AU615763B2 - Creación de Inventos y Patentes con Inteligencia Artificial

AU615763B2 – Non-invasive meter calibrating arrangement
– Google Patents

AU615763B2 – Non-invasive meter calibrating arrangement
– Google Patents
Non-invasive meter calibrating arrangement

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Publication number
AU615763B2

AU615763B2
AU37383/89A
AU3738389A
AU615763B2
AU 615763 B2
AU615763 B2
AU 615763B2
AU 37383/89 A
AU37383/89 A
AU 37383/89A
AU 3738389 A
AU3738389 A
AU 3738389A
AU 615763 B2
AU615763 B2
AU 615763B2
Authority
AU
Australia
Prior art keywords
meter
housing
magnetic flux
arrangement according
arrangement
Prior art date
1988-06-24
Legal status (The legal status 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 status listed.)

Ceased

Application number
AU37383/89A
Other versions

AU3738389A
(en

Inventor
Roberto Capriotti
George W. Schneider Jr.
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Elster American Meter Co LLC

Original Assignee
American Meter Co Inc
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.)
1988-06-24
Filing date
1989-05-05
Publication date
1991-10-10

1989-05-05
Application filed by American Meter Co Inc
filed
Critical
American Meter Co Inc

1990-01-12
Publication of AU3738389A
publication
Critical
patent/AU3738389A/en

1991-10-10
Application granted
granted
Critical

1991-10-10
Publication of AU615763B2
publication
Critical
patent/AU615763B2/en

2009-05-05
Anticipated expiration
legal-status
Critical

Status
Ceased
legal-status
Critical
Current

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Classifications

G—PHYSICS

G01—MEASURING; TESTING

G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME

G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume

G—PHYSICS

G01—MEASURING; TESTING

G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME

G01F3/00—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow

G01F3/02—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement

G01F3/20—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement having flexible movable walls, e.g. diaphragms, bellows

G01F3/22—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement having flexible movable walls, e.g. diaphragms, bellows for gases

G01F3/227—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement having flexible movable walls, e.g. diaphragms, bellows for gases characterised by the means for transfer of membrane movement information to indicating means

G—PHYSICS

G01—MEASURING; TESTING

G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME

G01F15/00—Details of, or accessories for, apparatus of groups G01F1/00 – G01F13/00 insofar as such details or appliances are not adapted to particular types of such apparatus

G01F15/06—Indicating or recording devices

G01F15/065—Indicating or recording devices with transmission devices, e.g. mechanical

G01F15/066—Indicating or recording devices with transmission devices, e.g. mechanical involving magnetic transmission devices

G—PHYSICS

G01—MEASURING; TESTING

G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME

G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume

G01F25/10—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters

G—PHYSICS

G01—MEASURING; TESTING

G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME

G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume

G01F25/10—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters

G01F25/15—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters specially adapted for gas meters

G—PHYSICS

G01—MEASURING; TESTING

G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME

G—PHYSICS

G01—MEASURING; TESTING

G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME

G01F3/222—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement having flexible movable walls, e.g. diaphragms, bellows for gases characterised by drive mechanism for valves or membrane index mechanism

G01F3/223—Measuring the volume flow of fluids or fluent solid material wherein the fluid passes through the meter in successive and more or less isolated quantities, the meter being driven by the flow with measuring chambers which expand or contract during measurement having flexible movable walls, e.g. diaphragms, bellows for gases characterised by drive mechanism for valves or membrane index mechanism with adjustment of stroke or timing; Calibration thereof; Testing

