CN110441546B - Device and method for measuring water flow velocity of water outlet structure - Google Patents
Device and method for measuring water flow velocity of water outlet structure Download PDFInfo
- Publication number
- CN110441546B CN110441546B CN201910830868.7A CN201910830868A CN110441546B CN 110441546 B CN110441546 B CN 110441546B CN 201910830868 A CN201910830868 A CN 201910830868A CN 110441546 B CN110441546 B CN 110441546B
- Authority
- CN
- China
- Prior art keywords
- hole
- vertical
- door body
- water flow
- conductivity
- Prior art date
- 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.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
- G01P5/18—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring the time taken to traverse a fixed distance
Abstract
The invention discloses a device and a method for measuring the water flow velocity of a water outlet building, which comprises at least one body, wherein the body is arranged at the upstream end of a section to be measured of water flow, the upper surface of the body is provided with a first conductivity sensor, the downstream end of the section to be measured of water flow is provided with a second conductivity sensor, the first conductivity sensor and the second conductivity sensor are respectively connected with the measuring end of a conductivity meter, the top of the body is provided with a vertical through hole, and an opening and closing device for opening or closing the vertical through hole and a cavity filled with electrolyte solution are arranged in the body; the opening and closing device comprises an elastic door body, a rod connected with the elastic door body and a driving structure connected with the rod, wherein the radial section of the head of the elastic door body is matched with the radial section of the vertical through hole, the elastic door body slides up and down under the action of the driving structure and the rod to seal or open the vertical through hole, so that the electrolyte solution is sealed in the body or pushed out of the body.
Description
Technical Field
The invention relates to a water outlet structure of a water conservancy and hydropower project, in particular to a device and a method for measuring the flow velocity of high-speed water flow of the water outlet structure.
Background
The current flow rate measurement methods mainly include: mechanical methods, pitot tube methods, hot wire velocimetry, doppler methods and particle imaging methods. The apparatus commonly used in practical applications are: the flow velocity measuring instrument comprises a propeller flow velocity meter, a pitot tube, a differential pressure sensor, an ultrasonic wave/laser Doppler flow velocity meter and the like, wherein the instruments belong to direct contact measuring instruments, and when the flow velocity is measured, a sensor of the flow velocity meter is required to be arranged at a measured point, so that the interference on a measured flow field is large, and the measuring accuracy is influenced. A Particle Image Velocimeter (PIV) belongs to a non-contact measuring instrument, and is a measuring technology for reflecting the flow velocity of the surface of a flow field by using trace particles.
Contact measurement instruments suffer from three main problems: (1) when a cantilever type mounting bracket is adopted for fixing the sensor, the mounting bracket must have enough rigidity to resist the impact of high-speed water flow and cannot generate too large interference on a flow field, and no feasible mounting bracket exists at present; (2) when the sensor is installed by utilizing the base pre-embedded in the concrete, the sensor protrudes out of the surface of the concrete, the sensor is easily damaged or failed, and the protruding sensor interferes a flow field to influence the accuracy of measurement; (3) the protruding flow velocity sensor will become a new cavitation source, deteriorating the water flow, so that the risk of cavitation damage exists on the overflow surface.
The non-contact measuring instrument adopts a particle imaging processing technology, has higher requirements on the definition of an image, and needs smooth surface and smooth flow line of water flow. However, the high-speed water flow is strongly sheared with the atmosphere in the moving process, entrainment and crushing and aeration atomization are carried out on the surface of the water flow, and trace particles cannot be displayed on an image through the existing imaging technology, so that the non-contact measuring instrument cannot be used for measuring the speed of the high-speed water flow.
Disclosure of Invention
The invention aims to solve the technical problem of providing a device and a method for measuring the water flow velocity of an outlet structure aiming at the defects of the existing flow velocity measuring instrument.
