Vega VEGADIF 65 Operating Instructions Manual page 47

Linearization curve with
level
Leak flow volume sup-
pression with flow
VEGADIF 65 • 4 ... 20 mA
6 Adjustment with the display and adjustment module PLICSCOM
1. Edit the bar value in the menu item "Max. adjustment" with [OK].
Max. adjustment
100.00 %
= -
0.5000 bar
DP
0.0000 bar
Information:
If the instrument has not yet been adjusted, the displayed pressure for
100 % corresponds to the nominal measuring range of the sensor (in
the above example 500 mbar).
2. Set the requested mbar value with [->] and [OK].
3. Confirm with [OK] and move to the menu overview with [ESC].
For an adjustment with flow, simply enter the actual measured value
indicated at the bottom of the display.
The max. adjustment is finished.
For level measurement, a linearization is necessary for all vessels in
which the vessel volume does not increase linearly with the level - e.g.
in a cylindrical or spherical tank - and the indication or output of the
volume is requested.
Respective linearisation curves are stored for these vessels. They
indicate the relation between the percentage level and the vessel vol-
ume. By activating the suitable curve, the percentage vessel volume
is displayed correctly.
Linearization curve
Linear
Enter the requested parameters via the appropriate keys, save your
settings and jump to the next menu item with the [->] key.
Caution:
Note the following if the VEGADIF 65 with corresponding approval is
used as part of an overfill protection system according to WHG (Water
Resources Act):
If a linearization curve is selected, the measuring signal is no longer
linear to the level. This must be taken into consideration by the user,
particularly when setting the switching point on the limit signal indica-
tor.
In some application, small flow quantities should not be detected.
With the creeping quantity suppression, the flow value can be sup-
pressed up to a certain % value. The default value is 5 % of the max.
flow value, corresponding to 0.25 % of the max. differential pressure
value. The limit value is 50 %. This function depends on the selected
linearization function and is only available with root extracted charac-
teristics.
The square root/bidirectional square root characteristics is very steep
at the zero point. This means that small changes in the measured
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