WO2008139237A1 - Flow rate sensor for water ducts and a method for measuring water flow - Google Patents
Flow rate sensor for water ducts and a method for measuring water flow Download PDFInfo
- Publication number
- WO2008139237A1 WO2008139237A1 PCT/IB2007/001204 IB2007001204W WO2008139237A1 WO 2008139237 A1 WO2008139237 A1 WO 2008139237A1 IB 2007001204 W IB2007001204 W IB 2007001204W WO 2008139237 A1 WO2008139237 A1 WO 2008139237A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- sensor
- support
- water
- duct
- lamina
- 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
- G01F1/68—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 thermal effects
- G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
-
- 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
- G01F1/68—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 thermal effects
- G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
- G01F1/688—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element
- G01F1/69—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element of resistive type
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49826—Assembling or joining
Definitions
- the present invention relates to devices for measuring physical parameters of a fluid flow and, in particular, it relates to a flow rate sensor for water flowing in water ducts.
- sensors For monitoring the flow, many sensors should be provided along the pipes of a net, and such sensors should be very cheap and easy to clean or to change without the need of stopping the flow.
- Many sensors exist, of different nature, capable of measuring the flow rate in ducts.
- thermal electronic solid state sensors exist capable of measuring the flow by meauring the heat transferred by a resistor to a liquid and, in particular, the temperature difference between a heater and a thermoresistance .
- An example of such sensors is described in US 6,494,090.
- thermo-dynamic principle preferably communicate the measured data to a control system, causing, in the known devices, high costs for creating cable connections with the result of a too low number of sensors mounted in a pipeline, sometimes insufficient for a precise flow control.
- known sensors that exploit this thermo-dynamic principle have the drawback that, during the measure, the heat of the resistor produces vapour bubbles, which in part remain attached to the sensor and in part are removed by the flow. Such bubbles, create an insulation around the sensor and negatively affect the flow measurements.
- the sensors that exploit this thermo-dynamic principle furthermore, enhance the deposit of calcium carbonate
- Another feature of the invention is to provide a water flow rate sensing device for water ducts capable of positioning a thermal flow rate sensor in a substantially central position with respect to the flow, where the flow is not much influenced by the walls of the duct.
- a further feature of the invention is to provide a water flow rate sensing device for water ducts capable of cheaply communicating with a central control unit .
- Another feature of the invention is to provide a water flow rate sensing device for water ducts, capable of avoiding the problem of the production of gas bubbles and the deposit of such bubbles on the surface of the sensor during the measurements .
- Another feature of the invention is to provide a water flow rate sensing device for water ducts, capable of minimizing the sensor degradation owing to the deposit of calcium carbonate.
- a further feature of the invention is to provide a water flow rate sensing device for water ducts, which allows discriminating the direction of the water flow in the pipes, by compact a flow rate solid state thermal sensor.
- a further feature of the invention is to provide a method that allows measuring the water flow for water ducts that achieves the above described objects.
- a water flow rate sensing device for water ducts comprising:
- a solid state thermal sensor having at least one heater and at least one thermoresistance at a same temperature of the water, said sensor being adapted to measure the flow rate by measuring the temperature difference between said at least one heater and said at least one thermoresistance, supplying an outlet signal proportional to said flow;
- a support for said sensor having elongated shape - A - with a first and a second end, said sensor being of said support, said first end being adapted to be inserted in a hole made in a duct in order to support said sensor in an inner point of said duct in a zone of flow distant from the walls of the duct;
- said support provides a lamina- shaped extension member to it integrally connected at said first end and adapted to be put in the water flow, said extension member holding said sensor distanced from said first end.
- said extension member comprises first electric contacts adapted to be coupled with respective electric contacts made in said support at said first end, said lamina having longitudinal electric paths for connecting said first contacts of said lamina with a housing for said sensor, in said housing said lamina having second electric contacts for coupling to respective contacts present in said sensor.
