CN109891211B - Sensor element for sensing particles of a measurement gas in a measurement gas chamber - Google Patents
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- CN109891211B CN109891211B CN201780065827.2A CN201780065827A CN109891211B CN 109891211 B CN109891211 B CN 109891211B CN 201780065827 A CN201780065827 A CN 201780065827A CN 109891211 B CN109891211 B CN 109891211B
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- 238000005259 measurement Methods 0.000 title claims abstract description 41
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- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- 238000012544 monitoring process Methods 0.000 description 5
- 238000004092 self-diagnosis Methods 0.000 description 5
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 4
- 238000002485 combustion reaction Methods 0.000 description 4
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- 229910044991 metal oxide Inorganic materials 0.000 description 4
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- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
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- 235000013980 iron oxide Nutrition 0.000 description 2
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- 229910052574 oxide ceramic Inorganic materials 0.000 description 2
- 239000011224 oxide ceramic Substances 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/06—Investigating concentration of particle suspensions
- G01N15/0656—Investigating concentration of particle suspensions using electric, e.g. electrostatic methods or magnetic methods
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/06—Investigating concentration of particle suspensions
- G01N15/0606—Investigating concentration of particle suspensions by collecting particles on a support
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N2015/0042—Investigating dispersion of solids
- G01N2015/0046—Investigating dispersion of solids in gas, e.g. smoke
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- Dispersion Chemistry (AREA)
- Physics & Mathematics (AREA)
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- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
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- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
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Abstract
The invention proposes a sensor element (110) for sensing particles of a measurement gas in a measurement gas chamber. The sensor element (110) comprises a carrier (112), wherein a first electrode arrangement (114) and a second electrode arrangement (116) are applied to the carrier (112), wherein the first electrode arrangement (114) and the second electrode arrangement (116) each have a plurality of electrode fingers (118), wherein each electrode finger (118) of the first electrode arrangement (114) is connected to at least one electrode finger (116) of the second electrode arrangement (118) via at least one terminating resistor (120).
Description
Background
A plurality of sensor elements for sensing particles of a measurement gas in a measurement gas chamber are known from the prior art. The measurement gas may be, for example, an exhaust gas of an internal combustion engine. In particular, the particles may be soot or dust particles. The invention will be explained below with particular reference to a sensor element for detecting soot particles, without limiting the further implementation and method of use.
Two or more metal electrodes can be mounted on an electrically insulating carrier. Particles, in particular soot particles, which accumulate under the action of a voltage form a conductive bridge between the electrodes, for example, of interdigitated electrodes which are embedded in a comb-like manner, in the collection phase of the sensor element, and these electrodes are thereby short-circuited. In the recovery phase, the electrodes are typically self-cleaning burned by means of an integrated heating element. Typically, particle sensors analyze the electrical properties of the process electrode structure that change due to particle accumulation. For example, a decreasing resistance or an increasing current can be measured when a voltage is constantly applied.
Sensor elements which operate according to this principle are generally denoted as resistive sensors and are present in various embodiments, which are known, for example, from DE 103 19 664 A1, DE 10 2006 042 362 A1, DE 103 53 860 A1, DE 101 49 333 A1 and WO 2003/006976 A2. Sensor elements configured as soot sensors are commonly used for monitoring diesel particulate filters. In the exhaust system of an internal combustion engine, a particle sensor of the type mentioned is usually received in a protective pipe, which at the same time allows the exhaust gas to flow through the particle sensor.
Due to increased environmental awareness and also partly due to legal regulations, soot emissions must be monitored during driving and the functionality of the monitoring ensured. This type of monitoring of functionality is commonly referred to as On-board diagnostics (On-board diagnostics). Devices and methods for the self-diagnosis of particle sensors are known, for example, from DE 10 2009 028 239 A1, DE 10 2009 028 283 A1, DE 2007 046 096 A1, DE 10 2006 042 605 A1 and US 2012/0119759 A1.
Despite these advantages of the sensor elements for sensing particles known from the prior art, the sensor elements also have the potential for improvement. It is therefore difficult to achieve legally required self-monitoring of soot sensors, in particular in terms of electrical functionality. In particular, continuous monitoring, preferably at a certain predetermined minimum frequency, for example at a frequency of at least 2Hz, is a challenge. Furthermore, parasitic effects, such as the impedance of the cable bundle to be measured together, can make self-diagnosis difficult. Accumulations with unknown electrical properties, for example on the electrode arrangement, can lead to a superposition of the desired measurement effects. Furthermore, the known method and/or the known device may have the following disadvantages: in the event of a fault, a complete fault is always detected even if the electrode arrangement is still partially operating normally in the event of a partial fault, in particular, for example, if it is still 90% operating normally.
