FMG-J Insertion Electromagnetic flow meter
- Smart Intelligent LCD display function
- Display Interface: English or Chinese
- Easy to Setup and install/Variety of sizes range.
- High Accuracy:±1.5% of reading(RD)
- Flow direction function: Plus or Reverse
- Alarm Function: Excitation and No fluid tubes Alarm.
Install Way: Adjustable and Fixed type
Flow measurement plays a very important role in fluid transport networks (e.g. gas pipelines, oil pipelines) and in all industrial equipment that needs to control the amount of fluid involved in processes such as in internal combustion engines, chemical reactors ...
Ever since the invention of the Woltman-style turbine flowmeter in the 1970s, automation experts have been eager to expect a flow meter for all other applications. But unfortunately, even though we already have 12 different flow measurement technologies, none of them can be applied to every application.
One of the most widely used methods in most applications, across most industries and with greater accuracy than the differential pressure measurement, is the electromagnetic flowmeter. According to Jesse Youder's studies, the flowmeter accounts for $ 4.7 billion in sales but the electromagnetic flowmeter accounts for only about 20% of them.
There are many electromagnetic flow meters produced every year. This device is used in all industrial processes: water, sewage, and mineral deposits, food and pharmaceuticals. This device is designed in treatment systems for almost all countries of chemical origin and coal sludge; resistant to wear, scratches and even cleaning the inside surface of pipes (designed for epidemiological hygiene applications).
Electromagnetic flowmeters are most widely used because the size of the meter can vary in size according to application requirements. Zuider Zee Company in the Netherlands was the first to use this technology for the sewer in the 1950s. Often the supplier produces products of size from
12mm to 914mm. Other brands can be supplied in sizes up to 3,048mm. Increasing or reducing such pipe size is directly related to the technology.
Principle of operation
In 1831, Michael Faraday discovered the law of electromagnetic induction, which was later named Faraday. In an electromagnetic flow meter, the coil is placed parallel to the flow and at the right angle inside the duct, there are a series of electrodes, creating a static magnetic field. The pipelines must be non-magnetic material, the inner surface of the pipe covered with insulators. As fluid flows, a small voltage appears on the electrodes. This voltage is proportional to the deviation of the magnetic field.
Modern electromagnetic flow meters operate based on a DC convertible DC field with the principle of no noise (probably from RFI, EMI and real electrical noise during fluid flow measurement). It works by turning off the magnetic field, measuring the voltage stored on the electrodes; then turn the magnetic field back on and subtract the values at the on and off for each other. This mechanism is implemented several times a second to eliminate drift, zero offset.
This means that the induced voltage on the electrodes is directly proportional to the average velocity in the pipe; This method is much more accurate than other velocity measurement methods.
Electromagnetic flow meters measure the velocity with considerable accuracy, accessible with the accuracy of the position measuring device. They are often used when measuring flow applications over a relatively long period. The accuracy of the electromagnetic flowmeter is 0.5% of the measured value (within the range of 0.1 to 10m / s). Some vendors say that accuracy is still up to 0.1%.
Use electromagnetic flowmeter
Electromagnetic flowmeters have a wide range of applications that can be said to be easier to tell where the electromagnetic flow meter is not working than to list all the applications of this device.
Electromagnetic flowmeters will not work well when the pipes are not full of fluid (except for some specifically designed for this application). Failure to fill the tube will cause a significant error. One of the most common examples of improper use of the electromagnetic flowmeter is the fluid flowing along the gravity vector to the air in a water tank. Another very common phenomenon is that the flow is very slow, the pipe is not full of water and the results obtained from the electromagnetic flowmeter will be wrong. Sometimes to reduce this phenomenon, it is possible to design a U-shaped tube to ensure the water in the pipe is always full.
Electromagnetic flowmeter will not work well when the pipes are full of gas or air. The reason is to change the calculation of pipe volume and change the flow volume through the measuring device.
