Brooks Instrument 5851E - Manual (Page 7)

1-1
Brooks ® Model 5851E
Section 1 Introduction
Installation and Operation Manual
X-TMF-5851E-MFC-eng
Part Number: 541B104AAG
November, 2008
1-1 Purpose
The Brooks ® Model 5851E Flow Controller is a mass flow measurement
device designed for accurately measuring and rapidly controlling flows of
gases. This instruction manual is intended to provide the user with all the
information necessary to install, operate and maintain the Model 5851E
Mass Flow Controller. This manual is organized into five sections:
Section 1 - Introduction
Section 2 - Installation
Section 3 - Operation
Section 4 - Maintenance
Section 5 - Replacement Parts
It is recommended that this manual be read in its entirety before attempting
to operate or repair the Model 5851E.
1-2 Description
The Brooks Model 5851E Mass Flow Controller is used widely in the
Semiconductor Industry as well as many others, where manual, electronic
or computer controlled gas handling occurs. The Model 5851E consists of
three basic units: a flow sensor, a control valve and an integral electronic
control system. This combination produces a stable gas flow, which
eliminates the need to continuously monitor and readjust gas pressures.
Standard features include:
-FAST RESPONSE CONTROL permits rapid gas settling times with little or
no over/undershoot. Refer to Figure 1-1.
-SOFT START provides a flow ramping function which slows down the
introduction of the process gas for those processes which cannot tolerate
rapid flow transition. Refer to Section 2-6 and Figure 1-2.
-VALVE OVERRIDE permits the user to fully open and close the control
valve independent of the command setting. Refer to Section 2-8.
-SETPOINT (Command) permits the user to program the mass flow
controller with an external 0-5 Vdc command voltage in lieu of a command
potentiometer. Refer to Section 2-7.
-LOW COMMAND VALVE INHIBIT (Auto Shut-off) typically prevents the
valve from opening whenever the set-point is less than 2% of full scale.
-REMOVABLE CLEANABLE SENSOR permits the user to clean or replace
the sensor. Refer to Section 4-4.
-OUTPUT LIMITING prevents possible damage to data acquisition devices
by limiting the output to +6.8 Vdc and -0.7 Vdc.
-VALVE OFF accessed via Terminal J on the Card Edge or Pin 4 on the
D-Connector version. This feature allows the user to close the control
valve independently of the command signal by supplying a TTL level low
signal to the proper terminal. This function is useful when performing
repetitive flow operations or as a safety shutdown. Refer to Section 2-11.