VEGA VEGAPULS 68 (≥ 2.0.0 - ≤ 3.8) 4 … 20 mA_HART two-wire - Manual (Page 41)

A
part from the medium, the vessel shape can also influence the
measurement. To adapt the sensor to these measuring conditions, this
menu item offers different options depending on whether liquid or solid
is selected. With "Solid" these are "Silo" or "Bunker", with "Liquid",
"
Storage tank", "Stilling tube", "Open vessel" or "Stirred vessel".
V essel form
Silo
E nter the requested parameter via the appropriate keys, save your
settings and jump to the next menu item with the [->] key.
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.
C
orresponding 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".
L inearisation curve
linear
E nter the requested parameter via the appropriate keys, save your
settings and jump to the next menu item with the [->] key.
F alse 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:
H
owever, 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.
G ating out of false signals
C hange now?
Vessel form
Linearisation curve
Gating out of false sig-
nals
VEGAPULS 68 • 4 … 20 mA/HART two-wire 41
6 S et up with the indicating and adjustment module PLICSCOM
29261
-EN
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