Float Tank Gauge LT11/12
Hauser
35
4.3
Indicating adjustment
Calibration method
1) Put actual measuring liquid into tank and calibrate to the measuring value
2) When tank is empty, calibrate through calculation
3) Put water into tank and calibrate to the measuring value
After removing the cover from the indicator of the gauge head, loosen the cap nut. The longer pointer (white)
can be turned freely, whereas the shorter one (yellowish green) can be freed by pulling it toward you.
1) First, set the shorter pointer at the division on the inner scan corresponding to the two lower digits of the
liquid level.
2) Then, set the longer pointer at the division corresponding to the upper digit(s) plus the two lower digits
(estimate by the eye).
4.3.1
Calibration using actual measuring liquid
By using a measuring tape which has been officially tested for accuracy of ±0.3 mm/m (±1.2mm/10 m),
measure liquid level two or three times to obtain a reliable value. Then set the indicator at the reading thus
determined.
4.3.2
Calibration through calculation for empty tank
Calculate liquid level Lƒ at which the float starts floating up by using the following equation.
For relationship between Lƒ and p, refer to Graph 1,2 .
4.3.3
Calibration utilizing water filling test
Measure water level and set the indicator at the level. Then, make the necessary correction by
adding Lß calculated by the following equation:
For relationship between Lß and p, refer to Graph 1,2 .
Lf = { Hf +
A x
ρ
( W - w ) - Q x
ρ
} x 10
Lf : When a float start to float, level height (mm)
W : Float Weight (g)
A : Aross-sectional area of float cylindrical part (cm
2
)
Hf : Half of float height (cm)
w : Measuring tape hoising force in conster (g)
ρ
: Gravity of actual liquid (g/cm
3
)
Q : Half of float volume (cm
3
)
L
B
=
ρ
x 10
W - w
A
( -1 )
1
L
B
: When filling water, Indicator corrective value (mm)
W : Float Weight (g)
A : Aross-sectional area of float cylindrical part (cm2)
Hf : Half of float height (cm)
w : Measuring tape hoising force in conster (g)
ρ
: Gravity of actual liquid (g/cm
3
)
Q : Half of float volume (cm3)
4 Display
