Changzhou Voha Instrument Co., Ltd.
Summary
The electromagnetic flowmeter is composed of two parts by electromagnetic flow sensor and electromagnetic flow converter.The operation of an electromagnetic flowmeter is based on Faraday law of electromagnetic induction.The mainly parts of the sensor are: measuring tube,electrode poles,excitation coil,iron core,yoke and housing. The measuring tube of the sensor is a short alloy tube whose diameter is D, the inner surface of it has an insulating liner.Two electrodes are fixed in the measuring tube along with the diameter direction of it and they usually flush with the inner surface liner.When excitation coil pulsed by two-way square wave,there generates a working magnetic field with a flux density B in the vertical direction of the measurement axis.In the meantime,if some electrical conductivity liquid flows at an average velocity V through the measuring tube ,cuts lines of the magnetic field,there generates induced electromotive force E.Electromotive force E is directly proportional to the product of flux density B、measuring tube diameter D and average velocity V,that's: E BVD. Electromotive force E(flow signal) is measured by the electrodes and transmitted to transducer through cable.After the transducer handles the flow signal by magnifying it, the flow and total amount can be displayed,also will output pulse and analog current etc.
Main technical parameters
◆ Technical parameters of whole flowmeter and sensor
Chart 1 | ||||||
Carried Standard | ANSI/DIN/JIS | |||||
DN | 3.6.10.15.20.25.32.40.50.65.80.100.125.150.200.250.300.350.400.450.500. | |||||
Max.Flow Velocity | 15m/s | |||||
Accuracy | ±0.5% of indicating value(flow velocity 0.8m/s); ±4mm/s(flow velocity＜0.8m/s ) | |||||
Fluid Conductivity | ≥5uS/cm | |||||
Nominal Pressure | 4.0MPa | 1.6MPa | 1.0MPa | 0.6MPa | 6.3,10MPa etc. | |
DN3~DN150 | DN15~DN600 | DN200~DN1000 | DN700~DN3000 | Special Ordering | ||
Lining Material | PTFE,Poly neoprene,Polyurethane,F46,PFA with net | |||||
| Sensor | -25 deg.C~+60 deg.C | ||||
Convertor and integrated type | -10 deg.C~+60 deg.C | |||||
Fluid Max.Temperature | Integrated type | 70 deg.C | ||||
Separated type | Poly Neoprene Lining | 80 deg.C;120 deg.C(notes in order) | ||||
Polyurethane Lining | 80 deg.C | |||||
PTFE Lining | 100 deg.C;150 deg.C(notes in order) | |||||
FEP Teflon | ||||||
PFA with net | ||||||
Material of signal electrode and ground electrode | SS316L,HastelloyB,HastelloyC,Ti,Ta,Platinum-iridium alloy,Stainless steel coating with tungsten carbide | |||||
Electrode drawknife apparatus | DN80～DN3000 | |||||
Connection flange material | Carbon steel | |||||
Connection ring material | Stainless steel1Cr18Ni9Ti | |||||
Enclosure protection | ND15~DN3000 separated sensor with rubber or PU lining | IP65 or IP68 | ||||
Integrated(rounded converter) | ||||||
Other sensors and separated converter | IP65 | |||||
Explosion proof sensor and converter | IP65 | |||||
Spacing(separated type) | Normally the separation distance between converter and sensor is less than 100m,if more please order specially.(Note: our company provide 10m length standardly,if need more, please indicate the length in order, and the cost will be add more) | |||||
Output of analog current | 0~10mA load resistance 0~1.5Ω | |||||
4~20mA load resistance 0~750Ω | ||||||
Frenquency output | 1~5000Hz | |||||
Pulse output | Separated type output by two way: forward and reverse flow; integrated type output one way | |||||
Frenquency range:0~5KHz,uper limit 1~5 optionally | ||||||
Square wave or pulse with 25ms pulse width | ||||||
Transistor switch output with isolation protection,can absorb 250mA current and withstanding 35V voltage | ||||||
Two-path alarm output | Alarmable(programable)high/low flow,blank pipe,fault condition,forward and reverse flow,simulation volume exceeds range,pulse volume exceeds range,disconnect pulse small signal | |||||
Transistor switch output with isolation protection,can absorb 250mA current and withstanding 35V voltage(Not isolated with pulse output) | ||||||
Digital communications | RS232,RS485,HART(add specially) | |||||
Explosion proof mark | Integration ExdeiaⅡCT4 | |||||
Separated Exd[ia] ⅡCT4(converter) ExdeiaⅡCT4(sensor) | ||||||
[Type Selection]
LDG □ □□□ □□ □ □ □ □ □ □□ □ □□
│ │ │ │ ││ ││ │ │ │
a b c d e f g h i j k
a. Connect type | e. electrode material |
b. Nominal bore(mm) | |
f. Shell protection | |
g.Explosion-proof mark | |
| a.Nominal pressure(MPa) 06 0.6 (DN700~DN3000) | |
h.Accessory
| |
i. Structure | |
j. Power supply | |
| b.lining material 1.FTFE(F4) (DN15~DN1000) | |
k. Converter type |
Changzhou Voha Instrument Co., Ltd.
