The invention relates generally to a sensing system used for measurement of at
least one parameter of a fluid by the propagation of ultrasonic wave energy along a
ultrasonic sensor rod located partially or fully in contact with the fluid.
It is often required to determine at least one parameter attributed to fluids in a
static state such as stored in containers, tanks conduits etc. or along flow paths, for
example in pipes. The parameters may include density of the fluid, fluid velocity, fluid
\Jp level, temperature, fluid phase, or the like. There are a number of known sensors, which
are used for detection of parameters associated with the fluids.
One such sensor used for detection of parameters associated with the fluids
includes a transducer assembly for generating an ultrasonic wave and a ultrasonic sensor
rod. One end of the ultrasonic sensor rod may be configured near the transducer assembly
for receiving and transmitting the ultrasonic wave. Other end of the ultrasonic sensor rod
may be immerged in a fluid. The ultrasonic sensor rod may have a sensing portion and a
reference portion with a circular or non-circular cross section.
In such a device, the ultrasonic sensor is partially or fully inserted into the fluid
whose property needs to be measured. Wave energy is guided along the sensor rod held
^ partially or fully in contact with the fluid. The parameter of the fluid surrounding the
ultrasonic sensor influences the ultrasonic wave characteristics, specifically the time of
flight of the wave mode. In other words, the interaction of the guided wave energy along
the ultrasonic sensor with the fluid results in a change in velocity of propagation of the
guided wave energy along the sensor, so that the change in flight time of the wave
provides an indication of a parameter of the fluid in contact with the sensor. In particular
circumstances, where at least one of the fluid composition, container geometry and
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ultrasonic sensor characteristics are known, a measurement of flight time of the wave
energy guided along the ultrasonic sensor may provide an indication of a parameter of the
fluid. However, known ultrasonic sensor devices have very low signal to noise ratio
(SNR). Particularly, the end reflections coming from the geometrical changes in the
reference section of the ultrasonic sensor rod may affect precise calculations. In addition,
the end sensor signal amplitude is low. Hence, none of the known ultrasonic sensor
designs results in an improvement in measurement of at least one fluid parameter.
As a result, there is a continued need for an improved ultrasonic sensor that
addresses at least one of these and other shortcomings. It may be noted that in the
following description the terms "ultrasonic sensor rod", "ultrasonic sensor" and "sensor
rod" have been used interchangeably.
BRIEF DESCRIPTION
In accordance with one exemplary embodiment of the present invention, a
ultrasonic sensor for immersion in a fluid and operable to propagate a ultrasonic wave for
sensing at least one parameter of the fluid is disclosed. The ultrasonic sensor includes a
sensing portion and a reference portion having a first end and a second end. The second
end of the reference portion is coupled to the sensing portion. The ultrasonic sensor
further includes a selectively attenuating portion provided in the reference portion.
In accordance with another exemplary embodiment of the present invention, a
ultrasonic sensor for sensing at least one parameter of the fluid is disclosed. The
^ ^ ultrasonic sensor includes a reference portion and a sensing portion having a plurality of
projections extending outward and spaced apart from each other wherein the sensing
portion is coupled to the reference portion through a tapered portion.
In accordance with yet another exemplary embodiment of the present invention, a
method of enhancing the Signal to Noise Ratio (SNR) for the end reflections on a
ultrasonic sensor rod for sensing at least one parameter of the fluid is disclosed. The
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ultrasonic sensor rod includes a reference portion and a sensing portion. The reference
portion has a first end and a second end and is connected to the ultrasonic portion at its
second end. The method includes providing a selectively attenuating portion in the
reference portion.
In accordance with another exemplary embodiment of the present invention, a
method of enhancing the Signal to Noise Ratio (SNR) for the end reflections on a
ultrasonic sensor rod for sensing at least one parameter of the fluid is disclosed. The
ultrasonic sensor rod includes a reference portion and a sensing portion. The reference
portion has a first end and a second end and is connected to the sensing portion at its
second end. The method includes providing a tapering portion between the second end of
the reference portion and the sensing portion.