Disclosure of Invention
It is therefore proposed within the scope of the present invention to provide a sensor element for sensing particles of a measurement gas in a measurement gas chamber. Within the scope of the present invention, a sensor element is understood to mean any device which is suitable for qualitatively and/or quantitatively sensing particles and which is capable of generating an electrical measurement signal, for example a voltage or a current, corresponding to the sensed particles by means of a suitable control unit and suitably configured electrodes. The sensed particles may be, inter alia, soot particles and/or dust particles. In this case, DC signals and/or AC signals can be used. Furthermore, for example, a resistive component and/or a capacitive component can be used for signal evaluation by the impedance.
The sensor element can be provided in particular for use in a motor vehicle. In particular, the measurement gas may be an exhaust gas of a motor vehicle. In principle other gases and gas mixtures are also possible. In principle, the measurement gas chamber can be any open or closed chamber in which the measurement gas is received and/or through which the measurement gas flows. For example, the measurement gas chamber may be an exhaust of an internal combustion engine, for example a combustion engine.
The sensor element comprises a carrier, wherein a first electrode arrangement and a second electrode arrangement are applied to the carrier. The first electrode arrangement and the second electrode arrangement each have a plurality of electrode fingers, wherein each electrode finger of the first electrode arrangement is connected to at least one electrode finger of the second electrode arrangement via at least one terminating resistor.
Within the scope of the present invention, a carrier is understood to mean in principle any substrate which is suitable for carrying the first electrode arrangement and the second electrode arrangement and/or to which the first electrode arrangement and the second electrode arrangement can be applied. Within the scope of the present invention, an electrode arrangement is understood to mean in principle any electrical conductor which is suitable for current and/or voltage measurement and/or which can apply at least one element in contact with the electrode arrangement with voltage and/or current. In the context of the present invention, the term "electrode" is understood to mean "any shape of the electrode arrangement on the primary side, the dimension of which in one dimension significantly exceeds the dimension in at least one further dimension, for example by a factor of at least 2, preferably by a factor of at least 3, particularly preferably by a factor of at least 5. In the context of the present invention, "plurality" is understood in principle to mean any number of at least two.
In the context of the present invention, a terminal resistance is understood to mean in principle any resistance which connects at least one electrode finger of the first electrode arrangement to at least one electrode finger of the second electrode arrangement in such a way that, in the absence of accumulated particles, in particular in the absence of accumulated soot or dust particles, a measurable current flows between the first electrode arrangement and the second electrode arrangement when a voltage is applied to the first electrode arrangement and the second electrode arrangement. In particular, with an applied voltage of 5 to 60V, the measurable current can have a current value of 0.1 μ Α to 10 μ Α when the operating temperature of the sensor element is in the temperature interval of 50 ℃ to 500 ℃.
The at least one terminating resistor can contact at least one section of the electrode fingers of the first electrode arrangement and at least one section of the electrode fingers of the second electrode arrangement. Within the scope of the present invention, a section of an electrode finger is understood to mean in principle any section of an electrode finger. In particular, the at least one terminating resistor can also contact one or more or all sections of all electrode fingers of the first electrode arrangement and one or more or all sections of all electrode fingers of the second electrode arrangement.
The at least one terminating resistor can be applied to the carrier, for example, as a discrete component. However, the at least one terminating resistor can also be formed as a doped region within the carrier, which doped region is also explained in more detail below. In a particularly preferred embodiment of the sensor element according to the invention, the at least one terminating resistance can be configured such that, in the absence of accumulated particles, in particular in the absence of accumulated soot or dust particles, preferably at the operating temperature of the sensor element, the total electrode resistance lies in the range from 1M Ω to 150M Ω, preferably in the range from 2M Ω to 75M Ω, and particularly preferably in the range from 5M Ω to 50M Ω. In the context of the present invention, the term "total electrode resistance" is understood to mean the resistance of the circuit formed by the first electrode arrangement, by the second electrode arrangement, by the at least one terminating resistor and, if appropriate, by further components. Based on the low resistance of the two electrode arrangements, the total resistance of the electrodes generally substantially comprises the termination resistance, or for the case where a plurality of termination resistances is present, the sum of these termination resistances.
In the context of the present invention, the expression "connected via a terminal resistor" is understood in principle to mean that each electrode finger of the first electrode arrangement is in electrical contact with at least one electrode finger of the second electrode arrangement by means of the terminal resistor.
