GB2551710A

GB2551710A - Housing for sensor assembly of after treatment system

Info

Publication number: GB2551710A
Application number: GB1611010.8A
Authority: GB
Inventors: A Niaz Naseer
Original assignee: Perkins Engines Co Ltd
Current assignee: Perkins Engines Co Ltd
Priority date: 2016-06-24
Filing date: 2016-06-24
Publication date: 2018-01-03
Anticipated expiration: 2036-06-24
Also published as: GB201611010D0; GB2551710B

Abstract

A housing (30) for a sensor assembly (24) of an after treatment system comprises a base (52) for mounting the sensor assembly, and two ducts (62, 64) for fluidly communicating with two ports on the sensor assembly (40, 42). Further two external ports (66, 70) are suitable for fluidly communicating with two ends of an after treatment module, for example of a diesel engine exhaust particle filter (DPF) system. Optionally, the sensor assembly is coupled to the housing in a removable manner, and the ducts/conduits split and branch to form further ports. Further, the housing may include fluid chambers, and the inlet ports may comprise movable, angularly adjustable ducts.

Description

(71) Applicant(s):

Perkins Engines Company Limited (Incorporated in the United Kingdom) Eastfield, PETERBOROUGH, PE1 5FQ, United Kingdom (72) Inventor(s):

Naseer A Niaz (56) Documents Cited:

WO 2016/035903 A1 US 20120304452 A1 (58) Field of Search:

INT CL F01N, G01D, G10L Other: WPI, EPODOC

US 7162927 B1 US 20050103115 A1 (74) Agent and/or Address for Service:

Caterpillar Legal Services Division Perkins Engines Company Limited, PETERBOROUGH, Cambridgeshire, PE1 5FQ, United Kingdom (54) Title of the Invention: Housing for sensor assembly of after treatment system Abstract Title: Housing for sensor assembly of an after treatment system (57) A housing (30) for a sensor assembly (24) of an after treatment system comprises a base (52) for mounting the sensor assembly, and two ducts (62, 64) for fluidly communicating with two ports on the sensor assembly (40, 42). Further two external ports (66, 70) are suitable for fluidly communicating with two ends of an after treatment module, for example of a diesel engine exhaust particle filter (DPF) system. Optionally, the sensor assembly is coupled to the housing in a removable manner, and the ducts/conduits split and branch to form further ports. Further, the housing may include fluid chambers, and the inlet ports may comprise movable, angularly adjustable ducts.

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FIG. 2

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FIG. 3

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FIG. 4

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FIG. 5

-1HOUSING FOR SENSOR ASSEMBLY OF AFTER TREATMENT SYSTEM

Technical Field

The present disclosure relates to a housing for a sensor assembly, and more specifically to the housing for the sensor assembly of an after treatment system.

Background

Engines, such as diesel engines, are equipped with an exhaust after treatment system. The exhaust after treatment system includes multiple after-treatment modules, such as a diesel particulate filter (DPF). Over a period of time, the DPF plugs with diesel particulate matter due to exhaust gas passing through the DPF. Generally, a differential pressure sensor assembly is coupled with an inlet and an outlet of the DPF to measure a pressure difference across the DPF. Typically, the differential pressure sensor assembly includes a housing for enclosing a sensor element, and a pair of inlet ports extending vertically from the housing. Such vertical orientation of the pair of inlet ports, while connecting the housing across the DPF, may result in increased installed height of the pressure sensor assembly with respect to other components of the after treatment systems. Thus, such a distant location of the differential pressure sensor assembly with respect to the DPF may cause high load and acceleration in the pressure sensor assembly during an operation of the engine. This may demand a differential pressure sensor assembly which is highly durable. Further, such specific vertical orientation of the pair of inlet ports may constrain packaging of the after treatment system.

US Patent Number 6,993,976, hereinafter referred to as the ’976 patent, describes a pressure measuring device. The pressure measuring device includes a housing in which a carrier equipped with a sensor element and electrical connection elements are located. The housing is made up of a housing chamber that encloses the sensor element and is connected with a first pressure channel of a first pressure connection. The housing also includes a sensor body chamber that is sealed off from the housing chamber and encloses the electrical connection

-2elements. The housing has a third housing chamber that is sealed off from the housing chamber and the sensor body chamber. The third housing chamber is connected with a second pressure channel of a second pressure connection. However, the housing, as disclosed in the ’976 patent, has a complex design which may increase cost of the pressure measuring device. Further, the pressure measuring device may not be easily retrofitted with existing arrangement of after treatment system.

