WO1997025595A1 - Flowmeter with pitot tube with average pressure - Google Patents
Flowmeter with pitot tube with average pressure Download PDFInfo
- Publication number
- WO1997025595A1 WO1997025595A1 PCT/US1996/020898 US9620898W WO9725595A1 WO 1997025595 A1 WO1997025595 A1 WO 1997025595A1 US 9620898 W US9620898 W US 9620898W WO 9725595 A1 WO9725595 A1 WO 9725595A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pressure
- flow rate
- transmitter
- stat
- static pressure
- Prior art date
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
- G01F1/05—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 using mechanical effects
- G01F1/34—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 using mechanical effects by measuring pressure or differential pressure
- G01F1/36—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 using mechanical effects by measuring pressure or differential pressure the pressure or differential pressure being created by the use of flow constriction
- G01F1/40—Details of construction of the flow constriction devices
- G01F1/46—Pitot tubes
Definitions
- the present invention relates to measurement of fluid flow. More specifically, the present invention relates to flow measurement of a process fluid using an averaging pitot tube type sensor.
- Measurement of flow rate of process fluid is necessary to control industrial processes .
- transmitters which measure flow rate (Q) are placed at remote locations in the field of a process control system. These transmitters transmit flow rate information to a control room. The flow rate information is used to control operation of the process.
- process fluid refers to both liquid and gaseous fluids.
- Head meters are the most common type of meter used to measure fluid flow rates. They measure fluid flow indirectly by creating and measuring a differential pressure by means of an obstruction to the fluid flow. Using well-established conversion coefficients which depend on the type of head meter used and the diameter of the pipe, a measurement of the differential pressure may be translated into a mass or volume rate.
- an averaging pitot tube type primary element for indicating flow consists of two hollow tubes that sense the pressure at different places within the pipe. These tubes can be mounted separately in the pipe or installed together in one casing as a single device. This design includes a forward facing tube which measures total pressure (P TOT ) . A second tube measures a down stream pressure. The differential pressure between the two tubes is proportional to the square of the flow as given in Equation 2.
- N Units conversion factor
- Y x Gas expansion factor (dimensionless)
- p Gas density (lb m /ft 3 )
- h Differential pressure (inches H 2 )
- the present invention provides a transmitter for measuring mass flow rate (Q) using an averaging pitot tube type primary element.
- the invention does not require a separate static pressure measurement .
- One aspect of the invention includes a total pressure sensor senses total pressure (P TOT ) of a process fluid from one pitot tube.
- a second pressure sensor measures a differential pressure between the tubes of the primary element.
- Circuitry in the transmitter calculates static pressure (P STAT ) based upon the total pressure.
- the calculated static pressure (P STAT ) is used to calculate fluid density (p) and the gas expansion factor (Y .
- Flow (Q) is calculated based upon the pressure measurements, the fluid density (p) and the gas expansion factor (Y .
- FIG. 1A shows a transmitter in accordance with the present invention coupled to a process pipe.
- Figure IB is a top cross sectional view showing an averaging pitot tube type primary element for use with the present invention.
- Figure IC shows the averaging pitot tube type primary element of Figure IC inserted in a process pipe.
- Figure 2 is a graph showing a comparison of gas density at maximum flow calculated using total pressure and calculated using static pressure versus differential pressure.
- Figure 3 is a graph showing the difference between total pressure and static pressure versus differential pressure for carbon dioxide gas in an 8 inch pipe.
- Figure 4 is a graph showing error in corrected static pressure calculated in accordance with the present invention versus differential pressure for carbon dioxide gas in an 8 inch pipe.
- Figure 5 is a simplified block diagram showing a transmitter for determining flow rate (Q) in accordance with the present invention.
- FIG. IA is a view of a process control system 10 including a transmitter 10 in accordance with the present invention coupled to process piping 12.
- Process piping 14 carries process fluid having a velocity (V) and a flow rate (Q) .
- Pipe 12 conducts flow of a fluid, either a gas or a liquid, in the direction indicated by arrow 16.