The carrier can comprise at least one ceramic material as carrier material. In particular, the support can comprise an oxide ceramic, preferably comprising alumina, in particular comprising Al 2 O 3 . However, other oxides, such as zirconia, are also possible. Furthermore, the carrier can comprise at least one electrically insulating material. The carrier can have a carrier surface. Within the scope of the present invention, a support surface is understood to mean in principle any layer which separates the support from its surroundings and to which the first and second electrode arrangements are applied.
The carrier can comprise at least one doped region, wherein the doped region contacts at least one section of the electrode fingers of the first electrode arrangement and at least one section of the electrode fingers of the second electrode arrangement. In particular, the doped region can also contact one or more or all sections of all electrode fingers of the first electrode arrangement and one or more or all sections of all electrode fingers of the second electrode arrangement. In the context of the present invention, the term "contact" is understood in principle to mean that two objects are in direct contact. In particular, two objects can be in electrical contact.
In the context of the present invention, a doped region is understood to mean in principle any region of the carrier which has impurity atoms, in particular metal atoms, introduced into the ceramic material, wherein the metal impurity atoms replace a part of the metal atoms contained in the ceramic material of the carrier. The doped region can thus comprise at least one doped support material, in particular aluminum oxide doped with a metal oxide. However, other oxides are also possible, in particular those which also serve as doping material.
The carrier can thus be doped with a doping material in the at least one doping region, wherein a doping material denotes an oxidized doping material provided with metal impurity atoms. In particular, the concentration of the doping material in the at least one doping region can have a value of 1mol% to 100mol%, preferably 10mol% to 90mol%, particularly preferably 20mol% to 80 mol%. In a particular embodiment, the carrier material can be completely replaced by the doping material in the doped region.
The doping material can preferably comprise a metal oxide, wherein the doping material is preferably selected from the group consisting of iron oxides, in particular Fe 2 O 3 ；ZrO 2 ；Cr 2 O 3 ；MgO；MnO；Sm 2 O 3 ；Tb 4 O 7 ；Gd 2 O 3 ；Y 2 O 3 And any mixture of these materials.
In a particularly preferred embodiment, the support can have Al 2 O 3 And the doped region can have 20mol% to 100mol% Fe 2 O 3 Preferably with 40 to 80mol% Fe 2 O 3 In particular because the mixed oxides of the ceramics thus achieved have a suitable conductivity.
In a further preferred embodiment, the oxide Sm 2 O 3 ；Tb 4 O 7 ；Gd 2 O 3 And/or Y 2 O 3 Is suitable for doping. In this case, the doping with a combination of at least two oxides can also prove advantageous, for example, in order to achieve the lowest possible temperature characteristic curve (temperature) of the electrical resistance of the doped support material within the selected temperature window. The concentration of the individual dopants in the at least one doped region can have a value of 0mol% to 100mol%, respectivelyFor example, sm in a ratio of 25%/50%/0%/25% is particularly advantageously used 2 O 3 /Tb 4 O 7 /Gd 2 O 3 /Y 2 O 3 The combination of materials of (1). However, other ratios are possible.
The width of the doped region can be in the range from 10 μm to 2mm, preferably from 25 μm to 500 μm and particularly preferably from 50 μm to 250 μm. Furthermore, the length of the doped region can lie in the range from 10 μm to 2mm, preferably from 25 μm to 500 μm and particularly preferably from 50 μm to 250 μm. Furthermore, the thickness of the doped region can lie in the range from 0.1 μm to 100 μm, preferably from 1 μm to 50 μm, particularly preferably from 2 μm to 20 μm.
In the context of the present invention, the width of the doped region is understood in principle as the dimension of the doped region in a spatial dimension which is parallel to the carrier surface and perpendicular to the main direction of extension of the electrode fingers with which the doped region is in contact. In the context of the present invention, the length of the doped region is understood in principle as the dimension of the doped region in a spatial dimension parallel to the carrier surface and parallel to the main direction of extension of the electrode fingers with which the doped region is in contact. In the context of the present invention, the thickness of the doped region is understood in principle as the dimension of the doped region in the spatial dimension extending perpendicular to the carrier surface.
The conductivity of the at least one doped region can be in the range of 1 x 10 over a temperature interval of 50 ℃ to 500 ℃ in the absence of accumulated particles -9 (Ωcm) -1 To 10 (Ω cm) -1 Preferably 1X 10 -8 (Ωcm) -1 To 1X 10 -2 (Ωcm) -1 Particularly preferably 1X 10 -7 (Ωcm) -1 To 1X 10 -3 (Ωcm) -1 Within the range of (1).
