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Mass Flow Controller w/RS485 Standard and Alarm Functions

FMA6500 Series

Mass Flow Controller w/RS485 Standard and Alarm Functions | FMA6500 Series

Mass Flow Controller w/RS485 Standard and Alarm Functions

SGD3,455.00 FMA6502ST

  • Digital and Analog Modes Operate Simultaneously
  • Programmable Flow Configurations
  • RS485 Standard, Multi-Drop Capability of Up to 256 units
  • Stores Calibration Data for Up to 10 Gases
  • Totalizer Indicates Total Gas Quantity
  • Alarm Limits for High and Low Gas Flow
  • Conversion Factors for Up to 256 Gases
  • Autotune Function for Optimum Control Response
  • Self Diagnostic Tests
Electronic Mass Flow Meters & Controllers - View related products


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.

Principles of Operation
Metered gases are divided into two laminar flow paths, one through the primary flow conduit, and the other through a capillary sensor tube. Both flow conduits are designed to ensure laminar flows and, therefore, the ratio of their flow rates is constant. Two precision temperature sensing windings on the sensor tube are heated, and when flow takes place, gas carries heat from the upstream to the downstream windings. The resultant temperature differential is proportional to the change in resistance of the sensor windings. A Wheatstone bridge design is used to monitor the temperature dependent resistance gradient on the sensor windings which is linearly proportional to the instantaneous rate of flow. The output of the Wheatstone bridge is converted to digital format with a 12 Bit ADC (analog to digital converter). An on-board microprocessor and nonvolatile memory store all calibration factors and directly control a proportional electromagnetic valve. The digital closed loop control system continuously compares the mass flow output with the selected flow rate. Deviations from the setpoint are corrected by compensating valve adjustments, with PID algorithm thus maintaining the desired flow parameters with a high degree of accuracy. Output signals of 0 to 5 Vdc or 4 to 20 mA are generated indicating mass molecular based flow rates of the metered gas.

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.

The firmware for the FMA6500 provides functions to register total gas quantity. The total mass of gas is calculated by integrating the actual gas flow rate with respect to time. Digital interface commands are provided to: SET the totalizer to ZERO; START /STOP totalizing the flow; READ the totalizer; START the totalizer at a preset flow STOP the flow at a preset total.

Multi-Gas Calibration
The FMA6500 is capable of storing primary calibration data for up to 10 gases. This feature allows the same FMA6500ST to be calibrated for multiple gases while maintaining the rated accuracy on each.

Conversion Factors
Conversion factors for up to 256 gases are stored in the FMA6500. Conversion factors may be applied to any of the ten gas calibrations via digital interface commands.

Flow Alarms
High and Low gas flow ALARM limits are programmed using the digital interface. Alarm conditions are reported via the digital interface or can activate the contact closure outputs.

Programmable Flow
OMEGA software supports programmable flow modes, allowing execution of custom programming of up to ten steps. Various flow configurations include ramping, linearized increasing and decreasing modes.

The AUTOTUNE function allows the FMA6500 to automatically optimize control response for the gas under actual process conditions. During the AUTOTUNE process, the instrument adjusts PID gains for optimum step response and determine key control valve characteristics (only available on units with less than 80 L/min maximum flow).

Contact Closure
Two sets of dry contact relay outputs are provided to actuate user supplied equipment. These are programmable via the digital interface such that the relays can be made to switch when a specified event occurs (e.g. when a low or high flow alarm limit is exceeded or when the totalizer reaches a specified value).

Valve Override
Means are provided to force the control valve fully open (purge) or fully closed via either the analog or digital interfaces.

Self Diagnostics
Whenever power is first applied, the FMA6500 runs a series of SELF DIAGNOSTIC TESTS to ensure that it is in optimum working condition.

Engineering Units
The flow setpoint, measured gas flow and associated totalizer data is scaled directly in engineering units via digital interface commands. The following units of measure are supported: % of FS, mL/min, mL/hr, scfm, scfh, sL/min, sL/hr, lbs/hr, lbs/min, and one user defined unit of measure.