- the present invention does not require a separate measurement of static pressure (P STAT ) a & provides an accurate estimation of the P STAT based upon the total pressure (P TO ) which is sensed by the forward facing tube in an averaging pitot tube type primary element, and the differential pressure (h) measured between the two tubes.
- the estimated of calculated static pressure is used in calculations for determining fluid density (p) and the gas expansion factor (Y .
- the technique for estimating static pressure requires less computational time and power than using typical prior art formulas.
- Transmitter 10 includes transmitter electronics module 18 and sensor module 22.
- Transmitter electronics module 18 also preferably includes a boss 20 for accepting an input from a resistive temperature device (RTD) , preferably a 100 ohm RTD which is typically inserted directly into the pipe or into a thermowell which is inserted into the pipe to measure the process fluid temperature.
- RTD resistive temperature device
- the wires from the RTD are connected to one side of a terminal block in a temperature sensor housing 24.
- the other side of the terminal block is connected to wires which run through tube 26 and are coupled to boss 20.
- Sensor module 22 includes a differential pressure sensor for measuring differential pressure (h) and a pressure sensor for measuring total pressure (P TOT ) .
- the two sensors provide pressure signals which are digitized and provided to a microprocessor.
- Module 22 connects to primary element 14 through manifold 21 supported by mount 23.
- the compensated, linearized and digitized signals are provided to the electronics module 18.
- the electronics module 18 in transmitter 10 provides an output signal indicative of process conditions such as flow rate (Q) of the process fluid flowing through pipe 12 to a remote location, by a 4-20 A two-wire loop preferably formed using twisted pair conductors, through flexible conduit 28. Further, in accordance with the present invention, transmitter 10 also provides an output signal indicative of flow rate.
- Transmitter 12 is coupled to primary element 14.
- Primary element 14 may comprise, for example, a pitot tube such as that shown in U.S. Patent No. 4,154,100 to Harbaugh et al. issued May 15, 1979, entitled Method And Apparatus For Stabilizing The Flow Coefficient For Pitot-Type Flowmeters With A Downstream-Facing Port.
- the pressure sensed by transmitter 10 is the static pressure (P STAT ) of the process fluid, for use in calculating the gas density (p) and the gas expansion factor (Y x ) . These values are used in calculating the flow rate.
- transmitter 10 is used with an averaging pitot tube type primary element such as that shown in U.S. Patent No. 4,154,100, and the pressure measured on the upstream side of the pitot tube is an average value of the total, sometimes called stagnation, pressure
- Figures IB and IC show a more detailed view of averaging pitot tube type primary element 14 which penetrates into pipe 12.
- Element 14 includes an elongated body 30A carrying a forward facing pitot tube 3OB and a second, downstream facing pitot tube 30C.
- Tubes 3OB and 30C include a plurality of openings 32 and 34, respectively, distributed along the length of the tubes. The multiple openings ensure that an average pressure is measured across the entire flow 16.
- Tubes 30B and 30C connect to sensor body 22 of transmitter 10 through piping 21A and 21B and manifold 21.
- A Area of pipe (in 2 )
- R g Specific gas constant (R ⁇ /Mol Wt)
- T Absolute temperature (°R)
- g c gravitational proportionality constant
- ⁇ ratio of specific heats (isentropic exponent)
- Equation 3 relates P TOT and P STAT .
- the temperature used in the expression is the total temperature.
- the temperature measured by an RTD will be assumed to represent the total temperature.
- the total pressure (P TO ⁇ ) calculated using this relationship represents the upstream pressure which would be otherwise measured by the transmitter 10 using tube 3OB. The procedure continues:
- FIG. 5 is a simplified block diagram showing transmitter 10 for implementing the present invention.
- Transmitter 10 includes microprocessor 40 coupled to analog to digital converter 42.
- Analog to digital converter 42 connects to pressure sensors 44 and 46 for sensing a pressure (P TO ) from tube 30B and a differential pressure (h) from tube 30C, respectively.
- Sensors 44 and 46 coupled to primary element 14 shown in Figure IA.
- Analog to digital converter 42 also receives a temperature input from temperature sensor 24.
- Microprocessor 40 operates in accordance with instructions stored in memory 50 at a clock rate determined by clock 52. Memory 50 also stores information for microprocessor 40.
