The electromagnetic flowmeter is widely used to measure the volume flow of conductive liquid and liquid-solid two-phase fluid. The measurement results are independent of the temperature, viscosity, density, pressure and liquid solid ratio of the fluid, and the change of conductivity will not affect the measurement results in a large range. Therefore, only by ordinary water calibration, it can be used to measure other conductive liquid and solid two-phase fluid medium flow, without any additional modification, so the electromagnetic flowmeter is a kind of real volume flowmeter. The electromagnetic flowmeter is composed of electromagnetic flow sensor and electromagnetic flow converter. They can be assembled into a single structure, and can also be installed separately and become a separate structure. The single structure installation is very convenient, which saves the shielding cable connection, and reduces the electrostatic interference and electromagnetic interference brought by the outside. But its on-site installation and application environment is higher than the separate structure.

main features

The measurement of flow is not affected by the change of density, viscosity, temperature, pressure and conductivity of the fluid. The sensor induced voltage signal has a linear relationship with the average velocity, and the measurement accuracy is high.
No mechanical inertia, sensitive reaction, can measure instantaneous pulsation flow, and the linearity is good. Therefore, the measured signal can be directly converted to the standard signal output by the converter, which can be indicated on the ground and can be transmitted in a long distance.
• no movable components in the tube are measured to facilitate maintenance and management, so the sensor has long service life and no flow resistance components, so no pressure loss.
Because the induced voltage signal is formed in the whole magnetic field space, and it is the average value on the cross section of the pipeline, so the main segment needed by the sensor is relatively short, which is usually 5D before 3D.
The sensor part only contacts the inner liner and the electrode with the tested liquid. As long as the electrode and lining materials are properly selected, corrosion resistance and wear resistance can be corroded.
Large caliber with multi electrode structure with high accuracy.
• use the grounding electrode structure to form a balance electrode surface to ensure that the whole measurement process is restricted to the surface of the balanced electrode. It can eliminate the interference of electrical noise well and provide accurate measurement results. One of the biggest benefits is that the sensors are not reliably grounded with the aging and rust of the pipes. The grounding electrode can be guaranteed very reliably for a long time with the grounding electrode, and the accuracy of the measurement is guaranteed.
Low frequency rectangular wave excitation, which improves the stability of flow measurement, low power loss and superior low flow velocity.
Bi-directional measurement system, which can measure forward flow and reverse flow.
Exclusive custom lined PFA, which can withstand a temperature of up to 180'C. It can also withstand negative pressure, and can fully meet the requirements of large caliber application in the heating industry.
It can be selected with the infrared hand-held keyboard, and all the functions of the remote non-contact operation converter.
The adjustable insert electromagnetic flowmeter with ball valves can be installed, unloaded, convenient and convenient for maintenance and maintenance.
It has RS-485 wired transmission and GPRS wireless remote transmission function.

Limitations

An electromagnetic flowmeter can not be used to measure gas, steam, and liquid containing a large amount of gas.
The electromagnetic flowmeter can not be used to measure the liquid medium with very low conductivity. The conductivity of the measured liquid medium can't be less than 5 S/cm, and it is not suitable for low conductivity media, such as distilled water, petroleum products or organic solvents.
As the temperature of the insulating lining material is limited by the measuring tube, the high temperature fluid can not be measured by the industrial electromagnetic condensation meter at present.
The electromagnetic flowmeter is affected by the velocity distribution. Under the axisymmetric distribution, the flow signal is proportional to the average velocity. Therefore, the electromagnetic flowmeter must have a certain length of straight front and rear tubes.
The measurement principle of the electromagnetic flowmeter is based on the law of Faraday electromagnetic induction, so it is easily affected by the external electromagnetic interference.

Working principle

The working principle of the electromagnetic flowmeter is based on the Faraday's law of electromagnetic induction. When the conductive liquid flows through the measuring tube enclosed in the magnetic field, the induced electromotive force E is proportional to the average velocity V, in the direction perpendicular to the two directions of velocity and magnetic field. The magnetic field intensity B is a constant (controlled by the coil current), and the distance between the detection electrodes is also fixed. Therefore, the liquid velocity V is the only variable of the induction electromotive force E. The output signal of the electromagnetic flowmeter is linearly related to the flow rate of the D.

Working principle diagram