U.S. patent application number 12/309432 was filed with the patent office on 2009-12-10 for multichamber ultrasonic sensor for determining a liquid level.
This patent application is currently assigned to CONTI TEMIC MICROELECTRONIC GMBH. Invention is credited to Oliver Beyer, Henning Grotevent, Bernd Harigel, Manfred Roth, Gerd Unverzagt, Andreas Weibert.
Application Number | 20090301187 12/309432 |
Document ID | / |
Family ID | 38686618 |
Filed Date | 2009-12-10 |
United States Patent
Application |
20090301187 |
Kind Code |
A1 |
Beyer; Oliver ; et
al. |
December 10, 2009 |
MULTICHAMBER ULTRASONIC SENSOR FOR DETERMINING A LIQUID LEVEL
Abstract
An ultrasound sensor for determining a fluid level with an
elongated housing (1) which comprises a lid (2) and a floor (3),
with a measuring chamber (4), arranged in the housing (1), in which
a fluid has the same level as outside the measuring chamber (4),
and with an ultrasound transmission receiver (5) on the floor (3)
within or outside the housing (1) in the area of the measuring
chamber (4), the transmitted sound signals of which are reflected
on the surface of the fluid and received by the ultrasound
transmission receiver (5), in order to determine the fluid level
from the signal run time, wherein in the housing (1), alongside the
measuring chamber (4), at least one further chamber (6, 7) is
arranged at least partially in front of the measuring chamber (4)
or at least partially around the measuring chamber (4), wherein the
outermost chamber forms the inlet chamber (7), and that the
chambers (4, 6, 7) are connected to each other.
Inventors: |
Beyer; Oliver; (Erlangen,
DE) ; Grotevent; Henning; (Nuernberg, DE) ;
Harigel; Bernd; (Zell unter Aichelberg, DE) ; Roth;
Manfred; (Grosshabersdorf, DE) ; Unverzagt; Gerd;
(Nuenrberg, DE) ; Weibert; Andreas; (Nuernberg,
DE) |
Correspondence
Address: |
FASSE PATENT ATTORNEYS, P.A.
P.O. BOX 726
HAMPDEN
ME
04444-0726
US
|
Assignee: |
CONTI TEMIC MICROELECTRONIC
GMBH
Nurnberg
DE
|
Family ID: |
38686618 |
Appl. No.: |
12/309432 |
Filed: |
July 18, 2007 |
PCT Filed: |
July 18, 2007 |
PCT NO: |
PCT/DE2007/001287 |
371 Date: |
January 20, 2009 |
Current U.S.
Class: |
73/290V |
Current CPC
Class: |
G01F 23/296 20130101;
G01F 23/2962 20130101 |
Class at
Publication: |
73/290.V |
International
Class: |
G01F 23/296 20060101
G01F023/296 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 18, 2006 |
DE |
10 2006 033 592.9 |
Aug 25, 2006 |
DE |
10 2006 039 872.6 |
Claims
1. An ultrasound sensor for determining a fluid level, with an
elongated housing (1) which comprises a lid (2) and a floor (3) a
measuring chamber (4), arranged in the housing (1), in which a
fluid comprises the same level as outside the measuring chamber (4)
an ultrasound transmission receiver (5) on the floor (3) inside or
outside the housing (1) in the area of the measuring chamber (4),
the transmitted sound signals of which reflect on the surface of
the fluid and are received by the ultrasound transmission receiver
(5), in order to determine the fluid level from the signal run
time, characterized in that in the housing (1) alongside the
measuring chamber (4) at least one further chamber (6, 7) is
arranged at least partially in front of the measuring chamber (4)
or at least partially around the measuring chamber (4), wherein the
outer chamber forms the inlet chamber (7), and that the chambers
(4, 6, 7) are connected to each other.