The electromagnetic flow meter will not work well if the flow starts and stops continuously because there is a delay between the flow starting and the indicator velocity indicated by the measuring device. This means that the electromagnetic flowmeter does not work well under conditions of continuous, repeated operation for short periods. In fact, there are exceptions for some special applications that will be designed to be able to respond very quickly.
Electromagnetic flowmeters do not provide information about the mass of flowing fluid but, when combined with a density measuring device, can provide highly accurate information. The combination will be good if the size of pipe size is 300mm. Applications of this type are quite common in the industry of mining or dredging rivers and harbors.
Most importantly, the electromagnetic flow meter will not work if the fluid is magnetic or the gas flow must be measured. The minimum conductivity of the permissible fluid is 5μS (microSiemens). In practice, it is not good to use an electromagnetic flowmeter to measure the velocity of a fluid with low average conductivity. The reason is because the internal resistance of the sensor must be much smaller than the input resistance of the measuring device.
Finally, the electromagnetic flowmeter will also work poorly if the fluid has a very high conductivity (brine or sea water). With these special applications, there is also a need for appropriate designs.
Use electromagnetic flowmeter
There are some simple rules for using an electromagnetic flow meter, which, if you follow it, will be highly effective.
Straight pipe fitting
The electromagnetic flowmeter needs to run a straight pipe less than most other electromagnetic flowmeters, usually 3.D in the opposite direction of the electrode plane and 0.D in the opposite direction. However, there are cases when pipelines with as many straight lines as possible, such as eddy phenomena, can occur in pipelines hundreds of D long in the case of a three-way turn error. These errors can cause serious errors in the measurement results, sometimes up to 40% of the measurement value.
Mount the electromagnetic flow meter vertically
One of the ways to ensure the user installs the meter correctly is to install the electromagnetic flowmeter so that the flow is vertical. This is useful for limiting whirlpools and can also help reduce airflow.
Choose the right measuring range
Although an electromagnetic flowmeter will operate over a range of 0.09 to 10m / s, it is best not to operate the device under conditions of maximum or minimum velocity measurement. In some applications there is solids in the duct that will be able to build up inside the tube, even on the electrodes. If a precipitation occurs in the duct, the calculation of the volume of the transmitted fluid will be wrong and if the aggregation on the electrode not only results will be wrong, it may damage the device. The best condition for an electromagnetic flowmeter is to operate at 60% of the maximum measured value.
Grounding the device
Note that the segments in the tube of the electromagnetic flowmeter must be non-conductive to ensure that the circuit operates correctly. Therefore, when installing the electromagnetic flowmeter, the grounding is not to be missed.
Temperature and pressure
Electromagnetic flowmeters are designed to work at moderate temperatures and pressures, and should not be emphasized in technical descriptions.
Electromagnetic flowmeters have been one of the most widely used technology lines in the 50 years since they were first introduced. They are simple and because the electromagnetic flowmeter has no moving parts, it is capable of operating for years without any maintenance or maintenance is simple.
