Battery power electromagnetic flowmeter

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Battery power electromagnetic flow meter adopting the new technology.Using the constant current low-…

Products overview:
ZW - LDE seriesBattery power electromagnetic flowmeterSpecially designed sensor excitation system and high-performance lithium battery power supply system, electromagnetic flow sensor is made use of Faraday's law of electromagnetic induction, when conducting liquid along the measuring tube in the alternating magnetic field in a direction perpendicular to the magnetic field lines, conducting liquid cutting lines of magnetic force induced potential, with the sounding pipe axis and the magnetic field lines are perpendicular to the pipe installed on a pair of electrodes, the electrode of the induction electric potential detection.The induction electric potential is proportional to the flow, measured the induction electric potential can be derived by the flow sensor.The traffic signal (induction electric potential) input converter converts and enlargement traffic signal proportional to the amount of digital signal, thus realize the flow measurement.

Second, the working principle:
ZW - LDE seriesBattery power electromagnetic flowmeter based on Faraday electromagnetic induction principle, with the sounding pipe axis and the magnetic field lines in the vertical tube wall installed on a pair of detecting electrodes, when conducting liquid along the measuring tube axis movement, conductive liquid cutting lines of magnetic force induced electric potential, the induction electric potential by two detection electrodes detection, numerical size and flow into a direct ratio, its value is: E = KBVD type:
E - induction electric potential;
K - factor related to the magnetic field distribution and the axial length;
B - magnetic induction intensity;
V - conductive liquid average flow velocity;
D - electrode gap;(the measuring tube diameter)
Sensor will be induced potential E as traffic signal, sent to the converter, amplifying, transform filter with a series of digital processing, USES dot matrix LCD display with backlight instantaneous flow and cumulative flow.Converter has 4 ~ 20 ma output, alarm output and frequency output, and is equipped with RS - 485 communication interface, and supports HART and MODBUS protocol.

Applications:
ZW - LDE seriesBattery power electromagnetic flowmeter specially designed for water industry, meet the water fee calculation of urban water supply to ensure accurate, are widely used in the field without power supply, such as: urban water supply, sewage treatment, water conservancy project, take water and other industries.

Four, the structure form:
1, the sensor:
Sensor is mainly composed of measuring tube and electrode, excitation coils, iron core, magnetic yoke and shell. 
A, measuring catheter: by stainless steel tube, the lining and the connecting flange, as the carrier of measured liquid measurement working conditions on site. 
B, measuring electrode: installed in the measuring tube inside wall, and the axial direction perpendicular to a pair of electrodes to measure liquid signal generation. 
: c, excitation coil in a magnetic field measurement of intraductal two excitation coil. 
D, iron core and magnetic yoke: the excitation coil of the magnetic field generated import liquid, and the magnetic circuit. 
E, the shell body: instrument packaging. 
2, converter that is smart the secondary table, it will flow signal amplification processing, single chip microcomputer after the operation, can display flow, total amount, and can output pulse and analog current signal, used in the measurement or control of fluid flow.
3, product assembly form: it into a shape and size in two forms. 
A, a shape: mounted sensors and switches. 
B, size: separation installation sensor and converter, through the connecting cable form flow metering system. 
C, in order to adapt to the measurement demands of the different medium, the lining of sensor and electrode materials can have many choices.

Five, the main features:
1, flow measurement is not affected by the fluid density, viscosity, temperature, pressure and conductivity changes, the influence of sensor induction voltage signal, and a linear relationship between the average flow, so the measurement precision is high.
Passage 2, measuring the pipe flow, so there is no additional pressure loss;Measurement of the pipe have no moving parts, so very long sensor life.
3, due to the induced voltage signal is formed in the whole space full of magnetic field, is the load average on the surface of the pipe, so the sensor for short straight pipe, the length of 5 times the pipe diameter.
Part 4, sensor only lining and electrode contact with liquid to be tested, as long as reasonable selection electrode and lining material, corrosion resistance and wear resistance.
5, LD converter adopts international advanced microcontroller (MCU) and surface mount technology (SMT), reliable performance, high precision, low power consumption, stable zero, parameter setting is convenient.Click on the Chinese display LCD, display cumulative percentage flow, instantaneous flow rate, flow velocity, flow, etc.
6, measuring system, the measurable positive flow, reverse flow.The use of special production technology and high quality materials to ensure the performance of the product in a long time remained stable.
7, electromagnetic flow meter for measuring the volume flow of conducting liquid and slurry in a closed pipe, such as clean water, sewage, all kinds of acid and alkali salt solution, slurry, pulp, paper pulp and liquid food, etc.
Six, the technical parameters:
1, precision instrument: pipeline magnitude 0.5, 1.0;Plug in 2.5 on the Richter scale are unlikely.
2, measuring medium: conductivity is greater than 5 mu S/cm of various liquid and liquid-solid two-phase fluid.
3, velocity range: 0.2 ~ 8 m/s.
4, work pressure: 1.6 MPa.
5, environmental temperature: - 40 ℃ ~ + 50 ℃.
6, medium temperature: ptfe lining 180 ℃ or less;Rubber lining material 65 ℃ or less.
7, explosion-proof marks: Exmibd Ⅱ BT4.
8, explosion-proof number: GYB01349.
9, outside magnetic interference: 400 a/m or less.
10, shell protection: integration type: IP65.
In mold: sensor IP68 (5 meters underwater, rubber lining only) converter IP65.
11, the output signal: 4 ~ 20 ma DC, load resistance Ω 0 ~ 750.
12, communication output: RS485 and CAN bus.
13, electrical connections: M20 x 1.5 internal thread, phi 10 cable hole.
14, power supply voltage: 90 ~ 220 v AC, 24 + / - 10% V.D C.
15, zui big power consumption: 10 or less va.

