Microprocessor driven digital flow controllers allow one to program, record, and analyze flow rates of various gases with a computer via an RS485 interface (optional RS232 is available). Controllers can be programmed for various control functions including flow setpoint, totalizer, stop totalizer, read totalizer, totalizer from preset flow, stop at preset total, auto zero, and more.

Interface
The digital interface operates via RS485 (optional RS232) and provides access to applicable internal data including FLOW SETPOINT, ACTUAL FLOW, ZERO ADJUSTMENTS, and LINEARIZATION TABLE ADJUSTMENTS. The analog interface provides 0 to 5 Vdc, 0 to 10 Vdc and 4 to 20 mA inputs and outputs.

Auto Zero
The FMA6500 automatically nulls the sensor zero offset whenever the flow setpoint is below 2% of full scale. To accommodate this feature the control valve must fully close under that condition. Provisions are made to either disable, force or store the current auto zero via digital commands.

Features

Accuracy (including linearity): 15 to 25°C (59 to 77°F) and 0.7 to 4 bar (10 to 60 psia): ±1% of FS, 0 to 50°C (32 to 122°F) and 0.3 to 10 bar (5 to 150 psia): ±2% of FS, ±1% of FS at a specific temperature and pressure with special calibration
Repeatability: ±0.15% FS
Turndown Ratio: 50:1
Response Time: 0.6 to 1.0 s to within ±2% of setpoint over 20% to 100% FS
Temperature Coefficient: 0.05% of full scale/°C or better
Pressure Coefficient: 0.01% FS/psi (0.07 bar) or better
Leak Integrity: 1 x 10-9 smL/sec Helium maximum to the outside environment
Optimum Gas Pressure: 1.73 bar (25 psig)
Max Gas Pressure: 34.5 bar (500 psig)
Max Diff. Pressure: 3.4 bar (50 psig) for up to 10 LPM, 2.8 bar (40 psig) for 15 LPM and greater
Gas and Ambient Temp: 5 to 50°C (41 to 122°F)
Output Signals: Linear 0 to 5 Vdc (2000 Ω min load impedance); 0 to 10 Vdc (4000 Ω min impedance); 4 to 20 mA optional (0 to 500 Ω loop resistance)
Communication Interface: RS485, standard; RS232, optional
Transducer Input Power: ±15 Vdc, 450 mA maximum
Wetted Parts: 316 stainless steel, 416 stainless steel, FKM O-rings; Neoprene or Perfluoroelastomer O-rings optional
Connections: Standard 1/4" compression fittings up to 30 LPM models; for 60 LPM models and greater: 3/8" compression fittings