The electrode fingers of the first electrode arrangement and/or the second electrode arrangement can have a meandering course. Within the scope of the present invention, a meandering course is understood to mean in principle any course of the electrode arrangement on the surface of the carrier, which has at least one S-shape and/or at least one serpentine shape and/or at least one meandering. In addition, the electrode fingers of the first electrode arrangement and the electrode fingers of the second electrode arrangement can be engaged with each other in a comb-like manner.
The electrode fingers of the first electrode arrangement can have a spacing relative to one another, wherein the spacing of the electrode fingers of the first electrode arrangement within the sensor element can be constant or at least vary over a portion of the sensor element. The electrode fingers of the second electrode arrangement can likewise have a spacing relative to one another, wherein the spacing of the electrode fingers of the second electrode arrangement within the sensor element can be constant or at least vary over a portion of the sensor element. The electrode fingers of the first electrode arrangement can have a spacing relative to the electrode fingers of the second electrode arrangement, wherein the spacing can be constant within the sensor element or at least vary over a portion of the sensor element.
The sensor element can have at least two terminal resistances. The termination resistances can have different values. But the termination resistances can also all have the same value. In the case of different values, the assignment of the error with respect to which region can be carried out if necessary, and thus a correction function in the control unit can be carried out, which enables the region-dependent compensation of the error with greater accuracy in the signal evaluation process.
The terminating resistor can be located entirely in a region of the sensor element, which can also be referred to as a "cold region" of the sensor element and to which no particles of the measurement gas are applied. The cold region of the sensor element can in particular comprise the side with the terminal contacts for the cable bundle and is usually separated from the hot exhaust gas by means of a sealing package and is therefore also cooler. However, the termination resistance can be located at least partially in a region of the sensor element, which can also be referred to as a "hot region" of the sensor element and to which particles of the measurement gas are applied. There may be actual measurement ranges for the electrodes; the stamped electrode leads can be mounted in the transition region. Furthermore, the termination resistor can be located at least partially in the controller. Placing the termination resistor at least partially in the controller enables a higher temperature stability than a termination resistor placed outside the controller.
In the case of a sensor element according to the invention having only a single terminating resistor, this terminating resistor can be arranged in the control unit. This enables a higher temperature stability compared to a termination resistor arranged outside the controller. However, this terminating resistor can also be located in the region of the sensor element to which no gas particles are applied. Furthermore, this terminating resistor can also be located in the region of the sensor element to which the gas particles are applied.
The sensor element can be configured in particular as a soot particle sensor. Furthermore, the sensor element can be received in at least one protective tube.
In a further aspect of the invention, a method for producing a sensor element for sensing particles of a measurement gas in a measurement gas chamber is proposed, which method comprises the following steps, preferably in a given sequence. In principle, other sequences are also possible. Furthermore, it is also possible to repeat one or more or all of the method steps. Furthermore, two or more method steps can also be carried out completely or partially overlapping in time or simultaneously. In addition to the method steps mentioned, the method can also comprise further method steps. The method comprises the following steps:
a) Providing a carrier;
b) Applying a first electrode arrangement and a second electrode arrangement to the carrier, wherein the first electrode arrangement and the second electrode arrangement have a plurality of electrode fingers;
c) At least one terminating resistor is produced on or in the carrier, wherein each electrode finger of the first electrode arrangement is connected to at least one electrode finger of the second electrode arrangement via the at least one terminating resistor.
The method can be used in particular for producing a sensor element according to the invention, i.e. according to one of the embodiments described above or according to one of the embodiments described in more detail below. Correspondingly, for the definition and alternative configurations, reference can be made to the description of the sensor element to a large extent. However, other configurations are also possible in principle.
In step c), a thick-layer technique can be used for applying a termination resistance to the carrier, or doping of the carrier can be carried out for producing at least one doped region in the carrier. When using thick-layer technology for producing the terminating resistor, the terminating resistor can be printed as a discrete component on a carrier, in particular on a ceramic substrate.
The proposed device and the proposed method have a number of advantages with respect to the known devices and methods. By means of the configuration according to the invention of the electrode arrangement, in particular of the electrode structure, the self-diagnostic capability of the sensor element for sensing particles of the measurement gas in the measurement gas chamber can be improved compared to the prior art. In particular, the electrode fingers of the first electrode arrangement and the electrode fingers of the second electrode arrangement can be monitored separately, in particular at a frequency of at least 2 Hz. In particular, in the event of a failure of one or several electrode fingers, this can be detected and the sensor element can be used on the basis of the remaining, intact electrode fingers.
Furthermore, in particular in the event of a failure of one or more electrode fingers, the accuracy, in particular the measurement accuracy, can be increased by means of the sensor element according to the invention compared to the prior art. In the event of a partial fault being detected, compensation of the measurement signal can be carried out, in particular, in accordance with a reduced sensitivity of the sensor element, as long as the sensitivity is not below a minimum value.