DRAWINGS
These and other features, aspects, and advantages of the present invention will
become better understood when the following detailed description is read with reference
to the accompanying drawings in which like characters represent like parts throughout the
drawings, wherein:
FIG. 1 is a block diagram of a sensing system for sensing at least one parameter
of a fluid flowing through a conduit in accordance with an exemplary embodiment of the
present invention;
! FIG. 2 is a theoretical graph of ultrasonic wave propagation in an ideal ultrasonic
sensor;
FIG. 3 is a perspective view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
4
FIG. 4 is a side view of a ultrasonic sensor in accordance with an exemplary
embodiment of the present invention;
FIG. 5 is an exemplary graph of a ultrasonic wave propagation in the exemplary
ultrasonic sensor illustrated with respect to FIG. 4;
FIG. 6 is a cross-sectional view of a ultrasonic sensor in accordance with another
exemplary embodiment of the present invention;
FIG. 7 is an exemplary graph of a ultrasonic wave propagation in the exemplary
ultrasonic sensor illustrated with respect to FIG. 6;
4 ) FIG. 8 is a side view of a ultrasonic sensor in accordance with an exemplary
embodiment of the present invention;
FIG. 9 is an exemplary graph of a ultrasonic wave propagation in the exemplary
ultrasonic sensor illustrated with respect to FIG. 8;
FIG. 10 is a partial side view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
! FIG. 11 is an exemplary graph of a ultrasonic wave propagation in the exemplary
ultrasonic sensor illustrated with respect to FIG. 10;
™ FIG. 12 is a partial side view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
FIG. 13 is an exemplary graph of a ultrasonic wave propagation in the exemplary
ultrasonic sensor illustrated with respect to FIG. 12;
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FIG. 14 is a partial side view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
FIG. 15 is a cross-sectional view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
FIG. 16 is a partial perspective view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
FIG. 17 is a partial perspective view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
^ p FIG. 18 is a partial perspective view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
FIG. 19 is a partial perspective view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
FIG. 20 is a partial perspective view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
FIG. 21 is a partial perspective view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
m
^ FIG. 22 is a partial perspective view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
FIG. 23 is a partial perspective view of a ultrasonic sensor in accordance with an
exemplary embodiment of the present invention;
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FIG. 24 is a flow chart illustrating the method of enhancing the Signal to Noise
Ratio (SNR) for the end reflections on a ultrasonic sensor rod in accordance with an
exemplary embodiment of the present invention; and
FIG. 25 is a flow chart illustrating the method of enhancing the Signal to Noise
Ratio (SNR) for the end reflections on a ultrasonic sensor rod in accordance with another
exemplary embodiment of the present invention.
It may be noted that to the extent possible, like reference numerals have been used
to represent like elements in the drawings. Further, skilled artisans will appreciate that
elements in the drawings are illustrated for simplicity and may not have been necessarily
been drawn to scale. For example, the dimensions of some of the elements in the
^ drawings may be exaggerated relative to other elements to help to improve understanding
of aspects of the present invention. Furthermore, the one or more elements may have
been represented in the drawings by conventional symbols, and the drawings may show
only those specific details that are pertinent to understanding the embodiments of the
present invention so as not to obscure the drawings with details that will be readily
apparent to those of ordinary skill in the art having benefit of the description herein.
DETAILED DESCRIPTION
While the invention is susceptible to various modifications and alternative forms,
specific embodiment thereof has been shown by way of example in the drawings and will
be described in detail below. It should be understood, however that it is not intended to
^F limit the invention to the particular forms disclosed, but on the contrary, the invention is
to cover all modifications, equivalents, and alternative falling within the spirit and the
scope of the invention as defined by the appended claims.
The parts of the device have been represented where appropriate by conventional
symbols in the drawings, showing only those specific details that are pertinent to
understanding the embodiments of the present invention so as not to obscure the
7
disclosure with details that will be readily apparent to those of ordinary skill in the art
having benefit of the description herein.
The terms "comprises", "comprising", or any other variations thereof, are intended
to cover a non-exclusive inclusion, such that one or more devices or sub-systems or
elements or structures proceeded by "comprises... a" does not, without more constraints,
preclude the existence of other devices or other sub-systems or other elements or other
structures or additional devices or additional sub-systems or additional elements or
additional structures. Similarly, a method step proceeded by "comprising" or any
variation thereof, does not, without more constraints preclude the existence of additional
steps or repetitive steps.