- said solid state thermal sensor has a first heater and a first thermoresistance placed adjacent to one another, along the direction of the flow, as well as a second heater and a second thermoresistance, in particular, said first and second thermoresistances being interdigited to each other.
- said lamina can be made in different lengths responsive to the diameters of the duct where the flow rate sensor according to the invention has to be applied.
- said lamina is made of ceramic and said paths are made with the thick film technology.
- said lamina has a section adapted to a use in fluid dynamics, and said sensor is inserted at one end of said lamina in order not to offer edges to the water flow, said lamina having a recess for receiving the sensor.
- thermoresistances are interdigited to each other, they are at a same temperature coincident to that of the water, whereas the first heater is located upstream and the second heater downstream from the flow, the second heater exchanging heat less than the first heater owing to the water flow, thus determining the flow direction by the difference of the signals obtained from the two couples of heaters and thermoresistances.
- said sensing device comprises means to supply electric energy to said sensor, selected from the group comprised of:
- - a self feeding device that uses the kinetic energy associated with the motion of the water in the duct, in particular, based on "energy harvesting” techniques .
- said battery can be rechargeable by an electric connection to the outside.
- said sensing device comprises means for transmitting said measuring signal to a remote central control unit.
- said means for transmitting is selected from the group comprised of:
- said support has tubular shape with closed ends, containing said battery and said means for transmitting.
- tubular support comprises a portion that can be opened for replacing the battery.
- releasable fastening means of said support in said hole is selected from the group comprised of:
- said water flow rate sensing device for water ducts comprises means for driving said sensor in a pulsed way by the electric power that has to be dissipated by the sensor.
- said gas or vapour bubbles which are formed by heating on the surface of the sensor after a certain period during the measuring step, are removed by the water flow between two measuring steps, avoiding noise disturbing the measure and the production of deposits.
- said water flow rate sensing device for water ducts comprises means for driving said sensor maintaining the heating element of the sensor at a temperature difference with respect to the water less than 50 0 C.
- said water flow rate sensing device for water ducts comprises means for driving said sensor maintaining the heating element of the sensor at a temperature difference with respect to the water less than 50 0 C.
- the above described objects are achieved by a method for measuring the water flow in water ducts, by a water flow rate sensing device for water ducts having a thermal flow rate sensor, characterised by the steps of:
- said sensor in the duct in order to be surrounded by the flow in a zone of the flow significant for the measure, in particular, in a zone sufficiently far from the walls of the duct; driving said sensor in a pulsed way with a signal at the electric power that has to be dissipated by the sensor, said step of driving comprising a succession of supply time having a duration Tl, with time-outs having a duration T2.
- the power of the signal is changed by a feedback control capable of keeping a predetermined temperature difference between the heater of the sensor and the water, balancing the variation of the water flow rate with a suitable variation of the amplitude of the supply signal.
- the supply signal amplitude is the information relative to the measurement of the water flow rate.
- said predetermined temperature difference is less than 50 0 C.
- a step is provided of discrimination of the direction of the water flow by the presence of two couples of heaters and thermoresistors .
- said supply time has a fixed duration Tl set between 0,1 and 8 seconds, preferably 4 seconds, and said time-outs have duration T2 longer than 0,1 seconds.
- - figures 1 and 2 show, respectively, a perspective view and a top plan view of a solid state thermal sensor of known type, adapted to measure a flow of a gaseous or liquid fluid
- - figure 3 shows such a known sensor mounted on an extension plate of alumina having the above described sensor at one end and a plurality of contact pads at the other, for fixing to a support;
- FIG. 4 shows a perspective view of the application of two sensors according to the invention, mounted along a duct so that the flow rate sensors are located far from zones of higher turbulence;
- FIG. 4A shows a cross sectional view of such an application of a sensor according to the invention to a duct through a flange connected to the duct same;
- FIG. 5 shows the same application in a longitudinal cross section of the duct
- - figure 6 shows a perspective view of a sensor according to the invention with a flow rate sensor mounted on an end thereof and having an electric external supply;
- FIG. 7 shows an elevational side view of such a sensor
- FIG. 8 shows a cross sectional view of a sensor according to the invention, containing inside at least one electric battery and an electronic control circuit, having, furthermore, an antenna for wireless communication of the measured flow data;
- FIG. 9 shows a cross sectional view of a duct where a sensing device according to the invention is mounted, where it is shown the production of bubbles of vapour that remain on the surface of the sensor, that can be avoided by a pulsed and controlled power supply to the sensor;
- FIG. 10 shows an example of a pulsed feeding current of the sensor versus measuring time. Description of the preferred exemplary embodiment
- thermoresistance 22 and 23 mounted on distinct circuits having respective contact pads at an end.
