VEGA VEGAPULS 56 Profibus PA - Manual (Page 59)

VEGAPULS 56 Profibus PA 59
Setup
Max.
Min.
100 % (1.270 m) correspond
to 1200 liters
Span (4.58 m)
0 % (5.850 m) correspond to
45 liters
Index marker 1 is at 0 % filling ( percentage
value [%]), corresponding in the example to
an actual distance to the product surface of
5.850 m (empty vessel). The volume is 45
liters (fluid remaining in the vessel).
Index marker 2 is at a filling level of 30 %
(30 % of the meas. distance of
1.270 m … 5.850 m). At a filling level of 30 %,
there are 576 liters in the vessel (in our exam-
ple).
Index marker 3 is at a filling level of 60 %. At
this filling level there are 646 liters in the ves-
sel.
Index marker 4 is at a filling level of 100 %
(product distance 1.270 m), where 1200 liters
are in the vessel.
Max. 32 index markers can be entered per
linearisation curve (value pairs).
Calculating the linearisation curve
(use previous tank example)
In the menu window " Linearisation -- user
programmable curve --“ you can start the
vessel calculation program. With the vessel
calculation program you can calculate (using
dimensions from the technical drawings of
the vessel) the correlation of filling height to
filling volume. If the curve is defined this way,
gauging by incremental filling is not neces-
sary - your sensor can then output volume as
a function of level.
• Click to " Calculate Calculate Calculate Calculate Calculate“.
The tank calculation program starts. In the
top left corner you choose the vessel type
(upright tank, cylindrical tank, spherical tank,
individual tank form or matrix). When choos-
ing matrix, you can enter a user programma-
ble linearisation curve by means of index
markers. This corresponds to the entering of
value pairs (linearisation points), as previ-
ously described.
In the following example, the tank calculation
program calculates the linearisation curve of
a vessel corresponding to the vessel in the
previous gauging example.
• Click to "individual tank form“ individual tank form“ individual tank form“ individual tank form“ individual tank form“ and choose
three round tank segments with the dimen-
sions 0.99 m • 0.9 m (height by diameter),
0.68 m • 0.37 m and 0.68 m • 1.02 m (this
tank form corresponds to the tank form of
the gauging example).