2. An ultrasound sensor according to claim 1, characterized in that
the inlet chamber (7) and the measuring chamber (4) comprise an
opening (8) on the side, respectively at a height close to the
floor (3) of the housing (1), to enable the fluid to flow in and
out.
3-20. (canceled)
21. An ultrasound sensor according to claim 1, characterized in
that at least one housing ventilation opening (10) is arranged in
the lid (2) or on an outer side of the inlet chamber (7) at a
height close to the lid (2).
22. An ultrasound sensor according to claim 1, characterized in
that the lid (2) is closed at least in the area of the measuring
chamber (4).
23. An ultrasound sensor according to claim 1, characterized in
that the measuring chamber (4) comprises on one outer side at a
height close to the lid (2) above the maximum measurable fluid
level at least one ventilation opening (11).
24. An ultrasound sensor according to claim 1, characterized in
that a calibration reflector (12) is arranged in the measuring
chamber (4) below the minimum possible fluid level, and the fluid
level can be determined from the run time ratio of the signal
reflected on the surface of the fluid and on the calibration
reflector (12).
25. An ultrasound sensor according to claim 1, characterized in
that the profile of at least one chamber (4, 6, 7) is essentially
round or square.
26. An ultrasound sensor according to claim 1, characterized in
that the outer sides of the chambers (6) which are arranged between
the inlet chamber (7) and the measuring chamber (4) are designed as
walls which extend from the floor (3) at the most up to a height
just below the minimum measurable fluid level.
27. An ultrasound sensor according to claim 26, characterized in
that the height and length of the outer side of the chamber (6)
which is closest to the measuring chamber (4) are dimensioned in
such a manner that the retention capacity of said chamber (6) is
greater than the retention capacity of the measuring chamber (4)
itself.
28. An ultrasound sensor according to claim 1, characterized in
that the outer side of the chambers (6) which are arranged between
the inlet chamber (7) and the measuring chamber (4) extend from the
floor (3) up to the lid (2), that on the outer side of said
chambers (6) close to the lid (2), at least one ventilation opening
(11) is arranged, and that on the outer side, at least of the
chamber (6) which is closest to the measuring chamber (4), between
the floor (3) and the lid (2), at a height below the minimum
measurable fluid level, at least one opening (8) is arranged to
enable the fluid to flow in and out.
29. An ultrasound sensor according to claim 28, characterized in
that the height in which an interim opening (13) is arranged, and
the length of the outer side of the chamber (6) which is closest to
the measuring chamber is dimensioned, in such a manner that the
retention capacity of said chamber (6) is greater than the
retention capacity of the measuring chamber (4) itself.
30. An ultrasound sensor according to claim 1, characterized in
that the outer sides of the chambers (6) which are arranged between
the inlet chamber (7) and the measuring chamber (4) are designed as
walls which extend from the floor (3) at least up to a height above
the maximum measurable fluid level, and that said outer sides of
the chambers (6) comprise at a height close to the floor (3) of the
housing (1) one opening (8) respectively to enable the fluid to
flow in and out.
31. An ultrasound sensor according to claim 30, characterized in
that the openings (8) are arranged in such a manner that the
openings (8) in succession in the direction of the measuring
chamber (4) are positioned as far away from each other as
possible.
32. An ultrasound sensor according to claim 1, characterized in
that the outer sides of the chambers (6) which are arranged between
the inlet chamber (7) and the measuring chamber (4) extend from the
floor (3) to the lid (2), and that said outer sides of the chambers
(6) comprise at a height close to the floor (3) of the housing (1)
one opening (8) respectively to enable the fluid to flow in and
out, and one ventilation opening (11) close to the lid (2).
33. An ultrasound sensor according to claim 32, characterized in
that the openings (8) are arranged in such a manner that the
openings (8) in succession in the direction of the measuring
chamber (4) are positioned as far away from each other as
possible.