- Input/output circuitry 54 connects to process control loop 28A through terminal connections 56. Loop 28A carries current I from a remote source of power, which is used by input/output circuitry 54 to generate power for transmitter 10. In one embodiment, transmitter 10 is wholly (or exclusively) powered by loop current I. Information is transmitted over loop 28A by input/output circuitry 54 by controlling the value of current I of control loop 28A. Additionally, input/output circuitry 54 may digitally modulate information onto loop 28A. Transmitter 12 is also capable of receiving instructions over loop 28A.
- Microprocessor 40 uses the equations discussed above and accurately calculates flow rate (Q) using the total pressure (P TOT ) to determine fluid density (p) .
- the present invention provides an estimated value of static pressure (P STAT ) based upon the pressure (P TOT ) anc * the differential pressure (h) from an averaging pitot tube type primary element. This eliminates the extra sensor in the prior art used to measure static pressure and the extra intrusion into the flow tube.
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP96945447A EP0871848B1 (en) | 1996-01-04 | 1996-12-31 | Flowmeter with pitot tube with average pressure |
JP52526497A JP4020433B2 (en) | 1996-01-04 | 1996-12-31 | Transmitter with average pitot tube type primary element and method of use thereof |
DE69629211T DE69629211T2 (en) | 1996-01-04 | 1996-12-31 | PITOT FLOW METER WITH AVERAGE PRESSURE |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/582,905 US5817950A (en) | 1996-01-04 | 1996-01-04 | Flow measurement compensation technique for use with an averaging pitot tube type primary element |
US08/582,905 | 1996-01-04 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1997025595A1 true WO1997025595A1 (en) | 1997-07-17 |
Family
ID=24330926
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1996/020898 WO1997025595A1 (en) | 1996-01-04 | 1996-12-31 | Flowmeter with pitot tube with average pressure |
Country Status (7)
Country | Link |
---|---|
US (1) | US5817950A (en) |
EP (1) | EP0871848B1 (en) |
JP (1) | JP4020433B2 (en) |
CN (1) | CN1105292C (en) |
CA (1) | CA2239497A1 (en) |
DE (1) | DE69629211T2 (en) |
WO (1) | WO1997025595A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102007030691A1 (en) | 2007-06-30 | 2009-01-02 | Endress + Hauser Flowtec Ag | Measuring system for a medium flowing in a process line |
DE102007030699A1 (en) | 2007-06-30 | 2009-01-15 | Endress + Hauser Flowtec Ag | Measuring system for a medium flowing in a process line |
DE102007030700A1 (en) | 2007-06-30 | 2009-05-07 | Endress + Hauser Flowtec Ag | Measuring system for a medium flowing in a process line |
DE102007030690A1 (en) | 2007-06-30 | 2009-05-07 | Endress + Hauser Flowtec Ag | Measuring system for a medium flowing in a process line |
WO2021061612A1 (en) * | 2019-09-27 | 2021-04-01 | ElectroSea, LLC | System and method for performing diagnostics of a water system on-board a watercraft |
Families Citing this family (71)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8290721B2 (en) | 1996-03-28 | 2012-10-16 | Rosemount Inc. | Flow measurement diagnostics |
US7949495B2 (en) | 1996-03-28 | 2011-05-24 | Rosemount, Inc. | Process variable transmitter with diagnostics |
US6539267B1 (en) | 1996-03-28 | 2003-03-25 | Rosemount Inc. | Device in a process system for determining statistical parameter |
US6907383B2 (en) * | 1996-03-28 | 2005-06-14 | Rosemount Inc. | Flow diagnostic system |
US6654697B1 (en) * | 1996-03-28 | 2003-11-25 | Rosemount Inc. | Flow measurement with diagnostics |