9 Embodiments of the present invention disclose a ultrasonic sensor for sensing at
least one parameter of a fluid. The ultrasonic sensor includes a reference portion and a
sensing portion coupled to the reference portion. The reference portion has a first end and
a second end. The second end is coupled to the ultrasonic portion and the first end is
configured to be in proximity of a transducer for receiving a ultrasonic wave. A
selectively attenuation portion is provided between the first end of the reference portion
and the second end of the reference portion. According to another exemplary
embodiment, a tapering portion is provided between the second end of the reference
portion and the sensing portion. The ultrasonic portion includes a plurality of projections
extending outward and spaced apart from each other. At least a portion of the ultrasonic
sensor is mountable for immersion in the fluid and operable to propagate a ultrasonic
wave that interacts with the fluid along the at least sensing portion of the ultrasonic
^ ^ sensor so as to affect propagation of the ultrasonic wave in a manner dependent on the at
least one parameter of the fluid. The at least one parameter include, but is not limited to,
absolute density, density profile, fluid level, absolute temperature, temperature profile,
absolute viscosity, viscosity profile, absolute flow velocity, flow velocity profile,
absolute fluid phase fraction, fluid phase fraction profile, or combinations thereof of the
fluid. The fluid may include a single-phase fluid, or a two-phase fluid mixture, or a multi-
8 phase fluid mixture. The exemplary ultrasonic sensor design substantial enhances the
Signal to Noise Ratio (SNR) for the end reflections on a ultrasonic sensor rod.
Referring to FIG. 1, a block diagram of a sensing system 10 for sensing at least
one parameter of a fluid 12 flowing through a conduit 14 is illustrated. In the illustrated
embodiment, and subsequent embodiments, the conduit may be a vertical arrangement or
a horizontal arrangement. It should be noted that even though a conduit is disclosed, the
sensing system 10 is applicable to any device containing a fluid for sensing at least one
parameter attributed to the fluid in both static and flowing conditions. The system 10
includes an ultrasonic sensor 16 partially immersed in the fluid 12 flowing through the
conduit 14. The ultrasonic sensor 16 includes a reference portion 18 and a sensing portion
20. A selectively attenuation portion 22 may be provided between a first end 24 of the
9 reference portion 18 and a second end 26 of the reference portion 18. The depth of the
ultrasonic sensor 16 immersed in the fluid 12 may be varied.
The system 10 further includes an excitation device 28 configured to generate a
ultrasonic wave energy for transmission through the sensor 16. A transducer device 30 is
configured to receive the ultrasonic wave from the excitation device and couple the same
to the ultrasonic sensor 16. The ultrasonic guided wave (or alternatively the ultrasonic
wave), which propagates along the ultrasonic sensor 16, detects the presence and nature
of the surrounding fluid 12. When the ultrasonic sensor 16 is partially immersed in the
fluid 12, the propagation of wave is affected by at least one parameter of the fluid 12.
Hence, at least one parameter of the fluid 12 may be measured by detecting the
propagation of wave energy along the ultrasonic sensor 16. At least one parameter
^ includes absolute density, density profile, fluid level, absolute temperature, temperature
profile, absolute viscosity, viscosity profile, absolute flow velocity, flow velocity profile,
absolute fluid phase fraction, fluid phase fraction profile, calorific value or combinations
thereof of the fluid 12. The fluid 12 may include a single-phase fluid, or a two-phase fluid
mixture, or a multi-phase fluid mixture. It should be noted herein that a two-phase fluid
mixture, or a multi-phase fluid mixture might include two or more fluids having different
densities. For example, a multi-phase fluid mixture may include oil, water, and gas. The
9
excitation device 28 may further have a wave generator such as but is not limited to,
piezoelectric, curved piezoelectric, phased array magneto strictive, Laser-based
electromagnetic acoustic transducer (EMAT), phased EMAT, CMUT and an amplifier.
In the illustrated embodiment, the transducer device 30 is configured to detect the
wave energy from the sensing portion 20 of the sensor 16. A corresponding output signal
from the transducer device 30 may be fed via a digital oscilloscope 32 to a processor
device 34, for example, a computer. The processor device 34 may be configured to
determine at least one parameter of the fluid 12 in response to the output signal from the
transducer device 34. It should be noted herein that the configuration of the sensing
system 10 is an exemplary embodiment, and should not construed in any way as limiting
the scope of the invention. The exemplary sensor 16 is applicable to any application
^p requiring detection of at least one parameter attributed to the fluid 12 in which the fluid is
contained in a vessel or flowing through a conduit. Typical examples include petroleum
industry, oil & gas, pharmaceutical industry or the like. The exemplary sensor design and
arrangement of sensors are explained in greater detail with reference to subsequent
embodiments.