Description

I i OPI DATE 12/01/90 APPLN. ID 37383 89 AOJP DATE 15/02/90 PCT Nu R PCT/US89/01868 T I INTERNATIONAL APPLICATIO B SH UN ERfE P NT COOPERATION TREATY (PCT) (51) International Patent Classification 4 (11) International ublication Number: WO 89/12804 G01F 25/00, 3/22 Al (43) International Publication Date: 28 December 1989 (28.12.89) (21) International Application Number: PCT/US89/01868 (81) Designated States: AT (European patent), AU, BE (European patent), CH (European patent), DE (European pa- (22) International Filing Date: 5 May 1.989 (05.05.89) tent), DK, FR (European patent), GB (European patent), IT (European patent), JP, KR, LU (European patent), NL (European patent), SE (European patent).
Priority data: 211,199 24 June 1988 (24.06.88) US Published With international search report.
(71) Applicant: AMERICAN METER COMPANY [US/US]; With amended claims.
13500 Philmont Avenue, P.O. Box 11600, Philadelphia, PA 19116 (US).
(72) Inventors: CAPRIOTTI, Roberto 1731 Robin Drive, Bensalem, PA 19020 SCHNEIDER, George, Jr. 3847 Shelley Road, Huntingdon Valley, PA 19006 (US).
(74) Agent: DAVIS, David, Plaza 9, 900 Route 9, Woodbridge, NJ 07095 (US).
(54) Title: NON-INVASIVE METER CALIBRATING ARRANGEMENT r’
I:
p t ‘i i l? (57) Abstract An arrangement for detecting cycles of operation of a positive displacement diaphragm gas meter sets up a magnetic field which is directed through the non-magnetic housing of the meter toward an internal cyclically moving ferromagnetic element of the meter. The strength of the magnetic field is varied as the ferromagnetic element moves toward and away from the source of the magnetic field. The strength of the magnetic field is detected and an ouput signal representative thereof is processed to define cycles of operation of the meter.
L
I ~1 -1 ii WO 89/12804 PCT/US89/01868 1- NON-INVASIVE METER CALIBRATING ARRANGEMENT BACKGROUND OF THE INVENTION This invention relates to motion detection arrangements and, more particularly, to an improved noninvasive arrangement for detecting the periodic pathwise movement of a ferromagnetic element enclosed within a non-magnetic housing.
Gas meters for domestic and industrial use are typically of the positive displacement diaphragm type.
Such a meter conventionally includes a housing with a vertical central partition dividing the housing into two sets of measuring chambers. Within each chamber is a flexible bellows (or convoluted sleeve diaphragm) connected to a central crankshaft by means of connecting rods. The crankshaft actuates a valve system which admits gas in and out of the bellows system. The bellows are caused to expand and contract by the passage of gas through the meter and act in the same manner as pistons to accurately displace a fixed volume of gas for each stroke, or cycle, of the bellows., j One complete cycle of the bellows produces one turn of the crankshaft. In addition to being connected to the i valve system, the crank shaft is also connected, through gearing, to a mechanical counter on the front of the meter. This counter is conventionally known as an index and usually contains one circular sweep hand for testing the accuracy of the meter. The dial including this circular sweep hand is commonly called the proving dial. Ut:: On typical household domestic type meters, the proving dial indicates a flow of two cubic feet of gas INTERNATIONAL SEARCH REPORT Internatlonal Application No PCT/US 89/01868 2 t 2 through the meter for each turn of its sweep hand.
However, due to the connecting gearing, the crankshaft usually makes eighteen turns for each turn of the proving dial sweep hand. Thus, eighteen complete cycles of the bellows are needed for one cycle of the proving dial sweep hand.
Meter accuracy is determined by measuring the actual volume of gas flowing through the meter for each turn of the proving hand. Meters are usually tested at 20% and 100% of their flow rate capacity. Since a domestic type meter normally has a capacity of 250 cubic feet per hour, it requires two minutes and twenty-four seconds for the proving hand to indicate two cubic feet at the capacity rate. This is extremely time consuming when testing meters on a production basis. Accordingly, it is an object of this invention to provide an arrangement for reducing the amount of time required to test meters for accuracy.
It would be desirable to be able to detect a single turn of the crankshaft. At the 20% capacity rate, this would take only eight seconds and at the 100% capacity rate, only one and six-tenths seconds. Therefore, by basing the meter accuracy test on only several turns of the crankshaft several cycles of the bellows) considerable time could be saved in proving the meter accuracy. It is therefore another object of this invention to provide an arrangement for accurately detecting the cycles of operation of a meter.
It is a further object of this invention to provide such an arrangement which is non-invasive in nature so that the detecting arrangement does not in any way affect the meter operation,
I
British patent specification 477,046 discloses a gas meter with an external indicating needle which is i ;3RSubstitute sheet ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. US 8901868 SA 29108 144 s ift I ;r I II f 2/1 magnetically coupled to follow the movement of an internal element of the meter. While non-invasive in nature, movement of this needle is sensed in a visual manner and is not readily adaptable for use in an automated meter calibration process. It is therefore still another object of this invention to provide a noninvasive meter calibration arrangement which may be utilized in an automated process.
10. SUMMARY OF THE INVENTION In accordance with the principles of this invention, it is recognized that within the meter there A 7 ?q Substitute sheet WO 89/12804 PCT/US89/01868 -3are ferromagnetic parts which undergo cyclic motion, and that the meter housing is generally of non-magnetic material. Accordingly, a magnetic field is set up and directed through the housing to one of the moving ferromagnetic parts. The strength of the magnetic field varies in accordance with the position of that part.
Since the motion of the part is cyclic, the magnetic field strength also varies cyclically. The field intensity is then detected and an electrical signal is i produced which corresponds with the change in intensity of the magnetic field. This electrical signal is then processed for defining cycles of the meter,.
BRIEF DESCRIPTION OF THE DRAWINGS The foregoing will be more readily apparent upon reading the following description in conjunction with the drawings in which like elements in different figures thereof have the same reference character applied thereto and wherein: FIG. 1 is a front view of a conventional diaphragm meter showing a portion of an arrangement constructed in accordance with the principles of this invention in place for detecting cycles of operation of the meter; and FIG. 2 is a schematic representation of the arrangement shown in FIG. 1 and taken as a side view through the meter illustrating changes in the magnetic field during the operation of the meter and the processing of electrical signals for defining cycles of operation of the meter.
