Table of Contents
9.12
Reference height / innage
measurement
If the unit is fitted with the additional load (see
Figure 9-8) then reference height / innage
measurement are possible.
Figure 9-8
Install the HERMetic equipment as per 9.9
"Installation of the instrument".
Open the valve by turning the handle.
Put the tape cleaner on the "DOWN" position.
Disengage the knob of the crank handle and
lower the sensing probe into the tank by
turning the reel. Make sure that the tape does
not rub on any sharp edge when lowering as
its insulation could be damaged.
When the sensing probe comes in contact with
the dip/datum plate record the distance shown
on the reading index. See Figure 9-9. The
exact distance from the plate to the reading
index is (reading + 4 mm) or (reading + 1/6")
which is the reference height providing the
reading index level has been adjusted to the
zero ullage level of the tank. If the tank zero
ullage is levelled above or below the reading
index, an additional correction shall apply. For
more details refer to section "Installation of the
gauging system".
Turn the tape cleaner on "UP" position.
Switch on the unit and raise up the sensing
probe until checking the oil/water interface if
any (see details in section 1.1 ""). To get a
better accuracy of the interface level, release
the tape cleaner on the "DOWN" position
during the final checking. Calculate the free
water height by subtracting the index reading
to the reference height.
50461/GTEX MMC/1111
Reengage the tape cleaner on the "UP"
position and raise up the sensing probe until
checking the ullage (see details in section 1.1
""). Release the tape cleaner for final checking
of the ullage. Calculate the innage by
subtracting the index reading and the free
water
height
determined before.
When the measurements are completed,
switch off the unit, engage the tape cleaner on
the "UP" position and wind up the tape until the
sensing probe is in the storage tube. The
reading on the tape shall be less than 420 mm
or 1 ft 5 inch.
Close the valve and disconnect the instrument
from the nipple.
Put the end cap back on the valve.
sensor
with load
33
to
the
reference
Tape reading + 4 mm (5/32") =
Distance from dip/datum plate
to reading index
Dip/Datum plate
Figure 9-9
UTImeter Gtex MMC
height
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
+ 4 mm
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