US6017143A (en) | 1996-03-28 | 2000-01-25 | Rosemount Inc. | Device in a process system for detecting events |
US6754601B1 (en) | 1996-11-07 | 2004-06-22 | Rosemount Inc. | Diagnostics for resistive elements of process devices |
US6601005B1 (en) | 1996-11-07 | 2003-07-29 | Rosemount Inc. | Process device diagnostics using process variable sensor signal |
US6519546B1 (en) | 1996-11-07 | 2003-02-11 | Rosemount Inc. | Auto correcting temperature transmitter with resistance based sensor |
CA2249797C (en) * | 1997-10-16 | 2001-03-27 | Yasuo Yamamoto | Fluid pressure detector and air flow rate measuring apparatus using same |
US6615149B1 (en) | 1998-12-10 | 2003-09-02 | Rosemount Inc. | Spectral diagnostics in a magnetic flow meter |
US6611775B1 (en) | 1998-12-10 | 2003-08-26 | Rosemount Inc. | Electrode leakage diagnostics in a magnetic flow meter |
US6505517B1 (en) | 1999-07-23 | 2003-01-14 | Rosemount Inc. | High accuracy signal processing for magnetic flowmeter |
US6321166B1 (en) * | 1999-08-05 | 2001-11-20 | Russell N. Evans | Noise reduction differential pressure measurement probe |
US6701274B1 (en) | 1999-08-27 | 2004-03-02 | Rosemount Inc. | Prediction of error magnitude in a pressure transmitter |
US6543297B1 (en) | 1999-09-13 | 2003-04-08 | Rosemount Inc. | Process flow plate with temperature measurement feature |
US6311568B1 (en) | 1999-09-13 | 2001-11-06 | Rosemount, Inc. | Process flow device with improved pressure measurement feature |
US6425298B1 (en) | 2000-02-17 | 2002-07-30 | Westinghouse Savannah River Company, Llc | Apparatus for passive removal of subsurface contaminants and volume flow measurement |
AU2001241641A1 (en) | 2000-03-08 | 2001-09-17 | Rosemount, Inc. | Piston position measuring device |
JP2003526097A (en) | 2000-03-08 | 2003-09-02 | ローズマウント インコーポレイテッド | Two-way differential pressure fluid sensor |
US20010037724A1 (en) | 2000-03-08 | 2001-11-08 | Schumacher Mark S. | System for controlling hydraulic actuator |
US6629059B2 (en) | 2001-05-14 | 2003-09-30 | Fisher-Rosemount Systems, Inc. | Hand held diagnostic and communication device with automatic bus detection |
US6588313B2 (en) | 2001-05-16 | 2003-07-08 | Rosemont Inc. | Hydraulic piston position sensor |
US6772036B2 (en) | 2001-08-30 | 2004-08-03 | Fisher-Rosemount Systems, Inc. | Control system using process model |
KR100432640B1 (en) * | 2001-12-05 | 2004-05-22 | 차은종 | A spirometer using a disposable mouthpiece |
US7284450B2 (en) * | 2002-04-09 | 2007-10-23 | Dieterich Standard, Inc. | Averaging orifice primary flow element |
US6935156B2 (en) * | 2003-09-30 | 2005-08-30 | Rosemount Inc. | Characterization of process pressure sensor |
US8112565B2 (en) | 2005-06-08 | 2012-02-07 | Fisher-Rosemount Systems, Inc. | Multi-protocol field device interface with automatic bus detection |
US20070068225A1 (en) | 2005-09-29 | 2007-03-29 | Brown Gregory C | Leak detector for process valve |
US7579947B2 (en) * | 2005-10-19 | 2009-08-25 | Rosemount Inc. | Industrial process sensor with sensor coating detection |
US7258000B2 (en) * | 2005-11-11 | 2007-08-21 | The Boeing Company | Scanner and method for detecting pressures on a member |
US7953501B2 (en) | 2006-09-25 | 2011-05-31 | Fisher-Rosemount Systems, Inc. | Industrial process control loop monitor |
US8788070B2 (en) | 2006-09-26 | 2014-07-22 | Rosemount Inc. | Automatic field device service adviser |
WO2008042290A2 (en) | 2006-09-29 | 2008-04-10 | Rosemount Inc. | Magnetic flowmeter with verification |
US8898036B2 (en) | 2007-08-06 | 2014-11-25 | Rosemount Inc. | Process variable transmitter with acceleration sensor |
JP4870633B2 (en) * | 2007-08-29 | 2012-02-08 | シーケーディ株式会社 | Flow rate verification system and flow rate verification method |
