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3.5 Setting the Control Limit
The Upper and Lower control limits can both be set over the full scale of
the
pro
CHEM
-S
. The unit is set up in the factory for the Upper Limit LED
and relay to be activated when the reading rises
above
the Upper Limit.
Similarly, the Lower Limit LED and relay are factory set to be activated
when the reading drops
below
the Lower Limit.
See section 3.5.3 for details on how to re-set the Upper or Lower limits
for the reverse of the default direction.
The hysteresis around the set point can be also be adjusted if necessary.
See section 3.5.4 for an explanation of hysteresis.
3.5.1 Setting the Upper Limit value
1. Switch the
pro
CHEM
-S
to
Set Upper Limit
.
The Upper Limit value is now displayed. Note that the Alarm LED and
output relays are now disabled. The 4-20mA or 0-1V outputs are still
active, and proportional to displayed value.
2. Adjust the
Set Upper Limit
control until the display reads the desired
set point value.
3.5.2 Setting the Lower Limit value
1. Switch the
pro
CHEM
-S
to
Set Lower Limit
.
The Lower Limit value is now displayed. Note that the Alarm LED and
output relays are now disabled. The 4-20mA or 0-1V outputs are still
active, and proportional to displayed value.
2. Adjust the
Set Lower Limit
control until the display reads the desired
set point value.