Electromagnetic flowmeters (EMF) is a new type of flow measurement instrument developed rapidly with the development of electronic technology from 1950s to 1960s. Electromagnetic flowmeter is an instrument which uses the principle of electromagnetic induction to measure the flow of conductive fluid according to the electromotive force induced by the conductive fluid passing through the external magnetic field& nbsp; The function of magnetic circuit system is to produce uniform DC or AC magnetic field. The DC magnetic circuit is realized by permanent magnet, which has the advantages of simple structure and less interference by AC magnetic field. However, it is easy to polarize the electrolyte liquid in the measuring tube, so that the positive electrode is surrounded by negative ions, and the negative electrode is surrounded by positive ions, that is, the polarization phenomenon of the electrode, which leads to the increase of internal resistance between the two electrodes, thus seriously affecting the normal operation of the instrument. When the diameter of the pipe is large, the permanent magnet is also large, bulky and uneconomic, so the electromagnetic flowmeter generally adopts alternating magnetic field, and is excited by 50 Hz power supply.
 
summary
Product features:
1. It is not affected by the changes of fluid density, viscosity, temperature, pressure and conductivity. The linear measurement principle can achieve high precision measurement.
2. There is no choke in the measuring pipe, so the pressure loss is small and the requirement of straight pipe section is low;
3. The nominal diameter dn6-dn2000 covers a wide range, and there are many choices of lining and electrode, which can meet the requirements of a variety of conductive fluids.
4. The converter adopts programmable frequency low frequency shaping wave excitation; The stability of flow measurement is improved; Low power loss.
5. The converter adopts general microprocessor, full digital processing, fast operation speed, strong anti-interference ability and low power loss.
6. High definition backlit LCD display, all Chinese characters (English) operation. The user can make the operation simple and easy to learn.
7 with RM85 or Hart digital communication signal output.
8. It has the function of conductivity measurement; It can judge whether the pipeline is empty or not, and has the function of self inspection and self diagnosis.
9.LDG_ S/LDY_ S series electromagnetic flowmeter with diameter from 6mm to 2000mm is mainly used in chemical industry, steel, coal, water supply and drainage, paper making, food, textile printing and dyeing, chemical fiber and other industrial fields. The volume flow rate of strong saprophytic and liquid-phase fluids such as liquidus, pyrogen and salt were measured. It can be matched with display, recording instrument, calculator or regulator. It can detect, calculate, adjust and control the flow and realize the long-distance transmission of signal. LDY_ SL battery powered electromagnetic flowmeter is suitable for areas without power supply (220 VAC). It can also accurately measure the volume flow of each medium. The installation forms of instruments are integrated type and split type.
10.LDY_ SJ clamping type / LDG_ W-type sanitary galvanometer is widely used in food, medicine, brewing and other industries with specific requirements for hygiene. The connection between sensor and process pipe adopts sanitary quick connector clamp type, which can be easily loaded and unloaded; Clean the books to the bottom.
11.LDG_/ K-type high-pressure electromagnetic flowmeter is specially used for oil exploration, geology or oilfield system to measure the volume flow of mud loading, high-pressure water injection and other media under high-pressure conditions; LDQ submersible electromagnetic flowmeter is an open channel flow meter for sewage discharge.
12. The plug-in electromagnetic flowmeter is simply installed in the existing pipeline, which can be inserted online. It can be installed and disassembled without stopping water in the case of low pressure or pressure.
13. Turbine flowmeter can adapt to the characteristics of high parameters due to its simple structure, less parts, light weight, high accuracy and large flow capacity. Widely used in petroleum, organic liquid, inorganic liquid, liquefied gas, natural gas and other measurement objects. Vortex flowmeter is characterized by less pressure vibration loss, large range and high accuracy. It is almost not affected by fluid density, pressure, temperature, viscosity and other parameters when measuring volume flow under working conditions. Widely used in gas, liquid, steam and other media.
 
working principle
The working principle of electromagnetic flowmeter is based on Faraday's law of electromagnetic induction. When a conductor moves in a magnetic field, the induced electromotive force will be generated at both ends of the conductor perpendicular to the direction of the magnetic field and the direction of the conductor's movement. The magnitude of the electromotive force is proportional to the speed of the conductor and the magnetic induction intensity of the magnetic field.