FIG. 2 is a graphical illustration of an ideal waveform 36 of ultrasonic wave
propagation employing an exemplary ultrasonic sensor such as described in further
embodiments, below. The 'Y' axis 38 indicates amplitude or displacement of the wave
and 'X' axis 40 indicates the wave propagation with respect to time. As illustrated
herein, the wave 36 attains first amplitude 42 near the input and is referred to as 'input
A excitation'. The wave 36 further attains a second amplitude 44corresponding to an echo
^ from the interface 46 of the reference portion 18 and the sensing portion 20 of the
ultrasonic sensor 16. Furthermore, the wave 36 attains a third amplitude 48 corresponding
to an echo from the bottom 50 of the ultrasonic sensor 16. In typical working conditions,
the waveform obtained may deviate from the ideal waveform 36 due to noise or
interferences. The objective of the present invention is to reduce other
noises/interferences and to get a waveform close to the waveform illustrated in figure 2.
10
Referring to FIG. 3, a perspective view of an exemplary ultrasonic sensor 16 is
illustrated. The exemplary ultrasonic sensor 16 includes the reference portion 18 and the
sensing portion 20. The reference portion 18 may have any suitable cross-section such as,
but is not limited to, circular, oval, quadrilateral, multi-edge shape etc., and may have
first end 24 and second end 26. The second end 26 of the reference portion 18 may be
coupled to the sensing portion 20. The sensing portion 20 includes one or more
projections 52 extending outward and spaced apart from each other. Specifically, the
sensing portion 20 may include, but is not limited to, the plurality of individual
projections 52 disposed symmetrically about a center section 54 of the sensing portion
20. According to other exemplary embodiments, the projections 52 may have any suitable
shape and size and may be disposed in any suitable orientation. The selectively
attenuating portion 22 may be provided between the first end 24 and the second end 26 of
V the reference portion 18. According to an exemplary embodiment, the attenuating portion
22 may be provided near to the first end 24 of the of the reference portion 18. The
selectively attenuating portion 22 may have any suitable length and cross section such as,
but is not limited to, circular, oval, quadrilateral etc. In another embodiment, the crosssectional
area of the attenuating portion 22 may be less than or more than the crosssectional
area of the reference portion 18. According to yet another embodiment, the
selectively attenuating portion 22 may include a material different than the material of the
reference portion 18. According to yet another embodiment, at least a part of the
selectively attenuating portion 22 may have knurling. According to yet another
embodiment, the ratio of the length of the selectively attenuating portion 22 to the
reference portion 18 is in the range of about 1:1000 to 1:1.
^ r According to yet another embodiment, a covering or bush of a suitable plastic
material such as, but is not limited to, Polytetrafluoroethylene (PTFE), NYLON,
Polyether ether ketone (PEEK), Polyoxymethylene (POM), Graphite, Ultem, Flexi-glass
etc. may be provided on the first end 24 of the reference portion 18. According to yet
another embodiment, the covering or bush may be press fitted onto the first end 24.
According to yet another embodiment, the cross-sectional area of the attenuating portion
22 is less then the cross-sectional area of the reference portion 18 and a dampening
11
material such as casted / plastic molded / Graphite / Glass to Metal seal (GMS), or filler
material such as, but is not limited to, Epoxy based material like DP460, or Tungstenloaded
epoxy may be filled in the attenuating portion 22.
The illustrated embodiments, may manage end reflections coming from the first
end 24 of the reference portion 18. The ultrasonic wave is excited in the first end 24 of
the reference portion 18. The guided wave propagates through both towards transducer
device 30 and the second end 26 of reference portion 18. The illustrated embodiment
helps in attenuating the guided wave propagated towards transducer device 30 thus
decreasing the interferences and increasing the Signal to Noise Ratio (SNR).
Referring to FIG. 4, a side view of an exemplary ultrasonic sensor 16 is
^"' illustrated. The exemplary ultrasonic sensor 16 may have the selectively attenuating
portion 22 near the first end 24 of the reference portion 18. According to yet another
embodiment, a tapered portion 56 is provided between the reference portion 18 and the
ultrasonic portion 20, such that the reference portion 18 is connected to the ultrasonic
portion 20 through said tapered portion 56. The transducer device 30 may be provided in
proximity to the attenuating portion 22 of the reference portion 18. The transducer device
30 transmits a ultrasonic wave at the first end 24 of the reference portion 18. The
ultrasonic wave is transmitted in the ultrasonic sensor 16 through the attenuating portion
22.
Referring to FIG. 5, a graph of the waveform 58 of ultrasonic wave propagation in
~ the exemplary ultrasonic sensor 16 described with reference to FIG. 4, is illustrated. The
w 'Y' axis 38 indicates amplitude or displacement of the wave and at 'X' axis 40 indicates
the wave propagation with respect to time. As illustrated herein, the input excitation 42
may be seen at about 0 and the interface reflection 44 may be seen at about 250* 10~6, the
echo 48 from the sensing end 54 may be seen at about 350* 10'6.