Khanh Linh (According to globalcontrol.com)
No. 105 (June 2009) ♦ Automation today
Model FMG-J FMG-I Adjustable Type Fixed Type Size(mm) 100~3000 Application Raw Water,Pure Water,Waste Water,Liquid of Conductivity >50μS/cm Peak flow rate 0.1~10.0 m/s Conductivity to be more than 50μS/cm Accuracy ± 1.5% of reading Repeatability ± 0.25% of reading Insertion tube size(mm) ø32mm or ø50mm Material of signal electrode and grounding electrode Mo-containing stainless steel,Hastelloy B,Hastelloy C,Titanium alloy,Tantalum alloy,Platinum-iridium alloy,Stainles-steel-coated wolfram Material of Piping Carbon Steel、Stainless steel 304、No piping Material of sensor Stainless steel 1Cr18Ni9Ti Max.Temperature with Lining material Polytetrafluoroethylene ＜70℃ Polyvinyl fluoride ＜70℃ Fluorinated ethylene-propylene ＜70℃ Polychloroprene rubber ＜70℃ Polyurethane ＜70℃ Max.Pressure DN100~DN3000 ≦1.6Mpa Display Line 2 Line with LCD Protection IP68 for Body and IP65 for Display Output 4~20 mA or 0~10mA or pulse Communication RS485(Option)、RS232(Option)、Hart(Option) with lightning protection Parts Vavle With Without Power supply AC 85~265V 45~63Hz or DC 11~40V DN Flow Range(m3/h) (mm) Qmin(0.5m/s) Q(1.0m/s) Q(2.0m/s) Q(3.0m/s) Q(4.0m/s) Q(5.0m/s) Q(6.0m/s) Q(7.0m/s) Q(8.0m/s) Q(9.0m/s) Qmax(10 m/s) 100 20 39 79 117 157 196 235 275 314 353 393 125 29 57 115 171 229 286 343 401 458 515 573 150 40 80 161 240 320 400 480 561 641 721 802 200 62 124 250 374 498 623 747 872 997 1121 1247 250 91 181 364 545 726 909 1090 1271 1454 1635 1818 300 127 254 509 763 1017 1272 1526 1780 2035 2289 2545 350 173 346 692 1039 1385 1731 2077 2423 2769 3116 3464 400 226 452 904 1356 1809 2261 2713 3165 3617 4069 4523 450 286 572 1145 1717 2289 2861 34347 4006 4578 5150 5725 500 353 707 1413 2120 2826 3533 4239 4946 5652 63559 7069 600 509 1017 2035 3052 4069 5087 6104 7122 8139 9156 10180 700 692 1385 2769 4154 5539 6924 8308 9693 11078 12463 13847 800 904 1809 3617 5426 7265 9043 10852 12660 14469 16278 18086 900 1145 2289 4578 6867 9156 11445 13734 16023 18312 20602 22891 1000 1413 2826 5652 8478 11304 14130 16956 19782 22608 25434 28260 1200 2035 4069 8139 12208 16278 20347 24417 28486 32556 36625 40694 1400 2769 5539 11078 16617 22156 27695 33234 38773 44312 49851 55390 1600 3617 7235 14469 22156 28938 36173 43407 50642 57876 65111 72346 1800 4578 9156 18312 28938 36625 45781 54937 64094 73250 82406 91562 2000 5652 11304 22608 33912 45216 56520 67824 79128 90432 101736 113040 2200 6839 13678 27356 41034 54711 68389 82067 95745 109423 123101 136778 2400 8139 16278 32556 48833 65111 81389 97667 113944 130222 146500 162778 2600 9552 19104 38208 57311 76415 955519 114623 133726 152830 171934 191038 2800 11078 22156 44312 66468 88623 110779 132935 155091 177247 199403 221558 3000 12717 25434 50868 76302 101736 127170 152604 178038 203472 228906 254340 Order Information FMG Code Model Type
J Adjustable Type(Standard type) I Fixed Type
Code Electrode Type N Standard type
Code Piping Type XXXX 100~3000 mm
Code 电极材质 0 Mo-containing stainless steel(Standard Type) 1 Hastelloy B 2 Hastelloy C 3 Titanium(Ti) 4 Tantalum(Ta) 5 Platinum(Pt)
Code Lining Material 0 No(Standard Type) 1 Polytetrafluoroethylene 2 Polyvinyl fluoride 3 Fluorinated ethylene-propylene 4 Polychloroprene rubber 5 Polyurethane
Code Max.Pressure 0 1.6Mpa for DN100~DN3000(Standard Type)
Code Output A 4~20 mA (Standard Type) P Scale Pulse Output R RS-485 MODBUS Communication C RS-232 Communication H Hart Communcation
Code Max Temperature 0 .~70 ℃(Standard Type)
Code Display Type N Traditional Chinese(Standard Type) S Simplified Chinese I English
Code Connection Line N Compact-type without cable(Standard Type)
Code Power Supply N AC 85~265V 45~63Hz(Standard Type) R DC 24
Code Logo F FGT Logo(Standard Type) N Printing customer Logo
FMG Complete Ordering Code ＊Note:Using customer Logo launch to more than 100 united for one year
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