- the two thermoresistances 22 and 23 can be interdigited to each other creating a single central rectangle, as described in US 6,494,090.
- the detected signal allows discriminating the direction of the flow, being thermoresistances 22 and 23 interdigited, and at the same temperature, coincident to that of the water, and being a heater 25 located upstream from the flow same and the other heater 24 downstream of it.
- This arrangement requires that the second heater 24 exchanges less heat owing to the convective action of the water flow, thus determining the flow direction by the difference of signals obtained from the two couples 22, 24 and 23, 25 of heaters and thermoresistances .
- the above described sensor is, moreover, mounted at the end of a lamina-shaped plate of alumina 30 that is then connected at one end 2 of sensing device 1 according to the invention, shown in figures 6, 7 and 8.
- Plate 30 integrates at one end sensor 20 and at the other end a plurality of contact pads 32 for connection to the sensor.
- a corresponding contact 28 is provided on plate 30 and between each contact 28 and a corresponding contact 32 a lead wire is provided that connects them.
- each contact 26 of sensor 20 and the corresponding contact 28 on plate 30 are connected by "bonding".
- Contact pads 28 are associated to connection paths of that come from contact pads 32 and are obtained with the thick film technology.
- the lamina plate 30 has fluidodynamic shape and is arranged parallel to the flow to minimize turbulences and resistance to flow.
- the free end 2 of the support may have a zone bent downwards for housing the sensor 20, so that sensor 20 does not protrude from lamina 30.
- a protection layer 27 is applied made of preformed steel with a substantially central opening adapted to contain sensor 20.
- the sensing device according to the invention comprises a support 9, for example a tubular support having a first end 2 adapted to house sensor 20 and a second opposite end 3, adapted to remain operatively external to the duct.
- the first end 2 can comprise a flattened portion adapted to be arranged parallel to the flow for not creating hydrodynamic resistance.
- Sensing device 1 according to the invention can use an external source of electric energy and a cable 8 for transmitting the measured data to a central external control unit.
- the power supply since the power supply is external, it is not necessary to open the support after assembling, so that the support can be sealed, for example by welding or filling it with an insulating polymer or wax or a hardening material in general. This way there are no parts that can be opened so that the sensing device can last a longer time.
- sensing device 1 can comprise a source of electric energy in the support same; in particular, if the support is tubular, a plurality of batteries 6 can be inserted inside capable of feeding sensor 20 and a control circuit 5, connected to an antenna 7 for transmitting the measured data towards an external control unit, for example by means of a wireless connection.
- a portion can be provided that can be opened, not shown, of support 9.
- the batteries 6 can be recharged by an outer loading unit connected by an electric cable, and also in this case a sealing step may be provided for support 9 in the way above described.
- Such a sensing device is very inexpensive, since the sensors are produced in a large quantity and also the remainder of the parts is not very expensive, which can lead to use of not rechargeable and sealed batteries, adapted to be replaced easily when the batteries are exhausted.
- FIG. 4 shows a perspective view of the application of two sensing devices 1, mounted along a duct 10 and 10' so that the flow rate sensors 20 are located far from the zones of higher turbulence .
- Figure 5 shows the same application but in a longitudinal cross section of the duct.
- FIG 4A shows the details of assembling steps of a sensing device 1 to a duct 10 by a metal tubular collar 13.
