WO1986002723A1 - Transducer with reduced acoustic reflection - Google Patents

Transducer with reduced acoustic reflection Download PDF

Info

Publication number
WO1986002723A1
WO1986002723A1 PCT/NL1985/000041 NL8500041W WO8602723A1 WO 1986002723 A1 WO1986002723 A1 WO 1986002723A1 NL 8500041 W NL8500041 W NL 8500041W WO 8602723 A1 WO8602723 A1 WO 8602723A1
Authority
WO
WIPO (PCT)
Prior art keywords
flow meter
transducer
ultrasonic flow
sound
fluid
Prior art date
Application number
PCT/NL1985/000041
Other languages
French (fr)
Inventor
Hendrik Johannes De Jong
Original Assignee
N.V. Nederlandsche Apparatenfabriek Nedap
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by N.V. Nederlandsche Apparatenfabriek Nedap filed Critical N.V. Nederlandsche Apparatenfabriek Nedap
Publication of WO1986002723A1 publication Critical patent/WO1986002723A1/en

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/66—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
    • G01F1/662—Constructional details
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/002—Devices for damping, suppressing, obstructing or conducting sound in acoustic devices

Definitions

  • the invention relates to a method of reducing un- desired echos in ultrasonic flow meters operating in accordance with the phase or transit time difference measuring principle.
  • the types of ultrasonic flow meters that operate in accordance with thephase or transit time difference measuring principle are often built up of two transducers mounted in spaced-apart, facing, parallel relationship and a calibrated measuring tube between these transducers.
  • the fluid to be measured flows past the transducers and throug the measuring tube.
  • An ultrasonic sound beam travelling downstream is seemingly accelerated while an ultrasonic sound beam travelling upstream is seemingly delayed.
  • the flow velocity of the fluid can be derived from a measurement of the phase or transit time difference between the received sound beams.
  • the period of time during which the two sound beams are transmitted must not exceed the time required for reaching the opposite transducer as the latte should then be switched to operation as a receiver. Consequently, the measurement extends over a very brief period of time. To achieve sufficient accuracy of the measurement, the procedure of transmitting and receiving is repeated continuously at an optimally high repetition rate.
  • the first object of the present invention is to prevent the occurrence of such undesired echos or to at least so reduce such echos that their effect is negligible
  • this object is achieved as the active surface of each of the transducers is pro ⁇ vided with one or more raised or recessed portions, as a result of which such a quenching pattern is introduced into the reflected sound by interference that no or sub ⁇ stantially no echo is incident upon the opposite trans ⁇ ducer. Steps have to be taken, however, to prevent the side lobes formed by this reflection effect from reaching the opposite transducer due to, for example, reflections against the inner wall of the measuring tube.
  • Figs. 1-4 Some examples of the effect of a transducer provided with a raised portion in accordance with the invention on the pattern of a reflected, planar ultrasonic sound beam are shown in Figs. 1-4.
  • the outlines drawn in these Figures are each time lines of equal sound intensity 2, while the wavelength of the sound in. the fluid to be measured is ⁇ .
  • the reflecting transducer 1 is flat and causes the normal reflection pattern.
  • the transducer is provided with a raised portion 3 of a height 1/4 ⁇ , with a varying • ⁇ rati
  • a quenching region is formed above the edge of the raised portion by interference.
  • the raised or recessed portions may have shapes other than those shown in the Figures, for example annular shapes, while the raised or recessed portions further need not have the same dimension h over the entire surface.
  • the total amount of reflected sound energy is not affected by the above steps.
  • the reduction of the reflect ⁇ ed sound intensity in the centre axis of the transducer results in an increase in the reflected sound intensity at the edge thereof, i.e., the formation of side lobes. Accordingly, there is a danger of the relatively energy- rich side lobes reflecting from the wall of the measuring tube to so disturb the measuring signal.
  • a second object of the present invention is there ⁇ fore to prevent the occurrence of objectional reflections of the side lobes from the wall of the measuring tube.
  • the tube wall is internally coated with a layer of a material in which the sound propagates at a velocity that is approximately equal to or smaller than the sound velocity in the fluid to be measured and which exhibits a relatively high internal damping.
  • a suitable material is, for example, a synthetic material called polysulfon.
  • Transducers 5 comprises a sleeve 6 in which the transducers 5 are mounted in enlarged sections thereof.
  • Transducers 5 have active surfaces provided, in accordance with the first part of the present invention, with, in this embodiment, raised portions for preventing undesired echos in the axial direction of the measuring tube 7.
  • This measuring tube 7 is formed by an inner coati on sleeve 6 and is of a material in which sound propagate at a velocity that is approximately equal to or smaller than that in water and which exhibits an optimally high sound damping.
  • This material may be, for example, the aforesaid polysulfon, in which the sound velocity is approximately 1880 m/s while that in water is approximate ly 1480 m/s.
  • Measuring tube 7 has its opposite ends provided with apertures 11 through which the fluid to be measured flows into and out of the tube.
  • a seal 12 such as an O-ring, is operative as a partition separating the entrance and the exit of the flow meter.
  • the embodiment of Fig. 8 is an ultrasonic flow meter that is made entirely of a material having the acoustic properties required for measuring tube 7 of Figs. 5-7. It is possible to use this material for the entire meter if no strong, for example metallic, sleeve 6 is required. Self-evidently, hybrids of the embodiments of Figs. 5-8 are possible, for example embodiments having metallic connecting pieces.