Summary of the Disclosure

In one aspect of the present disclosure, a housing for a sensor assembly of an after treatment system of an engine is provided. The sensor assembly includes a pair of sensing elements and a pair of fluid passages in communication with the pair of sensing elements. The housing includes a first surface adapted to couple with a base portion of the sensor assembly, a second surface opposite to the first surface, and a third surface extending between the first surface and the second surface. The housing further includes a first passage extending from at least one of the second surface and the third surface to the first surface, and a second passage extending from at least one of the second surface and the third surface to the first surface. The first passage and the second passage are adapted to fluidly communicate with the pair of fluid passages of the sensor assembly. The housing further includes a first port adapted to fluidly communicate the first passage with a first end of an after-treatment module of the after treatment system, and a second port adapted to fluidly communicate the second passage with a second end of the after-treatment module.

In another aspect of the present disclosure, a housing for a sensor assembly in fluid communication with a fluid conduit is provided. The sensor assembly includes a first fluid passage and a second fluid passage. The sensor assembly is adapted to determine an operational characteristic of fluid flowing through the fluid conduit. The housing includes a first chamber having a first inlet port and a first outlet port. The first inlet port is in fluid communication with a first end of the fluid conduit and the first outlet port is in fluid communication with the first

-3fluid passage of the sensor assembly. The housing further includes a second chamber having a second inlet port and a second outlet port. The second inlet port is in fluid communication with a second end of the fluid conduit and the second outlet port is in fluid communication with the second fluid passage of the sensor assembly. The first chamber and the second chamber are fluidly disconnected from each other.

Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

Brief Description of the Drawings

FIG. 1 is a perspective view of a portion of an exemplary after treatment system of an engine;

FIG. 2 is a schematic view of a housing for a sensor assembly coupled with a Diesel Particulate Filter (DPF) of the after treatment system, according to one embodiment of the present disclosure;

FIG. 3 is a schematic exploded sectional view of an assembly of the housing and the sensor assembly of FIG. 2, according to one embodiment of the present disclosure;

FIG. 4 is a schematic sectional view of a housing coupled with the sensor assembly, according to another embodiment of the present disclosure; and

FIG. 5 is a schematic perspective view of a housing coupled with the sensor assembly, according to yet another embodiment of the present disclosure.

Detailed Description

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts. Referring to FIG. 1, a perspective view of a portion of an exemplary after treatment system 10 of an engine 12 is illustrated. The after treatment system 10 may be implemented in the engine 12

-4to treat exhaust gas exiting an exhaust manifold (not shown) of the engine 12. The after treatment system 10 is disposed on the engine 12 and is fluidly connected to the exhaust manifold of the engine 12 to receive the exhaust gas. The exhaust gas may contain emission compounds, such as Nitrogen Oxides (NOx), unburned hydrocarbons, particulate matter and other combustion products. The after treatment system 10 may include various after treatment modules, such as Diesel Particulate Filter (DPF), Selective Catalytic Reduction (SCR), and Diesel Oxidation Catalyst (DOC) for removing unburned hydrocarbons, particulate matter, or other combustion products from the exhaust gas before discharging to atmosphere.

As shown in FIG. 1, the after treatment system 10 includes an after-treatment module 14, such as the DPF. The DPF 14 is disposed within a casing 18 of the after treatment system 10 to receive the exhaust gas. The DPF 14 collects particulate matter from the exhaust gas received from the engine 12. The DPF 14 includes a first end 20 and a second end 22. The first end 20 of the DPF 14 receives the exhaust gas and the filtered exhaust gas exits through the second end 22. The DPF 14 includes a filter media (not shown) disposed within the first end 20 and the second end 22 and in fluid communication with the first end 20 and the second end 22. The filter media filters the particulate matter from the exhaust gas received through the first end 20 before discharging the exhaust gas to atmosphere through the second end 22. In particular, the particulate matter present in the exhaust gas is filtered out or removed from the exhaust gas, when the exhaust gas flows through the filter media. An accumulation of the particulate matter within the DPF 14 may generate a differential pressure across the DPF 14 over a period of time.

Referring to FIG. 1, the after treatment system 10 includes a sensor assembly 24 that determines the differential pressure across the DPF 14. The sensor assembly 24 is mounted on the DPF 14 by a bracket 26. The bracket 26 is mounted on the casing 18 of the after treatment system 10 by a pair of fastening members 28.