DETAILED DESCRIPTION Referring now to the drawings, FIG. 1 illustrates a positive displacement diaphragm gas meter, designated generally by the reference numeral 10, with which an arrangement constructed in accordance with the -I i Is~- WO 89/12804 PCT/US89i 868 4 4principles of this invention may be utilized. The meter is illustratively of the type disclosed in U.S.
Patent No. 3,415,121, which issued on December 10, 1968 to R.R. Douglas, and includes a main housing which comprises a body member 12, a front cover 14, a back cover (not shown) and a top cover 16. As is conventional, the top cover 16 has integral inlet and outlet fittings 18 and 20, respectively, for connection into a gas line. At the front of the top cover is an index 22, driven from a crankshaft through internal gearing. The index 22 has a plurality of dials including a proving dial 24 having a circular sweep hand 26. The foregoing details are conventional and well known in the art, and the reader is invited to refer to the aforementioned patent if further elaboration is desired.
It is conventional that all of the elements making up the housing of the meter 10 the body member and the front, back and top covers) be manufactured from a non-magnetic material such as die cast aluminum.
Alternatively, these members may be made of a molded plastic composition if the technology so permits.
Within the housing of the meter 10, is a bellows assembly which includes a convoluted diaphragm sleeve element 28 fixedly mounted at one end (not shown) and sealed at the other end by a bellows pan 30. As is conventional, the bellows pan 30 is made of stampedI steel, which is a ferromagnetic material. The present invention makes use of the fact that during an operating cycle of the meter 10, the pan 30 travels over a known path. In particular, motion of the pan 30 is translatory toward and away from the front cover 14 over a distance S which is the stroke of the diaphragm 28. i One complete cycle of this motion from a position of the pan 30 closest to the front cover 14 to a position of the pan 30 furthest away from the front l WO 89/12804 PCT/US89/0 1868 cover 14 and back to the position closest to the front cover 14) corresponds to one complete cycle of operation of the meter 10, which indicates that a known volume of gas has passed through the meter 10. It typically requires eighteen of these cycles for the proving hand 26 to make one complete rotation.
According to this invention, motion of the pan is detected to define an operating cycle of the meter A proximity sensor, designated generally by the reference numeral 32, is held in position by a support I 34 close to the front cover 14, as shown in FIG. 2, and within the projected area of the pan 30, as shown in FIG. 1.
Illustratively, the proximity sensor 32 includes a magnetic structure 36 having north and south magnetic poles so arranged that the magnetic lines of flux are directed through the non-magnetic front cover 14 of the meter and are attracted by the pan 30. As the bellows are cycled by the gas flow, the pan 30 moves between the positions shown in solid and broken lines. This results in a change in length of the magnetic flux lines 38, as shown in FIG. 2. The increased length of the magnetic flux lines 38 when the pan 30 is in the broken line position reduces the total amount of magnetic flux which can flow through the magnet structure 36. Preferably, the magnet structure 36 comprises magnets 40 and 42 which are spaced apart and arranged with their poles in series aiding relationship to provide for a magnetic field with the lines of flux 38 passing through both the magnets 40 and 42. In the space between the magnets and 42 there is supported a magnetic flux detector 44.
The flux detector 44 is preferably a Hall effect sensor, illustratively a Model 3501 Linear Hall Effect Sensor manufactured by Sprague Electric. The detector 44 provides an output signal on the lead 46 which is representative of the magnitude of magnetic flux passing
L-
PC/US89/01868 WO 89/12804 6 through the detector 44. As the pan 30 moves toward and away from the proximity sensor 32, the magnitude of magnetic flux increases and decreases, respectively.
Accordingly, the output signal on the lead 46 varies in this manner, approaching a sinusoidal form. This output signal is amplified by the amplifier 48 and provided as an input to zero crossing detector 50. Zero crossing detector 50 processes the amplified output signal and provides at its output on the lead 52 pulses corresponding in time to the zero crossings of the amplified output signal. Since a complete cycle of a sinusoidal signal includes two zero crossings, the time between alternate pulses on the lead 52 is the time for a single cycle of operation of the meter 10, which in turn corresponds to a fixed volume of gas passing through the meter 10. The pulses on the lead 52 are provided as an input to the utilization means 54 which utilizes those pulses to calculate the cycle time and determine the accuracy of the meter 10, in a manner well know in the art of meter proving.
Although the magnets 40 and 42 are illustrated as being L-shaped, this particular shape is not critical.
What is required is a magnet structure so configured and positioned that the poles extend transverse to the housing 14 so that the magnetic field provided by the magnet structure is directed through the housing. Thus, a U- or horseshoe-shaped magnet structure would also be effective. Additionally, although the magnetic flux detector 44 is shown as being between separate magnets t 40 and 42, what is critical is that the detector is mounted within the magnetic field. Further, while the illustrative embodiment shows cooperation with the pan within the housing, any other ferromagnetic element of the meter which moves cyclically can be utilized.
Thus, for example, either the flag rod 56 or the flag rod arm 58 which is used in the linkage between the pan WO 89/12804 PCT/US89/01868 -7and the crankshaft, as is conventionally known, may be utilized as well, if it is made of ferromagnetic material.
Accordingly, there has been disclosed an improved arrangement for detecting periodic pathwise movement of a ferromagnetic element enclosed within a non-magnetic housing. It has been found that this arrangement, since it is not invasive, has no adverse effects upon the operation of the part whose motion is being detected.
It is understood that the above-described embodiment is merely illustrative of the application of the principles of this invention. Numerous other embodiments may be devised by those skilled in the art without departing from the spirit and scope of this invention, as defined by the appended claims.
i-