In order to solve the technical problem, the water flow velocity measuring device of the water outlet building comprises at least one body, wherein the body is arranged at the upstream end of a section to be measured of water flow, the upper surface of the body is provided with a first conductivity sensor, the downstream end of the section to be measured of water flow is provided with a second conductivity sensor, the first conductivity sensor and the second conductivity sensor are respectively connected with the measuring end of a conductivity meter, the top of the body is provided with a vertical through hole, and an opening and closing device for opening or closing the vertical through hole and a cavity filled with electrolyte solution are arranged in the body; the opening and closing device comprises an elastic door body, a rod connected with the elastic door body and a driving structure connected with the rod, wherein the radial section of the head of the elastic door body is matched with the radial section of the vertical through hole, the elastic door body slides upwards under the action of the driving structure and the rod to the top of the body, the head of the elastic door body is just inserted into the vertical through hole and seals the vertical through hole and the cavity, and when the elastic door body slides downwards, the head of the elastic door body is withdrawn from the vertical through hole and moves downwards for a distance, the vertical through hole is opened and is communicated with the cavity.
Furthermore, in order to enable the elastic door body to slide up and down more stably, the opening and closing device further comprises a sleeve cylinder communicated with the vertical through hole, a side hole communicated with the cavity is formed in the side wall of the upper portion of the sleeve cylinder, and the elastic door body is arranged in the sleeve cylinder and slides up and down along the sleeve cylinder.
Furthermore, a bypass pipe communicated with the bypass hole is further arranged in the body, and the bypass hole is communicated with the cavity through the bypass pipe.
Furthermore, in order to enable the upper sliding and the lower sliding of the elastic door body to be more stable, the head of the elastic door body can be accurately inserted into the vertical through hole, and the axis of the vertical through hole is coincided with the axis of the sleeve cylinder.
Further, for avoiding the head of the elastic door body to be sunken or protrude to the concrete surface interference flow field, simultaneously, avoid the head of the elastic door body to become new cavitation source, worsen rivers, the head of the elastic door body is inserted during the vertical through-hole, the head top surface of the elastic door body with the upper surface parallel and level of body, just first conductivity sensor with the upper surface of body flushes.
Further, the driving structure comprises a miniature submersible motor, the miniature submersible motor is horizontally installed, and the rod is connected through a gear and a rack.
The power cord of the miniature submersible motor is led out to the side face or the bottom face of the body, an upper travel limit control switch and a lower travel limit control switch are connected in a control loop of the miniature submersible motor to control the lifting distance of the elastic door body, the head is guaranteed to be below a bypass hole of the side wall of the sleeve cylinder when the elastic door body is pulled down, and the top face of the head is flush with the upper surface of the body when the elastic door body is pushed up.
The elastic door body is in clearance fit with the sleeve cylinder, so that opening and locking of the vertical through hole are realized through the opening and closing device, the driving structure is guaranteed to be always positioned in an anhydrous closed cavity, and external water bodies are prevented from being mixed with electrolyte solution.
The diameter of the bypass hole is smaller than the height of the elastic door body, so that the elastic door body can completely seal the bypass hole.
The bypass pipe, the cavity, the sleeve cylinder and the rod are made of aluminum alloy or stainless steel materials, so that the measuring device is prevented from being aged, rusted and damaged in the long-time service process.
The body is made of concrete or mortar materials, the elastic door body is made of rubber or polytetrafluoroethylene materials, the insulating materials of the conductivity sensor are one or more of epoxy resin, polyester, polyurethane and organic silicon resin, the electrodes are made of graphite with Shore hardness not less than 60, the abrasion resistance of the measuring device can be enabled not to be larger than that of local concrete, and certain surplus length is reserved at the top of the body and the head of the elastic door body; in the service process, along with the time, under the water flow abrasion effect, the head, the body top surface and the conductivity sensor of the elastic door body can be peeled off along with the peeling of the concrete surface layer, so that the top surface, the body top surface and the conductivity sensor of the head of the elastic door body are always flushed with the concrete surface, no depression or protrusion occurs, no new cavitation source is formed, and the good water flow state is ensured.
Further, the electrolyte solution adopts a high-concentration NaCl solution.
