The ratio of maximum flow rate to minimum flow rate is generally above 20: 1, and it is applicable to a wide range of industrial pipe diameters, up to 3m. The output signal has a linear relationship with the measured flow, and the accuracy is high. It can measure the flow of acid, alkali, salt solution, water, sewage, corrosive liquid, mud, pulp, pulp and other fluids with conductivity ≥5μs/cm. But it cannot measure the flow of gas, steam and pure water.
When a conductor cuts the magnetic field lines, it will produce an induced potential, which is proportional to the effective length of the conductor in the magnetic field and the speed of the conductor moving perpendicular to the magnetic field. Similarly, when the conductive fluid flows vertically in the magnetic field and cuts the magnetic induction force line, the induced potential will also be generated on the electrodes on both sides of the pipeline.
Extended data:
Characteristics of electromagnetic flowmeter
1, the measurement is not affected by the change of fluid density, viscosity, temperature, pressure and conductivity;
2. There is no obstruction and pressure loss caused by over-current parts in the measuring tube, and the requirements for straight pipe sections are low. It has unique adaptability to mud measurement;
3. Reasonable selection of sensor lining and electrode materials means good corrosion resistance and wear resistance;
4. The converter adopts novel excitation mode, with low power consumption, stable zero point and high precision. The flow range can reach150:1;
5. The converter can be integrated with or separated from the sensor;
6. The converter adopts 16-bit high-performance microprocessor, with 2x 16LCD display, which is convenient for parameter setting and reliable for programming;
7. The flowmeter is a two-way measuring system, which has three accumulators: forward accumulation, reverse accumulation and difference accumulation; It can display forward and backward flow, and has various outputs: current, pulse, digital communication, HART；;
8. The converter adopts surface mount technology (SMT), which has the functions of self-inspection and self-diagnosis;
9. The measurement accuracy is not affected by the change of fluid density, viscosity, temperature, pressure and conductivity. The voltage signal induced by the sensor has a linear relationship with the average flow, so the measurement accuracy is high.
10, measuring the unobstructed part in the pipeline, so there is no extra pressure loss; There are no moving parts in the measuring pipeline, so the service life of the sensor is extremely long.
1 1. Because the induced voltage signal is formed in the whole space full of magnetic field and is the average value of the surface of the pipeline carrier, the straight pipe section required by the sensor is short, and the length is five times the diameter of the pipeline.
12, the converter adopts the latest and most advanced single chip microcomputer (MCU) and surface mount technology (SMT), with reliable performance, high precision, low power consumption, stable zero point and convenient parameter setting. Click Chinese LCD to display cumulative flow, instantaneous flow, flow, flow percentage, etc.
13, two-way measuring system, which can measure downstream and countercurrent. Adopt special production technology and high-quality materials to ensure long-term stability of product performance.
References:
Baidu encyclopedia-electromagnetic flowmeter