Abstract

A transducer for use in an ultrasonic flow meter operating in accordance with the phase difference measuring principle or the transit time difference measuring principle, in which the transducer surface has raised and/or recessed portions of such shape and dimensions that a quenching pattern is imparted to the sound waves reflected from the transducer surface, which quenching pattern prevents the occurrence of objectionable echoes on an opposite transducer. An ultrasonic flow meter including such transducers is so arranged that sound waves directed towards the wall of the flow meter are absorbed and/or quenched.

Description

Transducer with reduced acoustic reflec¬ tion.
The invention relates to a method of reducing un- desired echos in ultrasonic flow meters operating in accordance with the phase or transit time difference measuring principle. The types of ultrasonic flow meters that operate in accordance with thephase or transit time difference measuring principle are often built up of two transducers mounted in spaced-apart, facing, parallel relationship and a calibrated measuring tube between these transducers. The fluid to be measured flows past the transducers and throug the measuring tube. An ultrasonic sound beam travelling downstream is seemingly accelerated while an ultrasonic sound beam travelling upstream is seemingly delayed. By transmitting a short duration sound beam concurrently via each one of the two transducers and, briefly thereafter, receiving the sound beams via these transducers as they arrive there, the flow velocity of the fluid can be derived from a measurement of the phase or transit time difference between the received sound beams. Self-evidently, the period of time during which the two sound beams are transmitted must not exceed the time required for reaching the opposite transducer as the latte should then be switched to operation as a receiver. Consequently, the measurement extends over a very brief period of time. To achieve sufficient accuracy of the measurement, the procedure of transmitting and receiving is repeated continuously at an optimally high repetition rate. However, when doing so the following problem is en¬ countered: when receiving, the transducers reflect part of the sound energy back into the measuring tube. This reflec tion effect is apt to repeat itself. The resultant echos will mix with the signals to be measured and measuring errors will result therefrom, thereby reducing the accurac of measurement of the present-day ultrasonic flow meters operating in accordance with the aforesaid principle. The first object of the present invention is to prevent the occurrence of such undesired echos or to at least so reduce such echos that their effect is negligible In accordance with the invention, this object is achieved as the active surface of each of the transducers is pro¬ vided with one or more raised or recessed portions, as a result of which such a quenching pattern is introduced into the reflected sound by interference that no or sub¬ stantially no echo is incident upon the opposite trans¬ ducer. Steps have to be taken, however, to prevent the side lobes formed by this reflection effect from reaching the opposite transducer due to, for example, reflections against the inner wall of the measuring tube.
Some examples of the effect of a transducer provided with a raised portion in accordance with the invention on the pattern of a reflected, planar ultrasonic sound beam are shown in Figs. 1-4. The outlines drawn in these Figures are each time lines of equal sound intensity 2, while the wavelength of the sound in. the fluid to be measured is λ.
In Fig. 1, the reflecting transducer 1 is flat and causes the normal reflection pattern.
In Figs. 2 and 3, the transducer is provided with a raised portion 3 of a height 1/4 λ, with a varying •§ rati A quenching region is formed above the edge of the raised portion by interference. The waves reflected from face 4 have to travel a distance that is 2 x 1/4 λ= 1/2 λ greate than the waves reflected from the face of raised portion Consequently, the first-named waves lag 180° in phase behind the last-named waves; local quenching occurs as a result of the mixing of two kinds of waves.