Referring to FIG. 6, a cross section view of an exemplary ultrasonic sensor 16 is
illustrated. The exemplary ultrasonic sensor 16 may have the selectively attenuating
12
portion 22 near the first end 24 of the reference portion 18. A covering or bush 60 of a
suitable plastic material such as, but is not limited to, Polytetrafluoroethylene (PTFE),
NYLON, Polyether ether ketone (PEEK), Polyoxymethylene (POM), Graphite, Ultem,
Flexi-glass etc. may be provided on the first end 24 of the reference portion 18. The
covering or bush may be press fitted onto the first end 24. According to yet another
embodiment, a dampening material 62 such as casted/plastic molded / Graphite / Glass to
metal seal (GMS) or filler material like Epoxy based material like DP460, Tungstenloaded
epoxy may be filled in the attenuating portion 22. The transducer device 30 may
be provided in proximity to the covering or bush 60. The transducer device 30 transmits a
ultrasonic wave at the first end 24 of the reference portion 18.
Referring to FIG. 7, a graph of the waveform 64 of ultrasonic wave propagation
^ 48 in the exemplary ultrasonic sensor 16 described with reference to FIG. 6 is illustrated.
The graph at 'Y' axis 38 indicates amplitude or displacement of the wave and at 'X' axis
40 indicates the wave propagation with respect to time. As illustrated herein, the input
excitation 42 may be seen at about 0, the echo from the interface 44 may be seen at about
320* 10"6 and echo from the bottom 48 may be seen at about 450* 10"6.
Referring to FIG. 8, a side view of an exemplary ultrasonic sensor 100 is
illustrated. The exemplary ultrasonic sensor 100 includes a reference portion 102 and a
ultrasonic portion 104. According to the illustrated exemplary embodiment, the length of
the reference portion 102 may be about 400 mm and the length of the ultrasonic portion
104 may be about 100 mm. The reference portion 102 may have a circular cross-section
^ with a diameter of about 9 mm. The reference portion 102 may have a first end 106 and a
^ ^ second end 108. The second end 108 of the reference portion 102 may be coupled to the
sensing portion 104 through a tapered portion 110. The length of the tapered portion 110
may be about 12 mm. The sensing portion 104 may include a plurality of projections
extending outward and spaced apart from each other. A selectively attenuating portion
112 may be provided between the first end 106 and the second end 108 of the reference
portion 102. The selectively attenuating portion 112 may be provided near to the first
end 106 of the reference portion 102. The length of the selectively attenuating portion
13
112 may be about 10 mm and the cross section diameter may be about 5.6 mm. A cross
hole 114 having a diameter of about 3 mm may be provided at the first end 106 of the
reference portion 102. The cross hole 114 may further help in improving the SNR in the
ultrasonic sensor and may also help in holding the sensor in a desired orientation in the
fluid.
Referring to FIG. 9, a graph of waveform 116 of ultrasonic wave propagation in
the exemplary ultrasonic sensor 100 described with reference to FIG. 8 is illustrated. The
graph at 'Y' axis 118 indicates amplitude or displacement of the wave and at 'X' axis
120 indicates the wave propagation with respect to time. As illustrated, the wave 116
attains first amplitude 122, which is input excitation. The wave 116 further attains second
amplitude 124 corresponding to an echo from the interface. Furthermore, the wave 116
^p attains third amplitude 126 corresponding to an echo from the bottom. The SNR values
obtained from the illustrated graph is as follows:
SNR I STD DEV I MEAN SNR I AVG SNR UNF I
3.28 0.05225 4.006 3J1
FIG. 10, illustrates a partial side view of an exemplary embodiment, of the
ultrasonic sensor 100 described in FIG. 8. As illustrated the ultrasonic sensor may have
knurling on the selectively attenuating portion 112.