Leak Integrity
1 x 10-9 smL/sec of Helium maximumto the outside environment.

Balanced Power Supply
The FMA6500 operates on ±15 Vdc. The current requirements for the positive and negative power supplies are balanced such that the current in the power supply common connection is minimized. Maximum power consumption is 13.5 watts at ±15 Vdc.

FMA6500 Series Transducers should not be used for monitoring Oxygen gas unless specifically cleaned and prepared for such application. See ordering instructions below.

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
Circuit Protection: Circuit boards have built-in polarity reversal protection; resettable fuses provide power input protection
Calibration Options: Standard 10-point NIST calibration optional up to 9 additional 10-point calibrations may be ordered for an additional charge
(Specify Model Number)
Part Number/Desc.
Controller: Max Flow and Compression Fitting Connection
Availability: 7 weeks
10 sccm 1/4"
Availability: 7 weeks
20 sccm 1/4"
Availability: 7 weeks
50 sccm 1/4"
Availability: 7 weeks
100 sccm 1/4"
Availability: 7 weeks
200 sccm 1/4"
Availability: 7 weeks
500 sccm 1/4"
Availability: 7 weeks
1 SLPM 1/4"
Availability: 7 weeks
2 SLPM 1/4"
Availability: 7 weeks
5 SLPM 1/4"
Availability: 7 weeks
10 SLPM 1/4"
Availability: 7 weeks
15 SLPM 1/4"
Availability: 7 weeks
20 SLPM 1/4"
Availability: 7 weeks
30 SLPM 1/4"
Availability: 7 weeks
50 SLPM 1/4"
Availability: 7 weeks
60 SLPM 3/8"
Availability: 7 weeks
80 SLPM 3/8"
Availability: 7 weeks
100 SLPM 3/8"
Availability: 1 week
Replacement cable 25 pin D-conn with 1.8 m (6') wire, branch to power supply
Availability: 5 weeks
Power supply with 25 pin female D-conn 110 Vac (±15 Vdc) branch 1.8 m (6') wire to computer port stripped
Availability: 5 weeks
Power supply with 25 pin female D-conn 110Vac (±15 Vdc) branch 1.8 m (6') wire to analog interface
Availability: 5 weeks
European power supply with 25 pin female D-conn 230 Vac (±15 Vdc) branch 1.8 m (6') wire to computer port stripped
Availability: 5 weeks
UK power supply with 25 pin female D-conn 230 Vac (±15 Vdc) branch 1.8 m (6') wire to computer port stripped
Availability: 5 weeks
25 pin D-conn with 1.8 m (6') wire to 15 pin DM, branch 1.8 m (6'), wire to computer port stripped
All prices on this site are shown in Singapore Dollars.
Note: Comes complete with operator’s manual, software, cable (FMA65-C), and NIST Certificate. Power supply sold separately.

** Flow ranges specified are for nitrogen or air at 20 psig inlet (up to 50 SLM) or 25 psig inlet (60 to 100 SLM units) and 0 psig outlet.

For custom calibration add suffix "-(*) to the model number, no additional cost. Replace the * in the model number with the gas or gasses and inlet/outlet pressures.

Calibrations done at ambient (20C/70F) temperature only.

To replace the standard RS485 communications, add suffix "-RS232" to the model number, no additional cost.

For a 4 to 20 mA output, add suffix "-I" to the model number, no additional cost.

To substitute Perflouoroelastomer O-Rings for the standard FKM, add suffix "-K" to the model number, add $364 to price.

For Oxygen cleaned units, add suffix "-C" to model number; add $125 to price.


Ordering Example: (1) FMA6502ST Mass flow Controller, SGD3,455.00  plus (1) FMA65PWC Power Suppy, SGD535.00, SGD3,455.00 + 535.00 = SGD3,990.00
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