I will take you through the details of the advantages, principles and applications of electromagnetic flowmeters.

In the food industry, accurate flow control of product bottling and canning directly affects profitability, so flow measurement errors must be minimized; in closed transport applications, such as crude oil and refined oil exchange between tanks and tankers in the oil industry - requires high precision measurement;

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As one of the most widely used flow technologies, one of the highest precision in liquid flow measurement, how much do you know about electromagnetic flowmeter?

Advantage 1 - The sensor of the electromagnetic flowmeter is generally connected to the pipeline, and its diameter is consistent with the diameter of the pipeline, so that the measurement does not interfere or limit the flow of the medium. Since the sensor is not directly immersed in the liquid, there are no moving parts, so there is no wear problem.

Advantage 2 - The volumetric flow is measured , which means that the measurement is insensitive to changes in parameters such as fluid density, temperature, pressure and viscosity. Once the electromagnetic flowmeter is calibrated with water, it can be used to measure other types of conductive fluid without further calibration. This is an important advantage that other types of flowmeters do not have.

Advantage 3 - Particularly suitable for measuring solid-liquid two-phase media , such as high-conductivity media with suspended solids, solid particles, fibers or viscous materials such as mud. It can be used to measure sewage, mud, pulp, pulp, chemical fiber pulp and other media. This makes it particularly suitable for the food, pharmaceutical and other industries, using it to measure corn syrup, juice, alcohol, drugs, plasma and many other special media.

The working principle of the electromagnetic flowmeter is based on Faraday's law of electromagnetic induction. When the conductor perpendicular to the direction of the magnetic field performs the movement of the cutting magnetic line at the velocity V, a certain induced electromotive force E is generated at both ends of the conductor, and the change in the liquid flow velocity is calculated by detecting the magnitude of the induced electromotive force.

The characteristics of the electromagnetic flowmeter include no pressure loss, no influence on viscosity, fluid density, temperature, pressure and conductivity, and it is suitable for high-precision measurement of pulp, mud and sewage.

Electromagnetic flowmeter systems include power, excitation, signal conditioning, analog-to-digital converters, processors, displays, keyboards, and logic I/O, as well as 4 mA to 20 mA, HART, RS-485/RS-422/RS-232, Various communication interfaces such as PROFIBUS, ® Modbus, and Foundation.

In order to properly design an electromagnetic flowmeter system, you must consider many different system requirements, including accuracy, bandwidth, and excitation frequency.

The output range of the electromagnetic flowmeter sensor can be as small as a few tens of μV and is usually accompanied by a large common mode voltage. The output impedance is often higher than a few megaohms. Therefore, front-end precision op amps or instrumentation amplifiers require ultra-high input impedance, very low leakage current, and excellent common-mode rejection ratio (CMRR).

The maximum measurement range of electromagnetic flowmeter products can be as high as 1500: 1, reflecting the flow rate

Surrounding: 0.01 m/s to 15 m/s.

Measurement accuracy can be as high as 0.2% of reading, which typically requires 16 to 24 bit analog to digital converters.

Connection to different fieldbuses, such as HART, PROFIBUS, Modbus, Foundation, RS-485/RS-422/RS-232, wireless HART, etc. Isolation is required between X system power supplies, central logic units, communications, and I/O; isolation levels range from 1 kV to 2.5 kV.

Portable electromagnetic flowmeters require ultra-low power MCUs, amplifiers, and ADC components.

High-frequency square wave excitation can improve the flow of mud and improve the immunity, but at the same time need to consider the zero stability.

The industrial site temperature environment is very complicated and even extremely bad. For a wide operating temperature range, low temperature drift coefficients and low power consumption are critical to electromagnetic flowmeters. ADI offers a complete product line that includes precision amplifiers, precision voltage references, precision analog-to-digital converters, and Cortex®-M3 core microprocessors.

In addition, EMC immunity such as surge, EFT and ESD is also a serious challenge for electromagnetic flowmeters. The high ESD rejection of ADI components can greatly improve product reliability and stability.

In addition, due to the limited internal space of the electromagnetic flowmeter, there is a high requirement for the system density, and thus the device size must be reduced. Recent advances in integration technology have enabled system designers to adopt smaller, lower power, lower cost solutions with comparable performance to those of larger systems. Continuous technological advancement requires continuous improvement in the integration of these solutions while improving their performance and diagnostic capabilities.

ADI offers market-tailored solutions that help simplify the design process. These solutions use industry-leading technology and offer a wide range of design options: from discrete component implementations to fully integrated solutions.

High-resolution, low-noise industrial electromagnetic flowmeter systems can be realized with ADI's amplifiers, data conversion, signal processing, communication and power technologies, and expertise.