US7654157B2 (en) * | 2007-11-30 | 2010-02-02 | Honeywell International Inc. | Airflow sensor with pitot tube for pressure drop reduction |
US7836780B2 (en) | 2008-02-26 | 2010-11-23 | Rosemount Inc. | Sensor tube with reduced coherent vortex shedding |
US8655604B2 (en) * | 2008-10-27 | 2014-02-18 | Rosemount Inc. | Multivariable process fluid flow device with fast response flow calculation |
US8104340B2 (en) * | 2008-12-19 | 2012-01-31 | Honeywell International Inc. | Flow sensing device including a tapered flow channel |
US7921734B2 (en) | 2009-05-12 | 2011-04-12 | Rosemount Inc. | System to detect poor process ground connections |
US8113046B2 (en) | 2010-03-22 | 2012-02-14 | Honeywell International Inc. | Sensor assembly with hydrophobic filter |
US8656772B2 (en) | 2010-03-22 | 2014-02-25 | Honeywell International Inc. | Flow sensor with pressure output signal |
US8397586B2 (en) | 2010-03-22 | 2013-03-19 | Honeywell International Inc. | Flow sensor assembly with porous insert |
US8756990B2 (en) | 2010-04-09 | 2014-06-24 | Honeywell International Inc. | Molded flow restrictor |
US9003877B2 (en) | 2010-06-15 | 2015-04-14 | Honeywell International Inc. | Flow sensor assembly |
US8418549B2 (en) | 2011-01-31 | 2013-04-16 | Honeywell International Inc. | Flow sensor assembly with integral bypass channel |
US9611856B2 (en) | 2010-12-30 | 2017-04-04 | Fluid Handling Llc | Mixed theoretical and discrete sensorless converter for pump differential pressure and flow monitoring |
US8700221B2 (en) | 2010-12-30 | 2014-04-15 | Fluid Handling Llc | Method and apparatus for pump control using varying equivalent system characteristic curve, AKA an adaptive control curve |
US8695417B2 (en) | 2011-01-31 | 2014-04-15 | Honeywell International Inc. | Flow sensor with enhanced flow range capability |
US9207670B2 (en) * | 2011-03-21 | 2015-12-08 | Rosemount Inc. | Degrading sensor detection implemented within a transmitter |
CA2856447C (en) | 2011-12-16 | 2019-06-04 | Fluid Handling Llc | Dynamic linear control methods and apparatus for variable speed pump control |
US9052240B2 (en) | 2012-06-29 | 2015-06-09 | Rosemount Inc. | Industrial process temperature transmitter with sensor stress diagnostics |
CN102788616A (en) * | 2012-07-24 | 2012-11-21 | 华中科技大学 | Flow distribution measuring device and method for lubrication system of combustion engine |
US9602122B2 (en) | 2012-09-28 | 2017-03-21 | Rosemount Inc. | Process variable measurement noise diagnostic |
US9052217B2 (en) | 2012-11-09 | 2015-06-09 | Honeywell International Inc. | Variable scale sensor |
US8960018B2 (en) * | 2013-03-14 | 2015-02-24 | Dieterich Standard, Inc. | Pitot tube traverse assembly |
US9157775B2 (en) * | 2013-03-15 | 2015-10-13 | Rosemount Inc. | Flowmeter for measuring flow of a process fluid through a conduit including process variable sensors mounted on a pitot tube |
US9207109B2 (en) * | 2013-04-09 | 2015-12-08 | Honeywell International Inc. | Flow sensor with improved linear output |
CA2826516C (en) * | 2013-08-30 | 2020-09-22 | Protecsom Amerique Du Nord Inc. | Flow measuring apparatus and inhalation apparatus comprising the same |
US10184678B2 (en) | 2013-09-06 | 2019-01-22 | Carrier Corporation | System and method for measuring duct leakage in a HVAC system |
US9250107B2 (en) * | 2013-09-17 | 2016-02-02 | Dieterich Standard, Inc. | Customizable averaging pitot tube probe and process variable transmitter |
TW201602524A (en) * | 2014-07-01 | 2016-01-16 | Univ Ishou | Fluid flow measurement device |
US9952079B2 (en) | 2015-07-15 | 2018-04-24 | Honeywell International Inc. | Flow sensor |
