WO2012146422A1

WO2012146422A1 - Sensor apparatus for detecting a parameter of a flowing fluid medium

Info

Publication number: WO2012146422A1
Application number: PCT/EP2012/053596
Authority: WO
Inventors: Alexander Martin; Martin Schilling; Richard Fix; Marc Brueck; Tobias WOERZ
Original assignee: Robert Bosch Gmbh
Priority date: 2011-04-29
Filing date: 2012-03-02
Publication date: 2012-11-01
Also published as: DE102011017780A1

Abstract

The invention proposes a sensor apparatus (110) for detecting at least one parameter of a fluid medium flowing through a flow pipe (130) in a main flow direction (114). The sensor apparatus (110) (for example a lambda probe in the exhaust gas stream of a motor vehicle) comprises at least one housing (112) and at least one sensor element (126), which is introduced into the housing (112), for detecting the parameter. The housing (112) can be connected to the flow pipe (130). The housing (112) has at least one external housing (118) and at least one internal housing (120) which is at least partially surrounded by the external housing (118). At least one annular gap (122) is formed between the external housing (118) and the internal housing (120). The housing (112) is formed in such a way that the fluid medium can flow into the annular gap (122) in an axial direction in order to arrive at the sensor element (126) and then to flow back into the flow pipe (130) through the internal housing (120). At least one guide element (142) is arranged in the annular gap (122), said guide element being designed to at least largely prevent transverse flow transverse to the axial direction at least in one section of the annular gap (122).

Description

Description title

PRIOR ART The invention is based on known sensor devices for detecting at least one parameter of a flowing fluid medium, for example a gas and / or a liquid. Such sensor devices may in principle be designed to qualitatively and / or quantitatively detect one or more physical and / or chemical parameters. For example, this may be a qualitative and / or quantitative detection of a composition of the fluid medium, for example a qualitative and / or quantitative detection of at least one component of the fluid medium, for example a gas component. In this way, for example, specifically one or more components of the fluid medium can be detected. Examples of such sensor devices are devices which are used to detect a proportion, for example a concentration or a concentration

Partialdrucks, a gas component of a gas are arranged, for example, an exhaust gas of an internal combustion engine, for example, sensor devices, which are adapted to detect an oxygen content and / or a nitrogen oxide content in the gas. Such sensor devices are known for example in the form of so-called lambda probes and are for example in Robert Bosch GmbH:

Sensors in the motor vehicle, edition 2007, pages 154-159 described. Alternatively or additionally, other types of parameters of the flowing fluid medium may also be determined, for example one or more flow parameters or a pressure, a temperature or other properties of the gas or combinations of said parameters.

In many such sensor devices, in particular in the case of current exhaust gas sensors, at least one sensor element is generally used, for example an electrically heated, ceramic sensor element in the case of lambda probes. This at least one sensor element is usually, as described in the above-mentioned prior art, by one or more protective tubes from direct contact with the Flow of the fluid medium at least partially shielded. The main tasks of such thermowells consist in limiting a flow, for example, an exhaust gas mass flow, via the sensor element, in keeping condensed water away in an exhaust system from the sensor element, ie a protection against water hammer on a hot ceramic, which could lead to breakage of a sensor element, a Ensuring sufficient probe dynamics in the form of a fast

Gas exchange near the sensor element, and in a protection of the

Sensor element against mechanical stress, for example in a shoring.

The requirements for the protective tubes are partly in opposite directions. Thus, high dynamics can only be achieved by a sufficient flow velocity through the protective tube, which in turn makes water transport to the sensor element more probable and also increases cooling of the sensor element by the colder exhaust gas and / or heating of the sensor element by a hotter exhaust gas.

