Kofloc EX-250S Series Digital Mass Flow Meter


Kofloc EX-250S Series Digital Mass Flow Meter device which is adopted the own developed both stable high-speed thermal sensors and small proportional solenoid valves and is realized high accuracy and quick response with RS 485 communication in spite of compact.

Kofloc EX-250S Feature

  • Lower cost but high accuracy measurement
  • High-speed response and zero stability
  • 0-5VDC or 4-20mA Input/output signal and +/-15VDC or 24VDC power supply
  • Mediocrity D-sub 9pin
  • Gases registered in EX-250S are usable by rotary-switch
    *Calculate the flow rate with conversion factor based onN2 gas
  • RoHS compliance, CE marked


Model Mass Flow Controller Mass Flow Meter
EX-250SC EX-250SM
Sensor type Thermal sensor
Valve type Normally closed proportional solenoid valve
Applicable gases(*1) N2、Air、H2、He、Ar、O2、CO2 etc.
(Gases not specifically mentioned here are subject to calibration for N2 equivalent.)
Flow range(*2) 10SCCM ~ 5SLM
Control(measure)range 2 ~ 100%(F.S.)
Response ≤ 1sec (within ± 2%F.S.)(*8)
Accuracy(*3) ± 1.0%F.S.
Repeatability ± 0.2%F.S.
Operating differential pressure(*4) 50 ~ 300kPa(Ar、CO2:100kPa ~ 300kPa)
Inlet maximum pressure 500kPa(G)
Proof pressure 980kPa(G)
External leak rate(He) ≤ 1.0 × 10-8Pa・m3/sec
Temperature Working temp. 5 ~ 50℃
Accuracy guaranteed temp. 15 ~ 35℃
Allowable storage temp. -10 ~ 60℃
Allowable operating humidity 10 ~ 90%RH (without dew condensation)
Materials of a gas contact part SUS316, SUS316L, magnetic stainless steel(*5), PTFE, FKM
Electrical connection Dsub 9pin KFC Standard(SEMI standard is compliant)
Flow rate setting signal 0~5VDC(input impedance: approx. 1M Ω)
or 4~20mA(input impedance: approx. 250 Ω)
Flow rate output signal 0 ~ 5VDC( load resistance ≧10k Ω)
or 4 ~ 20mA( load resistance ≧500 Ω)
Digital communication RS485 rotary-switch address setting
Required power supply (DC) +15VDC( ± 5%)100mA , -15VDC(± 5%)150mA
or +24VDC(± 10%) ≤180mA  (MFM would be ≤100mA)
Joint(*6) 1/4F900(standard)
Mounting posture Horizontal installation recommended.
Weight(*7) Approx.500g Approx.440g

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