Furthermore, the number of electrode fingers can be selected as large as possible. In this way, in the event of a fault, a distinction can be made between the faulty region and the sound region to the greatest possible extent. It is possible in particular that, in the case of a large number of electrode fingers, the failure of a single electrode finger or of several electrode fingers has only a small effect. In particular, a malfunction of one or a small number of electrode fingers can be compensated for, in particular, with a low sensitivity loss.
Furthermore, the terminating resistor can be located in a region to which no measurement gas particles are applied, in particular in a cold or colder region of the sensor element. Furthermore, the terminating resistor can also be located in the controller, which enables a high temperature stability.
Furthermore, it is possible that no further changes are required to implement the electrode arrangement to the terminating resistance when using thick-layer technology, in particular when using existing thick-layer technology.
Drawings
Further optional details and features of the invention are given by the following description of preferred embodiments, which are schematically illustrated in the drawings. The figures show:
fig. 1 to 3 show various exemplary embodiments of a sensor element according to the invention, wherein the sensor element is shown in a plan view;
FIG. 4 is a graph of the dependence of the total resistance of the electrodes or the self-diagnostic current on the number of electrode fingers for a fault in the sensor element; and
fig. 5 to 6 are cross-sectional views of different embodiments of a sensor element according to the invention.
Detailed Description
Fig. 1 to 3 show different embodiments of a sensor element 110 according to the invention for sensing particles of a measurement gas in a measurement gas chamber in plan view. Fig. 4 shows the electrode total resistance 128 and the dependence of the self-diagnosis current 126 on the number of faulty electrode fingers 132 in the form of a diagram 130, wherein the diagram 130 relates to the embodiment of the sensor element 110 according to the invention shown in fig. 3. In fig. 5 and 6, different embodiments of a sensor element 110 according to the invention for sensing particles of a measurement gas in a measurement gas chamber are shown. These figures will be set forth together below.
The sensor element 110 can be provided, in particular, for use in a motor vehicle. In particular, the measurement gas may be an exhaust gas of a motor vehicle. The sensor element 110 can comprise, in particular, one or more further functional elements not shown in the figures, such as electrodes, electrode leads and contacts, layers, heating elements, electrochemical cells or other elements, as is shown in the above-mentioned prior art. Furthermore, the sensor element 110 can be received, for example, in a protective tube, which is likewise not illustrated.
The sensor element 110 comprises a carrier 112, wherein a first electrode arrangement 114 and a second electrode arrangement 116 are applied to the carrier 112. The first electrode arrangement 114 and the second electrode arrangement 116 have a plurality of electrode fingers 118, wherein each electrode finger 118 of the first electrode arrangement 114 is connected to at least one electrode finger 118 of the second electrode arrangement 116 via at least one terminating resistor 120.
As shown in fig. 5, the at least one terminating resistor 120 can be applied to the carrier 112 as a discrete component. However, as shown in fig. 6, the at least one terminating resistor 120 can also be formed as a doped region 122 within the carrier 112, which is described in more detail below.
In these preferred embodiments, the carrier 112 can comprise at least one ceramic material as a carrier material. In particular, the support 112 can comprise alumina, in particular Al 2 O 3 . Furthermore, the carrier 112 can comprise at least one electrically insulating material.
The carrier 112 can comprise at least one doped region 122, wherein, as shown in fig. 6, this doped region 122 contacts at least one section of the electrode fingers 118 of the first electrode arrangement 114 and at least one section of the electrode fingers 118 of the second electrode arrangement 116. In particular, the doped region 122 can also contact a section or sections of all electrode fingers 118 of the first electrode arrangement 114 and a section or sections of all electrode fingers 118 of the second electrode arrangement 116. The section of the electrode finger 118 of the first electrode arrangement 114 contacting the doped region 122 and the section of the electrode finger 118 of the second electrode arrangement 116 contacting the doped region can be in electrical contact with this doped region 122.
The carrier 112 can have impurity atoms, in particular metal atoms, introduced into the ceramic material in the at least one doping region 122, wherein the metal impurity atoms replace a part of the metal atoms contained in the ceramic material of the carrier 112. Thus, the doped region 122 can comprise at least one doped ceramic material, in particular aluminum oxide doped with a metal oxide. However, other oxides are also possible. Thus, the carrier 112 can be doped with a doping material in the at least one doping region 122Wherein the dopant represents an oxide ceramic provided with metal impurity atoms. The doping material can preferably comprise a metal oxide, wherein the doping material is preferably selected from the group consisting of iron oxides, in particular Fe 2 O 3 ；ZrO 2 ；Cr 2 O 3 ；MgO；MnO、Sm 2 O 3 、Tb 4 O 7 、Gd 2 O 3 、Y 2 O 3 And any mixture of these materials.