US9996089B2 (en) | 2015-09-21 | 2018-06-12 | Blue-White Industries, Ltd. | Flow sensor devices and systems |
US10444367B2 (en) * | 2016-02-26 | 2019-10-15 | Honeywell International Inc. | Enhanced LiDAR air data using supplementary sensor outputs |
GB2555003B (en) * | 2016-09-23 | 2022-07-06 | Blue White Ind Ltd | Flow sensor devices and systems |
EP3710789A4 (en) * | 2017-11-15 | 2021-07-21 | Protecsom Amerique du Nord Inc. | Flow measuring apparatus and inhalation apparatus comprising the same |
US11513033B2 (en) * | 2019-02-21 | 2022-11-29 | Rolls-Royce Corporation | Gas turbine engine system with health monitoring of fuel pump condition |
GB2587844A (en) | 2019-06-07 | 2021-04-14 | Blue White Ind Ltd | Flow sensor devices and systems |
ES1266233Y (en) * | 2021-01-19 | 2021-07-28 | Albina Lopez De Armentia Inigo | Fitting for flow and volume measurement and consumption detection in hydrants, hydrants or any type of outlet |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4154100A (en) * | 1978-01-09 | 1979-05-15 | Dieterich Standard Corp. | Method and apparatus for stabilizing the flow coefficient for pitot-type flowmeters with a downstream-facing port |
US4320665A (en) * | 1979-12-17 | 1982-03-23 | Electric Power Research Institute, Inc. | Method and means for measuring flow of a two phase fluid |
US4559835A (en) * | 1983-08-11 | 1985-12-24 | Air Monitor Corporation | Flow measuring traverse probe |
US5365795A (en) * | 1993-05-20 | 1994-11-22 | Brower Jr William B | Improved method for determining flow rates in venturis, orifices and flow nozzles involving total pressure and static pressure measurements |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US817470A (en) * | 1905-03-15 | 1906-04-10 | John A Cole | Pitot-tube connection. |
US1093229A (en) * | 1912-08-05 | 1914-04-14 | Gen Electric | Pitot plug for fluid-meters. |
US1809376A (en) * | 1924-04-11 | 1931-06-09 | Edward S Cole | Orifice for flow measuring systems |
US3765241A (en) * | 1971-02-11 | 1973-10-16 | R Lambert | Universal sensing apparatus for sensing volumetric rate of fluid flow |
US3751982A (en) * | 1971-05-03 | 1973-08-14 | R Lambert | Fluid flow meter head and system using same |
US4425807A (en) * | 1982-02-11 | 1984-01-17 | Michael Victor | Flow measuring device with constant flow coefficient |
GB8321482D0 (en) * | 1983-08-10 | 1983-09-14 | Tekflo Ltd | Flowmeter |
US4559836A (en) * | 1984-10-17 | 1985-12-24 | Dieterich Standard Corp. | Pitot type flow measuring device and method of mounting |
US4754651A (en) * | 1986-04-18 | 1988-07-05 | Shortridge Instruments, Inc. | Differential pressure apparatus for measuring flow and velocity |
US4717159A (en) * | 1986-06-06 | 1988-01-05 | Dieterich Standard Corp. | Method and apparatus for seating and sealing a pitot tube type flow meter in a pipe |
US4768386A (en) * | 1986-08-14 | 1988-09-06 | Cambridge Filter Corp. | Air pressure measurement element and system incorporating same |
US4823615A (en) * | 1987-11-04 | 1989-04-25 | Preso Industries | Self-averaging pitot tube probe and method for measuring fluid flow |
US5313980A (en) * | 1993-04-06 | 1994-05-24 | Carlson Bengt A | Method of and valve for controlling flow in a hydronic system |
-
1996
- 1996-01-04 US US08/582,905 patent/US5817950A/en not_active Expired - Lifetime
- 1996-12-31 WO PCT/US1996/020898 patent/WO1997025595A1/en active IP Right Grant
- 1996-12-31 CA CA002239497A patent/CA2239497A1/en not_active Abandoned
- 1996-12-31 CN CN96199085A patent/CN1105292C/en not_active Expired - Lifetime
- 1996-12-31 DE DE69629211T patent/DE69629211T2/en not_active Expired - Lifetime
- 1996-12-31 JP JP52526497A patent/JP4020433B2/en not_active Expired - Lifetime
