Two circular tip of the probe apparatus for ultrasonic transmitting and receiving device, a collision can not be scratched with a hard object or, when installation will remove its protective cover; bottom mesh hole built-in pressure sensor can not use a hard object slender to reach out, when the installation of its protective film yer; four holes for the mounting holes wings, with M6 stainless steel screws fixed to the base.
II: Measuring principle
Product has three functions: measuring the average velocity, measuring depth, measured water temperature.
2.1: Measurement temperature: wherein the temperature measurement using a temperature probe, temperature probe is not in contact with the water, close to the top of the instrument packaging materials, need to be placed before a certain time underwater reflect the actual temperature of the temperature measurement object is corrected in an ultrasonic water speed, and correct the pressure sensor measured water level.
2.2: bathymetry (cross section area): bathymetry use of imported high-precision pressure sensor, placed in the bottom of the instrument, its sensor probe parts in direct contact with water; after the water depth measured by the cross-sectional shape of the channel segment rectifiable too water cross-sectional area.
2.3 average velocity measurements: the flow rate is measured by the ultrasonic probe (transducer) transmitting and receiving ultrasonic wave signal and make the appropriate calculation processing obtained: transducer 1 emits an ultrasonic signal frequency f1, at an angle from the water Under the emission surface, the water encountered in the suspended particles or bubbles, frequency shifted, and frequency f2 is reflected to the transducer
2.4 This is the Doppler will. Difference f2 and f1 of the Doppler frequency difference is there water fd. Let the fluid flow rate v, ultrasonic velocity is c, the Doppler frequency shift fd is proportional to the flow velocity v. A lot foreign particles and air bubbles, each one corresponding to a reflective particles Doppler frequency shift fd, by obtaining the flow rate can be evaluated in terms of the average velocity of the large number of particles that is the average flow velocity of the fluid.
By the average flow rate and water level and the size of the measured cross-section can be obtained by cross-sectional flow.
3: Product Advantages:
The first Doppler ultrasonic flowmeter domestic production, compared with similar foreign products, under the premise of the same performance, in addition to highly price advantage, has the following advantages: supporting terminals (with standard output interfaces), Chinese use interface, micro-power, high-current ground storage capacity. is to replace the existing water flow meter is widely used and ideal ultrasonic flowmeter.
3.1: Compared with the water level meter method:
• No head loss, no groove or weir construction
Without constant water flow rate curve, slow flow of water channels is particularly applicable law can not be measured; without construction, no construction cost, quick and easy to install and does not require drying.
• Simple installation, no water wells and other ancillary engineering facilities
Instrument probe part removably mounted directly to the bottom bracket to the channel wall easy, and with the place management room (or mini-workshop) control terminal through a communication cable (with control, display and storage function) connection.
• Low-power, no external power supply continuous field work
After the control terminal comes with a small battery can work for two months, recharge or replacement backup battery can work, but also external large battery or public electricity.
• Online display, storage, storage capacity of up to six months
Site automatically display the last measured data, historical data can also be queried by the display control buttons on the terminal; 10 minutes measurement time data can be stored six months.
• simultaneous measurement of flow, level, flow rate, water temperature
Level accuracy up to 1%, the flow rate accuracy up to 2%
• Standard output interface
Can be used directly GPRS, GSM communication module fast data remote transmission, the transmission can be timed and measured strokes and other measurement data via remote communication devices, but also for remote parameter settings (such as the measurement time interval, the interval timer transmission
3.2: Compared with transit-time ultrasonic flowmeter:
• Measurement accuracy is not change on water, no more group probe
Ultrasonic transit-time flowmeter large changes in the channel level required intervals at different elevations multiple sets of probes, measurement errors with the water level changes, its calibration accuracy generally refers to the accuracy of certain ideal state level, when the water level changes When the actual measurement error becomes large;
• Low power consumption, comes with battery (rechargeable) can work two months
Ultrasonic transit-time flowmeter normally takes AC power supply;
• Can be used as a portable flowmeter
Just when measuring the level of the probe against the flow of water into the canal bottom of the can;
• Simple installation
Both sides need the right direction, fixed to a specified location can be;
• obvious price advantage
Existing ultrasonic transit-time flowmeter price 1/6 - 1/3.
4.1: Water requirements:
Water body contains some minor impurities or bubbles, not too much water, floating debris.