Furthermore, the doping material can have a concentration of 1mol% to 100mol%, preferably 10mol% to 90mol%, particularly preferably 20mol% to 80mol%, in the at least one doped region 122. In particular, the carrier 112 can have Al 2 O 3 And the doped region 122 can have 40 to 80mol% Fe 2 O 3 。
The width b of the doped region 122 can lie in the range from 10 μm to 2mm, preferably from 25 μm to 500 μm, particularly preferably from 50 μm to 250 μm. Furthermore, the length of the doped region can lie in the range from 10 μm to 2mm, preferably from 25 μm to 500 μm, particularly preferably from 50 μm to 250 μm. Furthermore, the thickness d of the doped region can lie in the range from 0.1 μm to 100 μm, preferably from 1 μm to 50 μm, particularly preferably from 2 to 20 μm. The width b and thickness d of the doped region are shown in fig. 6. The conductivity of the at least one doped region may be at 1 x 10 in the temperature interval of 50 ℃ to 500 ℃ in the absence of accumulated particles -9 (Ωcm) -1 To 10 (Ω cm) -1 Preferably 1X 10 -8 (Ωcm) -1 To 1X 10 -2 (Ωcm) -1 Particularly preferably 1X 10 -7 (Ωcm) -1 To 1 × 10 -3 (Ωcm) -1 Within the range of (1).
The electrode fingers 118 of the first electrode arrangement 114 and/or the electrode fingers 118 of the second electrode arrangement 116 can have a meandering course 124. Fig. 1 and 2 show two examples of meandering runs 124. The electrode fingers 118 of the first electrode arrangement 114 and the electrode fingers 118 of the second electrode arrangement 116 can have a plurality of further meandering runs. Furthermore, as shown in fig. 1-3, 5 and 6, the electrode fingers 118 of the first electrode arrangement 114 and the electrode fingers 118 of the second electrode arrangement 116 can be comb-like fitted to each other.
As shown in fig. 1-3, 5, and 6, the sensor element 110 can have at least two termination resistances 120. The termination resistance 120 can have different values. The termination resistors 120 can all have the same value.
The electrode fingers 118 of the first electrode arrangement 114 can have a spacing a relative to one another, wherein the spacing a of the electrode fingers 118 of the first electrode arrangement 114, as shown in fig. 3, can be constant within the sensor element 110 or can vary at least over a portion of the sensor element 110. The electrode fingers 118 of the second electrode arrangement 116 can have a spacing c relative to one another, wherein the spacing c of the electrode fingers 118 of the second electrode arrangement 116, as shown in fig. 3, can be constant within the sensor element 110 or can vary at least over a portion of the sensor element 110. The electrode fingers 118 of the first electrode arrangement 114 can have a spacing e relative to the electrode fingers 118 of the second electrode arrangement 116, wherein the spacing e can be constant within the sensor element 110, as shown in fig. 3, or can vary at least over a portion of the sensor element 110.
The terminating resistor 120 can be located entirely in the region of the sensor element 110 to which particles of the measurement gas are not applied. However, the terminating resistor 120 can be located at least partially in the region of the sensor element 110 to which the particles of the measurement gas are applied. Furthermore, one or more of the existing termination resistors 120 can be located in a controller not shown in the figures.
In the context of the present invention, the total resistance of the electrodes is understood to be the resistance of the circuit formed by the first electrode arrangement, by the second electrode arrangement, by the at least one terminating resistor and, if appropriate, by further structural elements. The total electrode resistance can be in the range from 1 M.OMEGA.to 150 M.OMEGA.preferably in the range from 2 M.OMEGA.to 75 M.OMEGA.and particularly preferably in the range from 5 M.OMEGA.to 50 M.OMEGA.. Based on the low resistance of the two electrode arrangements, the total resistance of the electrodes generally substantially comprises the terminal resistance or, in the case of a plurality of terminal resistances, the sum of these terminal resistances, which is denoted R below ges 。
The total resistance R of the termination resistances 120 for the embodiment of the sensor element 110 shown in fig. 3 having a total of n electrode fingers 118 according to the invention can be calculated in particular in the following manner ges ：
Wherein the first electrode arrangement 114 has a number of n/2 electrode fingers 118, wherein the second electrode arrangement 116 also has a number of n/2 electrode fingers 118, and wherein each electrode finger 118 of the first electrode arrangement 114 is passed through at least one terminating resistor R i (120) Is connected to at least one electrode finger 118 of the second electrode arrangement. Terminal resistor R i 120 can all have the same value R 0 . The following total resistance R results for this case ges The calculation method of (2):
R ges /R 0 ＝1/n (3)
furthermore, the total resistance R for the embodiment of the sensor element 110 shown in fig. 3 according to the invention having m faulty electrode fingers 118 with a total of n electrode fingers 118 can be calculated in the following manner ges ，
Wherein the first electrode arrangement 114 has a number n/2 of possibly intact or at least partially defective electrode fingers 118, wherein the second electrode arrangement 116 likewise has a number n/2 of possibly intact or at least partially defective electrode fingers 118, and wherein each electrode finger 118 of the first electrode arrangement 114 is connected via at least one terminating resistor R i 120 is connected to at least one electrode finger 118 of the second electrode arrangement: terminal resistance R i 120 can all beHave the same value R 0 . The following total resistance R results for this case ges The calculation method of (2):
R ges /R 0 ＝1/(n-m) (6)
the sensor element 110 can be configured in particular as a soot particle sensor. Furthermore, the sensor element 110 can be received in at least one protective tube, which is not shown in the figures.
