4
3 Functions and features
3.1 Application area
The unit monitors the flow and the temperature of liquid and gaseous media
3.2 Flow and temperature monitoring with output S1
The unit detects the flow velocity and the current medium temperature It links the
two measured signals (logical function: AND) and switches output S1:
output S1
flow ≥ switch point SP1 and medium temperature ≥ switch point SP2
closed
•
flow < SP1 or
•
temperature < SP2 or
•
flow < SP1 and temperature < SP2
open
This applies to the unit on delivery: output = normally open If necessary you can change the
outputs to normally closed function (→ 8.2). It then applies: output S1 open if flow ≥ switch
point SP1 and medium temperature ≥ switch point SP2.
On flow monitoring function:
•
If the flow velocity increases, signal SP1 changes when the switch point is
reached
•
If the flow velocity falls again, signal SP1 changes when the value “SP1 minus
hysteresis” is reached
The hysteresis changes with the flow speed and it is essentially influenced by
the set monitoring range
It is 25 cm/s for the setting 5100 cm/s (= factory setting), it increases with
higher flow speeds
3.3 Temperature monitoring with output S2
The unit detects the current medium temperature and switches the output S2:
-
Output S2 closed if medium temperature ≥ SP2 / output open if medium
temperature < SP2
This applies to the unit on delivery: output = normally open In case of need you
can change the outputs to normally closed (→ 8.2). It then applies: output S2
open if medium temperature ≥ SP2.