- 1996-12-31 EP EP96945447A patent/EP0871848B1/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4154100A (en) * | 1978-01-09 | 1979-05-15 | Dieterich Standard Corp. | Method and apparatus for stabilizing the flow coefficient for pitot-type flowmeters with a downstream-facing port |
US4154100B1 (en) * | 1978-01-09 | 1987-11-03 | ||
US4320665A (en) * | 1979-12-17 | 1982-03-23 | Electric Power Research Institute, Inc. | Method and means for measuring flow of a two phase fluid |
US4559835A (en) * | 1983-08-11 | 1985-12-24 | Air Monitor Corporation | Flow measuring traverse probe |
US5365795A (en) * | 1993-05-20 | 1994-11-22 | Brower Jr William B | Improved method for determining flow rates in venturis, orifices and flow nozzles involving total pressure and static pressure measurements |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102007030691A1 (en) | 2007-06-30 | 2009-01-02 | Endress + Hauser Flowtec Ag | Measuring system for a medium flowing in a process line |
DE102007030699A1 (en) | 2007-06-30 | 2009-01-15 | Endress + Hauser Flowtec Ag | Measuring system for a medium flowing in a process line |
DE102007030700A1 (en) | 2007-06-30 | 2009-05-07 | Endress + Hauser Flowtec Ag | Measuring system for a medium flowing in a process line |
DE102007030690A1 (en) | 2007-06-30 | 2009-05-07 | Endress + Hauser Flowtec Ag | Measuring system for a medium flowing in a process line |
WO2021061612A1 (en) * | 2019-09-27 | 2021-04-01 | ElectroSea, LLC | System and method for performing diagnostics of a water system on-board a watercraft |
Also Published As
Publication number | Publication date |
---|---|
CN1204396A (en) | 1999-01-06 |
JP4020433B2 (en) | 2007-12-12 |
EP0871848B1 (en) | 2003-07-23 |
JP2000503123A (en) | 2000-03-14 |
CA2239497A1 (en) | 1997-07-17 |
DE69629211D1 (en) | 2003-08-28 |
EP0871848A1 (en) | 1998-10-21 |
DE69629211T2 (en) | 2004-04-22 |
CN1105292C (en) | 2003-04-09 |
US5817950A (en) | 1998-10-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5817950A (en) | Flow measurement compensation technique for use with an averaging pitot tube type primary element | |
US6957586B2 (en) | System to measure density, specific gravity, and flow rate of fluids, meter, and related methods | |
US11852517B2 (en) | Method for generating a diagnostic from a deviation of a flow meter parameter | |
US6412353B1 (en) | Vortex flowmeter with signal processing | |
JP5147844B2 (en) | Process equipment with density measurement | |
US7258024B2 (en) | Simplified fluid property measurement | |
WO1998043051A9 (en) | Vortex flowmeter with signal processing | |
CA2587175A1 (en) | Method and apparatus for determining flow pressure using density information | |
EP0166502A1 (en) | Dual orifice flow meter | |
JP2005017152A (en) | Flowmeter, flow rate calculation method, program and recording medium | |
RU2305288C2 (en) | Device for measuring parameters of gas flow | |
Olin | Generation-next mass flowmeter arrives | |
LIPTÁK et al. | 2.16 Pitot Tubes and Area Averaging Units | |
JPH0561570B2 (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 96199085.6 Country of ref document: CN |
|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): CA CN JP SG |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 1996945447 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2239497 Country of ref document: CA Ref document number: 2239497 Country of ref document: CA Kind code of ref document: A |
|
WWP | Wipo information: published in national office |
Ref document number: 1996945447 Country of ref document: EP |
|
WWG | Wipo information: grant in national office |
Ref document number: 1996945447 Country of ref document: EP |