The shape of this quenching region can be altered by changing the Q- ratio but also, as shown in Fig. 4, by changing the height h. Accordingly, the most favourable dimensions of the raised portions of the flow meter structure according to the invention can be determined by calculation and experiment. It is observed in this respec that, self-evidently, the freedom to choose the dimension in question is limited by the fact that each transducers is also used as a transmitter and the transmit character¬ istic is determined, inter alia, by the shape of the, the emissive, surface of the transducer. Practice has shown that favourable results are achieved when ratio =• is in the range of from 0.3 to 0.7.
It is emphasized that, instead of the raised portion shown in the Figures, also recessed portions in the trans- ducer surface may be used to achieve similar effects.
Moreover, the raised or recessed portions may have shapes other than those shown in the Figures, for example annular shapes, while the raised or recessed portions further need not have the same dimension h over the entire surface. The total amount of reflected sound energy is not affected by the above steps. The reduction of the reflect¬ ed sound intensity in the centre axis of the transducer results in an increase in the reflected sound intensity at the edge thereof, i.e., the formation of side lobes. Accordingly, there is a danger of the relatively energy- rich side lobes reflecting from the wall of the measuring tube to so disturb the measuring signal.
A second object of the present invention is there¬ fore to prevent the occurrence of objectional reflections of the side lobes from the wall of the measuring tube. To this end, the tube wall is internally coated with a layer of a material in which the sound propagates at a velocity that is approximately equal to or smaller than the sound velocity in the fluid to be measured and which exhibits a relatively high internal damping. When the fluid to be measured is water, a suitable material is, for example, a synthetic material called polysulfon. So e embodiments of a flow meter in accordance with the invention are shown in Figs. 5,6,7 and 8, all based on though not limited to a previous patent application to the same inventor. The embodiment of Fig. 5 comprises a sleeve 6 in which the transducers 5 are mounted in enlarged sections thereof. Transducers 5 have active surfaces provided, in accordance with the first part of the present invention, with, in this embodiment, raised portions for preventing undesired echos in the axial direction of the measuring tube 7. This measuring tube 7 is formed by an inner coati on sleeve 6 and is of a material in which sound propagate at a velocity that is approximately equal to or smaller than that in water and which exhibits an optimally high sound damping. This material may be, for example, the aforesaid polysulfon, in which the sound velocity is approximately 1880 m/s while that in water is approximate ly 1480 m/s. The critical angle for incident sound water/ polysulfon is hence very small, so that practically all sound incident at an angle upon the coating penetrates into the polysulfon and is absorbed there for the greater part. None or only a minor part of this obliquely inciden reflection sound from the side lobes will therefore reach the opposite transducer, so that this reflection sound has no or only a negligible effect on the measuring proce Another embodiment is shown in Fig. 6. The distance between each of the transducers and the associated end of the inner coating 7, which coating is identical to that of Fig. 5, is made so large that the side lobe sound 8 is not incident upon this coating and dies in the spaces 9. A further embodiment is shown in Fig. 7. The inner coating or measuring tube 7 is mounted loose within sleeve 6 and is centred therein by means of the centring shoulder 10 of the transducers 5.
In this manner, a perfect concentric transmission of the sound within measuring tube 7 is ensured, which enhances the accuracy of the measurement even at very low flow velocities. In the embodiments of Figs. 5 and 6, several tolerances play a part in this concentricity. Measuring tube 7 has its opposite ends provided with apertures 11 through which the fluid to be measured flows into and out of the tube. A seal 12, such as an O-ring, is operative as a partition separating the entrance and the exit of the flow meter.
Finally, the embodiment of Fig. 8 is an ultrasonic flow meter that is made entirely of a material having the acoustic properties required for measuring tube 7 of Figs. 5-7. It is possible to use this material for the entire meter if no strong, for example metallic, sleeve 6 is required. Self-evidently, hybrids of the embodiments of Figs. 5-8 are possible, for example embodiments having metallic connecting pieces.
****

