Kofloc DF-550C SERIES All-Metal Digital Mass Flow Controller

 DF-550C is now released as an all-metal model of the high-performance digital mass flow controller DF-250C Series. The metal sealed structure enables controlling the measurement of corrosive gases such as semiconductor process gases.


  • Response improved to 1 sec or faster in all flow rate ranges thanks to a new solenoid
  • The stainless steel seal supports high-reactive gases.
  • Lineup ranging from 10 SCCM to 10 SLM
  • Two communication ports enabling daisy-chaining
  • RS-485 communication function installed as standard
  • RoHS CE standard compliant

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Sensor typeThermal sensor
Valve typeNormally closed proportional solenoid valve
Applicable gases*1N2, Air, H2, He, Ar, O2, CO2, etc.
Gases not specifically mentioned here are subject to calibration for N2 equivalent.)
Flow range*210 SCCM to 10 SLM
Control range2 to 100% (F.S.)
Response*3Total flow rate control range ≤ 1 sec (within ±2% F.S.)
Operating differential pressure*550 to 350 kPa (100 to 350 kPa for F.S. 10 SLM)
Inlet maximum pressure500kPa(G)
Proof pressure980kPa(G)
External leak rate≤ 1.0 x 10-11 Pa·m3/sec (He)
TemperatureWorking temp.5 to 50℃
Accuracy guaranteed temp.15 to 35℃
Allowable storage temp.-10 to 60℃
Allowable operating humidity10 to 90% RH (without dew condensation)
Materials of gas contact partSUS316L, PTFE, and magnetic stainless steel
Electrical connectionD-sub 9-pin, KFC standard (SEMI standard compliant), RJ-45 modular jacks (two)
Flow rate setting signal0 to 5 V DC (input impedance approx. 1 MΩ)
Flow rate output signal0 to 5 V DC (load resistance 10 KΩ)
Digital communicationAddress setting with RS485 rotary switch: up to 99 devices (9600 bps)
Required power supply (DC)+15 V DC (±5%), 150 mA; -15 V DC (±5%), 150 mA
Joint1/4 VCR or equivalent
Mounting postureHorizontal installation recommended.
WeightApprox. 1100 g

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

*2 The flow rate 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 Guarantee for calibration gas: N2.

*4 Accuracy for calibration gas: N2, flow range (max. full scale).

*5 The operating differential pressure may differ depending on specifications.