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Brooks, Model 5851e – Brooks Instrument 5851E User Manual

Page 22

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3-2

Brooks

®

Model 5851E

Section 3 Operation

Installation and Operation Manual

X-TMF-5851E-MFC-eng

Part Number: 541B104AAG

November, 2008

• Soft Start
Enabled by moving a jumper on the PC board. Provides a slow injection of
gas as a protection to the process, particularly those using a volatile or
reactive gas. Full gas flow is achieved in approximately 15 seconds. Refer
to Section 2-6.
• Precision 5 Volt Reference
Allows the direct connection of a command potentiometer to a 0-5 Volt
command signal to the controller. A precision 10-turn 2 k ohm
potentiometer with an integral turns counter is recommended, this will
permit repeatable adjustments of command to 1 part in 1000. Refer to
Section 2-12 for activation.

• Valve Override
Allows full opening and closing of the control valve independent of the
command setting. Refer to Section 2-8.

• 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.

• Valve Test Point
Accessed via Terminal D on the Card Edge or Pin 7 on the D-Connector
version of the Model 5850E only. This feature allows the user to monitor
the control valve voltage during operation. Refer to Section 2-10.

Figure 3-1 Flow Sensor Operational Diagram