Active Member
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[China]
Address: No.21, Lane 697, Guangfulin Road, Songjiang District, Shanghai, China
Contact name:Nancy Zhao
Melan Measurement & Control Instruments (Shanghai) Co.,Ltd. |
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Electromagnetic Flow Meter 1 1/2 Inch(40mm) Heavy Duty & Good Quality
1. Introduction
MLF electromagnetic flowmeter works according to Faraday's law of electromagnetic induction, and is composed of sensors and converters. Used to measure the conductivity of liquid or solid. In general, its conductivity should be greater than 5μs/cm (tap water and raw water conductivity is about 100 ~ 500μs/cm), and it can also be used to measure acid, alkali, brine, pulp or pulp and other media. However, these media cannot contain a large amount of magnetic substances and bubbles.
MLF electromagnetic flowmeter is an instrument for measuring liquid fluidity. Widely used in metallurgy, chemical industry, paper making, environmental protection, petroleum, textile, food, urban management, water plant and other industries.
2.Working Principle
The principle of the sensor is based on Faraday’s law of electromagnetic induction.
It is installed a pair of detection electrodes on the pipe wall,where the measurement pipe axis and magnetic field lines are vertical. When the conductive liquid cuts magnetic field lines and produces induced electromagnetic force.Which can be measured by the two electrodes on the
meter pipe.The result can be calculated by formula: Induced electromotive force,(flow signal) E=KBDV
E——Induced electromotive force,V；
K——meter constant；
B——Magnetic flux density,T；
D——Internal diameter of measuring pipe,m；
V——Average velocity of pipe section,m/s.
MLF Series Electromagnetic Flow Meter
Assume the volume of liquid as qv(m3/s),qv=πD2V/4),so in the formula E=(4kB/πD)qv=kqv,
K is meter constant,K=4kB/πD.
Actually, the electromagnetic flow meter consists of two parts, transmitter and sensor, the measuring electrodes inspect the electromotive force, and transmit to the converter, the converter provides excitation current.
E is usually called a flow signal, after processing the flow signal by converter, output 4~20 mA/pulse(or frequency) signal which is proportional to the flow rate, then the flow rate recording,adjusting can be achieved.
3. Features
MLF electromagnetic flowmeter is explosion-proof design.
Low conductivity measurement function.
There are nine languages options to meet the needs of different customers.
It has self-regulation function and self-test.
Different outputs are optional: Hart, RS485, Profibus, 4-20mA, frequency, pulse.
4. Specification
| MLF Type | Divided Type | Integrated Type | Explosive Proof Integrated Type | Battery Powered Type | Heat Energy Type |
| Accuracy | ±0.2% or ±0.5% | ||||
| Pipeline Diameter | DN10-DN2000 | DN10-DN600 | DN25-DN2000 | ||
| Flange | GB, ANSI, JIS, BS, Others | ||||
| Pressure | DN10-DN600 1.0 1.6 2.5 4.0MPa | ||||
| DN700-DN2000 0.6 1.0 1.6MPa | |||||
| Liner Material | CR, PTFE, PU, Hard Rubber, PFA, FEP(F46) | ||||
| Conductivity | ≥5µs/cm(Please contact us if it is less than 5µs/cm) | ||||
| Electrode | 316L SS, Hb, Ta, Ti, Hc, Tungsten Carbide, Others | ||||
| Protection Class | IP65, IP66, IP67, IP68 | ||||
| Medium Temperature | -25~180℃ (Please refer to liner material) | -25~80℃(Please refer to liner material) | -25~180℃ (Please refer to liner material) | ||
| Ambient Temperature for Accuracy Influence | <±0.1%/10℃ or <±0.25%/10℃ at the ambient temperature of -25~60℃ | ||||
| Repetability | ≤±0.1% or ±0.25% | ||||
| Analog Output Error | ≤±0.02mA | ||||
| Velocity | 0.3~10m/s | ||||
| Electrical connection | M20x1.5 Seal Cartridge, GB1/2, NPT1/2 | ||||
| Output | 4-20mA, Pulse, RS485, Hart, Profibus | ||||
5. Selection of Electrode Materials
| Electrode Material | Main Performance |
| 316L | Good corrosion resistance to nitric acid, less than 5% corrosion of sulfuric acid, acetic acid, alkaline liquid, sulfite, seawater and acetic acid under certain pressure at room temperature, and can be widely used in petrochemical urea, vinylon and so on |
| Hb | Good resistance to all concentrations below boiling point of hydrochloric acid, but also resistant to non-oxidizing acids, alkalis, sulphuric acid, phosphoric acid, hydrofluoric acid, organic acid corrosion. |
| Hc | Resistant to the corrosion of oxidizing acid, such as nitric acid and mixed acid. The mixture of chromic acid and sulfuric acid, oxidized salts, such as Fe3+, Q3+, and other oxidants, such as the mixture of hypochlorite solution and seawater at higher than normal temperature. |
| Ti | It is resistant to corrosion of sea water, various chlorides, hypochlorite, oxidizing acid (including fuming nitric acid), organic acid or alkali, but not pure reducing acid (such as sulfuric acid, hydrochloric acid). However, if the acid contains oxidants (such as nitric acid, Fe3+, Q3 +), the corrosion resistance will be reduced. |
| Ta | Good corrosion resistance similar to glass. Resistance to the corrosion of chemical medium(including hydrochloric acid and fumiing sulfuric acid), but can not be used for sodium hydromide fluid. |
| Pt-Ir | Have good corrosion resistance of all acid, and can be resistance to the corrosion of alkali, all salt except aqua regia, ammonium slat and few other medium |
| Tungsten Carbide | For pulp and sewage, good resistance to solid particle interference. |
6. Instrument Testing & Maintenance
Electromagnetic Flowmeter has self-diagnosis function. In addition to power and hardware circuit failures, the system also alarm other faults in general use. The information is prompted in the lower right corner of the screen.
1. Maintenance and repair
a) sensor installation site should meet the requirements of Section 4, please keep the shell clean;
b) transmitters shall be placed in a clean, ventilated, dry place;
c) need to be checked every two years, for high-precision users, the instrument needs to be submitted for review.
2. Transport and storage
a) instruments must be packed before transportation, loading and unloading should be carefully light.
b) storage place must be dry, ventilated, avoid corrosive gas erosion, environmental temperature should not be too low or too high;
c) storage time should not exceed three years.
3. Open-box inspection
a) packing must not be opened with a heavy hammer, be careful not to damage the instrument
b) carefully check the contents according to the packing list.
7. Product Photos
