3-1
Brooks
®
Model SLA5840
Section 3 Operation
Installation and Operation Manual
X-PR-SLA5840-Series-RevB-RT-eng
Part Number: 541B201AAG
October, 2017
3-1 Overview
This section contains the following information:
• Theory of Operation
• Features
3-2 Theory of Operation for RT
The Brooks SLA5840 is a Remote Transducer (RT) pressure controller
with an integral Mass Flow sensor for flow indication. This device will
control the pressure in a vessel or feed or exhaust line by using the remote
transducer output signal as the transducer input of the SLA5840. This user
supplied pressure transducer can have a full scale pressure as low as10
mTorr or as high as several hundred psi and a full scale output signal of
5 or 10 Vdc. The control electronics PID circuit compares the pressure
signal to a setpoint and acts to regulate the flow through the integral
solenoid control valve to stabilize the pressure at the setpoint value. An
ntegral mass flow sensor, identical in design to the Brooks SLA5850 Mass
Flow Controllers, provides a signal proportional to the flow through the
control valve. A system block diagram is shown in Figure 3-1. The
integration of mass flow sensor, control electronics and control valve
into one unit results in a compact size. The mounting dimensions are
comparable to a mass flow controller. Refer to Figures 1-4 thru 1-6.
In the most common configuration, Downstream Pressure Control mode,
the pressure controller is positioned upstream of the pressure vessel. It
controls pressure in this downstream vessel by controlling flow into the
vessel. (see Figures 3-2 and 3-3)
In the upstream pressure control mode, the pressure controller is placed at
the outlet side of the pressure vessel. (thus controlling pressure upstream
of itself) (Figures 3-2 and 3-4).
Figure 3-1 Model SLA5840 System Block Diagram
