6.2.3 Make sure “LO BAT” does not show at left upper corner of display.
6.2.4 After grounding the assembly, insert the barrel of the gauging unit into the valve.
Un-lock the tape reel lock by rotating the brass lock thumbscrew
counterclockwise turning position hub seat. Grasp the knurled reel crank hand and
lower the sensor head tape assembly, which contains the sonic sensor, into the
tank. Always exert a retraining force to prevent the sensor from descending too
rapidly or free falling.
CAUTION!
Under no circumstances should the reel and tape be permitted to unwind without
restraint. Permanent damage may be incurred to the sensor head or to the
calibrated tape if the head is permitted to fall freely.
6.2.5 Lower the sensor head slowly until a steady tone is heard. If the surface of the
fluids is oil or other non-conductive fluid, a continuous audible tone will be heard.
If the surface of the fluid is water of other conductive fluid, the audible tone heard
will be a “beeping” tone.
6.2.6 Define measurement by raising the sensor head until the sound just ceases. Lower
until sound is just heard again, to refine ullage level.
6.2.7 Place gauging tape against ullage referenced point and read ullage on tape. Note
this reading as the surface liquid ullage level.
6.2.8 To find the oil-water interface point, continue to lower the sensor into fluid,
noting that the audible tone is continuous. When the audible signal changes to a
“beeping” tone, the sensor has entered the water column underneath the oil.
6.2.9 Raise the sensor very slowly until the tone once again becomes continuous.
Repeat if necessary to refine water entry point (Interface level).
6.2.10 Again, read the ullage on the tape. By subtracting the first reading obtained (step
7) from this reading, the total product depth is thus determined. By subtracting the
second water level ullage from the maximum tank depth, water level innage is
determined.
6.2.11 When the measurement is completed, place the spring-loaded wiper knob in the
“On” position while rewinding the tape until sensor is stored with the vapor valve
entry barrel. Do not close the vapor valve until the fully “stowed” position is
confirmed, by noting that yellow pop-up button on top of the wiper housing is up.
6.2.12 Lock the reel by rotating the crank/reel lock thumbscrew down position parallel to
hub. Depress power “On/Off” switch to conserve battery power.
6.2.13 Close the vapor valve, disconnect the valve securing cap, remove the gauging
unit, disconnect the grounding cable. Replace the vapor valve cap.
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