Many protective tubes, such as the protective tubes that protect the

Lambda probes are used in the above-described prior art, are geometrically configured as a double-protection tubes. Here, between a first and a second protective tube is a continuous annular gap whose

In some cases, the inlet cross-section is reduced by a so-called annular gap cover. In the context of investigations that led to the present invention, it has generally been shown that in conventional thermowells for

Sensor devices has a significant potential for improvement to the effect that flow conditions of the sensor element can change within the protective tubes depending on the exhaust gas flow. This change can have a considerable influence on the function of the sensor device and the associated sensor signal. It would therefore be desirable to have a sensor device in which such effects, which are dependent on the flow of the sensor device, do not occur or only to a greatly reduced extent.

Disclosure of Invention Accordingly, there is a sensor device for detecting at least one parameter of a main flow direction through a flow tube proposed flowing fluid medium, in particular for detecting at least one parameter of an exhaust gas of an internal combustion engine. With regard to the possible parameters to be detected, which can be detected qualitatively and / or quantitatively, reference may be made to the above description of the prior art. The flow tube may in particular be an exhaust pipe and / or an exhaust gas tract of an internal combustion engine. In the following, the invention will be described in particular with reference to sensor devices for qualitative and / or quantitative detection of a gas content in a gas, in particular for detecting an oxygen content and / or a nitrogen oxide content in the gas, but in principle also a variety of other configurations of the sensor device is possible ,

The sensor device comprises at least one housing and at least one sensor element introduced into the housing for detecting the parameter. Under a housing is generally a device to understand, which at least one

Interior encloses and which a protective function for one or more

Components of the sensor device exercises, which are accommodated in the at least one interior. In particular, the housing may be configured to provide a mechanical protection function. Alternatively or additionally, for example, protection against moisture, mechanical loads when installing the sensor device, thermal protection functions or others

Protective functions or combinations of said and / or other protective functions be given. Preferably, the housing may be arranged to ensure a protective effect against at least mechanical loads. For example, the housing may be at least partially made of a rigid material, which, for example, in a fixing of the housing in the flow tube of the fluid medium at normal forces, for example, at normal Verschraubungskräften, undergoes no deformation. The housing may for example be wholly or partly made of a metallic material and / or a plastic material.

A sensor element is understood to be an element which is set up to detect the at least one parameter and to generate at least one signal corresponding to this detection of the at least one parameter. For example, the sensor element may comprise at least one sensor chip and / or at least one ceramic layer structure. For example, the sensor element may comprise at least one sensor element which is based on the use of at least one Solid electrolyte based, in particular at least one ceramic solid electrolyte, such as zirconia. In this regard, reference may be made, for example, to the abovementioned lambda probes and, in particular, planar lambda probes. However, other embodiments of the sensor element are in principle possible.

The housing is connectable to the flow tube. For this purpose, the

Housing, for example, comprise at least one fixing element which is adapted to effect a mechanical fixation and / or stabilization of the housing relative to the flow tube.

The housing comprises at least one outer housing, in particular at least one outer tube. This outer housing can be made for example of a metallic material. Alternatively or additionally, however, other materials may also be used, for example ceramic materials and / or plastic materials. Under an outer tube is an element to understand, which is at least partially tubular, for example, as a hollow cylinder. Furthermore, the housing comprises at least one of the outer housing at least partially enclosed

Inner housing, in particular at least one inner tube. For example, you can

Outer casing and inner casing at least partially be tubular, wherein the outer casing, for example, the inner casing annular,

concentric, in particular. Between the outer housing and the inner housing at least one annular gap is formed, for example a

Cylinder annular gap. This annular gap can, for example, have a polygonal and / or an annular cross-section. The housing is designed such that the fluid medium in an axial direction, that is parallel to an axis of the

Sensor device and / or the housing, can flow into the annular gap.

