The installation method of clamp connected electromagnetic flowmeter has the advantages of easy installation and cleaning, and is commonly used in food production, pharmaceutical industry pharmaceutical measurement, and water purification monitoring.

The clamp type electromagnetic flowmeter measures flow based on Faraday’s law of electromagnetic induction. The advantages of electromagnetic flowmeter are minimal pressure loss and a wide range of measurable flow rates. The ratio of larger flow rate to smaller flow rate is generally above 20:1, suitable for a wide range of industrial pipe diameters. The output signal is linear with the measured flow rate and can measure liquids with conductivity ≥ 20 μ s/cm.

The clamp installation method of electromagnetic flowmeter has the advantages of easy installation and cleaning, and is commonly used in food production, pharmaceutical industry pharmaceutical measurement, and water purification monitoring.

Working principle of clamp type electromagnetic flowmeter

According to Faraday’s principle of electromagnetic induction, a pair of detection electrodes are installed on the tube wall perpendicular to the axis of the measuring tube and the magnetic field lines. When the conductive liquid moves along the axis of the measuring tube, it cuts the magnetic field lines and generates an induced potential. This induced potential is detected by the two detection electrodes, and the value is proportional to the flow rate. Its value is:

E=KBVD

In the formula:

E – Induced potential;

K – coefficient related to magnetic field distribution and axial length;

B – Magnetic induction intensity;

V – average flow velocity of conductive liquid;

D – electrode spacing; (Measuring the inner diameter of the tube)

The sensor uses the induced potential E as a flow signal, which is transmitted to the converter. After amplification, transformation, filtering, and a series of digital processing, the instantaneous and cumulative flow rates are displayed on a backlit dot matrix LCD. The converter has 4-20mA output, alarm output and frequency output, and is equipped with communication interfaces such as RS-485, and supports HART and MODBUS protocols.

Clamp type electromagnetic flowmeter product description

1. Suitable for liquid flow detection with conductivity greater than 5 μ s/cm. Changes in conductivity do not affect performance changes
2. Electromagnetic flow meters have long-term high measurement accuracy and are actually not affected by fluid physical properties
3. Easy to put into operation, the flowmeter is automatically set within the range of 0-10m/s, without the need to change the measurement range
4. The components in contact with the tested medium have good corrosion resistance and wear resistance, and are widely applicable
5. There are no movable parts or flow blocking components inside the pipeline
6. The measurement results are independent of physical parameters such as flow velocity distribution, fluid pressure, temperature, density, viscosity, etc
7. On site, the range can be modified online according to the actual needs of the user
8. High definition backlit LCD display, Chinese menu operation, easy to use, simple to operate, easy to learn and understand
9. All digital processing, strong anti-interference ability, reliable measurement, high accuracy, flow measurement range up to 150: one
10. There are three integrators inside that can display the forward cumulative and reverse cumulative amounts, as well as the difference cumulative amount. There is also a non power down clock inside that can record the power down time
11. There are communication signal outputs such as 4-20mA, RS485, RS232, Hart, and Modbus
12. It has self checking and self judging functions
13. The electromagnetic flowmeter is easy to use. After installation, simply connect the power supply without any other operation. Connect the signal line to output standard signals, which is convenient for non professionals to use. No mechanical moving parts, regular maintenance

Technical parameters of clamp type electromagnetic flowmeter

Ambient temperature	-10—+50℃
accuracy level	Pipe type: 0.5 grade, 1.0 grade
Temperature of the measured medium	Ordinary rubber lining: -20 – +60℃; High temperature rubber lining: -20 – +180℃ Polytetrafluoroethylene lining: -30 – +120℃; F46 lining: -30 – +200℃
Rated working pressure	DN10—DN65：2.5MPa DN80—DN150：1.6MPa. DN200—DN1200：1.0MPa DN700—DN3000：0.6MPa.
Output signal and load resistance	4-20mADC,0-500Ω
Electrode material	Molybdenum containing stainless steel, titanium (Ti), tantalum (Ta) Hastelloy (HB) and so on
Class of protection	Submersible type: IP68, other: IP65
Power supply	220VAC, 24VDC, 3.6V lithium battery
Length of straight pipe section	Pipeline type: upstream ≥5DN, downstream ≥2DN
Connection mode	The electromagnetic flowmeter is installed in the pipe type, and flange connections are adopted between it and the piping

Selection method of clamp type electromagnetic flowmeter:

(1) Select based on flow rate, velocity, and diameter

When the flow rate reaches full range, the selection range of liquid flow velocity is wide, ranging from 1 to 12m/s. Usually, the upper limit of flow velocity cannot exceed 5m/s, and the lower limit of flow rate is set to 1m/s. When electromagnetic flow meters are used as wear-resistant fluids such as slurry and sand, the flow rate is often controlled below 2 to 3m/s, which is a rule aimed at reducing electrode and liner wear.

Usually, the diameter range of clamp type electromagnetic flowmeter products is between 10mm and 3000mm. In practical engineering use, small-diameter electromagnetic flowmeters are more commonly used.

(2) Select based on the conductivity of the fluid to be tested

In practical industrial use, clamp type electromagnetic flow meters are designed for conductive tested liquids, and their valve threshold is set within the range of (5 × 10-6) to 10-4s/cm according to relevant rules, and the threshold varies depending on the model of the electromagnetic flow meter.

(3) Select based on the mixture contained in the tested fluid

When using wet methods to exercise zinc, the slurry often contains a large number of large particles. When these large particles collide on the electrode surface, they can interfere with the signal stability of the fluid. If an electromagnetic flowmeter with a diameter of 80mm is used for comparative tests of slurry flow rate and clean water, in general, the clamp type electromagnetic flowmeter will show a numerical change of 7% to 10%, and the appearance error of the magnetic flux induction coil equipped with it will be approximately within ± 2%.