Seven, flowmeter installation requirements:
The choice of installation environment
1, should as far as possible away from strong electromagnetic field equipment.Such as big motor, transformer, etc.
2, the installation place should not have a strong vibration, environmental temperature change is not big.
3, easy to install and maintenance.
The choice of the installation position
1, sensors, flow mark on the direction of the measured medium flow and the pipe must be consistent.
2, installation location must ensure that the measuring tube in the book is full of measured medium.
3, and the choice of fluid flow pulse smaller places, which should be far away from the pump and local resistance (valve, elbow, etc.)
4, the measurement of two-phase fluid, should choose is not easy to cause the location of the phase separation.
A negative pressure, avoid installed in a tube of five places.
6, when makes the electrode measured medium, measure the tube inner surface adhesion, scaling, suggest the measuring tube flow velocity of no less than 2 m/s.
At this time can use reducing pipe diameter slightly smaller than the process.For uninterrupted flow in the process piping cleaning electrode and the measuring tube, sensor can be used parallel installations, and cleaning.
The choice of the installation site
In order to make the transmitter work stability, when choosing the location should be paid attention to the following requirements:
1, try to avoid strong ferromagnetic objects and concrete equipment of electromagnetic field (such as a big motor, transformer, etc.), so as to avoid the magnetic field of magnetic field effect sensor and traffic information.
2, should be installed in a dry and ventilated place, should not be in damp, easy seeper place of installation.
3, should try to avoid weathered, avoid environmental temperature is higher than 45 ℃ and relative humidity is more than 95.9%.
4, choose to facilitate maintenance and convenient place.
5, flow meter should be installed in the pump back end, never on the suction side of the installation;Valve should be installed in the downstream flow meters.

Eight, is still the main deficiencies are as follows:
1, cannot be used for measuring gas, steam and liquid contains a lot of gas.
2, low cannot be used to measure the conductivity of liquid medium, such as the petroleum products or organic solvent such as medium, the electromagnetic flowmeter is powerless.
3, ordinary electromagnetic flow meter used in industry due to the measuring tube lined with the limitation of materials and electrical insulation materials, can not be used in measuring high temperature medium;If without special treatment, also cannot be used for the measurement of low temperature medium, in order to prevent the measuring tube condensation (frost) destruction of insulation.
4, the influence of electromagnetic flowmeter vulnerable to external electromagnetic interference.

Nine, troubleshooting:
Due to all kinds of faults in the operation of flowmeter in can cause measurement is allowed to occur, generally in the electromagnetic flow meter of faults in the operation probably can be divided into two classes.Kind of fault for flow meter itself, component damage caused by fault;The change caused by the fault for external conditions, such as the output flow instability, countless times, large error and so on.Here are some simple troubleshooting way:
A, the instability of the output: 1. The unstable flow field;2. Through the sensor of the gas in the liquid, solid block;3. The electrical connection in the empty pick up;4. Bad earth;5. The electrode leakage solution: 1. The transformation pipeline, or increase the false sensor installation;2. Normal phenomenon;3. Check the wiring, then good line;4. Good earthed;5. Repair sensors.
B, no liquid output: 1. Between the converter and signal transmission cable conductor by the two;2. Power did not pick up or poor contact;3. The sensor instrument piping, shell, end face has a leakage.Solution: 1. The thread;2. Connect the power supply, for maintain good contact;3. Repair sensors.
C, liquid flows have not output: 1. Between the converter and signal transmission cable connection circuit;2. Signal cable to the electrode connection circuit;3. The electrode surface contamination or sedimentary insulating layer;4. Bad earth or open circuit.The solution: 1. Connect the cable for;2. Open the sensor, in again;3. Wash electrode surface;4. Good earthed.
Too much d, error: 1. The zero point is too high;2. Not completely filled with liquid.3. Power supply distortion is too large;4. Bad earth.The solution: 1. To adjust the zero point;2. Improve the conditions of pipeline, sensor is always full of liquid.(3) improve the power supply condition, conform to the normal working conditions;4. Good earthed.