- Collar 13 has the same inner diameter of the outer diameter of support 9, and an appropriate length.
- the collar 13 is welded out of duct 10, with axis orthogonal to the side surface of duct 10. Then in it in a special drill tip is put, not shown in the figure, and a hole 16 is made in the duct. At the end of the drilling step of hole 16 the drill tip is partly withdrawn.
- Collar 13 has a side slit orthogonal to its axis not shown in the figure, in which a block can be put, not shown, which works as a gate.
- the lamina shaped plate is inserted for preventing to water to come out.
- the support 9 is introduced, checking that the block is extracted at a right moment. This way, the water is prevented from exiting from the collar. Then, the support is caused to penetrate in the hole of the duct, in order to position suitably the lamina.
- Releasable lock means can be provided for support 9 in collar 13, or alternatively support an collar are welded. In the latter case, the device 1 once broken or exhausted, can be left in the duct, and replaced making a hole in another point of duct 10.
- the sensor of figures 1 and 2 comprises a heater, 24 and 25, the operation of sensor 20 and then the measurement steps heat the water that flows around creating vapour bubbles 11, shown in figure 9, some of which remain attached to the sensor, affecting the measurements .
- the present invention provides a method for measuring the water flow in a pipe 10 of water ducts, by piloting said sensor 20 in a pulsed way concerning the electric power that has to be dissipated by the sensor.
- the steps of driving sensor 20 in a pulsed way is shown as an example in figure 10. This way, the measure is carried out intermittenthy, by alternating measuring step 40 and time outs without measurements .
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Volume Flow (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BRPI0721593-2A BRPI0721593A2 (en) | 2007-05-10 | 2007-05-10 | Flow index sensor for Water ducts |
EP07734515A EP2153179A1 (en) | 2007-05-10 | 2007-05-10 | Flow rate sensor for water ducts and a method for measuring water flow |
CN200780052928.2A CN101688801A (en) | 2007-05-10 | 2007-05-10 | The flow sensor and the method that is used to measure flow that are used for water pipe |
US12/596,934 US20100162809A1 (en) | 2007-05-10 | 2007-05-10 | Flow rate sensor for water ducts and a method for measuring water flow |
PCT/IB2007/001204 WO2008139237A1 (en) | 2007-05-10 | 2007-05-10 | Flow rate sensor for water ducts and a method for measuring water flow |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/IB2007/001204 WO2008139237A1 (en) | 2007-05-10 | 2007-05-10 | Flow rate sensor for water ducts and a method for measuring water flow |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2008139237A1 true WO2008139237A1 (en) | 2008-11-20 |
Family
ID=38462019
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/IB2007/001204 WO2008139237A1 (en) | 2007-05-10 | 2007-05-10 | Flow rate sensor for water ducts and a method for measuring water flow |
Country Status (5)
Country | Link |
---|---|
US (1) | US20100162809A1 (en) |
EP (1) | EP2153179A1 (en) |
CN (1) | CN101688801A (en) |
BR (1) | BRPI0721593A2 (en) |
WO (1) | WO2008139237A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2600120A1 (en) | 2011-12-01 | 2013-06-05 | Sensus Spectrum LLC | Method and device for measuring a fluid flow velocity |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017089459A1 (en) * | 2015-11-24 | 2017-06-01 | Ifm Electronic Gmbh | Thermal flowmeter, and method for operating a flowmeter |
