# SI-3101 Electromagnetic Water Flow Meter

Electromagnetic water flow meter is the flow meter for water flow rate measurement. In most industrial water supply pipes, 1 inch, 3 inch, and so on, need the inline flow measurement. Indicator outdoor and send the 4-20mA output, or RS485. In industrial waste water treatment, Magnetic flow meter measure the volume flow of conductive liquid and slurry in a closed pipe.

Electromagnetic digital flow meter works for: Domestic water. Industrial water. Raw water. Ground water. Urban sewage. Industrial wastewater. Pulp slurry, etc.

 Diameter DN6~DN3000mm Accuracy ±0.5% Flow rate 0.3~10m/s Electrode 316L (Suitable for domestic water, industrial water, raw water, underground water, sewage, etc.; not applicable to acid and alkali salt) Lining material Chloroprene rubber(CR), polyurethane rubber(PU)

## How Electromagnetic Flowmeter works?

Magnetic flow meters use the principle of Faraday’s Law of Electromagnetic Induction to measure the flow rate of liquid in a pipeIn the magnetic flowmeter pipe parts, a magnetic field is generated, and channeled into the liquid flowing through the pipeFaraday’s Law states that the voltage generated is proportional to the movement of the flowing liquidA conductor moving through a magnetic field produces an electric signal within the conductor. And the singal is proportional to the velocity of the water moving through the field. As fluid flows through the magnetic field, conductive particles in the fluid create changes. This variation is used to measure and calculate the velocity of water flow through the pipe. When the fluid moves faster, more voltage is generated. The electronic transmitter processes the voltage signal to determine liquid flow.

### Electromagnetic flow meter Working Principle

The operation principle of a magnetic flow meter or mag meter is based upon Faraday’s Law. Faraday’s Law states the voltage generated is proportional to the movement of the flowing liquid. The transmitter processes the voltage signal to determine liquid flow.

To apply this principle to flow measurement with a magnetic flow meter. First is to state that the fluid being measured must be electrically conductive for the Faraday principle to apply.
As applied to the design of magnetic flow meters, Faraday’s Law indicates that:
the signal voltage (E) is dependent on V, B, D.
V is the average liquid velocity ;
B is the magnetic field strength ;
D is the length of the conductor ( which in this instance is the distance between the electrodes).

## Electromagnetic flow meter advantages and disadvantages

### Advantages of electromagnetic flowmeter

1. The flow barrier of the Electromagnetic water flow meter is almost zero. Therefore this type of meter can be used to measure heavy suspensions. Including mud, sewage and wood pulp.
2. Except for the straight tube length used by the Electromagnetic water flow meter, this flow meter has no head loss.
3. Electromagnetic water flow meter is not greatly affected by upstream flow disturbance.
4. Electromagnetic water flow meter is virtually unaffected by changes in density, viscosity, pressure, and temperature.
5. Power requirements may be low (15 or 20 W), especially for pulsed DC types.
6. Electromagnetic water flow meter can be used as a two-way meter.
7. Electromagnetic water flow meter is suitable for most acids, alkalis, water and aqueous solutions. Because the selected lining material is not only a good electrical insulator, but also has corrosion resistance.
8. Electromagnetic water flow meter is widely used in mud services. Not only because they are less blocking. And because some linings (such as polyurethane, neoprene, and rubber) have good abrasion or corrosion resistance.
9. Electromagnetic water flow meter can handle extremely low flow.

### Disadvantages of electromagnetic flowmeter

1. Electromagnetic water flow meter can only be used for fluids with proper conductivity.
2. The accuracy is only within the range of ± 1% within the flow range of 5%.
3. The size and cost of the excitation coil and circuit increase disproportionately to the size of the tube hole. Therefore, the small-sized Electromagnetic water flow meter is bulky and expensive.

Best Technology Guide to Magnetic Flow Meters

A Magnetic flow meter, also called electromagnetic flow meter, mag flow meter, or magmeters. A magnetic flow meter is a volumetric flow meter that works with principle of magnetic technology. Magnetic flow meters do not have any moving parts. An electromagnetic flowmeter consists of two parts: Electrode (sensor) and Transmitter. Installation types of magmeters could be: Compact, remote, insertion.

## Electromagnetic water flow meter Installation

1.Installation location
Avoid the magnetic objects and equipment with stong electromagnetoc field;
should installa the flow meter at ventilated location;
Avoid the location wherer ambient temperature above 50ºC and relative humidity above 90%;
The water flowmeter should be installaed at somewhere spacious;
The DH1000 series Digital Electromagnetic Water Flow Meter with RS485 Signal should be installaed behind pump and the value should installa at downstream.