34. An ultrasound sensor according to claim 1, characterized in
that at least one chamber (6, 7) is arranged around or in front of
the measuring chamber (4), and that at least in one chamber (4, 6,
7) a separation device (9) is provided, which pre-specifies the
flow direction of the fluid on its journey from one chamber (4, 6,
7) into the next chamber (4, 6, 7) through the respective opening
(8).
35. An ultrasound sensor according to claim 34, characterized in
that the separation device (9) is realised by a separating web
(9).
36. An ultrasound sensor according to claim 34, characterized in
that the separation device (9) is realised by means of the fact
that respectively, the outer sides of two successive chambers (4,
6, 7) touch each other at least at one point.
37. An ultrasound sensor according to claim 1, characterized in
that each chamber (6, 7) comprises at least one interim web (14),
wherein on the interim web (9), at a height close to the floor (3)
of the housing (1), an interim opening (13) is arranged to enable
the fluid to flow in and out.
38. An ultrasound sensor according to claim 34, characterized in
that each chamber (6, 7) comprises at least one interim web (14),
and that the separation devices (9) and the interim webs (14) are
higher than the maximum measurable fluid level.
Description
[0001] The invention relates to an ultrasound sensor for
determining a fluid level in accordance with the generic term of
claim 1.
[0002] Sensors of this type are used in automobile technology, for
example, for measuring the level of engine oil or fuel. A sensor on
the container floor emits ultrasound impulses. The echo from the
fluid surface is reabsorbed by the transmission receiver. The
filling level is proportionate to the sound run time. According to
the German patent application DE 33 30 059 A1, the sound is guided
through a hollow conduit or sound conducting tube which is arranged
in a container. At the lower end of the sound conducting tube, the
ultrasound transmission receiver is attached. The tube is
positioned in the fluid and is filled with fluid via at least one
offset opening until the filling level corresponds to that in the
container. In the sound conducting tube, which can be curved, the
filling level is measured using ultrasound. An embodiment of this
type is primarily designed for measuring the filling level with
irregularly formed fluid containers. A great disadvantage of this
arrangement is that foam from the fluid to be determined can
penetrate into the sound conducting tube and slightly falsify the
determination of the fluid level.
[0003] The problem of foam formation with a sensor based on
ultrasound to determine the fluid level lies, in particular with
engine oil, in the fact that due to circulations in the oil while
the engine is running, air bubbles of different sizes are created.
These air bubbles have the property, depending on their size, of
either scattering or reflecting the ultrasound signals. Under these
circumstances, a sufficiently precise, error-free measurement
cannot be guaranteed.
[0004] An approach to the problem to date of holding a fine-mesh
filter (mesh width approx. 60 .mu.m), does not give a satisfactory
result. The penetration of air bubbles is prevented by the filter,
but this method fails as a result of the dirt particles and other
impurities in the oil. Due to these particles, the filter becomes
clogged after a very short time, so that a comparison of the level
in the measuring chamber with the level of oil in the engine to be
determined is no longer possible. Thus, the operation of the sensor
in the engine cannot be guaranteed for the entire operational life
span.
[0005] Against this background, the object of the invention is to
provide an ultrasound sensor of the type described in the
introduction, which due to its geometric structure prevents air
bubbles from penetrating into the measuring chamber, and which thus
enables a permanent and reliable determination of the fluid
level.
[0006] This object is attained according to the invention by means
of an ultrasound sensor according to the generic term of claim 1 by
the features of the characterising part of claim 1.
[0007] In the housing of the sensor, alongside the measuring
chamber, in particular at least one further chamber is arranged at
least partially in front of the measuring chamber or at least
partially around the measuring chamber, wherein the outer chamber
forms the inlet chamber. In order to enable the fluid from the
inlet chamber to enter the measuring chamber, the chambers are
connected to each other.
[0008] The inlet chamber and the measuring chamber comprise on
their side, preferably in each case at a height close to the floor
of the housing, an opening to enable the fluid to flow in and out.
