3-2
SLA7900 Series
Installation and Operation Manual
X-TMF-SLA7900-MFC-eng
Part Number: 541B022AAG
August, 2009
Section 3 Operation
3-3 Features
Note: All Model SLA7950 mass flow controllers are configured at the factory
according to customer order and do not require adjustment. Not all features are
available on all instruments.
The Model SLA7950 is a full-featured digital MFC. The Model SLA7950
performs much like a traditional analog MFC, but with improved accuracy,
step response and valve control. The analog interface matches that of
Brooks' popular analog MFCs so the Model SLA7950 can be retrofitted into
tools using analog MFCs. Other versions of the Model SLA7950 can
provide a variety of digital protocols, for example DeviceNet.
The Model SLA7950 is capable of storing up to 10 different sets of gas
calibration data. Each set includes a calibration curve, PID controller
settings, valve performance data, and information about the calibration
conditions. The Model SLA7950 can contain calibrations for different gases
or for the same gas at multiple conditions (pressures, full-scale flow rates).
Section 3-5 Analog Mode of Operation describes more information about
the data contained in the calibration table and how to access the data.
Calibrations will appear in the calibration table in the same order as they
appeared on the Model SLA7950 customer order, unless otherwise
specified. The first listed gas will appear as calibration #1, the second as
calibration #2 and so on. Note that unless specified otherwise on the
customer order Model SLA7950’s containing a single calibration will have
that calibration stored in calibration #1.
Figure 3-1 Flow Sensor Operational Diagram
Heater
TMF principle of measurement
Sensor
Sensor
Flow A
Flow A
Sensor
Flow A
Heater
Valve (if equipped)
T1
Upstream
Temperature
Sensor
T2
Downstream
Temperature
Sensor
Flow B
Flow B
Inlet
Flow A & B
Outlet
Flow A & B
Restrictor
Flow B
TMF principle of measurement
TMF principle of measurement