For self-diagnosis, a measurement voltage can be applied at least temporarily between the first electrode arrangement 114 and the second electrode arrangement 116, and a self-diagnosis current 126 and/or a total electrode resistance 128 can be measured. The self-diagnostic current 126 flows through the first electrode arrangement 114, the second electrode arrangement 116 and the at least one terminating resistor 120. The self-diagnostic current 126 can be a measure of the functionality of the sensor element 110 and/or the quality of the sensor element 110.
Fig. 4 illustrates a graph 130 in which the self-diagnostic current 126 is shown in relation to the number of faulty electrode fingers 132, and the total electrode resistance 128 is shown in relation to the number of faulty electrode fingers 132. The diagram 130 in fig. 4 relates to the embodiment of the sensor element 110 shown in fig. 3. Current 134 is plotted with respect to the number of failed electrode fingers 132, and resistance 136 is plotted with respect to the number of failed electrode fingers 132.
Claims (12)
1. A sensor element (110) for sensing particles of a measurement gas in a measurement gas chamber, wherein the sensor element (110) comprises a carrier body (112), wherein a first electrode arrangement (114) and a second electrode arrangement (116) are applied to the carrier body (112), wherein the first electrode arrangement (114) and the second electrode arrangement (116) each have a plurality of electrode fingers (118), wherein each electrode finger (118) of the first electrode arrangement (114) is in electrical contact with at least one electrode finger (118) of the second electrode arrangement (116) via at least one of a plurality of terminating resistors (120), wherein the plurality of terminating resistors (120) are applied to the carrier body (112) as discrete components.
2. The sensor element (110) according to claim 1, wherein the carrier (112) comprises at least one doped region (122), wherein the doped region (122) contacts at least one section of an electrode finger (118) of the first electrode arrangement (114) and at least one section of an electrode finger (118) of the second electrode arrangement (116).
3. The sensor element (110) according to claim 2, wherein the carrier (112) is doped with at least one doping material in the at least one doping region (122), wherein the doping material is selected from the group consisting of iron oxide, zrO, and combinations thereof 2 、Cr 2 O 3 、MgO、MnO、Sm 2 O 3 、Tb 4 O 7 、Gd 2 O 3 And Y 2 O 3 And (4) forming.
4. The sensor element (110) according to claim 3, wherein the doping material is present in the at least one doped region (122) in a concentration of 1mol% to 100 mol%.
5. The sensor element (110) according to any one of claims 2 to 4, wherein the at least one doped region (122) has a width of 10 μm to 2mm and/or a length of 10 μm to 2mm and/or a thickness of 0.1 μm to 100 μm.
6. The sensor element (110) according to any of claims 2 to 4, wherein the at least one doped region (122) has a1 x 10 temperature range within 50 ℃ to 500 ℃ -9 (Ωcm) -1 To 10 (Ω cm) -1 The conductivity of (a).
7. The sensor element (110) according to any one of claims 1 to 4, wherein the sensor element (110) has at least two termination resistances (120).
8. The sensor element (110) according to claim 7, wherein the at least two termination resistances (120) respectively have different values from each other.
9. The sensor element (110) according to claim 7, wherein the at least two termination resistances (120) have the same value.
10. The sensor element (110) according to any one of claims 1 to 4, wherein the termination resistance (120) is introduced into a controller.
11. The sensor element (110) according to any one of claims 1 to 4, wherein the total electrode resistance is at least the resistance of the first electrode arrangement (114), the resistance of the second electrode arrangement (116) and the total resistance R of the at least one termination resistance (120) ges Has a value of 1 to 150M omega.