FIG. 11, illustrates a graph of waveform 128 of ultrasonic wave propagation in
the exemplary ultrasonic sensor 100 described with reference to FIG. 10. The graph at
^ 'Y' axis 118 indicates amplitude or displacement of the wave and at 'X' axis 120
indicates the wave propagation with respect to time. As illustrated, the wave 128 attains
first amplitude 130, which is input excitation. The wave 128 further attains second
amplitude 132 corresponding to an echo from the interface. Furthermore, the wave 128
attains a third amplitude 134 corresponding to an echo from the bottom. The SNR values
obtained from the illustrated graph is as follows:
I SNR I STD DEV I MEAN SNR I AVG SNR UNF I
2.71 0.09841 325 2/71
! 1 —•• —-i -1 —•. —• I 1 ]
14
Referring to FIG. 12, a partial side view of an exemplary embodiment, of the
ultrasonic sensor 200 is illustrated. The exemplary ultrasonic sensor 200 includes a
reference portion 202 and a ultrasonic portion (not shown). The reference portion 202
includes a first end 204 and a second end (not shown). A selectively attenuating portion
206 may be provided at the first end 204 of the reference portion 202. According to an
embodiment, a covering or bush of a suitable plastic material such as, but is not limited
to, Polytetrafluoroethylene (PTFE), NYLON, Polyether ether ketone (PEEK),
Polyoxymethylene (POM), Graphite, Ultem, Flexi-glass etc. may be provided on at least
a part of the selectively attenuating portion 206. According to one embodiment, the
covering may be provided on the whole selectively attenuating portion 206. According to
yet another embodiment, the covering or bush may be press fitted onto selectively
^ F attenuating portion 206.
FIG. 13 illustrates a graph of waveform 208 of ultrasonic wave propagation in the
exemplary ultrasonic sensor 200 described with reference to FIG. 12. The graph at 'Y'
axis 210 indicates amplitude or displacement of the wave and at 'X' axis 212 indicates
the wave propagation with respect to time. As illustrated, the wave 208 attains first
amplitude 214, which is input excitation. The wave 208 further attains second amplitude
216 corresponding to an echo from the interface. Furthermore, the wave 208 attains a
third amplitude 218 corresponding to an echo from the bottom. The SNR values obtained
from the illustrated graph is as follows:
SNR I STD DEV I MEAN SNR I AVG SNR UNF I
4.04 0.03638 6.537 4^06
9 I 1 1 1 1
FIG. 14 illustrates a partial cross section view of another embodiment, of the
exemplary ultrasonic sensor 200 as described with respect to FIG. 12. The exemplary
ultrasonic sensor 200 may further have knurling on the selectively attenuating portion
206. According to yet another embodiment, a plurality of grooves 220 may be provided
on the horizontal wall joining the attenuating portion 206 with the reference portion.
According to yet another embodiment, a covering or bush of a suitable plastic material
15
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such as, but is not limited to, Polytetrafluoroethylene (PTFE), NYLON, Polyether ether
ketone (PEEK), Polyoxymethylene (POM), Graphite, Ultem, Flexi-glass etc. may be
provided on at least a part of the selectively attenuating portion 206 with knurling.
Referring to FIG. 15, a partial cross section view of an exemplary embodiment, of
the ultrasonic sensor 300 is illustrated. The exemplary ultrasonic sensor 300 includes a
reference portion 302 and a ultrasonic portion (not shown). The reference portion 302
includes a first end 304 and a second end (not shown). A selectively attenuating portion
306 may be provided at the first end 304 of the reference portion 302. The selectively
attenuating portion 306 may be detachably coupled to the reference portion 302. As
illustrated at least a part 308 of the selectively attenuating portion 306 have a crosssectional
area greater then the cross-sectional area of the reference portion 302 and at
^ p least a part 310 of the selectively attenuating portion 306 have a cross-sectional area less
than the cross-sectional area of the reference portion 302. The reference portion 302 may
have a face hole 312 to accommodate the selectively attenuating portion 306. According
to an embodiment, the selectively attenuating portion 306 may be made up of a suitable
metal or non-metallic material.
FIGs. 16-19, illustrate various other configurations of the selectively attenuating
portion according to exemplary embodiments, of the invention. Referring to FIG. 16, the
selectively attenuating portion 402 may have a quadrilateral cross section and provided at
the first end 404 of the reference portion 406. Referring to FIG. 17, the selectively
attenuating portion 402 may have a quadrilateral cross section, provided at the first end
404 of the reference portion 406 and have a cross hole 408. Referring to FIG. 18, at least
™ a part of the selectively attenuating portion 402 may have a quadrilateral cross section
410 and a cross hole 408 may be provided on the first end 404 of the reference portion
406. Referring to FIG. 19, at least a part of the selectively attenuating portion 402 may
have a circular cross section 412 and at least a part have a quadrilateral cross section 414
with a cross hole 408 provided on the quadrilateral cross-sectional part 414 of the
selectively attenuating portion 402.