For example, this axis may be aligned substantially perpendicular to the main flow direction of the fluid medium. The fluid medium should be able to flow into the annular gap in the axial direction in such a way that it can reach the sensor element and then flow back into the flow tube through the inner housing. For example, in the annular gap, a first flow path

be formed, which of the fluid medium in an axial direction of the

Flow pipe can be flowed away, wherein at the end of this flow path is a connection to the at least one sensor element, wherein the fluid medium, for example, with the sensor element and / or at least one

Measuring surface of the sensor element can come into contact and / or in the Sensor element can flow before the fluid medium can then flow in an opposite axial direction, for example in the direction of the flow tube, through the inner housing back into the flow tube. In that regard, the housing may for example correspond to known housings for sensor elements, for example according to the above-described prior art. In studies on such housings has been found that, especially when the annular gap is partially covered on the inlet side by an annular gap cover, can form a so-called rotation angle dependence in the flow through the annular gap. This can mean that, depending on the orientation of the annular gap cover relative to the main flow direction, for example the exhaust gas flow, a different flow field can form inside the annular gap and / or the entire housing, with a corresponding influence on the function of the sensor device. For example, due to a changed flow and a change in the pulse input, a flow with variation of the

Flow velocity no longer run axially and for example act on the flow-facing openings at the bottom of the annular gap, but the annular gap and, for example, the e.g. cylindrically designed inner housing at least partially flow around and act on the flow-facing openings in the annular gap. As a result of this changed loading of the sensor element with the fluid medium, measurements of the at least one parameter, for example, can change considerably.

Based on this knowledge will solve the problem mentioned

proposed that the sensor device comprises at least one guide element, which is arranged in the annular gap, wherein the guide element is adapted to a

Transverse flow transverse to the axial direction at least in a portion of the annular gap to prevent at least substantially. For example, a transverse flow can be prevented so far that the fluid medium in the region of at least one

Guide element in the annular gap can surround the annular gap to not more than a quarter in a circumferential direction, preferably not more than one-fifth and more preferably not more than a sixth. Under a guide element is to be understood an element having the said guiding action, for example an element having at least one guide surface to deflect the fluid medium in the annular gap in an axial direction and, for example, a pulse of the fluid Medium in a direction transverse to the axial direction, for example in a tangential direction to record.

The inner housing may in particular have at least one hollow cylindrical section, the outer housing preferably enclosing the hollow cylindrical section at least in sections.

The guide element may in particular be selected from the group consisting of a guide blade, in particular a planar guide blade; a baffle,

in particular a flat baffle; a guide wing, in particular a plane

Guide vanes. The terms guide blade, baffle and guide vanes are not distinguished below, and these terms uniformly means a planar element, with a lateral extent, which exceeds a thickness of this element considerably, for example by at least a factor of 2, preferably at least one factor 5, in particular at least a factor of 10 or even at least a factor 100. For example, the guide element may be made of a plastic material or a metallic material having a thickness of less than 2 mm,

in particular less than 1 mm, and a longitudinal extent of at least 5 mm or even at least 10 mm in one or both directions of the guide surfaces.

For example, the guide element can be configured as a planar guide element, ie as an element with two opposite guide surfaces with a rectangular cross section.

The guide element can extend in particular from an outer wall of the inner housing through the annular gap to an inner wall of the outer housing. This can mean that, at least in the section of the annular gap in which the guide element is arranged, the guide element completely fills the annular gap in the radial direction.

The guide element may in particular have at least one guide surface arranged substantially parallel to a radial direction of the sensor device.

For example, these may be the above-mentioned planar guide surfaces which are opposite one another, for example in the case of a rectangular guide element. A direction substantially parallel to a radial direction is to be understood as meaning a direction in which the guide surface deviates from a parallel orientation to the radial direction by no more than 20 °, preferably by not more than 10 ° and particularly preferably by not more than 5 ° or even not more than 2 ° or not more than 0 °. Under a radial direction is generally a direction perpendicular to an axis the sensor device to understand, for example, an axis which is aligned perpendicular to the main flow direction of the fluid medium.