-5Although, the sensor assembly 24, as shown in FIG. 1, is mounted on the DPF 14, it should be understood that the sensor assembly 24 may be remotely mounted at any location in the engine 12. The sensor assembly 24 is configured to measure an operational characteristic, such as the pressure of the exhaust gas flowing through the DPF 14. More specifically, the operational characteristic is the differential pressure measured across the DPF diesel particulate filter. In order to measure the differential pressure across the DPF 14, the sensor assembly 24 is adapted to fluidly communicate with the exhaust gas either entering or leaving the DPF 14. In an example, the sensor assembly 24 is in fluid communication with the exhaust gas flowing through the first end 20 and the second end 22 of the DPF 14. A housing 30 is attached to the sensor assembly 24 to fluidly couple the sensor assembly 24 with the DPF 14. Specifically, the housing 30 is connected to the first end 20 and the second end 22 of the DPF 14 via a first fluid line 48 and a second fluid line 50.

FIG. 2 illustrates a schematic view of the housing 30 coupled with the sensor assembly 24 of the after treatment system 10. For the illustration purpose of the present disclosure, various internal components of the housing 30 and the sensor assembly 24 are shown in hidden lines in FIG. 3. The sensor assembly 24 includes a pair of sensing elements, individually referred to as a first sensing element 36 and a second sensing element 38, and a sensor body 34 for enclosing the pair of sensing elements. The first sensing element 36 and the second sensing element 38 is configured to determine a pressure of the exhaust gas flowing through the first end 20 and the second end 22 of the DPF 14Examples of the first and second sensing elements 36, 38 may include, but not limited to, pressure transducers.

The sensor body 34 further includes a pair of fluid passages 39 in communication with the first sensing element 36 and the second sensing element 38. The pair of fluid passages 39 includes a first fluid passage 40 and a second fluid passage 42. The first fluid passage 40 is in fluid communication with the first sensing element

-636 and the second fluid passage 42 is in fluid communication with the second sensing element 38. The first fluid passage 40 and the second fluid passage 42 further extend from a base portion 46 defined in the sensor body 34 of the sensor assembly 24. The base portion 46 engages with the housing 30 to fluidly couple the sensor assembly 24 with the DPF 14. The sensor body 34 further includes a pair of through holes 37 for mounting the sensor assembly 24 on the bracket 26, and a receptacle portion 44 for coupling with an electrical connector (not shown). The electric connector may be in communication with a power source and/or a control unit, such as an Engine Control Unit (ECU) (not shown).

FIG. 3 illustrates a schematic sectional exploded view of an assembly of the housing 30 and the sensor assembly 24. Sectional view of the housing 30 and the sensor assembly 24 is shown in FIG. 3 for illustration purpose of the present disclosure. The housing 30 includes a first surface 52 for coupling with the base portion 46 of the sensor assembly 24, and a second surface 54 opposite to the first surface 52. In an example, the housing 30 is permanently coupled to the base portion 46 of the sensor assembly 24. In another example, the housing 30 is removably coupled to the base portion 46 of the sensor assembly 24. The first surface 52 may include a first threaded section that may engage with a second threaded section of the base portion 46. In another example, the first surface 52 may include a first connecting portion that may engage with a second connecting portion of the base portion 46 to couple the housing 30 with the sensor assembly 24. In yet another example, the housing 30 may include one or more through holes extending from the second surface 54 to the first surface 52 such that the housing 30 may be fastened to the sensor assembly 24 by fastening members, such as bolts. In yet another example, the housing 30 and the sensor assembly 24 may be welded together. Further, one or more sealing members may be disposed between the first surface 52 and the base portion 46 for providing a fluid tight connection between the base portion 46 of the sensor assembly 24 and the first surface 52 of the housing 30.

-7The housing 30 also includes a third surface 56 that extends between the first surface 52 and the second surface 54. The housing 30 further includes a first passage 58 and a second passage 60 defined at a first end 62 and a second end 64, respectively, of the housing 30. The first passage 58 extends from the third surface 56 to the first surface 52 at the first end 62 and the second passage 60 extends from the third surface 56 to the first surface 52 at the second end 64. The first passage 58 is adapted to fluidly communicate with the first fluid passage 40 of the sensor assembly 24 and the second passage 60 is adapted to fluidly communicate with the second fluid passage 42 of the sensor assembly 24. In particular, the first passage 58 and the second passage 60 are aligned with the first fluid passage 40 and the second fluid passage 42, respectively, of the sensor assembly 24 for obtaining fluid communication therebetween, when the housing 30 is assembled with the sensor assembly 24.