In order to make the route which the fluid travels from the inlet
chamber into the measuring chamber, and thus the time during which
air bubbles which are present can rise to the surface of the fluid,
as long as possible, the opening into the inlet chamber and the
opening into the measuring chamber are generally arranged radially
as far apart from each other as possible.
[0009] The air which escapes from the surface out of the fluid can
leave the sensor through at least one housing ventilation opening
which is arranged in the lid or on an outer side of the inlet
chamber at a height close to the lid.
[0010] However, it should be ensured that the lid is closed at
least in the area of the measuring chamber. This prevents fluid
from the area surrounding the sensor, which in high probability
contains air bubbles, from directly entering the measuring
chamber.
[0011] The pressure compensation in the measuring chamber is
created in particular by the fact that on the outer side of the
measuring chamber at a height close to the lid, in particular above
the maximum measurable fluid level, at least one ventilation
opening is included into the chambers outside of the measuring
chamber.
[0012] The fluid level in the measuring chamber can be calculated
from the run time ratio of the signal reflected on the surface of
the fluid and on a calibration reflector. Here, the calibration
reflector in the measuring chamber is preferably arranged below the
minimum possible fluid level.
[0013] The profile of the chambers can differ from chamber to
chamber. This depends, among other things, on the geometry of the
installation site. Thus, the inlet chamber can for example comprise
an essentially round profile, and the measuring chamber can
comprise an essentially square profile.
[0014] The outer sides of the chambers which are arranged between
the inlet chamber and the measuring chamber are in particular
designed as walls which extend from the floor at the most to a
height just below the minimum measurable fluid level of the
measuring chamber. The fluid flows through the inlet opening into
the inlet chamber. The inlet chamber fills up to the height of the
outer side of the next chamber. Further fluid continues to flow
through the inlet opening and literally washes over the wall into
the next chamber, and so on. The air bubbles rise to the surface of
the fluid during this time and disintegrate. The fluid in the
chamber in front of the measuring chamber is then advantageously
already free of bubbles.
[0015] In order to ensure when the fluid level in the chamber in
front of the measuring chamber increases that from this chamber,
only bubble-free fluid is able to enter the measuring chamber, the
height and length of the outer side of said chamber are measured in
such a manner that the fluid retention capacity of this chamber is
greater than the retention capacity of the measuring chamber
itself.
[0016] Alternatively, the outer side of the chambers which are
arranged between the inlet chamber and the measuring chamber can
extend from the floor to the lid. In order to enable the air which
is formed from the disintegrating air bubbles to escape, at least
one ventilation opening is arranged on the outer side of said
chambers, in each case close to the lid. In order to enable the
fluid to enter the measuring chamber from the inlet chamber, at
least one opening to allow the fluid to flow in and out is arranged
on each of these outer sides. This opening is located on the outer
side at least of the chamber which is closest to the measuring
chamber, between the floor and the lid at a height below the
minimum measurable fluid level. In a similar manner to the
embodiment described above, it is also the case here that the
retention capacity of the chamber in front of the measuring chamber
is greater than the retention capacity of the measuring chamber
itself.
[0017] In a further variant, the outer sides of the chambers which
are arranged between the inlet chamber and the measuring chamber
are designed as walls which extend from the floor at least up to a
height above the maximum measurable fluid level. In order to enable
the fluid to flow from the inlet chamber into the measuring
chamber, these outer sides of the chamber comprise at a height
close to the floor of the housing one opening each to allow the
fluid to flow in and out. In order to make the journey which the
fluid has to cover during this process, and thus the time in which
the fluid and the air bubbles can separate, as long as possible,
the openings are arranged in such a manner that the openings which
occur in sequence in the direction of the measuring chamber are
positioned as far apart as possible from each other.
[0018] With a slightly varied version of the last embodiment of the
sensor described, the walls of the chambers extend between the
inlet chamber and the measuring chamber up to the lid. Ventilation
openings close to the lid ensure that the necessary pressure
compensation is provided into the inlet chamber or into the
surrounding area.