The sensor device may in particular comprise a plurality of such guide elements, in particular a plurality of identically configured guide elements. For example, the plurality of guide elements can be arranged distributed equidistantly in the annular gap,

For example, as described above, substantially parallel to a radial direction and / or in the radial direction of the sensor device. The guide elements may divide at least a portion of the annular gap into at least two, preferably at least four, more preferably at least eight sectors,

For example, in twelve sectors. In particular, the sectors may cover an angular range of not more than 50 ° of the annular gap, preferably not more than 40 ° and more preferably not more than 30 °. The housing may in particular have at least one inflow opening of the annular gap, for example an annular inflow opening, which can enclose the inner housing on the circumferential side. The fluid medium can flow through the inlet opening into the annular gap. The inner housing can have at least one outflow opening, wherein the fluid medium can flow out of the inner housing into the flow tube through the outflow opening. For example, the outflow opening may have a cross section of a circular disk. For example, in a viewing direction parallel to an axis of the sensor device, the inflow opening can surround the outflow opening concentrically. The outflow opening can in particular be arranged further in the flow tube than the inflow opening. For example, as described above, at least one fixing element can be provided, by means of which the housing can be fixed in the flow pipe, so that the inflow opening and the outflow opening are arranged in the flow pipe, wherein the outflow opening projects further into the flow pipe than the inflow opening. The housing may in particular be arranged such that it can be fixed substantially perpendicular to the main flow pipe, in particular by means of at least one fixing element, wherein the guide element may preferably be oriented substantially perpendicular to the main flow direction. By substantially perpendicular to the main flow direction is meant in this context generally an orientation which is preferably 90 °, which, however, not more than 20 ° can deviate from 90 °, preferably by not more than 10 ° and more preferably by not more than 5 ° or even not more than 2 °.

In the at least one annular gap may further be arranged at least one throttle element, that is, an element which is adapted to accumulate the inflowing fluid medium and to cause a pressure increase in this area. In this way it can be ensured, for example, that there is a lower pressure at the outflow opening as a result of the Bernoulli effect than in the region of the inlet opening, which can provide a chimney effect and thus a flow through the housing in the direction from the inflow opening to the outflow opening. In particular, the at least one throttle element may comprise at least one throttle plate having a plurality of openings, wherein preferably, when the annular gap is divided into a plurality of sectors by the at least one guide element, in each case at least one opening may be provided for each sector. The throttle element may in particular directly in the annular gap connect to the guide element, so that, for example, the fluid medium directly from the guide element to the

Throttle element can get.

The sensor device with the features described above has a multiplicity of advantages over conventional sensor devices. So can

According to the invention, in particular an at least substantial independence of a flow through the housing of the sensor device from an angular position of the sensor housing with respect to a direction of flow or the main flow direction of the fluid medium and / or independence from a flow velocity are ensured. This makes it possible to significantly improve the reproducibility of the detection of the at least one parameter by means of the sensor device according to the invention. Also, at least one gap may be present between throttle element and guide element, which may lead to a homogenization of the flow and / or to a pressure equalization.

Brief description of the drawings

Embodiments of the invention are illustrated in the figures and are explained in more detail by way of example below.

Show it: FIGS. 1A and 1B show a sensor device with a conventional housing under different inflow conditions; and FIGS. 2 and 3 a sensor device according to the invention.

Embodiments of the invention

To illustrate the problem described above conventional

Sensor devices, in FIGS. 1A and 1B, a sensor device 1 10 is shown with a housing 112 which is flowed by a fluid medium, for example an exhaust gas, in a main flow direction 14. The fluid medium can by an annular inflow opening 116 between an outer housing 1 18, hereinafter also called outer tube, and an inner housing 120, hereinafter also called inner tube, in an annular gap 122 between the outer housing 1 18 and the

Flow inside housing 120, then flow in an axial direction parallel to an axis 124 of the sensor device 1 10 and the housing 1 12 downward, there get to a sensor element 126, not shown, and then through the inner housing 120 through in the reverse axial direction to a Outlet opening 128 reach.

