Electromagnetic flow meter is constitut by the primary and the converter two parts, based on faraday’s laws of electromagnetic induction carry on work, use to measure the electric conductivity liquid or two phase medium for which required electric conductivity generally must more than 5 μs/cm (original electric conductivity of the running water about is 100~500μs/cm ), can be used to metering various acid、alkali、brine solution、paper pulp、ore pulp medium etc., but can not include more ferromagnetic substance and considerable air bubbl in them.
Electromagnetic flow measurement for many industry department such as petroleum、chemical industry、metelargy、light and textile industry、papermaking、environment protection、food etc. and municipal management、water projects construction field etc.
Working principle
The metering system of the electromagnetic flow meter primary is base on Faraday’s laws of electromagnetic induction, on the channel border which is vertical each other with metering tube axis and line of magnetic field mount one pair detecting electrode, when the conductive liquid move alon metering tube axis conductive liquid cutting the line of magnetic field induce the inductive E.M.F. This EMF detect out by two electrodes on the metering tube, numerical value size is:
E=KBVD
Here: E inductive EMF;
K instrument constant;
B magnetic induction
V average flow velocity in metering tube section;
D metering tube inner diameter;
When measure flow rate fluid flow through magnetic field which is vertical to flow direction, conductive liquid movement induce one EMF in direct proportion to average flow velocity, so that require measured flow liquid have higher than lowest limit conductivity. Its induction voltage signal is detected by two electrodes, and pass through a cable transmit to converter, after through signal treatment and correlative operation, take the integrating flow and the instantaneous delivery indicate on the display screen of the converter.
Instrument characteristic
1.1 In metering tube have not flow resistance and movable component therefore can not cause extra energy loss also can not cause stop up, so that its energy saving effect is remarkable. Especial suit to measure liquid solid two phase flow such as sewage、slurry、ore pulp、water-coal pulp、paper pulp and so on.
1.2 Of contact with measured medium only have liner and electrode, as long as reasonably select liner and electrode material it can attain good non-corrodibility and wear ability, so that can measure various acid and alkali etc. chemical solution.
1.3 Installation demand is low. A straight upstream section only need 5D and downstream section is 2D (D is inner diameter of selected instrument).
1.4 Measurement accuracy non-subject the influence of fluid density、viscosity、temperature、pressure and conductivity variation, also can measure positive / negative two directional flow rate, thus is has provided the very good means for precise measurement of flow rate.
1.5 Instrument watt consumption is small, lower than 5VA.
1.6 Converter have good changeability, need not renew real flowing calibration can gain measurement accuracy. Because the electromagnetic flow meter have a serial strong point, so that it in various industry gain the more the wide application, become a first choice instrument of liquid flow measurement.
Main technic parameter
Conductivity ?μs/ cm Flow rate scope 0.5~10m/s Current output bidirection double-way, full isolation,
0~10 mA (load resistance 0~1.2kΩ)
4~20mA (load resistance 0~600Ω) Frequency output up-limitation set up in 1~3 KHz, with photoelectric isolated transistor collect rode is open-circuit output. Pulse output up-limitation can reach to 5000 cp/s, pulse equivalent is 0.0001~10m3/cp. Pulse width is 10ms~2.5s. with photoelectric isolated transistor collect rode is open-circuit output. Alarm output with photoelectric isolated transistor collect rode is open-circuit output, positive-negative direction flow state collect rode open-circuit output.
Outside connected power of above three output all not larger than 35V, when conduction collect rode max. current is 250mA. Communication interface RS485 Isolation insulation voltage between nalogic output、pulse output、alarm output and earth not smaller than 500V. Supply power 220V AC, 24V DC Power ?0W Environment temperature -10~+60?br />
Display high clearness backlight LCD display、instantaneous、integrating(have positive direction integrating、negative direction integrating and difference value integrating) Power cut-off protection integrating value data can be stored over 10 years. Case protection IP65、IP67
Technic parameter of Integrative III type and Split III type
Choose language chinese 、english display, selectable. Conductivity ?μs/ cm Current output bidirection double-way, full isolation, 0~10mA,(load resistance 0~1.5KΩ), 4~20mA, (load resistance 0~75Ω). Frequency output Frequency can be set within 1~5000Hz range, transistor collector open-loop output which with photo electric isolation. Pulse output Pulse equivalence is 0.001~10M3/cp(L/cp), pulse width is 4~400ms. Alarm output Transistor collctor open-loop alarm output which with photoelectric isolation, external connection power for above threee output items all not exceed 36V DC, max. collctor current when breakover is 250mA. Empty pipe measurement need not to add electrode empty pipe measurement function, continuous measurement, constant value alarm. Record function Power-off time record function, auto-record power pulsation time of instrument system, makeup calculate miss addition flow. Infrared remote control Infrared had-hold operation keyboad. Communication interface RS485, RS232, HART. Isolation Analog output, pulse output, alarm output, insulation voltage between output and earth not smaller than 1000V DC Supply power 110~220±15%, 50Hz; 24V DC, I?00mA Power ?0W(after connect transducer) Display high clearness backlight LCD display、instantaneous、integrating(There are forward cunulation、backward cumulation and difference value cumulation) Case protection IP65、IP67
China · Fu Jian Wide Plus Precision Instruments Co., Ltd.
ADD: NO.1, Cha shan Road, Mawei Hi-tech Development Zone, Fuzhou, China.
Tel?86-591-83969908 83969918 Fax?86-591-83969222 83969444
http://www.wideplus.com E-mail：info@wideplus.com