[0019] In a further embodiment, at least one chamber is arranged at
least partially around or in front of the measuring chamber.
Furthermore, a separation device is provided between at least two
chambers of such a design that the flow direction of the fluid on
its journey from one chamber into the next chamber is pre-specified
by the respective opening for inflow and outflow. Preferably, as a
result, the flow direction of chambers which are arranged in
sequence is reversed, and thus the flow journey of the fluid from
the inlet opening of the inlet chamber to the measuring chamber is
made as long as possible. This separation device can for example in
particular be realised with a sensor consisting of concentrically
arranged tubes by a separating web which runs radially within one
chamber. The same separation effect can also be realised when in
each case the outer sides of two successive chambers touch each
other, at least at a point preferably above the entire height.
[0020] A further possibility of influencing the flow speed of the
fluid is to attach interim webs within a chamber. The flow speed is
then determined in particular by the profile and the attachment
location of an interim opening located on the interim web. The
interim opening is preferably arranged at a height close to the
floor of the housing.
[0021] For embodiments with which the fluid is guided on the
journey from one chamber into the next through openings close to
the floor, the existing separation devices and interim webs must be
higher than the maximum possible fluid level.
[0022] Further features, advantages and details of the invention
can be found in the following description, in which preferred
exemplary embodiments are explained in greater detail with
reference to the appended drawings, wherein:
[0023] FIG. 1 shows a profile view of an ultrasound sensor with
three chambers, without fluid
[0024] FIG. 2 shows a top view of the sensor in FIG. 1 at level
A-A
[0025] FIG. 3 shows a profile view as in FIG. 1, with fluid and the
surrounding system, not in operation
[0026] FIG. 4 shows a profile view as in FIG. 1, with fluid and
surrounding system, in operation
[0027] FIG. 5 shows a profile view as in FIG. 1, with fluid to a
large extent drained
[0028] FIG. 6 shows a profile view as in FIG. 1, outer wall of the
chamber in front of the measuring chamber up to the lid and the
opening at a height below the minimum measurable fluid level
[0029] FIG. 7 shows a profile view as in FIG. 6, with the opening
at a height close to the floor
[0030] FIG. 8 shows a top view of the sensor from FIG. 7 at A-A
level
[0031] FIG. 9 shows a top view of a sensor at A-A level, with
separation webs and interim webs
[0032] FIG. 10 shows a top view of a sensor at A-A level, with a
separating web and a further separation device
[0033] FIG. 11 shows a top view of a sensor at A-A level, with
square profile and with a separating web in the inlet chamber,
wherein chambers are at least partially arranged in front of and
around the measuring chamber
[0034] An ultrasound sensor, briefly referred to as sensor, will
now be described below as it is used for example in automobiles for
measuring the engine oil level. Here, the levels in the sensor and
in the engine itself are identical, and the measuring range of the
sensor generally lies between a minimum and a maximum value. FIG. 1
and FIG. 2 show a sensor with three chambers (4, 6, 7) without
fluid. The profile is round and the individual chambers (4, 6, 7)
are formed by concentrically arranged tubes. The outer tube ends
with a floor (3) and a lid (2), and forms the housing (1) of the
sensor. The middle tube extends from the floor (3) to the lid (2)
and forms the measuring chamber (4). The outer chamber, also.
referred to as the inlet chamber (7), and the measuring chamber (4)
each have on their respective outer side close to the floor (3) an
opening (8) to enable the engine oil to flow in and out. The inlet
chamber (7) and the measuring chamber (4) enclose a further chamber
(6), wherein the outer side of said chamber (6) is formed by the
inner side of the inlet chamber (7) and the inner side of the
chamber (6) is formed by the measuring chamber (4). The outer side
of the chamber (6) forms a wall which extends from the floor (3)
until just below the minimum level to be measured. Outside the
housing (1), on the floor in the region of the measuring chamber
(4), an ultrasound transmission receiver (5) is attached.