Claims (7)

1. An arrangement for non-invasively calibration testing a positive displacement diaphragm gas meter having a non-magnetic housing and an internal cyclically moving ferromagnetic element which forms an operating part of said meter, the arrangement including a magnet outside the housing in proximity to the ferromagnetic element, characterized by: means for fixedly supporting said magnet outside said housing so that movement of said ferromagnetic element causes the strength of the magnetic field of said magnet to cyclically vary; magnetic flux detector means for providing (an electrical signal representative of the magnitude of magnetic flux passing through said magnetic flux detector means; means for fixedly mounting said magnetic flux detector means outside said housing and within the magnetic field of said magnet; and means utilizing said electrical signal for defining cycles of operation of said meter.

2. The arrangement according to Claim 1 characterized in that said ferromagnetic comprises a bellows pan of said meter.

3. The arrangement according to Claim 1 characterized in that said ferromagnetic comprises a flag rod of said meter.

4. The arrangement according to Claim 1 further element further element further characterized comprises a flac SSubstitute sheet .T in that said ferromagnetic element Srod arm of said meter.i SUBSTITUTE S! -9 The arrangement according-to any one of the preceding claims further characterised in that said magnet comprises first and second series aiding parts and said magnetic flux detector means is mounted between said first and second series aiding parts.

6. The arrangement according to any one of the preceding claims further characterised in that the poles of said magnet extend transverse to said housing so that said magnetic field is directed through said housing. S.7. The arrangement according to any one of the preceding claims further characterised in that said magnetic flux detector means comprises a Hall effect sensor.