FIGS. 1A and 1B show flow lines of the fluid medium which result from a flow simulation and which can symbolically represent the flow conditions in the housing 112. In this case, between the state in Figure 1A and the state in Figure 1 B, the flow velocity of a flow increased. Due to a thus increased impulse entry, the flow in the annular gap 122 no longer bends down vertically and no longer extends purely in the axial direction, but partially surrounds the annular gap 122. However, this means that, for example, openings arranged in the FIGS. 1A and 1B at the bottom of the annular gap 122 are differently charged with the fluid medium. By the reinforced

Flow around the inner housing 120 in the situation in Figure 1 B, for example, a side facing away from the flow of the annular gap 122 and / or openings in the region of this side facing away from the fluid medium acted as in the situation shown in Figure 1A. In contrast, FIGS. 2 and 3 show a sensor device 110 according to the invention. 2 shows a sectional view of the sensor device 1 10 in a plane parallel to a main flow direction 114 of the fluid medium and parallel to an axis 124 of the sensor device 1 10, and Figure 3 shows a perspective view looking towards an inlet opening 16 and an outflow opening 128th the sensor device 110. Both representations are described together below.

Again, the sensor device 110, analogous to Figures 1A and 1B, a housing 112 with an outer housing 1 18 and an inner housing 120, wherein between the outer housing 118 and the inner housing 120, an annular gap 122 is formed. At the bottom of the annular gap, the sensor element 126 is shown symbolically. However, in contrast to the chip-shaped sensor element 126 shown here, at least one differently configured sensor element 126 may be located in this region, for example at least one planar ceramic sensor element, for example with a longitudinal extension parallel to the axis 124.

As can be seen in FIG. 2, the outflow opening 128 is preferably further in the interior of a flow tube 130 which is separate from the fluid medium in the flow tube

Main flow direction 1 14 is flowed through, arranged as the inflow opening 116. This can, for example, by one or more in Figure 2 only indicated

Fixing elements 132 take place, by means of which the sensor device 110 in the

Flow tube 130 is fixed, for example by one or more

Glands. As a rule, the fluid medium continues inside the

Flow tube 130 has a higher flow velocity, formed in this way preferably from a chimney effect. In this way prevails in the region of the outflow opening 128 preferably a lower pressure than in the region of

Inflow port 1 16, where a higher pressure due to the accumulation effect can occur.

For example, the fluid medium, in particular the exhaust gas flow, on the inner housing 120 projecting beyond the outer housing 118, in particular, for example, over an outer protective tube, in particular above a second protective tube, in the region above the inflow opening 116, in particular of the

Ringpaltenintritts be dammed, for example, as stagnation point flow and / or congestion zone, and thereby be delayed. With this delay, in particular by a reduction in the flow rate may be accompanied by an increase in static pressure. This can lead to the formation of an overpressure zone in the region above the inflow opening 16, in particular above the annular gap opening.

Furthermore, as indicated above, an available free cross-section in the flow tube 130, in particular an exhaust pipe, by the installation of the

Sensor device 1 10, in which the sensor element 126 is introduced, can be reduced. In this case, a minimal cross section may be located, in particular in a section transverse to the main flow direction 1 14 of the fluid medium, in particular of the exhaust gas, through an axis of symmetry of the sensor device 110, for example as a probe. The fluid medium, in particular the flow, can be accelerated with decreasing cross section. As a result, for example, a drop in the static pressure to follow. Thus, above the

Outlet opening 128, in particular above an end hole, for example, an outlet opening of an inner protective tube, in particular of the inner housing 120, set a negative pressure zone.

