LDG-250 LDG-300 Magnetic flowmeter
Features of LDG-250 LDG-300 Magnetic flowmeter
● Simple structures, firm, no movable parts and long operation life.(Guarantee in 1 year)
● No intercepting fluid parts, no pressure loss and fluid clogging.
● No mechanical inertia, quick response and good stability, application in automatic examination
adjustment & controlling.
● Measuring accuracy not influenced by physical parameters such as style, temperature, viscosity,
density and pressure.
● Employ Teflon or rubber liner and different combination of electrode material such as Hastelloy
C,Hastelloy B, 316L, and Titanium and adapt the need of different mediums.
● Supply many styles of flow meters such as inline type and insertion type, etc.
● Adopt EEPROM memory to measure operation data, safe and reliable protection of memory.
● Integral type flow meters and remote type flow meters
● LCD back light display with high clearness (Option: LED back light display)
● Bi-direction measurement (Option)
● Approved from CE,EMC,ISO
● Programming language: English
LED display(Option)
Data Logging ability
Range-ability(turn down): 20:1
Reputability: Below 0.25%
Description of LDG-250 LDG-300 Magnetic flowmeter
Electromagnetic flow meter is a kind of induction instrument designed by Faraday’s law of
electromagnetic induction to measure flow of conductive media in the tube. It adopts the technology
of insertion of single chip to realize digital excitation and employs CAN local fieldbus.
Electromagnetic flow meter can realize local indication and output electrical current signal of
4-20mA which can be used to record, adjust and control. Electromagnetic flow meters are widely
used in industrial sectors such as chemical industry, environmental protection, metallurgy,
pharmaceutical, paper making, wate supply and removal etc.Besides measuring flow of general
conductive liquid electromagnetic flow meter can measure flow of liquid- solid mixed
fluid, high-viscosity fluid and salt, strong acid and strong alkali.
Working principle of LDG-250 LDG-300 Magnetic flowmeter
Electromagnetic flow meter is based on Faraday,s law of electro-magnetic induction. The measuring tube is a non
-magnetic-conductive alloy short pipe with a inside-liner of insulated materials. Along the pipeline the two electrodes perforate the pipe and are fixed on the measuring pipe.The head of the electrodes is basically paralleled with inner
surface of the liner . When excitation coils excited by bidirectional square-wave pulse, a working magnetic field with magnetic flux density B will generate in the direction vertical with the measuring pipeline. At this time if the flux with specific electro-conductivity flows through the measuring pipe, the line of magnetic force will induct electromotive force E. Electromotive force E is in positive proportion to magnetic flux B, product of inside diameter d and average flow velocity v, electromotive force E (flow signal) is examined by electrodes and sent through cable to transducer. After the transducer magnifies flow signal, the flow rate of flux will be displayed, and capable of outputting pulse and analog current, used to control and adjust flow In the formula, d is a constant. Because the excitation current is constant B is also a constant.
We can know from E = KBdV that volume flow Q is in positive proportion to signal voltage E, that is, signal voltage E inducted by flow velocity is in linear relation to volume flow Q. So if only E is measured ten flow rate Q can be defined.
This is the basic working principle of electromagnetic flow meter. From E=KBdV we can know that the temperature of
measured flux, density, pressure, electro-conductivity and the liquid-solid proportion of the liquid-solid mixed flux will
not affect measurement result. To moving condition if only it accords with the flow of axial symmetry (such as laminar flow) it will not affect the result of measurement. Therefore, we say that electromagnetic flow meter is a genuine volume flow meter.For manufacturer and users, if only practically calibrated with average water can volume flow of any other conductive flux be measured, without any amendment. This is a prominent merit of electromagnetic flow meter while any other flow meter doesn’t possess. In the measuring pipe there’s no moving and choking parts, therefore there’s nearly no pressure loss, and the reliability is very high.
Confirmation of measuring range
Generally for LDG-250 LDG-300 Magnetic flowmeter used in industry the flow velocity of measured medium should be 2〜4m/s. Under special conditions the minimum flow rate should be not less than 0.3m/s, and the maximum should be not more than 8m/s. If the medium includes solid granules, the usual flow rate should be less than 3m/s to prevent the liner and electrodes from excessively rubbing. To those viscous liquid, the flow rate should be more than 2m/s. The bigger flow rate is conducive to automatically eliminating the role of viscid substances apposed on the electrodes and advancing the accuracy. Under the condition that the span Q is defined, diameter D of flow meter can be decided according to the above flow velocity V, and the value is counted according to the following formula:
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Model
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LDG LDE LDCK
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Size
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DN10〜DN1800
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Material
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PTFE, Soft rubber, Hard rubber, F46, FS, PUR.
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Electrode
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316L, Hastelloy C, Hastelloy B, Titanium, Tantalum, etc.
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Accuracy
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0.3% (Option), 0.5%, 1.0% of F.S..
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Output
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4-20ma
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Communication
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RS-232; RS-485; HART
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