Claims

* C L A I M S *
1. A transducer for ultrasonic flow meters operating in accordance with the phase or transit time difference measuring principle, characterized in that the transducer surface against which reflection takes place includes raised and/or recessed portions of such shape and dimen¬ sions that a quenching pattern is imparted to the sound waves reflected from said surface, which quenching pattern serves to fully or practically fully prevent objectionable echos on the opposite transducer. •
2. A transducer according to claim 1, characterized in that the difference in height between the raised and/or recessed portions of the transducer surface against which reflection takes place is in the range of from 1/4 λ to 1/ λ, in which λ is the wavelength of the sound in the fluid the flow velocity of which is to be measured.
3. A transducer according to claims 1 and 2, characterisedin that the active surface of the transducer is circular and includes a raised or recessed portion th is concentric therewith.
4. A transducer according to claim 3, characterized in that said concentric, circular raised or recessed por¬ tion has a diameter that is between 0.3 and 0.7 times the diameter of the total surface against which reflection takes place.
5. An ultrasonic flow meter operating in accordance with the phase or transit time difference measuring prin¬ ciple, which meter includes transducers in accordance wit claims 1-4, characterized in that means are provided for preventing the side lobes formed by the interference of the reflected ultrasonic sound signal from adversely affe ing the accuracy of the measurement.
6. An ultrasonic flow meter according to claim 5, characterized in that the energy in the side lobes is captured and absorbed in an inner coating of the measurin tube of the flow meter, which inner coating is of a mate¬ rial in which sound propagates at a velocity that is approximately equal to or smaller than the sound velocity in the fluid 'to be measured and which exhibits a relativel high internal acoustic damping.
7. An ultrasonic flow meter according to claim 6, characterized in that the ends of said inner coating are spaced such a distance from the transducers that the side lobes fall outside the circumference of the inner coatin where said side lobes die in acoustic spaces provided for this purpose.
8. An ultrasonic flow meter according to claim 6, characterized in that said inner coating is a loose tube centred by means of centring shoulders on the transducers which tube is provided with apertures in its wall adjace the transducers for permitting the fluid to be measured to flow into and out of the tube, and which tube is ex¬ ternally provided with a sealing means, such as an O-rin for dividing the flow meter into two compartments and the by preventing the fluid from bypassing said tube.
9. An ultrasonic flow meter according to claim 5, characterized in that said meter is made entirely of a material in which sound propagates at a velocity that is approximately equal to or smaller than the sound velocity in the fluid to be measured and which exhibits a relative ly high internal damping.
10. An ultrasonic flow meter according to claim 9, characterized in that the connecting pieces for connect¬ ing the flow meter to components of the circuit through which the fluid to be measured flows are of a different, strong material, such as a metal.
11. An ultrasonic flow meter according to claims 5- 10, characterized in that said material for the inner coating or the entire meter is polysulfon.
12. An ultrasonic flow meter according to claims 5-10, characterized in that said material for the inner coating or the entire meter is PTFE.
13. An ultrasonic flow meter according to claims 5-10, characterized in that said material for the inner coating or the entire meter is polyamide.
&&&&
PCT/NL1985/000041 1984-10-23 1985-10-23 Transducer with reduced acoustic reflection WO1986002723A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL8403222 1984-10-23
NL8403222A NL8403222A (en) 1984-10-23 1984-10-23 METHOD OF REDUCING UNDESIRABLE ECHO'S IN ULTRASONIC FLOW SPEEDOMETERS.

Publications (1)

Publication Number Publication Date
WO1986002723A1 true WO1986002723A1 (en) 1986-05-09

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ID=19844652

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/NL1985/000041 WO1986002723A1 (en) 1984-10-23 1985-10-23 Transducer with reduced acoustic reflection

Country Status (3)

Country Link
EP (1) EP0203936A1 (en)
NL (1) NL8403222A (en)
WO (1) WO1986002723A1 (en)