12. Method for manufacturing a sensor element (110) for sensing particles of a measurement gas in a measurement gas chamber, wherein the method comprises the steps of:
a) Providing a carrier (112);
b) Applying a first electrode arrangement (114) and a second electrode arrangement (116) to the carrier (112), wherein the first electrode arrangement (114) and the second electrode arrangement (116) comprise a plurality of electrode fingers (118);
c) Producing a plurality of terminating resistors (120) on or in the carrier (112), wherein each electrode finger (118) of the first electrode arrangement (114) is in electrical contact with at least one electrode finger (118) of the second electrode arrangement (116) via at least one of the plurality of terminating resistors (120), wherein the plurality of terminating resistors (120) are stamped as discrete components onto the carrier (112).
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102016220832.2 | 2016-10-24 | ||
| DE102016220832.2A DE102016220832A1 (en) | 2016-10-24 | 2016-10-24 | Sensor element for detecting particles of a measuring gas in a measuring gas chamber |
| PCT/EP2017/075907 WO2018077615A1 (en) | 2016-10-24 | 2017-10-11 | Sensor element for detecting particles of a measuring gas in a measuring gas chamber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109891211A CN109891211A (en) | 2019-06-14 |
| CN109891211B true CN109891211B (en) | 2023-02-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201780065827.2A Active CN109891211B (en) | 2016-10-24 | 2017-10-11 | Sensor element for sensing particles of a measurement gas in a measurement gas chamber |
Country Status (4)
| Country | Link |
|---|---|
| KR (1) | KR20190071719A (en) |
| CN (1) | CN109891211B (en) |
| DE (1) | DE102016220832A1 (en) |
| WO (1) | WO2018077615A1 (en) |
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| DE102006042605A1 (en) * | 2006-09-11 | 2008-03-27 | Robert Bosch Gmbh | Sensor element for gas sensors and method for operating the same |
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| DE10149333B4 (en) | 2001-10-06 | 2007-06-28 | Robert Bosch Gmbh | Sensor device for measuring the humidity of gases |
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| DE102006042362A1 (en) | 2006-09-08 | 2008-03-27 | Robert Bosch Gmbh | Sensor unit for gas sensor i.e. soot sensor, has sub units arranged parallel to each other with respect to main surfaces, and electrical lines overlapped to each other and separated from each other by gap that is open for gas mixture |
| DE102007046096A1 (en) | 2007-09-26 | 2009-04-02 | Robert Bosch Gmbh | Method for the self-diagnosis of a particle sensor, suitable particle sensors for carrying out the method and their use |
| DE102009028239A1 (en) | 2009-08-05 | 2011-02-10 | Robert Bosch Gmbh | Method and device for self-diagnosis of a particle sensor |
| DE102009028283B4 (en) | 2009-08-06 | 2023-07-27 | Robert Bosch Gmbh | Method and device for self-diagnosis of a particle sensor |
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| US8823401B2 (en) * | 2012-03-30 | 2014-09-02 | Delphi Technologies, Inc. | Particulate matter sensor with two pairs of sensing electrodes and methods of using same |
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2016
- 2016-10-24 DE DE102016220832.2A patent/DE102016220832A1/en not_active Withdrawn
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2017
- 2017-10-11 WO PCT/EP2017/075907 patent/WO2018077615A1/en active Application Filing
- 2017-10-11 KR KR1020197011708A patent/KR20190071719A/en not_active IP Right Cessation
- 2017-10-11 CN CN201780065827.2A patent/CN109891211B/en active Active
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| DE102006042605A1 (en) * | 2006-09-11 | 2008-03-27 | Robert Bosch Gmbh | Sensor element for gas sensors and method for operating the same |
| DE102007021910A1 (en) * | 2007-05-10 | 2008-11-20 | Robert Bosch Gmbh | Sensor for detecting particles in a gas stream |
| CN102257383A (en) * | 2008-12-22 | 2011-11-23 | 罗伯特·博世有限公司 | Sensor array comprising a temperature probe |
| DE102009000077A1 (en) * | 2009-01-08 | 2010-07-15 | Robert Bosch Gmbh | Particle sensor for detecting conductive particles in gas flow, has measuring cell and electrode system with one electrode, another electrode and semi-conducting or small conducting material |
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Also Published As
| Publication number | Publication date |
|---|---|
| WO2018077615A1 (en) | 2018-05-03 |
| DE102016220832A1 (en) | 2018-04-26 |
| KR20190071719A (en) | 2019-06-24 |
| CN109891211A (en) | 2019-06-14 |
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