5
Linearization
For tanks in which volume is not directly proportional to level, e.g. for horizontal cylinders
or tanks with conical outlets, the linearization converts the level measurement into a
measurement of capacity.
Parameters for linearization are selected and entered at fields V2H0
…
V2H8. In addition,
the field V3H0 determines whether the associated calibration is to be performed in level
or volume units (0 = level
…
default, 1 = volume). The following linearization modes can
be entered at V2H0:
0 = linear, default value
1 = horizontal cylinder
3 = manual entry
4 = cancel current setting
The modes horizontal cylinder and manual entry for conical outlets are described in
Sections 5.1 and 5.2, all others in Section 5.3.
Two important rules must be observed when performing a linearization:
•
All level (or volume) entries must be made in the units you have chosen for
calibration at V0H1 and V0H2.
•
The levels for linearization and calibration must be referenced to the same
datum point.
After linearization
After linearization:
•
The volume of liquid currently in the tank can be read from V0H0.
•
The level before linearization can be read from V0H9.
•
The 0/4
…
20 mA signal range must be set in the volume units entered,
see Chapter 6.
30.00
VH
00
133.0
VH
00
7.000
VH
00
VH
00
120.0
BA119Y63
»Empty« = 10%
»Full« = 90%
»Empty« = 35 hl
»Full« = 500 hl
»Empty« = 0.5 ft
»Full« = 9 ft
»Empty« = 20 gal
»Full« = 150 gal
Fig. 5.1:
Linearization for a vessel with a
conical outlet
Chapter 5: Linearization
Silometer FMX 570
24
