Features of electromagnetic flowmeters

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Features of electromagnetic flowmeters – Working principle: Electromagnetic flowmeters are designed and manufactured based on Faraday’s law of electromagnetic induction. When a conductive fluid moves in a magnetic field, an induced electromotive force is generated, and this induced electromotive force is proportional to the flow velocity of the fluid. Feature 1: Linear measurement principle for high-precision measurements ； 2. There are no components that impede flow inside the measuring tube, resulting in no pressure loss; the requirement for straight sections is low ； 3. The measurement is not affected by changes in fluid density or viscosity ； 4. Can detect conductive liquids with a conductivity of ≥5μS/cm ； 5. The proper selection of electrode materials and lining materials can meet the requirements for corrosion resistance. Application areas: Electromagnetic flowmeters are suitable for use in various industrial fields such as agricultural irrigation, mining and metallurgy, power generation, the chemical industry, water supply and drainage, paper manufacturing, pharmaceuticals, and food processing. They are used to measure the volumetric flow rate of conductive liquids and slurries in closed pipelines. Product classification: The MF series of electromagnetic flowmeters consist of a sensor and a converter, and can be configured as either integrated or separate flowmeters. Among them, instruments with explosion-proof properties can be used in designated explosion-proof areas. The ways in which sensors are connected to pipes include flange connection, clip-on connection, and weld connection. There are 7 electrode materials and 5 linings available for selection. Product standards for the overall unit and sensor parameters: JB/T9248-1999; Calibration standard: JJG1033-2007. Structural types: Integrated type (DN10-600) and separate type (DN3-2000). Maximum flow velocity: 10 m/s for types B, C, and D ； Type E 15 m/s accuracy ±0.3% ； ±0.5% liquid conductivity ≥5μS/cm; nominal pressures of 0.6MPa, 1.0MPa, 1.6MPa, 2.5MPa, 4.0MPa; other values can be provided according to customer requirements. Liner materials: neoprene, polyurethane rubber, polytetrafluoroethylene, perfluoroethylene, Teflon. Signal electrode and grounding electrode materials: molybdenum-containing stainless steel, Hastelloy B, Hastelloy C, titanium. Flange materials: carbon steel, stainless steel (as per customer requirements). Grounding ring material: stainless steel 1Cr18Ni9Ti. Imported protective flange material: stainless steel 1Cr18Ni9Ti. Operating temperature range: –20°C to +60°C. Maximum temperature of the fluid medium: for integrated flow meters, 70°C℃ ； Separable flow meter: Neoprene: 80℃ ； Polyurethane rubber: 70℃ ； Polyester vinyl fluoride: 120℃ ； Polyperfluoroethylene (F46): 150℃ ； Teflon (PFA): 180℃ ； Protection rating IP65: dust-tight and splash-proof. All sensors and converters have an IP68 rating, meaning they can remain submerged continuously. Sensors feature separate neoprene and polyurethane linings. Explosion protection rating: EXdmbIIBT6. Cable length: For separate flow meters, the length of the signal cable between the sensor and the converter shall not exceed 100 m ； Converter technical parameters: Power supply voltage 220V, powered by electrical supply ； Powered by 24V supply ； Powered by a 3.6V lithium battery, capable of continuous operation for over 3 years ； Output signal: pulse output, 485 protocol, GPRS output. Design selection – reference for ensuring the measurement accuracy of electromagnetic flowmeters. Necessary conditions: 1. The fluid being measured must be conductive and fill the pipeline completely ； 2. The flow meter measurement system must be properly grounded ； 3. The straight pipe sections before and after the flow meter meet the specified technical requirements ； 4. Strong electromagnetic field interference should be avoided near the flow meter accessories. General selection principles 1. Recommended flow rate: A. The generally recommended range for flow rate is between 1-5 m/s. Within this range, the flow meter offers good measurement accuracy, low power consumption, and minimal wear on the flow meter’s lining and electrodes caused by the fluid medium ； B. For fluid media containing solid particles, a recommended flow rate range is between 1-3 m/s, as this helps to prevent excessive wear of the flow meter’s lining and electrodes caused by the suspended solid particles at high flow rates ； C. For fluid media in pipelines where deposits may form, the recommended flow rate range is between 2 and 5 m/s. If the requirements cannot be met, and pressure loss permits it, a flow meter with a smaller diameter than that of the pipe can be used, along with the installation of special-shaped pipes.