8. The arrangement according to any one of the preceding claims further characterised by an amplifier and a zero crossing detector electrically coupled between said S magnetic flux detector means and said utilising means.

9. An arrangement for non-invasively calibration testing a positive displacement diaphragm gas meter substantially as herein defined with reference to the accompanying drawings. DATED this 17th day of July 1991 AMERICAN METER COMPANY By their Patent Attorneys GRIFFITH HACK CO. A I~ n< S:19810L AU37383/89A 1988-06-24 1989-05-05 Non-invasive meter calibrating arrangement Ceased AU615763B2 (en) Applications Claiming Priority (2) Application Number Priority Date Filing Date Title US07/211,199 US4848148A (en) 1988-06-24 1988-06-24 Cyclic motion detection arrangement US211199 1988-06-24 Publications (2) Publication Number Publication Date AU3738389A AU3738389A (en) 1990-01-12 AU615763B2 true AU615763B2 (en) 1991-10-10 Family ID=22785937 Family Applications (1) Application Number Title Priority Date Filing Date AU37383/89A Ceased AU615763B2 (en) 1988-06-24 1989-05-05 Non-invasive meter calibrating arrangement Country Status (8) Country Link US (1) US4848148A (en) EP (1) EP0420870B1 (en) JP (1) JPH03503452A (en) KR (2) KR930010471B1 (en) AU (1) AU615763B2 (en) CA (1) CA1319829C (en) DK (1) DK305290D0 (en) WO (1) WO1989012804A1 (en) Families Citing this family (8) * Cited by examiner, † Cited by third party Publication number Priority date Publication date Assignee Title GB2242273B (en) * 1990-03-20 1994-01-12 Smith Meters Ltd Dry gas meter US5228469A (en) * 1991-08-15 1993-07-20 Otten Bernard J Fluid control system US5419191A (en) * 1992-08-17 1995-05-30 Qed Environmental Systems, Inc. Apparatus for counting cycles of fluid flow US5606514A (en) * 1995-08-21 1997-02-25 American Meter Company Cyclic signal processing HU0700754A2 (en) 2007-11-26 2009-05-28 Korrektometer Kft Electronic arrangement of safety measuremen for mechanical diaphragm type gas meter JP5512347B2 (en) * 2010-03-26 2014-06-04 株式会社エネゲート Gas flow measurement system US9234876B2 (en) 2013-03-29 2016-01-12 Stmicroelectronics Pte Ltd. Durable miniature gas composition detector having fast response time CN104075762B (en) * 2014-06-30 2017-10-27 辽宁航宇星物联仪表科技有限公司 Electron temperature amendment diaphragm gas meter flow sampling device Citations (3) * Cited by examiner, † Cited by third party Publication number Priority date Publication date Assignee Title GB477046A (en) * 1936-06-22 1937-12-21 Thomas Charles Braddock Improvements in and relating to dry gas meters DE1498415A1 (en) * 1965-10-26 1970-03-26 Pollux Gmbh Add-on device for checking water meters FR95936E (en) * 1968-08-01 1972-03-10 Heitz Albert Centralized metering for all fluids and energies. Family Cites Families (10) * Cited by examiner, † Cited by third party Publication number Priority date Publication date Assignee Title GB1183503A (en) * 1967-06-16 1970-03-11 Kent Ltd G Improvements in or relating to the measurement of fluid flow JPS5141049A (en) * 1974-10-05 1976-04-06 Senjin Kk GOSEIJUSHI SORYUBUTSUNO SEIZOSOCHI GB1602630A (en) * 1978-05-31 1981-11-11 Ferraris Dev & Eng Co Ltd Apparatus for monitoring respiratory performance JPS5611320A (en) * 1979-07-11 1981-02-04 Tamura Electric Works Ltd Check unit of gas meter US4488113A (en) * 1982-07-15 1984-12-11 The United States Of America As Represented By The Secretary Of The Navy Magnetic bridge proximity sensor JPS59226824A (en) * 1983-06-08 1984-12-20 Matsushita Electric Ind Co Ltd Flow rate measuring device US4565090A (en) * 1983-10-17 1986-01-21 Motohiro Gotanda Detection device for detecting and indicating