VEGA VEGAPULS 68 (≥ 2.0.0 - ≤ 3.8) Foundation Fieldbus - Manual (Page 41)

A linearization is necessary for all vessels in which the vessel volume
does not increase linearly with the level - e. g. with a cylindrical or
spherical tank - and the indication or output of the volume is required.
Corresponding linearization curves are preprogrammed for these
vessels. They represent the correlation between the level percentage
and vessel volume. By activating the appropriate curve, the volume
percentage of the vessel is displayed correctly. If the volume should
not be displayed in percent but e.g. in l or kg, a scaling can be also set
in the menu item "Display".
Linearisation curve
linear
Enter the requested parameter via the appropriate keys, save your
settings and jump to the next menu item with the [->] key.
False reflections by vessel installation can impair the measurement as
described in chapter "Mounting". A false echo storage detects and
marks these false echoes, so that they are no longer taken into
account for the level measurement. To detect these interfering
reflections over the complete measuring range, the gating out of false
echoes should be carried out with empty vessel.
Information:
However, the measuring signals are not damped by the product in
completely empty, closed metal vessels. Due to this, considerable
multiple reflections can be caused by which the noise level can
increase. In such vessels, it is recommended to carry out the gating
out of false echoes with part filling.
Gating out of false signals
Change now?
Proceed as follows:
1 Move from the measured value display to the main menu by
pushing [OK].
2 Select the menu item "Service" with [->] and confirm with [OK].
Now the menu item "False signal suppression" is displayed.
3 Confirm "False signal suppression - Change now" with [OK] and
select in the below menu "Create new". Enter the actual distance
from the sensor to the product surface. All false signals in this area
are detected by the sensor and saved after confirming with [OK].
Linearisation curve
Gating out of false sig-
nals
VEGAPULS 68 • Foundation Fieldbus 41
6 Set up with the indicating and adjustment module PLICSCOM
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-EN
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