MKS PR 4000 F, Инструкция по эксплуатации

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PR4000F Chapter 4: Operation
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4.6 Operation with mass flow controllers (MFC)
For the use with mass flow controllers (MFC) only, it is recommended to simplify the setup settings
by using the default configuration for flow
DEFAULT F : All flow readouts are set to sccm, all
analog inputs and outputs are set to 5 V. Most (if not all) parameters to be edited are set to
standard values but should be checked anyway. See the table in appendix C for all default
settings. Change the setup settings where needed.
Always check the correct setting of parameter GAIN to consider the right gas correction factor!
As readouts one will preferably use display 1 and display 2 for displaying both flow and setpoint.
Example: use display 1 for flow readout and display 2 to enter and display the setpoints.
The setpoints can be entered in either the setup menu or in the respectively configurated display.
To activate the setpoint output press the ON key. The activation is indicated by the LED
SETPOINT . Press the key OFF to switch off the setpoint output. If no LED SETPOINT is activated
then none of both channels was pre-selected, that means the valve switch is off. Refer to the
section
Control Display, VLV1, VLV2 .
Note
The setpoint voltage will be applied only to channels which have been
pre-selected with the valve switch
VLV1 or VLV2.
Beside the thermal mass flow controllers also pressure based MFC’s by MKS Instruments type
1150, 1151 and 1152 can be combined to the PR4000F.
Control Modes with Mass Flow Controllers:
a. INDEP Use this mode if the MFC shall be operated independently from the
other channel and setpoints are entered manually through the front
panel keys.
b. EXTRN In this mode the MFC shall be operated independently too but the
setpoint comes from an external signal source.
The range of the external setpoint voltage must be defined in the
setup section for
EI1 or EI2 respectively.
The setting of the scaler SCL determines the ratio of the external
setpoint to be applied to the respective channel.
Example for an MFC, control range 0 - 100 sccm, external setpoint
voltage range 0 – 5 VDC. At 5 VDC external setpoint voltage a
flow rate of 40 sccm shall be generated.
Therefore you must set the scaler
SCL : 40 sccm !
The external setpoint signal however could be derived from the
flow signal of an other PR4000 sein. This allows for example to
configurate several channels to a gas mixing system.
The value of the external voltage can be displayed: Use the EX
mode in the display configuration (ref. to section Setup ).