2.Installa the flow sensor
Must to ensure the pipeline is fulled and without bubbles to keep the high accuracy;
The flow direction shoudl keep with sign on the body of flowmeter;
Ensure the double electrodes keep Horizontal;
If the medium is mixed by liquid and solid,Pls installa it at vertical to extend the working life of lining;
If the environment with shocked pls installa the bracket at both front and behind;
If the medium is pollution liquid,should installa the flow meter at bypass pipe and don’t interrupted when you on service;

3.Requirement of Straight pipe
The straight of pipe at inlet must more than 10×DN,Suggest 15DN;at outlet,the straight pipe at least 5×DN;
If at the upstearm of flowmeter,there are values,elbow,the straight must need 15×DN;
Pls installa the shut-off value at both front and behind of flow meter;

The installation location for you reference.

## Techincal Support

### Wastewater flow meter

Wastewater Flow meters are flowmeters for water and wastewater treatment. Electromagnetic flow meters are suitable for open channel and underground industrial water pipes.

### Potable Water

Potable water flow meter also called Drinking water. Potable water flow meters are important for Domestic industries. Accurate flow measurement is essential to cost-conscious drinking water and potable water system.

### Digital Water Flow Meter

Digital water flow meter, is the electronic flow meter, which display the flow rate of water. Different Industrial liquid, different pipe for 1 inch, 2 inch, use different flow meters

### Cooling Water

The cooling water flow meter is used to measure the cooling water flow rate. Cooling water flow meters are commonly used in cooling water towers, circulation systems, pipes, tanks, and pumps.

## Q&A

The electromagnetic flowmeter is a flowmeter that measures flow according to Faraday’s law of electromagnetic induction.
Faraday’s law of electromagnetic induction, a fluid with a certain conductivity flows through the measuring tube, and the cutting line of force will induce an electromotive force E. The electromotive force E is proportional to the product of the magnetic flux density B, the inner diameter d of the measuring tube, and the average flow velocity V. The electromotive force E (flow signal) is detected by the electrodes and sent to the converter through the cable. After the converter amplifies the flow signal, it can display the fluid flow and output pulses and analog current signals for flow control and adjustment.

1. General-purpose electromagnetic flowmeter is used in metallurgy, petrochemical, papermaking, textile, water supply and drainage, and sewage treatment. The general electromagnetic flowmeter in the industrial field is the main type of electromagnetic flowmeter. There is a range requirement for the conductivity of the measured medium, which generally cannot exceed its upper and lower limits.
2. Explosion-proof type of electromagnetic flowmeter is used in places with explosive atmosphere. Due to the large magnetic current energy, the flameproof type is still the main type. In recent years, an intrinsically safe type, that is, a safe spark type electromagnetic flowmeter, has appeared in foreign countries, and the exciting power has been greatly reduced. Can be made into one type, all work in hazardous areas.
3. Hygienic electromagnetic flowmeter is used in industries such as medicine, food, food and biochemistry. In terms of regular bacteria, easy to disassemble and clean, it must meet the relevant sanitary requirements.
4. Water-proof electromagnetic flowmeter is used to be installed under the ground, and can withstand short-term water immersion.
5. The submersible electromagnetic flowmeter is used to measure the flow when the free surface of the open channel or non-full pipe underdrain is free flowing. The sensor is under the open channel interception baffle and works under long-term immersion in water. The structure and use are different from general electromagnetic flow meters.
6. Plug-in electromagnetic flowmeter is used for large-diameter electromagnetic flow sensor. The sensor is inserted radially from the opening of the pipe to measure the local flow rate to estimate the flow. Lower accuracy, but cheaper, suitable for control systems.

A flow meter works by measuring the amount of liquid, gas, or vapor flowing through or around a flow meter sensor. Flowmeter sensors work differently, but have the same end goal: to provide the most accurate and repeatable flow measurement for a specific application, whether it is process control, routine research activities, or semiconductor processing.

Flow meters measure volume or mass. The flow (Q) is equal to the cross-sectional area of the pipe (A) in the volumetric flowmeter, and the velocity (v) of the flowing fluid: Q = A * v. The mass flow rate can be expressed as follows: ṁ = Q ∗ ρ (where Q is the volume flow rate and ρ is the fluid density).

In many cases, especially in combustion, chemical reactions, or buying and selling gases, mass flow rate is a key consideration.

For more please refer to our Flow Meter Technologies.

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