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16
Referring to FIG. 20, a partial cross section view of an exemplary embodiment, of
the ultrasonic sensor 500 is illustrated. The exemplary ultrasonic sensor 500 includes a
reference portion 502 and a sensing portion 504. The reference portion 502 may have any
suitable cross-section such as, but is not limited to, circular, oval, quadrilateral etc., and
may have a first end (not shown) and a second end 506. The second end 506 of the
reference portion 502 may be coupled to the sensing portion 504 through a tapered
portion 508. The ultrasonic portion 504 includes a plurality of projections 510 extending
outward and spaced apart from each other. According to exemplary embodiments, the
projections 510 may have any suitable shape and size and may be disposed in any
suitable orientation. According to an exemplary embodiment, the tapered portion 508
may include multiple tapered portions, such that each tapered portion have a different
angle of tapering as compared to other tapered portions. According to yet another
^ p embodiment, the tapered portion 508 may include a first tapered portion 512 and a
second tapered portion 514 such that the first tapered portion 512 have a different angle
of tapering as compared to the second tapered portion 514. According to yet another
embodiment, the tapered portion 508 may extends from the reference portion 502 in
between the plurality of projections 510 provided on the sensing portion. FIG. 21 and
FIG.22 further illustrate various other configuration of the tapered portion 508 according
to various exemplary embodiments, of the invention. These embodiments may help in
transferring greater energy in the sensing portion there by increasing the reflection
amplitude of the sensor tip (enhanced SNR).
Referring to FIG. 23, a partial cross section view of an exemplary embodiment, of
the ultrasonic sensor 600 is illustrated. The exemplary ultrasonic sensor 600 includes a
^ ^ reference portion 602 and a sensing portion 604. The reference portion 602 may have any
suitable cross-section such as, but is not limited to, circular, oval, quadrilateral etc., and
may have a first end (not shown) and a second end 606. The second end 606 of the
reference portion 602 may be coupled to the sensing portion 604 through a tapered
portion 608. The ultrasonic portion 604 includes a plurality of projections 610 extending
outward and spaced apart from each other. According to exemplary embodiments, the
projections 610 may have any suitable shape and size and may be disposed in any
i"
suitable orientation. The tapered portion 608 may extend from the reference portion 602
in between the plurality of projections 610 provided on the sensing portion. According to
an embodiment, the tapered portion 608 may include multiple tapered portions.
According to an exemplary embodiment at least some tapered portion 612 have
continuous profile and at least some tapered portion 614 may have discontinuous profile
such that the tapered portion 614 may have a different angle of tapering. According to an
embodiment, the tapered portion 612 having continuous profile may be provided between
the projections 610 having wider angle there between and the tapered portion 614 having
discontinuous profile may be provided between the projections 610 having narrow angle
there between.
Referring to FIG. 24 a flow chart illustrating a method 700 of enhancing the
^ P Signal to Noise Ratio (SNR) for the end reflections on a ultrasonic sensor rod for sensing
at least one parameter of the fluid is disclosed. At step 702, a ultrasonic sensor rod is
provided. The ultrasonic sensor rod includes a reference portion and a ultrasonic portion.
The reference portion may have a first end and a second end. The second end is
connected to the ultrasonic portion. At step 704, the method 700 includes providing a
selectively attenuating portion between the first end and the second end of the reference
portion. At step 706, the method 700 may further include providing a covering of a
dampening material such as, but is not limited to, Polytetrafluoroethylene (PTFE),
NYLON, Polyether ether ketone (PEEK), Polyoxymethylene (POM), Graphite, Ultem,
Flexi-glass etc. on at least a part of the torsion sensor rod near an end that is close to a
transducer assembly. According to another embodiment, at step 708, the method 700 may
further includes providing a tapered portion between a reference portion and a ultrasonic
^ ^ portion of the ultrasonic sensor rod.
Referring to FIG. 25 a flow chart illustrating a method 800 of enhancing the
Signal to Noise Ratio (SNR) for the end reflections on a ultrasonic sensor rod for sensing
at least one parameter of the fluid is disclosed. At step 802, a ultrasonic sensor rod is
provided. The ultrasonic sensor rod includes a reference portion and a sensing portion.
The reference portion may have a first end and a second end. The second end is
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connected to the sensing portion. At step 802, the method 800 includes providing a
tapering portion between the second end of the reference portion and the sensing portion.
The disclosed exemplary embodiment, of the invention helps to minimize the end
reflections coming from the circular end of the ultrasonic Sensor thereby improving the
SNR ratio. According to exemplary embodiments, of the invention, the disclosed
ultrasonic senor rod enhances the SNR, which is about 2X from the existing known
sensors.
While only certain features of the invention have been illustrated and described
herein, many modifications and changes will occur to those skilled in the art. It is,
therefore, to be understood that the appended claims are intended to cover all such
^ ) modifications and changes as fall within the true spirit of the invention.