The pressure difference between the storage zone above the inflow opening 116, in particular the annular gap inlet, and the vacuum zone above the outflow opening 128, in particular the front hole, for example, may be a driving force for a probe flow. This preferably depends only on the flow, in particular of the fluid medium, and can hardly or not at all be influenced, for example, by means of "probe-internal" measures, however, for example, this predetermined pressure difference can be applied to different proportions

flowing through sections in the probe interior, in particular in the interior of the

Sensor device 110, to be allocated. In the interior of the annular gap 122, preferably at its lower end, at least one throttle element 134 may be provided, for example a throttle plate having a plurality of openings 136. For example, with the aid of a twisting apparatus, which, for example, the throttle element 134 and / or a drier several of the guide elements 142, such an allocation of the components of the pressure difference take place. The twisting apparatus can be designed in such a way, for example by varying gap widths of the guide elements 142, in particular vanes, and / or by varying the diameter of the openings 136, in particular of holes, that a high flow resistance can be present. The annular gap 122 may in particular comprise a gap. The gap can be partially, preferably completely circulate around the annular gap. The gap can be located in particular between the guide elements 142 and the throttle elements 134. Due to the gap, for example, the baffles do not end on the throttle element 134, but at a certain distance, for example at a distance of 0.5 mm to 5 mm, in particular at a distance of 1 mm to 3 mm. The gap can in particular cause an adjustment of a pressure equalization above the twisting apparatus. Through this

Pressure equalization, in particular a uniform flow through several, in particular all openings 136, in particular all openings 136 of the twisting apparatus, are possible. Without gap could due to a deflection of the inflow in the annular gap 122, the area of the twisting apparatus, which in a plan view of the

Sensor device 110, in particular the probe, for example below the

Overpressure zone and / or the storage zone may be due to a high pulse of the registered flow, for example, more with the fluid medium, in particular gas, are applied as areas laterally on a circumference. The twisting apparatus can, in particular the guide elements 142 and / or the throttle element 134, in particular through the gap to equalize the flow through a portion of the

Openings 136 or all openings 136 are configured leader.

Due to the pressure difference, the fluid medium flows on a first flow path 138, as indicated in Figure 2, through the inflow opening 1 16 in the annular gap 122, passes through the openings 136 at the lower end of the annular gap 122, device in contact with the sensor element 126 and flows subsequently via a second flow path 140 in the interior of the inner housing 140 again in the axial direction upward through the outflow opening 128 back into the flow tube 130th

In order to prevent or at least reduce the inflow effect described above, at least one guide element 142, which is set up in the annular gap 122, is provided in the sensor device 110 according to FIGS. 2 and 3

Cross flow transverse to the axial direction at least in a portion of the annular gap 122 to reduce or prevent. This guide element 142 is configured in the illustrated embodiment in the form of several, for example, rectangular baffles 144, which are aligned parallel to the axis 124 and which are visible in Figure 3. These baffles 144, which preferably extend over the entire height of the annular gap 122 or preferably over at least 40% of this height, subdivide the annular gap 122 into sectors 146, preferably equidistantly. For example, as shown in FIG. 3, twelve baffles 144 may be provided, so that the Annular gap 122 is divided into twelve equal sectors with an angle of 30 ° of the annular gap 122. For example, each sector 146 is associated with exactly one or more openings 136 in the restrictor 134 at the lower end of the annular gap 122.

According to the invention, the annular gap 122 between the inner housing 120 and the outer housing 118 can be subdivided into separate sections, referred to here as sectors 146, by means of the guide elements 142, for example by means of the guide plates 144. These can provide a geometrically small division of the annular gap cross-section, For example, in a division with respect to the axis 124 in rotationally symmetric

Sectors 146 and chambers, and thus for a directed flow guidance. The baffles are located in the annular gap 122 between the inner housing 120 and the outer housing 1 18. They can, for example, begin immediately at the inlet opening 1 16, so for example at an upper edge of the outer housing 1 18 and outer protective tube. The guide elements 142 may, for example, to the bottom of the

Annular gaps 122 extend or even above this bottom end and leave a space for a transverse exchange of the flow. This division is preferably not more than 30 ° to a small angle of rotation dependence at a rotation of the

