Endress+Hauser LT5, Руководство по эксплуатации

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LT5 Setting
Hauser 71
D
S
Lx
1
2
A0041235
 58 Indicator setting for a spherical tank
1 Center of the tank
2 Center of float installation
6.3.3 Calibration with water-filled tank
A water-filling test is generally performed once the tank is complete; however, because it
is difficult to take measurements after actual liquid has been injected, the indicator is
calibrated when the tank is filled with water and then it is readjusted when actual liquid is
injected. In this case, the following equation is used to determine the difference in the
initial floating position of the float when the tank is filled with water and actual liquid in
order to correct the value that is indicated when the tank is filled with water.
After setting the LT indicator to the measured value for water, determine L
B
using the
equation below. If L
B
is a positive value, it is added to the determined indicator value,
and if it is a negative value, it is subtracted from the determined indicator value to
determine the final indicator value.
Equation: For LT5-1 5 000 g (11.02 lb) with a φ400 mm (15.75 in) float
1.
Float draft when the tank is empty
h
2
Lf = +
S
V
2
W - T
ρ
-
= 42.88 mm
Float diameter D 400 mm (15.75 in) Float height h 109 mm (4.29 in)
Float mass W 5 000 g (11.02 lb) Float volume V 10 520 cm 3
Waterline cross
section S 1 256.64 cm 2 Tape tension T 1 200 g (2.65 lb)
Density limits ρ 1 g (0.002 lb)/cm
3
(assume that "empty" = "water")
2.
Correction of indicated value with simulated actual liquid
Lb = Lf (water) - Lf (actual liquid)
= 56.50 mm
Float diameter D 400 mm (15.75 in) Float height h 109 mm (4.29 in)
Float mass W 5 000 g (11.02 lb) Float volume V 10 520 cm 3
Waterline cross
section S 1 256.64 cm 2 Tape tension T 1 200 g (2.65 lb)
Density limits ρ 0.8 g (0.001 lb)/cm 3 (with actual liquid)