[0035] After the first filling, the oil travels through the opening
(8) close to the floor into the inlet chamber (7). The inlet
chamber (7) fills up to the height of the outer side of the next
chamber (6). If oil continues to flow through the opening (8), it
literally washes over the wall into the next chamber (6). The air
bubbles rise during this time to the surface of the oil and
disintegrate. From the chamber (6), the oil travels through the
opening (8) close to the floor into the measuring chamber (4).
[0036] FIG. 3 shows the ratios in the sensor in particular as they
occur when the surrounding system, i.e. the engine, is not in
operation. The measuring chamber (4) and in particular, the
important lower area of the chamber (6) which is positioned before
it, are bubble-free. The air which escapes from the remaining oil
can escape through a housing ventilation opening (10) in the edge
area of the lid (2). The lid is closed in the area of the measuring
chamber (4), as a result of which oil containing bubbles is
prevented from penetrating directly into the measuring chamber (4)
from the engine area. The housing ventilation opening (10) could
then be provided on the outer side of the inlet chamber (7),
preferably close to the lid (2).
[0037] FIG. 4 shows the ratios in the sensor which are possible
when the engine is in operation. The oil is distributed through the
moving parts such as the crankshaft and the connecting rod in the
engine. As a result, the level in the oil pan, and therefore also
in the sensor, decreases. The pressure fluctuations in the
measuring chamber (4) which are caused by the changes in level are
offset by the ventilation opening (11) close to the lid on the
outer side of the measuring chamber. In the chamber (6) positioned
in front of the measuring chamber (4), preferably only bubble-free
oil is present. If oil flows on through the opening (8) into the
inlet chamber (7), bubble-free oil is pressed into the measuring
chamber (4) from the chamber (6). Due to the fact that in
particular the retention capacity of the chamber (6) is greater due
to the dimensioning of the height and length of the wall which
surrounds said chamber (6) than that of the measuring chamber (4),
it is ensured that with all possible changes in level, only
bubble-free oil is present in the measuring chamber. The
measurement of the run time of the ultrasound signals which are
transmitted by the ultrasound transmission receiver and which are
reflected on the calibration reflector (12) or on the surface of
the oil present in the measuring chamber (4) is thus advantageously
not falsified at any point in time by air bubbles. The calibration
reflector (12) mentioned is in particular formed on the inner side
of the measuring chamber (4) below the minimum level to be
measured.
[0038] FIG. 5 shows the situation in which the oil is drained from
the sensor and from the oil pan of the engine which occurs when oil
is changed, for example. In the measuring chamber (4) and in the
chamber (6) positioned in front of it, only bubble-free oil is
present. After the oil pan, and thus also the sensor, has been
re-filled, the measurement of the level can begin immediately.
[0039] FIG. 6 shows a sensor as in FIG. 1 to 5, with the difference
that here, the outer side of the chamber (6) extends up to the lid
(2). The oil travels from the inlet chamber (7) through an opening
(8) into the chamber (6) at a height just below the minimum fluid
level to be measured. The relative position of the openings (8) in
the inlet chamber (7), the chamber (6) in front of it and the
measuring chamber (4) is arbitrary with this embodiment in
particular. The profile of the openings (8) and the number of
openings (8) per chamber (4, 6, 7) can vary among each other, and
influences the flow speed of the oil in the sensor. The ventilation
opening (11) is arranged on the outer side of the chamber (6) close
to the lid (2).
[0040] FIGS. 7 and 8 show a further embodiment of the sensor. The
openings (8) in the outer side of each chamber (4, 6, 7) are
respectively arranged close to the floor (3). This has the
advantage that when the oil is changed, possible residues such as
oil sludge and fillings are to a large extent also flushed out.
