Offset level, V3H1
The offset is the hydrostatic pressure in mbar acting on the probe when the vessel is
filled to the desired »empty« level. When the value is entered at V3H1, the Silometer will
indicate 0 for this level.
•
If the default value 0 is used, the zero level is at the point of installation of the
Deltapilot probe.
The hydrostatic pressure is calculated from the density and »empty« level:
p
mbar
=
ρ
(kg/dm
3
) x g (m/s
2
) x
∆
h (m) x 10 mbar
Example
The Silometer must display 0 for an »empty« level of 45 cm water, the offset p
mbar
is:
p
mbar
=
1.0 x 9.807 x 0.45 x 10 = 44.13 mbar
Display sensitivity, V3H2
The sensitivity specification in V3H2 determines the increase in the measured value
per mbar pressure rise at the Deltapilot S probe.
Sensitivity
mbar/digit
= p
max
/required display at V0H0 for p
max
Example
The maximum level 10 m corresponds to 1526 m
3
p
max
=
ρ
(kg/dm
3
) x g (m/s
2
) x h (m) x 10 mbar
=
1.0 x 9.807 x 10 x 10
=
980.7 mbar
To display
volume (m
3
)
Sensitivity
mbar/digit
=
980.7/1526 =
0.64266 mbar/digit
To display
level (m)
Sensitivity
mbar/digit
=
980.7/10 =
98.07 mbar/digit
Procedure
The calibration, described here for operating mode 1, should be carried out preferably
with an empty tank (probe at bottom, dry and unpressurized). If tank is partially filled,
take over f0 from stick-on label.
•
Initial filling of the tank should be carried out under close supervision so that
the results of a possible calculation error can be recognized in good time.
Step
Matrix
Entry
Significance
1
V9H5
e.g. 672
Reset transmitter
2
-
»E«
Register entry
3
V0H2
e.g. 1526
Enter volume used for sensitivity calculation
-
for level measurement enter level (e.g. 10 m)
4
-
»E«
Register entry
5
V3H5
e.g. 99.5
Enter frequency »f
o
« at V0H8
6
-
»E«
Register entry
7
V3H6
e.g. 1.054
Enter sensitivity »
∆
f«
8
-
»E«
Register entry
9
V3H1
e.g. 44.13
Enter offset level (V0H0 = 0 for 45 cm water)
10
-
»E«
Register entry
11
V3H2
e.g. .6426
Enter display sensitivity (V0H0 = 1526 for 10 m water)
-
for level enter e.g. 98.07
12
-
»E«
Register entry
Silometer FMC 671 Z/676 Z
Chapter 8: Other Applications
42
Summary of Contents for silometer FMC 671 Z
Page 63: ...Silometer FMC 671 Z 676 Z...
Page 66: ...Silometer FMC 671 Z 676 Z...
Page 67: ...Silometer FMC 671 Z 676 Z...