In order to solve the technical problem, the invention provides a measuring method of a water flow velocity measuring device of an outlet structure, which comprises the following steps:
1) measuring the distance between the first conductivity sensor and the second conductivity sensor, and connecting the first conductivity sensor and the second conductivity sensor with a conductivity meter;
2) when the electrolyte is not discharged, opening the vertical through hole of the body, injecting the electrolyte solution into the cavity from the vertical through hole, and then closing the vertical through hole;
3) when the flow velocity is measured, the driving structure is started, the head of the elastic door body is pulled downwards to the position below the bypass hole on the side wall of the sleeve cylinder, so that external water enters the vertical through hole and is mixed with the electrolyte solution in the cavity in the sleeve cylinder above the head of the elastic door body to form the electrolyte solution;
4) starting the driving structure again, pushing the elastic door body upwards to the top of the sleeve cylinder, inserting the head of the elastic door body into the vertical through hole of the body and closing the vertical through hole, and pushing the electrolyte solution in the sleeve cylinder above the head of the elastic door body out of the body in the process;
5) the conductivity meter synchronously measures the change condition of the conductivity of the flowing water flow of the first and second conductivity sensors along with the time while the electrolyte solution in the sleeve cylinder above the head of the elastic door body is pushed out of the body;
6) measuring the delay time of the water flow conductivity pulses of the first and second conductivity sensors;
7) and dividing the distance between the first conductivity sensor and the second conductivity sensor by the delay time of the conductivity pulse of the flowing water flow to obtain the flow velocity of the flowing water flow.
Furthermore, the bodies are arranged in a plurality of along the water flow direction, the conductivity sensor on the latter body is used as the second conductivity sensor of the former body, and the change of the flow speed along the flow can be measured by repeating the steps.
The invention utilizes the elastic door body to push the electrolyte solution in a pulse mode, and the migration speed of the electrolyte solution can be obtained by measuring the migration time of the electrolyte solution between the first conductivity sensor and the second conductivity sensor when the distance between the first conductivity sensor and the second conductivity sensor is known.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention not only provides a new method for measuring the flow velocity of water flow, but also the first conductivity sensor is flush with the upper surface of the body, thereby eliminating the interference of the contact sensor to the measured flow field, avoiding the damage and failure of the sensor caused by the impact of the water flow and avoiding the risk of cavitation damage of the overflow surface.
2. According to the invention, the opening and the locking of the vertical through hole are realized through the opening and closing device, and the driving structure is ensured to be always positioned in the anhydrous closed cavity, so that the external water body is prevented from being mixed with the electrolyte solution.
3. The measuring device is directly embedded in concrete when the concrete is poured after the measurement device is packaged, so that a sensor is not required to be installed at the later stage, and the operation procedure is simplified.
Drawings
Fig. 1 is a schematic structural view (activated state/electrolyte solution introduced state) of a first embodiment of the present invention.
Fig. 2 is a sectional view taken along the plane a-a in fig. 1.
Fig. 3 is a sectional view taken along the plane B-B in fig. 1.
Fig. 4 is a schematic structural diagram of a deactivated state/electrolyte solution pushing state according to an embodiment of the invention.
FIG. 5 is a graph of the change in conductivity of water flow measured by the first and second conductivity sensors when the present invention is in use.
In the figure: 1-a body; 2-opening and closing device; 3 — a first conductivity sensor; 4-electrolyte solution; 5-a second conductivity sensor; 6-conductivity meter; 11-vertical through holes; 12-a by-pass pipe; 13-a cavity; 21-elastic door body; 22-a rod; 23-cylinder sleeving; 24-a drive arrangement; 211-head; 231 — bypass holes.
Detailed Description
The invention is further described below with reference to specific preferred embodiments, without thereby limiting the scope of protection of the invention.
For convenience of description, the description of the relative position of the components (e.g., up, down, left, right, etc.) is described with reference to the layout direction of the drawings, and does not limit the structure of the patent.