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0249689A1 (en) * 1986-06-17 1987-12-23 Landis & Gyr Betriebs AG Sensor for the determination of the flow of a flowing fluid
GB2248502A (en) * 1990-10-02 1992-04-08 British Gas Plc Acoustic fluid flowmeter
GB2253907A (en) * 1991-03-21 1992-09-23 Halliburton Logging Services Device for sensing fluid behaviour
EP0538930A1 (en) * 1991-10-25 1993-04-28 Schlumberger Industries Apparatus for measuring the speed of a flowable medium
EP0565851A1 (en) * 1992-04-14 1993-10-20 Landis & Gyr Technology Innovation AG Ultrasonic transducer for liquid flow measurement
WO1994020822A1 (en) * 1993-03-09 1994-09-15 Commonwealth Scientific And Industrial Research Organisation Fluid meter construction
WO1994020821A1 (en) * 1993-03-09 1994-09-15 Commonwealth Scientific And Industrial Research Organisation Mode suppression in fluid meter conduits
DE4330363A1 (en) * 1993-09-08 1995-03-09 Krohne Messtechnik Kg Volume flow metering device
EP0681162A1 (en) * 1994-05-05 1995-11-08 Hydrometer GmbH Detector for ultrasonic measurement of fluid flows
WO1997006415A1 (en) * 1995-08-04 1997-02-20 Schlumberger Industries S.A. Fluid meter of the ultrasonic type for attenuation of parasitic ultrasonic waves
EP0790490A1 (en) * 1996-02-16 1997-08-20 Landis & Gyr Technology Innovation AG Utrasonic sensor to determine flow rate of a flowing liquid
EP0800062A2 (en) * 1996-04-04 1997-10-08 Georg Fischer Rohrleitungssysteme AG Device for measuring the flow velocity of a fluid
AU682498B2 (en) * 1993-03-09 1997-10-09 AGL Consultancy Pty. Limited Fluid meter construction
GB2313910A (en) * 1996-06-07 1997-12-10 Kromschroeder Ag G Acoustic fluid flowmeter
EP0897102A1 (en) * 1997-08-14 1999-02-17 Electrowatt Technology Innovation AG Ultrasonic flowmeter
EP0897101A1 (en) * 1997-08-14 1999-02-17 Electrowatt Technology Innovation AG Ultrasonic flowmeter
DE19921984A1 (en) * 1999-05-12 2000-11-23 Georg F Wagner Volume flow measurement unit, comprises two ultrasound transducers located in front and behind measurement tube
EP1387149A2 (en) 2002-07-31 2004-02-04 Hydrometer GmbH Ultrasonic flowmeter as well as operation method of the same
DE10235060A1 (en) * 2002-07-31 2004-02-26 Hydrometer Gmbh Ultrasound apparatus for measuring flow rate of fluid comprises curved channel in which reflector is mounted, inner wall of channel being made from material with similar ultrasound resistance to fluid
DE10356114A1 (en) * 2003-11-27 2005-06-23 Endress + Hauser Flowtec Ag, Reinach Device for determining and / or monitoring the volume and / or mass flow rate of a measuring medium
DE102004053860A1 (en) * 2004-11-04 2006-05-11 Hydrometer Gmbh Ultrasonic meter for e.g. liquid, has flow conducting units provided in inlet side in area of inlet opening of measuring section, which prevents or reduces or disposes formation of secondary flow in cross direction or opposite direction
EP1887328A1 (en) * 2006-08-08 2008-02-13 Siemens VDO Automotive AG Coaxially mounted ultrasound mass flow meter
DE202008014619U1 (en) * 2008-11-04 2009-12-24 Junker, Raul Ultrasonic flow meter
DE202009011310U1 (en) * 2009-08-19 2010-09-30 Junker, Raul Ultrasonic flowmeter with universal sensor carrier
WO2015000487A1 (en) * 2013-07-02 2015-01-08 Kamstrup A/S Flow meter with unbroken liner

Citations (8)

