Kofloc EX-550 Metal Digital Mass Flow Meter

In comparison with the conventional mechanical products, the mass flow measurement/control technology used in a mass flow meter and controller extracts electrical signals from the flow without significantly influencing the temperature or pressure, thus permitting sophisticated flow measurement and control. The technology is widely used for manufacturing semiconductors, liquid crystal, optical fibers and other electronic devices, gas supply for fuel cells, and fuel gas control for burners, foods, biotechnology, as well as for experimental facilities and production/inspection systems in many other industries.


  • Metal sealing design
  • 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-550 are usable by rotary-switch.
    *Calculate the flow rate with a conversion factor based on N2 gas.
  • RoHS compliance, CE marked


ModelMass Flow ControllerMass Flow Meter
Sensor typeThermal sensor
Valve typeNormally 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)range2 ~ 100%(F.S.)
Response≤ 1sec (within ± 2%F.S.)(*4)
Accuracy± 1.0%S.P. (25%F.S. ~ 100%F.S.) , ± 0.25%F.S. ( ~ 25%F.S.)
Repeatability± 0.2%FS
Operating differential pressure(*3)50 ~ 300kPa(Ar、CO2:100kPa ~ 300kPa)-
Inlet maximum pressure350kPa(G)
Proof pressure980kPa(G)
External leak rate(He)≤ 1.0 × 10-11Pa・m3/sec
TemperatureWorking temp.5 ~ 50℃
Accuracy guaranteed temp.15 ~ 35℃
Allowable storage temp.-10 ~ 60℃
Allowable operating humidity10 ~ 90%RH(without dew condensation)
Materials of a gas contact partSUS316L、PTFE、Ni-Co
Electrical connectionDsub 9pin KFC Standard(SEMI standard is compliant)
HR-10A × 2
Flow rate setting signal0~5VDC(input impedance: approx. 1M Ω)-
or 4~20mA(input impedance: approx. 250 Ω)
Flow rate output signal0 ~ 5VDC( load resistance ≧10k Ω)
or 4 ~ 20mA( load resistance ≧500 Ω)
Digital communicationRS485 rotary-switch address setting
Required power supply (DC)+15VDC( ± 5%)100mA , -15VDC(± 5%)150mA
or +24VDC(± 10%) ≤180mA  (MFM would be ≤100mA)
Mounting postureFree
WeightApprox.800g Approx.550g

(*1) The gases must be dry and clean, free of corrosive components and foreign matter such as dust and mist.

(*2) The flow rate calibration units SCCM and SLM indicate a mass flow rate converted to a volume flow rate in cc/min and L/min at 0°C and 1 atm.

(*3) The operating differential pressure may differ depending on specifications.

(*4) Pressure condition would be needed when you order.