Housing 112 to ensure the axis 124. The guide elements 142, for example, the baffles 144, preferably on the outer housing 1 18 and outer

Protective tube and / or on the inner housing 120 or inner protective tube or on a housing bottom 1 12 or the throttle element 134 may be attached or introduced as a separate component in the annular gap 122. The guide elements 142, for example the baffles 144, which may each have at least one guide surface 148, in this case in each case two mutually opposite guide surfaces 148, can by their sewer effect for suppressing a pulse transverse exchange of the flowing into the annular gap 122 mass of the fluid medium , For example, the incoming gas mass, provide, and thus for a parallel to the axis 124 in the direction of an annular gap floor directed flow. An envelope in the flow around the inner housing 120 at higher

Flow velocity, such as in Figures 1A and 1B, can thus be at least largely prevented.

Claims

Sensor device (1 10) for detecting at least one parameter of a fluid medium flowing with a main flow direction (1 14) through a flow tube (130), comprising at least one housing (1 12) and at least one sensor element (126) inserted into the housing (1 12) ) for detecting the parameter, wherein the housing (1 12) with the flow tube (130) is connectable, wherein the housing (1 12) at least one outer housing (1 18) and at least one of the outer housing (1 18) at least partially enclosed inner housing (120), wherein between the outer housing (1 18) and the inner housing (120) at least one annular gap (122) is formed, wherein the housing (1 12) is formed such that the fluid medium in an axial direction in the annular gap (122) can flow to get to the sensor element (126) and

then flowing back through the inner housing (120) back into the flow tube (130), wherein in the annular gap (122) at least one guide element (142) is arranged, wherein the guide element (142) is adapted to a transverse flow transverse to the axial direction at least in a portion of the annular gap (122) to prevent at least substantially.

Sensor device (1 10) according to the preceding claim, wherein the guide element (142) extends from an outer wall of the inner housing (120) through the annular gap (122) to an inner wall of the outer housing (1 18).

Sensor device (1 10) according to one of the preceding claims, wherein the guide element (142) at least one substantially parallel to a radial

Having direction of the sensor device (110) arranged guide surface (148).

Sensor device (1 10) according to one of the preceding claims, wherein a plurality of guide elements (142) are provided, wherein the guide elements (142) are distributed equidistantly in the annular gap (122).

Sensor device (110) according to one of the preceding claims, wherein a plurality of guide elements (142) in the annular gap (122) are arranged, wherein the guide elements (142) divide at least a portion of the annular gap (122) in at least two sectors (146).

6. sensor device (110) according to the preceding claim, wherein the sectors (146) each overlap an angle Ibereich of not more than 50 ° of the annular gap (122), in particular of not more than 40 ° and more preferably of not more than 30 ° ,

7. Sensor device (1 10) according to one of the preceding claims, wherein the housing (1 12) at least one inflow opening (1 16) of the annular gap (122), wherein the fluid medium through the inflow opening (116) into the annular gap (122). can flow, wherein the inner housing (120) at least one

Outflow opening (128), wherein the fluid medium through the outflow opening (128) from the inner housing (120) can flow out into the flow tube (130), wherein the outflow opening (128) is arranged further in the flow tube (130) than the inflow opening (128). 116).

8. Sensor device (1 10) according to any one of the preceding claims, wherein the housing (1 12) is arranged such that this is substantially perpendicular to the main flow direction (1 14) fixable, in particular by means of at least one fixing element (132).

9. sensor device (1 10) according to any one of the preceding claims, wherein in the annular gap (122) further at least one throttle element (134) is arranged, in particular at least one throttle plate having a plurality of openings (136), preferably in each case at least one opening (136 ) for each sector.

10. Sensor device (1 10) according to the preceding claim, wherein the

Throttle element (134) in the annular gap (122) directly adjoins the guide element (142).