3-5
Brooks
®
Model SLA5840
Section 3 Operation
Installation and Operation Manual
X-PR-SLA5840-Series-RevB-RT-eng
Part Number: 541B201AAG
October, 2017
D. Valve Override
This input allows the valve to be forced to its most closed state or its most
open state, regardless of the setpoint. If this input is not electrically connected
the RT will operate in normal control mode according to the active values
of the other RT inputs. If this input is held at 0 Vdc or -15 Vdc the valve will
be forced to its most closed state. If this input is held at +5 Vdc or greater
(max. = 15 Vdc), the valve will be forced to its open state.
E. Mode Select
The SLA5840 RT can operate in either a Remote Transducer mode (PID
response to the connected remote transducer) or in the Mass Flow
Controller mode (PID response to the on board thermal mass flow sensor)
Switching between modes can only be done by use of a software tool
called BEST (available for download on the Brooks Instrument website).
NOTE: It is recommended to only change operating modes during no-flow
conditions
F. Zeroing (Self-zero)
It may be desirable to re-zero the flow sensor if it is operated at its
temperature extremes or if it is positioned in an attitude other than that
specified on the customer order.
Note: Before zeroing the instrument, zero pressure differential MUST be
established across the device. If there is pressure across the instrument
during the zero process, any detected flow through the sensor will be
misinterpreted as the zero flow reading.
Figure 3-5 Externally Accessible Zero for all Meters/Controllers.
Zero Button