 
Ldg-s / ldy-s electromagnetic flowmeter
Ldy-sl electromagnetic flowmeter
caliber
DN6-DN2000
DN10-DN800
Electrode materials
1Cr18Ni9Ti ocr18ni12mo2ti Ti TA HB HC Pt etc
1Cr18Ni9Ti, etc
Electrode form
Standard, scraper & gt; DN80) three electrode
Standard, scraper & gt; DN80) three electrode
Lining material
PTFE / Neoprene / hard rubber / PFA / polyurethane rubber / F46
PTFE / Neoprene / hard rubber / PFA / polyurethane rubber / F46
medium
Conductive liquid (including solid-liquid two-phase)
Conductive liquid (including solid-liquid two-phase)
Dielectric conductivity
> 20μ S/cm
> 20μ S/cm
Matching accuracy level
0.3,0.5
0.3,0.5
Velocity range
0.5m/s-10m/s
0.5m/s-15m/s
working temperature
-25℃—+ 150 ℃ (rubber lining & lt; 80℃）
< 150℃(PFA,F46)< 80 ℃ (rubber lining)
working pressure
4.0mpa-0.6mpa (by caliber)
4.0mpa-1.0mpa (by caliber)
Sensor model
Cole d-f
Cole d-f
Protection level
Standard type IP65 special type IP67 diving type IP68
IP67 IP68
Matching converter model
Cole Z-1 / 2 / 3 / 4 (optional Cole Z-6)
Cole Z-1 / 2 / 3 / 4 (optional Cole Z-6)
output signal
0-10mA 4-20mA frequency / pulse
GPRS/CDMA
communication interface
RS485/232C HART Modbus Profibus
RS485/232C HART Modbus Profibus
Applicable power supply
220VAC/24VDC
Built in lithium battery
application
Acid base and other corrosive, slurry, mud and other two-phase liquid
Water supply and drainage engineering measurement
display
Flow rate, instantaneous flow rate, percentage, cumulative flow rate, etc
Instantaneous flow, cumulative flow, etc
Installation form
Split type / one type
All in one


technical parameter
Executive Standard & nbsp;
  Electromagnetic flowmeter (jjg1033-2007)
Nominal diameter (mm) & nbsp< br />
(special specifications can be customized) & nbsp;
  Pipe type PTFE lining: DN 10-dn 600
  Pipe type rubber lining: dn40-dn2000
Flow direction & nbsp;
  Positive, negative, net flow
Range ratio & nbsp;
  150:1
Repeatability error & nbsp;
  The & plusmn; 0.1%
Accuracy level & nbsp;
  Grade 0.5, grade 1.0
Temperature of measured medium & nbsp;
  Conventional rubber lining: - 20 ～ + 60 ℃
  High temperature rubber lining: - 20 ～ + 90 ℃
  PTFE lining: - 30 ～ + 120 ℃
  High temperature PTFE lining: - 20 ～ + 160 ℃
Rated working pressure & nbsp< br />
(high voltage customizable) & nbsp;
  DN10～DN25≤ 4.0MPa
  DN32～DN150≤ 1.6MPa
  DN200～DN600≤ 1.0MPa
  DN700～DN2000≤ 0.6MPa
Velocity range & nbsp;
  0.1-15m/s
Conductivity range & nbsp;
  Conductivity of measured fluid & Ge; 5μ s/cm
Signal output & nbsp;
  4 ~ 20mA (load resistance 0 ~ 750 & omega;), Pulse / frequency, control level
Communication output & nbsp;
  RS485, MODBUS protocol, HART protocol, PROFIBUS DP protocol
Power supply & nbsp;
  220 VAC, 15% tolerance or 24 VDC, Ripple & le; 5%
Required length of straight pipe & nbsp;
  Upstream & Ge; 5dn, downstream & Ge; 2DN
Connection mode & nbsp;
  The flow meter and piping are connected by flange, and the flange meets the international standard: GB / t9113.1-2000
Explosion proof grade & nbsp;
  Exd[ia]iaqIICT5
Protection level & nbsp;
  IP65, special customized up to IP68
Ambient temperature & nbsp;
 - 25～+60℃
Relative humidity & nbsp;
  5%～95%
Total power consumed & nbsp;
  Less than 20W