• When too much water, but floating debris when using this instrument, weed or plastic bags, which are likely to cover the work of the probe that make them fail, then the need in the instrument does not work properly when the timely removal of the cover on the probe when conditions permit may be provided upstream trash rack, trash rack from the instrument but not less than five times the distance the hydraulic radius, in order to avoid deposition in front of trash rack and other plants will cause instability in the flow state, when the debris in front of the need to regularly remove trash rack (When plants and other debris too much interference instrument, to be processed on the measurement results, which will remove interference data, in particular by software or manually to achieve; if the interference is serious, then processed disturbance data requires experienced professionals to carry out).
• When the secondary drinking water meet, choose a bubble point (such as water or down at a distance downstream gate) were measured. When the bubble flow regime at the unstable flow pattern does not meet the test requirements and can not take effective aid steady flow measures (such as rectifying the gate or the steady flow cover), then only select segments steady flow state is measured and the use of the following special means:
a: When is a certain amount of irrigation water when placed in the measurement of the upstream channel bottom clods: the flow rate is low can be maintained for a long time; when the flow rate becomes larger clods will be washed away, but this time the water will produce bubble and meet measurement requirements. Therefore, when the flow rate increase after another smaller, the need to relocate a certain amount of clods in the upstream channel bottom.
b: at a location upstream of the measurement device is set to drop water bubbles (such as retaining grille, this time would produce a certain head loss, and it is possible to increase the flow rate to produce turbulence within a certain distance downstream).
4.2: Measuring the flow cross-section selection (fluidized request):
Flow measurement requires a straight section of the upstream section of the hydraulic radius of 10 times, five times the downstream straight section of the hydraulic radius, and stable cross-sectional shape the rules to ensure that the flow regime of uniform and stable mounting position.
If the installation position of the flow state is poor or short straight sections, one approach is setting rectification upstream gate (or steady flow cover) to stabilize the flow state, you should note that when the water weeds can clog when excessive rectification gate and the opposite effect, the solution is at the gate promptly remove weeds clogging rectification or additional trash rack upstream; Another approach is to set the rate of a correction factor or set up a table for each instrument in the same position along the rivers or The instrument installed in the middle of the channel. These two approaches will affect the measurement accuracy.
4.3: sandy channel applications
Instruments are divided into A, B, C three models to suit different sediment concentration of water quality:
Sediment concentration chosen model 6 ~ 25kg / m3 A type 3 ~ 6 kg / m3 B type 0 ~ 3 kg / m3 C Type
Five: The overall installation instructions
The picture shows the installation effect Rendering
5.1 The probe installation
5.1.1 Installation location
The probe should be installed in the channel downstream straight section has a fixed section, the straight length is preferably 5-10 times the hydraulic radius of the channel (the longer the straight segment higher measurement accuracy), and must not have been within this distance range flow barrier (such as locks, weirs, etc.) to ensure uniform and stable flow pattern of the front end of the probe.
The probe should be installed near the canal at the end, when the channel bottom sediments and aquatic plants growing there are impurities or rolling pebbles, you can raise the mounting location to avoid the channel bottom sediments and plants covering the probe or probe pebble dash; probe from the canal bottom Specific height is preferably 100mm-250mm, the lowest measured water channel bit depending on availability. When higher channel depth and has a certain minimum level, in order to facilitate the installation as long as the probe is attached to the lowest level at 0.5 times the following can be.
Probe mounting position in a rectangular cross section channels
Probe mounting position at the channel cross section generally as follows (channel width of 20m or less): rectangular cross section attached to the channel width of 0.15-0.2 times the place; trapezoidal cross section is attached to the foot of the slope at; for larger channel width, You need to install two or two or more of the probe, depending on the specific location of the flow state distribution channel width and the cross section may be.
Probe mounting position in the ladder Section Channel
5.1.2 Installation Method
The probe should be installed perfectly level to the channel bottom (note not level), while ensuring consistency with the flow direction parallel to the probe distal end (no communication cable end) against the flow direction and the flow direction of the angle of 180 degrees, and the tip of the probe shall not stop flow pattern was interference, communication cables the best water drawn from the downstream along the channel bottom and channel slope of the probe or lead water pipe from the mounting bracket.
The probe should be perfectly parallel to the direction of flow
For completely without water channels, the probe can be fixed bracket (mounting bracket can be locally customized, and probe some of the best stainless steel plate and screws) fixed directly to the channel bottom; for not entirely without water and after closing upstream still a higher level of inconvenience channels underwater operations, stand can be secured to the drainage canal arm fixed to the bracket arm in two ways: with a combination of stent Simple stand Simple stand mainly for a bent pipe or tube of zinc bottom welded to a horizontal plate fixed probe, by the erection of the steel pipe is fixed to the horizontal wing canal arm; a combination bracket consists of a base and removable parts, the probe is mounted on a detachable part of a one-time fixed base attached to the flow measurement section Office (provisional closing lower after the upstream water level, with expansion bolts fixed on the concrete slope), the detachable portion by a bolt on the water and the base is connected to the fixed, so the probe to facilitate future maintenance and replacement.