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WE CLAIM:
1. A ultrasonic sensor comprising:
a sensing portion configured to sense at least one parameter of a fluid;
a reference portion comprising a first end and a second end, the second end of the
reference portion being coupled to the sensing portion; and
a selectively attenuating portion provided in the reference portion.
2. The ultrasonic sensor of claim 1, wherein the cross-sectional area of at least a part
of the selectively attenuating portion comprises a cross-sectional area less or more than
the cross-sectional area of the reference portion.
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3. The ultrasonic sensor of claim 1, wherein the selectively attenuating portion
comprises a material different than the material of the reference portion.
4. The ultrasonic sensor of claim 3, wherein the selectively attenuating portion is
covered with a layer of a material selected from PTFE, Nylon, PEEK, POM, Glass to
metal seal. Graphite, ultem, Flexi-glass, Epoxy based material like DP460, Tungstenloaded
epoxy and a combination thereof
5. The ultrasonic sensor of claim 1, wherein the selectively attenuating portion is
provided in proximity of the first end of the reference portion.
^ ^ 6. The ultrasonic sensor of claim 1, further comprising a cross hole near the first end
of the reference portion.
7. The ultrasonic sensor of claim 1, wherein the selectively attenuating portion forms
the first end of the reference portion.
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8. The ultrasonic sensor of claim 1, wherein the selectively attenuating portion is
detachable connected to the reference portion.
9. The ultrasonic sensor of claim 1, wherein the reference portion have a circular
cross-section.
10. The ultrasonic sensor of claim 1, wherein the reference portion have a multi-edge
cross-section.
11. The ultrasonic sensor of claim 1, wherein at least a part of the selectively
attenuating portion have quadrilateral cross-section.
^ ^ 12. The ultrasonic sensor of claim 1, wherein at least a part of the selectively
attenuating portion have multi-edge cross-section.
13. The ultrasonic sensor of claim 1, wherein at least a part of the selectively
attenuating portion have knurling.
14. The ultrasonic sensor of claim 1, wherein the ratio of the length of the selectively
attenuating portion to the reference portion is in the range of 1:1000 to 1:1.
15. The ultrasonic sensor of claim 1, wherein the sensing portion have a one or more
projections extending outward and spaced apart from each other.
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^ 16. The ultrasonic sensor of claim 1, wherein the reference portion is coupled to the
sensing portion through a tapered portion.
17. The ultrasonic sensor of claim 16, wherein the tapered portion comprises a single
tapered portion.
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18. The ultrasonic sensor of claim 16, wherein the tapered portion comprises multiple
tapered portions including a first tapered potion and a second tapered portion, the first
tapered portion having differing angles of tapering.
19. A ultrasonic sensor comprising: for sensing immersion in a fluid and operable to
propagate a ultrasonic wave for sensing at least one parameter of the fluid, the ultrasonic
sensor comprising:
a reference portion; and
a ultrasonic portion comprising a plurality of projections extending outward and
spaced apart fi-om each other, wherein the sensing portion is coupled to the reference
portion through a tapered portion and configured to sense at least one parameter of a
fluid..
20. The ultrasonic sensor of claim 19, wherein the tapered portion extends fi-om the
reference portion in between the plurality of projections provided on the ultrasonic
portion.
21. The ultrasonic sensor of claim 19, wherein the tapered portion comprises multiple
tapered portions including a first tapered potion and a second tapered portion, the first
tapered portion having differing angles of tapering.
22. A method of enhancing the Signal to Noise Ratio (SNR) for the end reflections on
a ultrasonic sensor rod for sensing at least one parameter of the fluid, the ultrasonic
sensor rod comprising a reference portion and a ultrasonic portion, said reference portion
^ ^ having a first end and a second end and being connected to the sensing portion at its
second end, the method comprising:
providing a selectively attenuating portion in the reference portion.
23. The method of claim 22, fiirther comprising providing a covering of a dampening
material on at least a part of the reference portion of the sensor rod near an end that is
close to a transducer assembly.
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24. The method of claim 22, further comprising providing a tapered portion between
a reference portion and a sensing portion of the ultrasonic sensor rod.
25. A method of enhancing the Signal to Noise Ratio (SNR) for the end reflections on
a ultrasonic sensor rod for sensing at least one parameter of the fluid, the ultrasonic
sensor rod comprising a reference portion and a sensing portion, said reference portion
having a first end and a second end and being connected to the sensing portion at its
second end, the method comprising:
providing a tapering portion between the second end of the reference portion and
the sensing portion.