In order to fluidly communicate the first passage 58 with the first end 20 of the DPF 14, the housing 30 includes a first port 66. The first port 66 is defined by a first duct 68 extending from the third surface 56 along an axis XX’ of the housing 30. The first duct 68 is disposed at the first end 62 of the housing 30. In one example, the first duct 68 may be an integral member of the housing 30 and extend from the third surface 56 along the first passage 58. In another example, the first duct 68 may be an external member coupled with the third surface 56 of the housing 30 at the first end 62 and aligned with the first passage 58. It should be noted that the first duct 68, and hence the first port 66, may be inclined at an angle with respect to the axis XX’. Further, additionally or alternatively, the first port 66 may be defined in the second surface 54 of the housing 30.

In order to fluidly communicate the second passage 60 of the housing 30 with the second end 22 of the DPF 14, the housing 30 includes a second port 70. The second port 70 is defined by a second duct 72 extending from the third surface 56 along the axis XX’ of the housing 30. The second duct 72 is disposed at the second end 64 of the housing 30. In one example, the second duct 72 may be an

-8integral member of the housing 30. In another example, the second duct 72 may be an external member coupled with the third surface 56 of the housing 30 at the second end 64. It should be noted that the second duct 72, and hence the second port 70, may be inclined at an angle with respect to the axis XX’. Further, additionally or alternatively, the second port 70 may be defined in the second surface 54 of the housing 30.

Referring to FIGS. 2 and 3, the first port 66 of the housing 30 is in fluid communication with the first end 20 of the DPF 14 through the first fluid line 48. The first port 66 also communicates with the first fluid passage 40 of the sensor assembly 24 through the first passage 58. In particular, the first port 66, the first passage 58 and the first fluid passage 40 provide a fluid communication between the first end 20 of the DPF 14 and the first sensing element 36. Similarly, the second port 70 of the housing 30 is in fluid communication with the second end 22 of the DPF 14 through the second fluid line 50. The second port 70 also communicates with the second fluid passage 42 of the sensor assembly 24 through the second passage 60. In particular, the second port 70, the second passage 60 and the second fluid passage 42 provide a fluid communication between the second end 22 of the DPF 14 and the second sensing element 38. Hence, the first sensing element 36 and the second sensing element 38 are exposed to the exhaust gas present at the first end 20 and the second end 22 of the DPF 14, respectively, to determine the differential pressure across the DPF 14. In an example, the control unit that is in communication with the first sensing element 36 and the second sensing element 38 may determine the differential pressure across the DPF 14 based on signals received from the first sensing element 36 and the second sensing element 38.

FIG. 4 illustrates a schematic sectional view of a housing 74 coupled with the sensor assembly 24, according to another embodiment of the present disclosure. The housing 74 is a hollow body having a first wall 76 that couples with the base portion 46 of the sensor assembly 24. The housing 74 includes a second wall 78

-9opposite to the first wall 76, and a third wall 80 extending between the first wall 76 and the second wall 78. The first wall 76, the second wall 78 and the third wall 80 together define a hollow chamber. The housing 74 further includes a wall member 86 disposed within the hollow chamber and extend between the first wall 76 and the second wall 78. Thus, a first chamber 82 and a second chamber 84 are defined in the housing 74. The first chamber 82 and the second chamber 84 are fluidly disconnected from each other by the wall member 86.

The first chamber 82 is adapted to fluidly communicate with the first end 20 of the DPF 14 (shown in FIG. 1). The first chamber 82 also includes a first inlet port 88. The first inlet port 88 is defined by a first duct 89 extending from the second wall 78 of the housing 74. The first inlet port 88 is angularly adjustable about a plane “A-A” passing through a center of the first inlet port 88. Specifically, the first inlet port 88 is angularly adjustable between a first position ‘Pl’ and a second position ‘P2’ about the plane “A-A”. The first chamber 82 includes an additional first inlet port 87 defined in the third wall 80 at a first end 75 of the housing 74. The additional first inlet port 87 is defined by a second duct 81 extending from the third wall 80 of the housing 74.

During assembly of the housing 74 with the DPF 14, one of the first inlet port 88 and the additional first inlet port 87 is connected to the first fluid line 48 to fluidly communicate the first end 20 of the DPF 14 with the first chamber 82. The first chamber 82 also includes a first outlet port 90 defined in the first wall 76 of the housing 74. The first outlet port 90 communicates with the first fluid passage 40 of the sensor assembly 24 such that the exhaust gas received from the first fluid line 48 (shown in FIG. 1) enters the first fluid passage 40 through the first outlet port 90.