CN117086601B (en) * | 2023-07-18 | 2024-03-12 | 江苏沙子电器有限公司 | PCT heater processing device and processing method |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3803913A (en) * | 1970-07-06 | 1974-04-16 | J Tracer | Apparatus for determining heat-transfer rates and thus the flow rates or thermal conductivities of fluids |
US4016758A (en) * | 1975-09-09 | 1977-04-12 | Taylor Julian S | Thermal gauge probe |
GB2216269A (en) * | 1988-02-16 | 1989-10-04 | Bosch Gmbh Robert | Air mass measuring device |
US5186051A (en) * | 1988-08-29 | 1993-02-16 | Robert Bosch Gmbh | Device for measuring a flowing air quantity |
US5965811A (en) * | 1997-06-19 | 1999-10-12 | Mitsubishi Denki Kabushiki Kaisha | Flow rate detecting element and flow rate sensor using same |
US6152597A (en) * | 1997-06-27 | 2000-11-28 | Potega; Patrick H. | Apparatus for monitoring temperature of a power source |
DE19939942A1 (en) * | 1999-08-23 | 2001-03-01 | Abb Research Ltd | Thermal flow meter |
EP1637847A1 (en) * | 2003-06-18 | 2006-03-22 | Hitachi, Ltd. | Thermal air meter |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4523463A (en) * | 1981-07-22 | 1985-06-18 | Masco Corporation Of Indiana | Electronic air filtering apparatus |
JPS61178614A (en) * | 1985-02-02 | 1986-08-11 | Nippon Soken Inc | Direct heating type flow rate sensor |
US4756190A (en) * | 1985-08-09 | 1988-07-12 | Nippon Soken, Inc. | Direct-heated flow measuring apparatus having uniform characteristics |
JPS62123318A (en) * | 1985-08-13 | 1987-06-04 | Nippon Soken Inc | Direct heat type flow rate sensor |
US4813280A (en) * | 1987-04-01 | 1989-03-21 | The Dow Chemical Company | Thermal pulse flow meter with disposable cell |
DE4426100C2 (en) * | 1994-07-22 | 1997-07-10 | Bosch Gmbh Robert | Device for measuring the mass of a flowing medium |
JP3404251B2 (en) * | 1997-04-17 | 2003-05-06 | 三菱電機株式会社 | Flow detector |
US6647777B1 (en) * | 1997-10-15 | 2003-11-18 | Mitsui Mining & Smelting Co., Ltd. | Flow rate sensor, flow meter, and discharge rate control apparatus for liquid discharge machines |
CN1515878A (en) * | 1998-08-18 | 2004-07-28 | ͬ�Ϳ�ҵ��ʽ���� | Flow sensor and filter integrated flowmeter |
JP3553422B2 (en) * | 1999-06-08 | 2004-08-11 | 三菱電機株式会社 | Flow sensor |
JP3587734B2 (en) * | 1999-06-30 | 2004-11-10 | 株式会社日立製作所 | Thermal air flow sensor |
JP3555017B2 (en) * | 1999-09-22 | 2004-08-18 | 三菱電機株式会社 | Thermal flow sensor |
JP3900334B2 (en) * | 2001-10-22 | 2007-04-04 | 三菱電機株式会社 | Flow sensor |
JP2003329495A (en) * | 2002-05-13 | 2003-11-19 | Mitsubishi Electric Corp | Air flow rate measuring device and its installing structure |
JP3817497B2 (en) * | 2002-06-10 | 2006-09-06 | 株式会社日立製作所 | Thermal flow meter |
US7107835B2 (en) * | 2004-09-08 | 2006-09-19 | Honeywell International Inc. | Thermal mass flow sensor |
JP4609019B2 (en) * | 2004-09-24 | 2011-01-12 | 株式会社デンソー | Thermal flow sensor and manufacturing method thereof |
US7748267B2 (en) * | 2008-04-21 | 2010-07-06 | Sierra Insturments, Inc. | Mass flow meter with solder/braze-flow secured spacer |
-
2007
- 2007-05-10 US US12/596,934 patent/US20100162809A1/en not_active Abandoned
- 2007-05-10 BR BRPI0721593-2A patent/BRPI0721593A2/en not_active IP Right Cessation
- 2007-05-10 EP EP07734515A patent/EP2153179A1/en not_active Withdrawn
- 2007-05-10 CN CN200780052928.2A patent/CN101688801A/en active Pending
- 2007-05-10 WO PCT/IB2007/001204 patent/WO2008139237A1/en active Application Filing
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3803913A (en) * | 1970-07-06 | 1974-04-16 | J Tracer | Apparatus for determining heat-transfer rates and thus the flow rates or thermal conductivities of fluids |
US4016758A (en) * | 1975-09-09 | 1977-04-12 | Taylor Julian S | Thermal gauge probe |