operation of a gas meter EP0172451B1 (en) * 1984-07-31 1990-04-25 Matsushita Electric Industrial Co., Ltd. Flow rate detecting device JPS626178A (en) * 1985-06-13 1987-01-13 Korugu:Kk Signal variation detection circuit JPH05245953A (en) * 1991-07-25 1993-09-24 Totani Giken Kogyo Kk Hot blade support device of automatic bag making machine 1988 1988-06-24 US US07/211,199 patent/US4848148A/en not_active Expired - Fee Related 1989 1989-04-24 CA CA000597530A patent/CA1319829C/en not_active Expired - Fee Related 1989-05-05 JP JP1506272A patent/JPH03503452A/en active Pending 1989-05-05 EP EP89906551A patent/EP0420870B1/en not_active Expired - Lifetime 1989-05-05 AU AU37383/89A patent/AU615763B2/en not_active Ceased 1989-05-05 KR KR1019900700401A patent/KR930010471B1/en active 1989-05-05 WO PCT/US1989/001868 patent/WO1989012804A1/en active IP Right Grant 1989-05-05 KR KR1019900700401A patent/KR900702339A/en not_active IP Right Cessation 1990 1990-12-21 DK DK305290A patent/DK305290D0/en not_active Application Discontinuation Patent Citations (3) * Cited by examiner, † Cited by third party Publication number Priority date Publication date Assignee Title GB477046A (en) * 1936-06-22 1937-12-21 Thomas Charles Braddock Improvements in and relating to dry gas meters DE1498415A1 (en) * 1965-10-26 1970-03-26 Pollux Gmbh Add-on device for checking water meters FR95936E (en) * 1968-08-01 1972-03-10 Heitz Albert Centralized metering for all fluids and energies. Also Published As Publication number Publication date WO1989012804A1 (en) 1989-12-28 KR900702339A (en) 1990-12-06 JPH03503452A (en) 1991-08-01 DK305290A (en) 1990-12-21 EP0420870A1 (en) 1991-04-10 CA1319829C (en) 1993-07-06 DK305290D0 (en) 1990-12-21 US4848148A (en) 1989-07-18 KR930010471B1 (en) 1993-10-25 EP0420870B1 (en) 1993-02-03 AU3738389A (en) 1990-01-12 Similar Documents Publication Publication Date Title US5231876A (en) 1993-08-03 Method and apparatus for wind speed and direction measurement CA2033992C (en) 1996-07-16 Improved stability coriolis mass flow meter AU615763B2 (en) 1991-10-10 Non-invasive meter calibrating arrangement US3678750A (en) 1972-07-25 Liquid level indicator system KR20060060575A (en) 2006-06-05 Linear position sensor US20020189368A1 (en) 2002-12-19 Flow meter with a self-illuminating floater US4554828A (en) 1985-11-26 Measuring device for the magneto-inductive measuring of the flow rate of a liquid medium CN101231155B (en) 2011-10-05 Position detector for a component moved in a pipe US5493917A (en) 1996-02-27 Meter reading CN104677432A (en) 2015-06-03 Magnetostrictive displacement sensing flowmeter and flow measuring method JPH1090025A (en) 1998-04-10 Float type flow meter CN200975911Y (en) 2007-11-14 Liquid level and liquid quantity measuring device EP0417317A1 (en) 1991-03-20 Differential pressure gauge CN208313373U (en) 2019-01-01 A kind of flow counting sensor module JP2003014511A (en) 2003-01-15 Flow rate measuring apparatus US5606514A (en) 1997-02-25 Cyclic signal processing CN210625805U (en) 2020-05-26 Wide-range float-type flow sensor CN215524730U (en) 2022-01-14 Device for detecting relative flow of liquid CN108627210A (en) 2018-10-09 A kind of flow counting sensor module CN211042346U (en) 2020-07-17 A novel flowmeter for diesel injector test GB2388193A (en) 2003-11-05 Flowmeter and method of use RU25218U1 (en) 2002-09-20 IN-TUBE MULTI-CHANNEL PROFILE SU538236A1 (en) 1976-12-05 Liquid level sensor CN209446113U (en) 2019-09-27 A kind of sensing fingers side dress without magnetomechanical core EP2286186A1 (en) 2011-02-23 Diaphragm flow meter with rotating magnets
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