IFM Electronic efector300 SI0509 Notice Utilisateurs page 35

Hysteresis function
maximum flow
switch point (SP)
minimum flow
OUT
OUT
When the flow rises, the output switches when the switch point (SP)
has been reached.
When the flow falls again, the output switches back when the value
"SP minus hysteresis" has been reached.
The hysteresis is considerably influenced by the choice of the operat-
ing range on the sensitivity curve of the sensor:
• In the case of adjustment to HI-Flow values in the range 0 ... 60cm/s
the hysteresis is 2 - 4 cm/s (values apply to water).
• In the case of adjustment to HI-Flow values above 100 cm/s the
hysteresis increases as the flow rises.
Response time
The unit processes 2 signals during the evaluation:
• Proportional flow signal (= flow velocity in relation to the set
detection range).
• Differential flow signal (= variation rate of the flow velocity).
Due to this, the unit very quickly reacts to flow changes (increasing
flow velocity as well as decreasing flow velocity).
36
flow
1
0
1
0
hysteresis
t