GB2216269A (en) * | 1988-02-16 | 1989-10-04 | Bosch Gmbh Robert | Air mass measuring device |
US5186051A (en) * | 1988-08-29 | 1993-02-16 | Robert Bosch Gmbh | Device for measuring a flowing air quantity |
US5965811A (en) * | 1997-06-19 | 1999-10-12 | Mitsubishi Denki Kabushiki Kaisha | Flow rate detecting element and flow rate sensor using same |
US6152597A (en) * | 1997-06-27 | 2000-11-28 | Potega; Patrick H. | Apparatus for monitoring temperature of a power source |
DE19939942A1 (en) * | 1999-08-23 | 2001-03-01 | Abb Research Ltd | Thermal flow meter |
EP1637847A1 (en) * | 2003-06-18 | 2006-03-22 | Hitachi, Ltd. | Thermal air meter |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2600120A1 (en) | 2011-12-01 | 2013-06-05 | Sensus Spectrum LLC | Method and device for measuring a fluid flow velocity |
DE102011119823A1 (en) | 2011-12-01 | 2013-06-06 | Sensus Spectrum Llc | Method and device for measuring the flow velocity of fluids |
Also Published As
Publication number | Publication date |
---|---|
US20100162809A1 (en) | 2010-07-01 |
EP2153179A1 (en) | 2010-02-17 |
BRPI0721593A2 (en) | 2013-01-15 |
CN101688801A (en) | 2010-03-31 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN107543625B (en) | Process fluid temperature measurement system with improved process intrusion | |
CN204718656U (en) | Flow measurement probe and Flow Measuring System | |
EP0153661B1 (en) | Temperature probe | |
CN109477378B (en) | Apparatus and method for sensing temperature along a wellbore using a resistive element | |
US20070194792A1 (en) | Non-metallic flow-through electrodeless conductivity sensor with leak and temperature detection | |
US7624632B1 (en) | Constant-temperature-difference flow sensor, and integrated flow, temperature, and pressure sensor | |
KR102277609B1 (en) | Thermal type flow meter | |
JP2007529749A5 (en) | ||
CN102575951B (en) | Method for detecting flow and thermal flow meter | |
CZ20001995A3 (en) | Liquid level analog sensor | |
JPH04213066A (en) | Flowing-state sensor for detecting flowing state in pipe | |
US20100162809A1 (en) | Flow rate sensor for water ducts and a method for measuring water flow | |
US11280651B2 (en) | Thin film thermal mass flow sensor in fluid applications | |
KR101454773B1 (en) | Pre-insulation pipe having multi-signal water leakage sensing device | |
JP5313597B2 (en) | Anti-freezing heater and anti-freezing system | |
EP1102047A1 (en) | Sensor mounting for a heating/ventilation system | |
CN102165658A (en) | Cable installation apparatus | |
CN106197580A (en) | There is the magnetic flowmeter flow tube of process fluid discharge external member | |
EP0957348A1 (en) | Sensor | |
CN111322062A (en) | Logging instrument | |
KR101041434B1 (en) | Mass Flow Meter and Controller | |
TW202043709A (en) | Full bore magnetic flowmeter assembly with temperature sensing element | |
US7028544B2 (en) | Mass flowmeter for measuring by the CT method | |
CN103048065A (en) | Portable type temperature sensing cable testing apparatus | |
JP2001296187A (en) | Temperature detecting device and control system using the device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200780052928.2 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 07734515 Country of ref document: EP Kind code of ref document: A1 |
|
DPE1 | Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101) | ||
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12596934 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2007734515 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: PI0721593 Country of ref document: BR Kind code of ref document: A2 Effective date: 20091109 |