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Publication number Priority date Publication date Assignee Title
US2912856A (en) * 1955-07-29 1959-11-17 Kritz Jack Electroacoustic flowmeter
US4081786A (en) * 1976-08-16 1978-03-28 Etat Francais Represente Par Le Delegue Ministeriel Pour L'armement Hydrophone having a directive lobe in the form of a cardioid
FR2369561A1 (en) * 1976-10-27 1978-05-26 Medicor Muevek Measuring device for combustible gases in air - has test chamber with two incandescent filaments, one with catalyst, connected to differential amplifier
GB2011219A (en) * 1977-12-21 1979-07-04 Emi Ltd Ultrasonic probes
GB2017914A (en) * 1978-03-29 1979-10-10 Flowmetering Instr Ltd Improvements in or relating to ultrasonic flowmeters
EP0088235A1 (en) * 1982-03-01 1983-09-14 LGZ LANDIS & GYR ZUG AG Flow quantity transmitter for a flowing liquid
US4420707A (en) * 1982-08-09 1983-12-13 Automation Industries, Inc. Backing for ultrasonic transducer crystal
EP0108852A1 (en) * 1982-11-10 1984-05-23 Franz Rittmeyer AG Method of measuring fluid flow velocity and transmit/receive transducer for carrying out the method

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2912856A (en) * 1955-07-29 1959-11-17 Kritz Jack Electroacoustic flowmeter
US4081786A (en) * 1976-08-16 1978-03-28 Etat Francais Represente Par Le Delegue Ministeriel Pour L'armement Hydrophone having a directive lobe in the form of a cardioid
FR2369561A1 (en) * 1976-10-27 1978-05-26 Medicor Muevek Measuring device for combustible gases in air - has test chamber with two incandescent filaments, one with catalyst, connected to differential amplifier
GB2011219A (en) * 1977-12-21 1979-07-04 Emi Ltd Ultrasonic probes
GB2017914A (en) * 1978-03-29 1979-10-10 Flowmetering Instr Ltd Improvements in or relating to ultrasonic flowmeters
EP0088235A1 (en) * 1982-03-01 1983-09-14 LGZ LANDIS & GYR ZUG AG Flow quantity transmitter for a flowing liquid
US4420707A (en) * 1982-08-09 1983-12-13 Automation Industries, Inc. Backing for ultrasonic transducer crystal
EP0108852A1 (en) * 1982-11-10 1984-05-23 Franz Rittmeyer AG Method of measuring fluid flow velocity and transmit/receive transducer for carrying out the method

