Our mass flow controller is based on the SEMIIE12-91(semi-standard).
The applied unit is SLM (Standard Liter per Minute) or SCCM (Standard Cubic per
Minute). The status of this gas is the same as the reference(normal) conditions of 0℃,
101.325kPa(abs). If the applied flow unit and definition thereon differ, inquire us of it or
give us your instructions. If the unit you require is a SI unit or unit approved by the current
measuring law, we will make a production on the basis of the unit you require.
FGT® Model TMFC Mass Flow Controller/Mete
2. Principle of Operation
The detection sensor for Mass Flow is wound
thermo-resistance wires on the outsides of the
two positions (upstream and downstream) of the
metal tubing. Flowing a certain quantity of current
into its wires and self-heating them allow the
thermo-resistance wires on the two positions to
have a balance at the same temperature during
gas with no flow in the metal tubing. When gas
flows in this metal tubing, the thermo-resistance
wires on the up-per flow side is deprived of heat
by the gas, thereby lowering the temperature.
The downstream is conveyed the heat of the
upstream. This raises the temperature and
breaks the initial balance, thus also causing a
difference between the resistances. The
temperature difference of theses position grows
in proportion to the gas flow amount and a
volume of the heat capacity specified with the
specific gravity and specific heat determines the
ratio of the temperature difference change. The
change of the gas flow amount is caught of the
resistance value. Thus detecting the Mass Flow.
(=Principal of the thermal flow sensor).
Installation and Operation Manual
Part number:0912TWAD
The change of the Mass Flow is represented as
a change of the voltage signal by the electronic
circuit, through utilization of this principal.
Selecting-mounting a bypass capillary for
making the flow detecting sensor bypass the
flow limits the gas flow in this section, thus
enabling the flow rating to be determined. In
addition, mount a comparative control circuit
onto the combination of the flow detection
sensor and control valve for this Mass Flow,
thereby providing it with signals for setting the
flow detection sensor and flow. The
comparative control circuit compares these two
signals. Then if the output signal is smaller than
the setting signal, turn the opening of the control
valve greater, thus changing the current added
to the solenoid valve, the standard valve is of
normal closing type, with the power not-being
On, the flow route is closed.
U-TMFC--EN
October,2009
www.fgttw.com
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FGT® Model TMFC Mass Flow Controller/Meter
r
m
Installation and Operation Manual
U-TMFC--EN
Part number:0912TWAD
October,2009
FGT® Model TMFC Mass Flow Controller/Mete
Installation and Operation Manual
U-TMFC--EN
Part number:0912TWAD
October,2009
3.. Standard configuration and Wiring Connection
3-1. Standard Configuration
WARNING
Do not operate this instrument in excess of the specifications. Failure to heed this
warning may result in serious personal injury and / or damage to the equipment
Standard Ranges Output Signal(Fig-4)
z10 sccm to 500 slpm (nitrogen equivalent) z0~5 Vdc into 2kΩor greater. Maximum
ripple 3 mV. Jumper selectable 4~20 mA.
Refer to Fig-4 for maximum total loop
resistance.
Accuracy 5 Volt reference Output
z±1.0% scale including linearity at calibration
conditions. ±1.50% full scale including
linearity for floe ranges greater than 20 slpm
z 5 V ±0.2%.Maximum load 1KΩ
Repeatability Command Input(Fig-2/Fig-3)
z 0.25% of rate z Jumper Selectable: 0~5 Vdc, Input resistance
200KΩ or 4~20 mA, Input resistance 75Ω
Response Time Leak Integrity
zLess than 3 seconds response to within 2%
full scale final value with 0 to 100%
command step.
z 1x 10
-9
Atm. CC/sec helium
Power Requirements Control Range
z+15 ~ + 28 Vdc 350mA z50 to 1
3-2. Electric connection Diagram
Electrical Connection(Fig-1)
D-type Connections Pin out
Pin Assignment of Dsub 15-Pin Connector per Standards
Pin No.Signal Pin No.Signal
1 COM ground 9 Power Source COM
2 Flow output 0~5VDC 10 Flow output Ground
3 No used 11 +5 Vdc reference output
4 Flow output 4~20mA 12 Valve Override
5 +15~28 VDC Power Source 13 No used
6 -15 VDC Power source 14 Chassis ground
7 Current flow input COM 15 No used
8 Voltage flow Input COM
*Because a differential input system is used for the products, pin 2&8 for TMFC30V and pin
4&7 for TMFC30A choice one kind of signal input/output to use.
Fig-1
CAUTION
Ambient temperature Limits Mechanical Connection (Fig-5)
z Operating:5 ~ 65 (40 to 150℃℉)
z No-Operating:-25 to 100 (℃ -13 to 212℉)
z Range. Consult factory for details.
z Interchangeable with most popular mass
flow controller .Fig-5
Working Pressure Electrical Connection(Fig-1)
z 1300/1000 psi maximum zD-type:Dsub 15-pin connector, Mating