The probe is fixed directly mounted to the channel bottom
Simple stand site renderings
Schematic combination bracket
5.2: Communication cable installation
Communication cables along the channel bottom and drainage should be drawn from the probe wall downstream of the water, the best sets of PVC pipe to protect and along fixed; when using the probe arm bracket, the communication cable can be drawn along the surface of the hollow steel bracket.
There is the probe comes within a period of communication cable ventilation ducts, so pay attention to it must not be bent. When the communication cable leads to the water, can be accessed by ordinary cables, and you should make the downward opening direction of the ventilation duct, and with breathable tape is protected against water and foreign matter from entering the vent tube.
After fixing the communication cable is installed, you need the adapter cable is connected to the terminal via a four-core wire adapter cable are: Yellow is the power positive, blue negative power supply, the red data lines A, black is the data line B ( communications cable in the corresponding wires are: red and black lines merged into power positive, negative shielded cable for the power, and the rest two for the R485 data lines A and B)..
5.3: the terminal installation
Fixed terminals should be erected in the management room or mini-workshop, watch waterproof terminals communicate with the probe carried by cable adapter cable; when the terminal is connected with the communication device or computer, you need to use the output of input data input and output lines. data lines are R232 and R485 both modes, when using the serial port of a laptop is no access to the site, to be self R232 to USB adapter
6.1: Using Process
Location Select OK → → probe mounting cable lines and fixed way to go do the mounting bracket → → Install the probe and the cable connection → → fixed terminal adapter cable and communication cable → through the output terminal and the input data line connection data protocol (using a wireless communication mode) → connect the wireless communication device rechargeable power supply → Connect terminals (if online charging) → Press the button terminal acquisition, inspection probe work mode → → design terminal protocol checking working conditions → install wireless surveillance Software (wireless communications) or laptop access software and statistics for software
6.2 Monitoring Software
See box with CD
Monitoring software in two ways: on-site monitoring software and wireless monitoring software, on-site monitoring software installed on a laptop, notebook through standard R232 or R485 with the meter terminal directly connected to the input-output interface for reading measurements and historical data terminals set the operating parameters; wireless monitoring software is installed on the upper management machine, through a wireless communication device to read and set the operating parameters of the terminal real-time measurement data.
Monitoring software mainly has the following functions:
• measuring point management: measuring point increase or deletion;
• For each measuring point terminal parameter settings;
• reads and stores the measurement data of each measuring point;
• measurement data query statistical analysis;
• In the electronic map display measuring point and click directly on the graph query real-time measurement value of each point (wireless mode).
Seven: routine maintenance
7.1: Routine Maintenance
7.1.1 Probe Maintenance
Two circular ultrasonic transceiver tip of the probe should avoid a hard object hit or scratched in soft cover protection when not in use, when it is applied on top of foreign matter adhering to rinse or a soft cloth slightly observed; the bottom of the pressure sensor is located in the mesh permeable hole, the pressure membrane is very fragile, can not get in touch with a hard object, out of the water when not in the instrument should also be protected, should be permeable holes around the foreign matter adhering carefully removed.
7.1.2: battery maintenance:
Battery-free power supply should be at least one and a half charge and discharge time.
7.1 3: terminal maintenance
The terminal should be placed in a dry place, site conditions should pay attention to moisture in more humid, the available plastic film packaging.
• Communication cable Because it contains a snorkel, so we can not bend over, to prevent their breaking;
• Communication cable inside the vent pipe and the probe inside the circuit board connected, not water, should be installed so that the open end of the vent tube down to prevent moisture probe circuit at the rear wall of the inflow of water along the junction;
• Communication cable should be led by the probe surface as far as possible along the outer PVC pipe protection and internal fixation or along the stent tube alignment to avoid direct tension generated by the hydraulic shock, especially plants more channels when the cable line hanging grass It will produce a lot of tension and it is possible to pull off the cable;
• probe in front of the circular ultrasonic wave transceiver device is not subjected to shock and scratches;
• After installing the probe to its previous ultrasonic transceiver protective cover removed, the protective film and the hole at the bottom mesh yer;
• terminal and wiring the probe must be properly connected, otherwise it will cause damage to the instrument;
• The instrument probe should avoid prolonged exposure in the sun, the temperature is too high so as not to cause failure (the probe temperature not exceeding 70 ℃.).