Example 1:
as shown in fig. 1 to 4, one embodiment of the device for measuring the water flow velocity of the outlet structure of the present invention comprises a cylindrical body 1 made of concrete or mortar material, wherein a bypass pipe 12, a cavity 13 and an opening and closing device 2 are arranged in the body 1; the top of the body 1 is provided with a vertical through hole 11 communicated with the upper water body, the vertical through hole 11 is communicated with the top of a sleeve cylinder 23 of the opening and closing device 2, and the axis of the vertical through hole 11 is superposed with the axis of the sleeve cylinder 23; a bypass hole 231 is formed in the side wall of the upper part of the sleeve cylinder 23, one end of the bypass pipe 12 is communicated with the bypass hole 231, and the other end of the bypass pipe is communicated with the cavity 13; the opening and closing device 2 comprises an elastic door body 21, a rod 22, a sleeve cylinder 23 and a driving structure 24, wherein the radial section shape of the head 211 of the elastic door body 21 is matched with the radial section shape of the vertical through hole 11, the elastic door body 21 slides up and down along the inner wall of the sleeve cylinder 23 under the combined action of the driving structure 24 and the rod 22, so that the head 211 of the elastic door body 21 is just inserted into the vertical through hole 11 to close the vertical through hole 11, or the head 211 of the elastic door body 21 is withdrawn from the vertical through hole 11 to open the vertical through hole 11; the first conductivity sensor 3 is arranged on the top of the body 1 and is flush with the upper surface of the body 1; the bypass hole 231, the bypass pipe 12, and the cavity 13 are filled with the electrolyte solution 4.
The device for measuring the water flow velocity of the water outlet building further comprises a second conductivity sensor 5 arranged at the downstream end of the measured section of the water flow and a conductivity meter 6 connected with the first and second conductivity sensors 3 and 5.
The first and second conductivity sensors 3 and 5 and the conductivity meter 6 in this embodiment are commercially available products, and thus the structure thereof will not be described further.
The driving structure 24 adopts a miniature submersible motor, the submersible motor is horizontally installed, and an upper travel limit control switch and a lower travel limit control switch are arranged in a control loop of the driving structure 24 through a gear rack structure connecting rod 22 and an elastic door body 21.
The cavity 13 is made of aluminum alloy material, and the bypass pipe 12, the rod 22 and the sleeve cylinder 23 are made of aluminum alloy material; the elastic door body 21 is made of rubber material, and the electrolyte solution 4 is a high-concentration NaCl solution with the mass percentage concentration of 25%.
The invention discloses a water flow velocity measuring device of a water outlet structure, which is used for measuring the water flow velocity, wherein a body 1 is embedded at the upstream end of a measured section of water flow, and the specific measurement comprises the following steps:
1) measuring the distance between the first conductivity sensor and the second conductivity sensor to be 1m, and connecting the first conductivity sensor and the second conductivity sensor with a conductivity meter;
2) when the liquid is not discharged, opening the vertical through hole of the body, injecting electrolyte solution (NaCl solution with the mass percent concentration of 25%) into the cavity from the vertical through hole, and then closing the vertical through hole;
3) when the flow velocity is measured, the driving structure is started, the head of the elastic door body is pulled downwards to the position below the bypass hole on the side wall of the sleeve cylinder, so that external water enters the vertical through hole and is mixed with the electrolyte solution in the cavity in the sleeve cylinder above the head of the elastic door body to form the electrolyte solution;
4) starting the driving structure again, pushing the elastic door body upwards to the top of the sleeve cylinder, inserting the head of the elastic door body into the vertical through hole of the body and closing the vertical through hole, and pushing the electrolyte solution in the sleeve cylinder above the head of the elastic door body out of the body in the process;
5) while the electrolyte solution in the sleeve cylinder above the head of the elastic door body is pushed out of the body, the conductivity meter synchronously measures the change of the conductivity of the water flow passing through the first and second conductivity sensors along with the time (as shown in figure 5);
6) measuring the delay time of the water flow conductivity pulses of the first and second conductivity sensors;
7) and dividing the distance 1m between the first conductivity sensor and the second conductivity sensor by the delay time 0.03s of the conductivity pulse of the flowing water flow to obtain the flow velocity of the flowing water flow of 30.3 m/s.
The above description is only for the preferred embodiment of the present application and should not be taken as limiting the present application in any way, and although the present application has been disclosed in the preferred embodiment, it is not intended to limit the present application, and those skilled in the art should understand that they can make various changes and modifications within the technical scope of the present application without departing from the scope of the present application, and therefore all the changes and modifications can be made within the technical scope of the present application.