Cited By (43)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0249689A1 (en) * 1986-06-17 1987-12-23 Landis & Gyr Betriebs AG Sensor for the determination of the flow of a flowing fluid
GB2276242A (en) * 1990-10-02 1994-09-21 British Gas Plc Acoustic fluid flowmeter
GB2248502A (en) * 1990-10-02 1992-04-08 British Gas Plc Acoustic fluid flowmeter
GB2276242B (en) * 1990-10-02 1995-06-14 British Gas Plc Measurement system
GB2248502B (en) * 1990-10-02 1995-06-14 British Gas Plc Measurement system
GB2280267A (en) * 1991-03-21 1995-01-25 Halliburton Co Device for sensing fluid behaviour
GB2280267B (en) * 1991-03-21 1995-05-24 Halliburton Co Device for sensing fluid behaviour
GB2253907A (en) * 1991-03-21 1992-09-23 Halliburton Logging Services Device for sensing fluid behaviour
GB2253907B (en) * 1991-03-21 1995-05-24 Halliburton Logging Services Device for sensing fluid behaviour
US5383369A (en) * 1991-10-25 1995-01-24 Schlumberger Industries Device for measuring the velocity of a fluid
EP0538930A1 (en) * 1991-10-25 1993-04-28 Schlumberger Industries Apparatus for measuring the speed of a flowable medium
FR2683046A1 (en) * 1991-10-25 1993-04-30 Schlumberger Ind Sa DEVICE FOR MEASURING THE SPEED OF A FLUID.
EP0565851A1 (en) * 1992-04-14 1993-10-20 Landis & Gyr Technology Innovation AG Ultrasonic transducer for liquid flow measurement
US5728948A (en) * 1993-03-09 1998-03-17 Commonwealth Scientific And Industrial Research Organisation Fluid meter construction
WO1994020822A1 (en) * 1993-03-09 1994-09-15 Commonwealth Scientific And Industrial Research Organisation Fluid meter construction
AU674937B2 (en) * 1993-03-09 1997-01-16 AGL Consultancy Pty. Limited Mode suppression in fluid meter conduits
WO1994020821A1 (en) * 1993-03-09 1994-09-15 Commonwealth Scientific And Industrial Research Organisation Mode suppression in fluid meter conduits
AU682498B2 (en) * 1993-03-09 1997-10-09 AGL Consultancy Pty. Limited Fluid meter construction
DE4330363A1 (en) * 1993-09-08 1995-03-09 Krohne Messtechnik Kg Volume flow metering device
DE4330363C2 (en) * 1993-09-08 1999-04-01 Krohne Messtechnik Kg Volume flow meter
EP0681162A1 (en) * 1994-05-05 1995-11-08 Hydrometer GmbH Detector for ultrasonic measurement of fluid flows
DE4415889A1 (en) * 1994-05-05 1995-11-16 Hydrometer Gmbh Transducer for measuring liquid flows with ultrasound
WO1997006415A1 (en) * 1995-08-04 1997-02-20 Schlumberger Industries S.A. Fluid meter of the ultrasonic type for attenuation of parasitic ultrasonic waves
EP0790490A1 (en) * 1996-02-16 1997-08-20 Landis & Gyr Technology Innovation AG Utrasonic sensor to determine flow rate of a flowing liquid
EP0800062A3 (en) * 1996-04-04 1998-04-15 Georg Fischer Rohrleitungssysteme AG Device for measuring the flow velocity of a fluid
EP0800062A2 (en) * 1996-04-04 1997-10-08 Georg Fischer Rohrleitungssysteme AG Device for measuring the flow velocity of a fluid
GB2313910A (en) * 1996-06-07 1997-12-10 Kromschroeder Ag G Acoustic fluid flowmeter
EP0897102A1 (en) * 1997-08-14 1999-02-17 Electrowatt Technology Innovation AG Ultrasonic flowmeter
EP0897101A1 (en) * 1997-08-14 1999-02-17 Electrowatt Technology Innovation AG Ultrasonic flowmeter
DE19921984A1 (en) * 1999-05-12 2000-11-23 Georg F Wagner Volume flow measurement unit, comprises two ultrasound transducers located in front and behind measurement tube
DE19921984C2 (en) * 1999-05-12 2003-04-10 Schubert & Salzer Control Syst Device for volume flow measurement based on the ultrasonic transit time principle
DE10235060A1 (en) * 2002-07-31 2004-02-26 Hydrometer Gmbh Ultrasound apparatus for measuring flow rate of fluid comprises curved channel in which reflector is mounted, inner wall of channel being made from material with similar ultrasound resistance to fluid
EP1387149A2 (en) 2002-07-31 2004-02-04 Hydrometer GmbH Ultrasonic flowmeter as well as operation method of the same
DE10235032B3 (en) * 2002-07-31 2004-04-08 Hydrometer Gmbh Method for operating an ultrasonic flow meter and corresponding ultrasonic flow meter
DE10235060B4 (en) * 2002-07-31 2006-11-30 Hydrometer Gmbh Curved ultrasonic measuring section
EP1387149A3 (en) * 2002-07-31 2007-04-04 Hydrometer GmbH Ultrasonic flowmeter as well as operation method of the same
DE10356114A1 (en) * 2003-11-27 2005-06-23 Endress + Hauser Flowtec Ag, Reinach Device for determining and / or monitoring the volume and / or mass flow rate of a measuring medium
DE102004053860A1 (en) * 2004-11-04 2006-05-11 Hydrometer Gmbh Ultrasonic meter for e.g. liquid, has flow conducting units provided in inlet side in area of inlet opening of measuring section, which prevents or reduces or disposes formation of secondary flow in cross direction or opposite direction
DE102004053860B4 (en) * 2004-11-04 2009-04-16 Hydrometer Gmbh Ultrasonic counter for determining the flow rate of a flowing medium
EP1887328A1 (en) * 2006-08-08 2008-02-13 Siemens VDO Automotive AG Coaxially mounted ultrasound mass flow meter
DE202008014619U1 (en) * 2008-11-04 2009-12-24 Junker, Raul Ultrasonic flow meter
DE202009011310U1 (en) * 2009-08-19 2010-09-30 Junker, Raul Ultrasonic flowmeter with universal sensor carrier
WO2015000487A1 (en) * 2013-07-02 2015-01-08 Kamstrup A/S Flow meter with unbroken liner

Also Published As

Publication number Publication date
EP0203936A1 (en) 1986-12-10
NL8403222A (en) 1986-05-16

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