Ten, notable matters of installation:
1, when moving and lifting sensor, should will sling set beside the sensor on both ends of the flange neck position, do not in the measurement, hoisting so as not to damage the lining tube inserted into the pipe to help.
2, before the installation, the sensor electrode with alcohol cotton in carefully erased due to causes such as hand touch the surface of the electrode material grease stain.
3, the inner diameter of the sealing washer when installation should be consistent with the sounding pipe lining inside.
4, must ensure that the terminal box is dry, otherwise the instrument measurement error may result.
The preparing work before running:
1, put into operation after installation wiring should be checked again before the installation, wiring is correct.(the size)
2, before the bed bottom valve is opened, the sensor after the valve closed, let the sensor with the medium.
3, after the completion of the preparation, upstream of the valve to open the first sensor, then slowly open the downstream of the valve, observe the converter instantaneous flow display should be toward the direction of change, that signal lines in the right direction.Otherwise, will signal A and B connection swap position.(the size)
4, open the sensor before and after the valve, drainage for a few minutes, the gas discharge tube.
5, close the sensor downstream of the valve, then close upstream of the valve, the measured medium is inside the sensor.And then to form a complete set of adjustment.Sensor and converter matching coefficient of zero adjustment and instrument set converter specifications, please read them.

Eleven,The main technical data:

1, the whole machine and the technology of sensor data:

2, converter technology data:

3, the choice of the lining:

4, import protection flange and the choice of grounding flange ring (or ground) :

5, the choice of electrode:

Twelve, correct selection:

Instrument selection is very important work in instrumentation, relevant data show that the instrument in two-thirds of faults in the practical application is instrument error caused by selection or wrong installation, please pay special attention to.

1, collect data:

By measurement of body composition;
Large flow, small flow;
Z high work pressure;
, z z high temperature low temperature;

2, range scope confirmation:

General industrial use measured medium velocity of electromagnetic flowmeter with 2 ~ 4 m/s advisable, under special circumstances, z low velocity should not be less than 0.2 m/s, high z should be not more than 8 m/s.If the medium containing solid particles, commonly used flow rate should be less than 3 m/s, prevent excessive friction lining and electrode;For viscous flow, the velocity can choose more than 2 m/s, larger velocity help eliminate electrode automatic on the effect of viscous material, to improve accuracy of measurement.

Under the condition of the range of Q have been identified, according to the velocity V can be decided to the size of the flow meter diameter D, the range of the values calculated by the next type:

Q = PI D2V / 4
Q: flow (㎡ / h) D: pipe diameter V: velocity (m/h)

Electromagnetic flow meter range of Q zui flow value should be greater than expected, the flow of the normal value in a full scale slightly greater than the flowmeter calibration 50 is advisable.

3And the reference flow range:

4, selection of code:

13, design selection and ordering information:

1, the measured medium: name, composition, status, electrical conductivity and electrical conductivity;

2, working temperature (℃);

3, work pressure (Mpa);

4, the pipe diameter (DN), the smallest, normal, scope of quantity (m3 / h);

5, corrosion resistance, wear resistance, whether there is a negative pressure;

6, installation requirements and the environment: a body or fission, signal output, communications, power supply;

7, installation environment: protection grade and explosion-proof requirements.

After-sales service commitment:

1, from the date of signing of the contract, I in the way provided for products of the company offers free maintenance and maintenance service, commitment to lifelong maintenance service;

2, jiangsu wei measurement and control instrument co., LTD. Sales manager will be in regular contact with customers, understand the usage of products, and solve the problems of the customers to use in the process of produce, free of charge to provide technical support;

3 the man-made damage is found, the warranty period, our company is responsible for the maintenance, and the resulting maintenance fee;

4, product quality problems or are not satisfied with product, the user can choose unconditional return, wei tt&c don't charge any fees, appear quality problem, bear the freight back and forth.