Claims (10)
1. The device for measuring the water flow velocity of the water outlet building comprises at least one body (1), and is characterized in that the body is arranged at the upstream end of a section to be measured of water flow, a first conductivity sensor (3) is arranged on the upper surface of the body, a second conductivity sensor (5) is arranged at the downstream end of the section to be measured of water flow, the first conductivity sensor and the second conductivity sensor are respectively connected with the measuring end of a conductivity meter (6), a vertical through hole (11) is arranged at the top of the body, and an opening and closing device (2) for opening or closing the vertical through hole and a cavity (13) filled with electrolyte solution are arranged in the body; the opening and closing device comprises an elastic door body (21), a rod (22) connected with the elastic door body and a driving structure (24) connected with the rod, wherein the radial section of the head (211) of the elastic door body is matched with the radial section of the vertical through hole, the elastic door body slides upwards under the action of the driving structure and the rod to the top of the body, the head of the elastic door body is just inserted into the vertical through hole and closes the vertical through hole and the cavity, and when the head of the elastic door body slides downwards to withdraw from the vertical through hole and move downwards for a distance, the vertical through hole is opened and is communicated with the cavity.
2. The device for measuring the water flow velocity of an outlet building as claimed in claim 1, wherein the opening and closing device further comprises a sleeve cylinder (23) communicated with the vertical through hole, a side wall of the upper portion of the sleeve cylinder is provided with a bypass hole (231) communicated with the cavity, and the elastic door body is arranged in the sleeve cylinder and slides up and down along the sleeve cylinder.
3. An outlet building water flow rate measuring device according to claim 2, wherein a bypass pipe (12) is further provided in the body in communication with the bypass hole, the bypass hole communicating with the cavity through the bypass pipe.
4. The outlet building current flow rate measuring device of claim 2, wherein an axis of said vertical through hole coincides with an axis of said sleeve cylinder.
5. The outlet building current flow rate measuring device of claim 1, wherein said first conductivity sensor is flush with an upper surface of said body.
6. The apparatus as claimed in claim 1, wherein when the head of the resilient door body is inserted into the vertical through hole, the top surface of the head of the resilient door body is flush with the upper surface of the body.
7. The apparatus as claimed in claim 1, wherein the driving structure comprises a micro-submersible motor, and the micro-submersible motor is horizontally mounted and connected to the rod by a gear and a rack.
8. The apparatus as claimed in claim 1, wherein the electrolyte solution is NaCl solution.
9. The apparatus as claimed in claim 2, wherein the resilient door body is in clearance fit with the casing, and the diameter of the bypass hole is smaller than the height of the body of the resilient door body.
10. A method of measuring the flow rate of outlet building construction water flow as claimed in any one of claims 1 to 9, including the steps of:
1) measuring the distance between the first conductivity sensor and the second conductivity sensor, and connecting the first conductivity sensor and the second conductivity sensor with a conductivity meter;
2) when the electrolyte is not discharged, opening the vertical through hole of the body, injecting the electrolyte solution into the cavity from the vertical through hole, and then closing the vertical through hole;
3) when the flow velocity is measured, the driving structure is started, the head of the elastic door body is pulled downwards to the position below the bypass hole on the side wall of the sleeve cylinder, so that external water enters the vertical through hole and is mixed with the electrolyte solution in the cavity in the sleeve cylinder above the head of the elastic door body to form the electrolyte solution;
4) starting the driving structure again, pushing the elastic door body upwards to the top of the sleeve cylinder, inserting the head of the elastic door body into the vertical through hole of the body and closing the vertical through hole, and pushing the electrolyte solution in the sleeve cylinder above the head of the elastic door body out of the body in the process;