Preferably, the openings (8) which follow in succession in the
direction of the measuring chamber (4) are positioned as far apart
from each other as possible. As a result, the journey which the oil
has to cover through to the measuring chamber (4) is with this
embodiment of the sensor as long as possible. When it enters a
chamber (6, 7), the oil can however move towards the opening (8)
into the next chamber (6, 7) partially in a clockwise direction and
partially in an anti-clockwise direction.
[0041] The time during which the oil lingers in a chamber (6, 7)
can be prolonged by inserting a separation device (9), as shown in
FIG. 9. The separation device (9) in the inlet chamber (7) lies to
the right of the opening (8). As a result, in the inlet chamber
(7), the flow direction into the next chamber (6) is pre-specified
as being in a clockwise direction. The separation device (9) in the
next chamber (6) lies to the left of the opening (8) into said
chamber (6). This, in this chamber (7) the flow direction is
pre-specified as being in an anti-clockwise direction. Due to the
fact that the openings (8) and the separation devices (9) lie in
the top view in a narrow angle range, and the separation devices
(9) of two adjacent chambers (6, 7) lie in alternation to the left
and right of the respective openings (8), in this example, the time
which the oil requires from entering the inlet chamber (7) until it
reaches the measuring chamber (4) is the longest. The arrangement
of the separation devices (9) and the openings (8) can naturally
vary from embodiment to embodiment. A separation device (9) can for
example be realised by a separating web (9) which runs within a
chamber (6, 7) from one wall to the other wall. The separation
device (9) must in particular be higher than the maximum possible
oil level. Preferably, the separation device (9) extends from the
floor (3) to the lid (2). The flow speed can also be influenced by
the arrangement of at least one interim web (14) within a chamber
(6, 7). For the height of an interim web (14), the same applies as
for a separating web (9). In contrast to the separating web (9), an
interim web (14), can be permeated by the oil, however. For this
purpose, an interim opening (13) is arranged in the interim web
(14), preferably close to the floor. The number of interim webs
(14) per chamber (6, 7) and the profile and number of the interim
openings (13) can vary depending on requirements. In FIG. 9, two
interim webs (14) are provided in the inlet chamber (7) and one
interim web (14) is provided in the chamber (6). The openings (8)
to enable the oil to flow in and out to and from a chamber (4, 6,
7) and the interim openings (13) are here positioned at one level
in particular. This is not absolutely necessary, however.
[0042] In FIG. 10, the separation device (9) in the inlet chamber
(7) is formed by means of the fact that the outer sides of the
successive inlet chambers (7) and the chambers (6) touch each other
at least one point, here via a small part of the circumference. In
the chamber (6), a separating web (9) is provided to the left next
to the opening (8) into this chamber (6). The opening (8) into the
chamber (6) does not have to lie at the same level as the opening
(8) into the inlet chamber (7) or into the measuring chamber
(4).
[0043] FIG. 11 shows a top view onto a sensor with a square
profile. The inlet chamber (7) is arranged around the measuring
chamber (4), and the chambers (6) are arranged at least partially
in front of or around the measuring chamber (4).
[0044] The multi-chamber ultrasound sensor described guarantees a
slowdown of the oil in the sensor and a bubble-free measuring
chamber.
[0045] The present invention has been described with reference to
the description provided in such a manner as to explain in the best
possible manner the principle of the invention and its practical
application. However, with appropriate modifications, the invention
can naturally also be used in numerous other embodiments and
combinations.
LIST OF REFERENCE NUMERALS
[0046] 1 Housing
[0047] 2 Lid
[0048] 3 Floor
[0049] 4 Measuring chamber
[0050] 5 Ultrasound transmission receiver
[0051] 6 Chamber
[0052] 7 Inlet chamber
[0053] 8 Opening to enable the fluid to flow in and out
[0054] 9 Separation device
[0055] 10 Housing ventilation opening
[0056] 11 Ventilation opening
[0057] 12 Calibration reflector
[0058] 13 Interim opening
[0059] 14 Interim web
* * * * *