Further, the second chamber 84 is adapted to fluidly communicate with the second end 22 of the DPF 14 (shown in FIG. 1). The second chamber 84

-10includes a second inlet port 91. The second inlet port 91 is defined by a third duct 92 extending from the second wall 78 of the housing 74. The second inlet port 91 is angularly adjustable about a plane “B-B” passing through a center of the second inlet port 91. Specifically, the second inlet port 91 is angularly adjustable between a third position ‘P3’ and a fourth position ‘P4’ about the plane “B-B”. The second chamber 84 also includes an additional second inlet port 85 defined in the third wall 80 at a second end 77 of the housing 74. The additional second inlet port 85 is defined by a fourth duct 83 extending from the third wall 80 of the housing 74.

During assembly of the housing 74 with the DPF 14, one of the second inlet port 91 and the additional second inlet port 85 is connected to the second fluid line 50 to fluidly communicate the second end 22 of the DPF 14 with the second chamber 84. The second chamber 84 also includes a second outlet port 93 defined in the first wall 76 of the housing 74. The second outlet port 93 communicates with the second fluid passage 42 of the sensor assembly 24 such that the exhaust gas received from the second fluid line 50 enters the second fluid passage 42 through the second chamber 84. Hence, the first sensing element 36 and the second sensing element 38 are exposed to the exhaust gas present at the first end 20 and the second end 22 of the DPF 14, respectively, to determine the differential pressure across the DPF 14.

FIG. 5 illustrates a schematic perspective view of a housing 94 coupled with the sensor assembly 24, according to yet another embodiment of the present disclosure. The housing 94 includes a first surface 95 adapted to couple with the base portion 46 of the sensor assembly 24, and a second surface 96 opposite to the first surface 95. The housing 94 also includes a third surface 97, a fourth surface 98 and a front surface 99. The front surface 99, the third surface 97, and the fourth surface 98 extend between the first surface 95 and the second surface 96. The housing 94 further includes a first passage 100 in fluid communication with the first fluid passage 40 of the sensor assembly 24. The first passage 100 — 11— extends from the first surface 95 and branches to the second surface 96, the third surface 97, and the front surface 99. As such, the first passage 100 includes a first portion 100A extending from the first surface 95, and a second portion 100B extending from the first portion 100A to the third surface 97. The first passage 100 also includes a third portion (not shown) that extends from the first portion 100A to the second surface 96, and a fourth portion (not shown) that extends fro the first portion 100A to the front surface 99.

The housing 94 also includes a first port 101 in fluid communication with the second portion 100B of the first passage 100, a second port (not shown) in fluid communication with both the third portion of the first passage 100, and a third port (not shown) in fluid communication with the fourth portion of the first passage 100. The first port 101 is defined by a first duct 102 extending from the third surface 97. The second port is defined by a second duct 103 and a third duct 104 extending from the front surface 99. Further, the fourth port is defined by a fourth duct 105 extending from the second surface 96. In order to fluidly communicate the sensor assembly 24 with the DPF 14, one of the first port 101, the second port, and the third port is fluidly coupled to the first fluid line 48.

The housing 94 further includes a second passage 106 in fluid communication with the second fluid passage 42 of the sensor assembly 24. The second passage 106 extends from the first surface 95 and branches to the second surface 96, the fourth surface 98 and the front surface 99. As such, the second passage 106 includes a first portion 106A extending from the first surface 95, a second portion (not shown) extending from the first portion 106A to the fourth surface 98, a third portion (not shown) extending from the first portion 106A to the front surface 99, and a fourth portion (not shown) that extends from the first portion 106A to the second surface 96. The housing 94 also includes a first port (not shown) in fluid communication with the second portion of the second passage 106, a second port (not shown) in fluid communication with the third portion of the second passage 106, and a third port (not shown) in fluid communication with the fourth portion

-12of the second passage 106. The first port is defined by a first duct 111 extending from the fourth surface 98. The second port is defined by a second duct 112 and a third duct 113 extending from the front surface 99. Further, the fourth port is defined by a fourth duct 114 extending from the second surface 96. In order to fluidly communicate the sensor assembly 24 with the DPF 14, one of the first port, the second port, the third port, and the fourth port is fluidly coupled to the second fluid line 50.

Although the housings 30, 74, and 94 are described to mount the sensor assembly 24 across the DPF 14, it may be understood that the sensor assembly 24 along with one of the housings 30, 74, and 94 may be mounted with a fluid conduit, such as the DPF 14, for determining a pressure difference across the fluid conduit.

Industrial Applicability

Embodiments of the present disclosure have applicability in mounting the sensor assembly 24 in or on the after treatment system 10. As described earlier, the housings 30, 94, and 74 include the first surfaces 52, and 95, and the first wall 76, respectively, that are adapted to couple with the base portion 46 of the sensor assembly 24. In one embodiment, the housings 30 includes the first port 66 and the second port 70 that are connected to the first fluid line 48 and the second fluid line 50 for receiving the exhaust gas from the first end 20 and the second end 22, respectively, of the DPF 14. In another embodiment, the housing 74 includes the first inlet port 88, the additional first inlet port 87, the second inlet port 91 and the additional second inlet port 85. Based on a space available within the after treatment system 10, one of the first inlet port 88, the and the additional first inlet port 87 is connected to the first fluid line 48 in order to fluidly communicate the sensor assembly 24 with the first end 20 of the DPF 14. Similarly, one of the second inlet port 91 and the additional second inlet port 85 is connected to the second fluid line 50 in order to fluidly communicate the sensor assembly 24 with the second end 22 of the DPF 14. In yet another embodiment, the sensor assembly 24 may be connected with the first end 20 of the DPF 14 via one of the

-13first port 101, the second port, the third port, and the fourth port of the first passage 100. Likewise, the sensor assembly 24 may be connected with the second end 22 of the DPF 14, via one of the first port, the second port, the third port, and the fourth port of the second passage 106.

Therefore, the housings 30, 74, and 94 of the present disclosure provide flexibility in connecting the sensor assembly 24 at any location within the after treatment system 10. The housings 30, 74 and 94 may be conveniently retrofitted to existing sensor assemblies. The first surfaces 52, 76, and 95 of the housings 30, 74 and 94 may be removably or permanently coupled with the sensor assembly 24. Various housings, such as the housings 30, 94, and 74 may be manufactured and used to mount the existing assemblies. The housings 30, 94, and 74 also facilitates mounting of the sensor assembly 24 at a lower height within the after treatment system 10 based on a space available in the after treatment system 10. Specifically, the housings 30, 74, and 94 may be conveniently retrofitted in existing arrangement of the after treatment system 10. Further, the housings 30, 74, and 94 have simple design which may reduce a number of components and cost of the after treatment system 10.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

Claims

Claims What is claimed is:

1. A housing for a sensor assembly of an after treatment system of an engine , the sensor assembly including a pair of sensing elements and a pair of fluid passages in communication with the pair of sensing elements, the housing comprising:

a first surface adapted to couple with a base portion of the sensor assembly;

a second surface opposite to the first surface;

a third surface extending between the first surface and the second surface;

a first passage extending from at least one of the second surface and the third surface to the first surface;

a second passage extending from at least one of the second surface and the third surface to the first surface, wherein the first passage and the second passage are adapted to fluidly communicate with the pair of fluid passages of the sensor assembly;

a first port adapted to fluidly communicate the first passage with a first end of an after-treatment module of the after treatment system; and a second port adapted to fluidly communicate the second passage with a second end of the after-treatment module.

2. The housing of claim 1, wherein at least one of the first port and the second port is defined in the third surface.

3. The housing of claim 1, wherein at least one of the first port and the second port is defined in the second surface.

4. The housing of claim 1, wherein

-15the first passage extends from the first surface and branches to the second surface and the third surface; and the second passage extends from the first surface and branches to the second surface and the third surface.

5. The housing of claim 1, wherein the first surface of the housing is removably coupled to the base portion of the sensor assembly.

6. A housing for a sensor assembly in fluid communication with a fluid conduit, the sensor assembly including a first fluid passage and a second fluid passage and configured to determine an operational characteristic of fluid flowing through the fluid conduit, the housing comprising:

a first chamber having a first inlet port and a first outlet port, the first inlet port being in fluid communication with a first end of the fluid conduit and the first outlet port being in fluid communication with the first fluid passage of the sensor assembly; and a second chamber having a second inlet port and a second outlet port, the second inlet port being in fluid communication with a second end of the fluid conduit and the second outlet port being in fluid communication with the second fluid passage of the sensor assembly, wherein the first chamber and the second chamber are fluidly disconnected from each other.

7. The housing of claim 6, wherein one of the first inlet port and the second inlet port is angularly adjustable about a plane passing through a center thereof.

Intellectual

Property

Office

Application No: Claims searched:

GB1611010.8

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