5) while the electrolyte solution in the sleeve cylinder above the head of the elastic door body is pushed out of the body, the conductivity meter synchronously measures the change of the conductivity of the flowing water flow of the first and second conductivity sensors along with the time;
6) measuring the delay time of the water flow conductivity pulses of the first and second conductivity sensors;
7) and dividing the distance between the first conductivity sensor and the second conductivity sensor by the delay time of the conductivity pulse of the flowing water flow to obtain the flow velocity of the flowing water flow.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910830868.7A CN110441546B (en) | 2019-09-04 | 2019-09-04 | Device and method for measuring water flow velocity of water outlet structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910830868.7A CN110441546B (en) | 2019-09-04 | 2019-09-04 | Device and method for measuring water flow velocity of water outlet structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110441546A CN110441546A (en) | 2019-11-12 |
| CN110441546B true CN110441546B (en) | 2021-03-26 |
Family
ID=68439072
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910830868.7A Active CN110441546B (en) | 2019-09-04 | 2019-09-04 | Device and method for measuring water flow velocity of water outlet structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110441546B (en) |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102009036703A1 (en) * | 2009-08-05 | 2011-02-17 | Technische Universität Ilmenau | Apparatus and method for measuring the speed of movement of moving electrically conductive substances |
| CN101713785B (en) * | 2009-11-09 | 2012-12-12 | 水利部交通运输部国家能源局南京水利科学研究院 | Electroconductibility single-hole diluting method for detecting seepage speed |
| CN101825646B (en) * | 2010-05-07 | 2012-11-07 | 中国农业大学 | Method for measuring flow rate of thin water flow by electrolyte tracing |
| CN102147381A (en) * | 2011-02-28 | 2011-08-10 | 天津大学 | Double-cross-section impedance type long waist internal cone sensor and multiphase flow measuring device |
| CN102680732B (en) * | 2012-05-24 | 2014-04-16 | 中国农业大学 | Method and system for measuring velocity of sheet flow on slope |
| EP3538901B1 (en) * | 2016-11-08 | 2021-01-06 | Helmholtz-Zentrum Dresden - Rossendorf e.V. | Method and system for calibration-free determination of a flow velocity of an electrically conductive fluid |
-
2019
- 2019-09-04 CN CN201910830868.7A patent/CN110441546B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110441546A (en) | 2019-11-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Schraub et al. | Use of hydrogen bubbles for quantitative determination of time-dependent velocity fields in low-speed water flows | |
| CN107167295B (en) | Vertical bearing temperature is adjustable experiment water hole | |
| CN110441546B (en) | Device and method for measuring water flow velocity of water outlet structure | |
| CN110441547B (en) | Water flow velocity measuring method | |
| CN210347683U (en) | Water flow velocity measuring device for water release structure | |
| CN102288376B (en) | Top-movable vortex-induced vibration rotating device for vertically-arranged vertical pipe under uniform flow and step flow | |
| Colicchio | Violent disturbance and fragmentation of free surfaces | |
| CN106814175B (en) | A kind of seawater measuring device | |
| CN107833502A (en) | A kind of utilizing ocean current analogue experiment installation | |
| CN111650403A (en) | Novel Doppler current profiler calibration device and calibration method thereof | |
| CN210180592U (en) | Hydrodynamic pressure measuring device | |
| JP2006201102A (en) | Ultrasonic flow measuring method | |
| CN203772890U (en) | Hand-held hollow flow meter | |
| CN114670975A (en) | Hydrological water resource monitoring device and monitoring method | |
| CN212110152U (en) | Non-full pipe type electromagnetic flowmeter | |
| CN109541607B (en) | Multi-phase flow slug flow and mixed flow liquid film thickness distribution type ultrasonic measuring device | |
| CN209857977U (en) | Be applied to not full pipe metering device of open channel low discharge, high velocity of flow | |
| CN205539047U (en) | Pressure sensing formula open channel tachymeter | |
| CN205720294U (en) | Flow velocity automatic measurement mechanism | |
| CN202066564U (en) | Magnetic force coupling type liquid level measuring device | |
| CN201407029Y (en) | Direct reading packer float flow logger | |
| CN204802143U (en) | Portable filling metering device | |
| De Cesare et al. | Turbidity current monitoring in a physical model flume using ultrasonic Doppler method | |
| CN105911306B (en) | Flow velocity automatic measurement mechanism and measurement method | |
| CN214309354U (en) | Be applicable to unmanned on duty pipeline test device that closes water |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |