust gas sensor. [5] Method according to one of the preceding claims, wherein the exhaust gas sensor (10) further comprises a first pumping cavity (20) arranged in the main body (12), which is fluidically connected between the exhaust gas tract and the measuring cavity (40) and in which a first pumping electrode (24) is arranged, and / or a second pumping cavity (30) arranged in the main body (12), which is fluidically connected between the first pumping cavity (20) and the measuring cavity (40) and in which a second pumping electrode (34) is arranged, wherein the first pumping electrode (24) forms an amperometric first pumping cell with the exhaust gas electrode (22) and / or the second pumping electrode (34) forms an amperometric second pumping cell with the exhaust gas electrode (22), the method further comprising: - Determining the electrical impedance of the amperometric first pump cell and / or the amperometric second pump cell, and - determining an impedance ratio between the determined electrical impedance of the amperometric measuring cell and the determined electrical impedance of the amperometric first pump cell and / or the amperometric second pump cell, wherein the determination of the corrected nitrogen oxide content is based at least partially on the determined impedance ratio. [6] Method according to one of the preceding claims, wherein the determined electrical impedance of the measuring cell increases with increasing exhaust gas temperature. [7] Exhaust gas sensor (20) for determining a corrected nitrogen oxide content in an exhaust gas flowing through an exhaust tract (10) of an internal combustion engine, the exhaust gas sensor (20) comprising: - a main body (12), - a measuring cavity (40) arranged in the main body (12), which is fluidically connected to the exhaust tract (10) and in which a measuring electrode (44) is arranged, - an exhaust gas electrode (22) mounted on an outer side of the main body (12) and exposed to the exhaust gas flowing through the exhaust tract, which forms an amperometric measuring cell with the measuring electrode (44), - a reference cavity (50) arranged in the main body (12) and connected to the ambient air, in which a reference electrode (52) is arranged, and - a control device (XX) which is electrically connected to the measuring electrode (44), the exhaust gas electrode (22) and the reference electrode (52) and is designed to carry out a method for determining a corrected nitrogen oxide content in the exhaust gas flowing through the exhaust tract (10) of an internal combustion engine according to one of the preceding claims. [8] Exhaust gas sensor (20) according to claim 7, further comprising: - a first pump cavity (20) arranged in the main body (12), which is fluidically connected between the exhaust gas tract (10) and the measuring cavity (40) and in which a first pump electrode (24) is arranged, wherein the first pump electrode (24) forms an amperometric first pump cell with the exhaust gas electrode (22), and / or - a second pump cavity (30) arranged in the main body (12), which is fluidly connected between the first pump cavity (20) and the measuring cavity (40) and in which a second pump electrode (34) is arranged, wherein the second pump electrode (34) forms an amperometric second pump cell with the exhaust gas electrode (22). [9] Vehicle with an exhaust gas sensor (20) according to one of claims 7 and 8.

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