Electronics International FL-1 - Manual (Page 11)

Selecting the Proper Filter: Selecting the Proper Filter: Selecting the Proper Filter: Selecting the Proper Filter: Selecting the Proper Filter:
The filter may be programmed for a response time of 8, 16, 32, 64 or 128 seconds (time to 100%
respond to a change in the fuel level). The advantage and disadvantage of a fast and slow filter setting is
discussed below.
Advantages of a faster filter setting (8 to 16 seconds) - A fast response time may show some fluctua-
tions in the fuel level during sloshing or turns. This can give you a good feeling the instrument is working,
and there is fuel in the tank. If you ever fly with low fuel levels, this can be very comforting. Once you
reach level flight and the fuel has leveled out, accurate fuel levels will be displayed in 8 to 16 seconds
depending on the filter setting.
Disadvantages of a faster filter setting (8 to 16 seconds) - With the fuel sensor mounted in a wing tank,
a fast response time could show excessive fluctuation in the fuel level that could be annoying. This is
especially true for thin wet long wing tanks with little dihedral. Fluctuation can cause the FL-1 to read from
near empty to near full.
Advantages of a slower filter setting (32 to 128 seconds): - A slower filter can stabilize the display and
remove all short term fluctuations.
Disadvantages of a slower filter setting (32 to 128 seconds): - With the fuel sensor mounted in a wing
tank and if you stay in a turn for a long period of time, aircraft with thin wet long wings tanks and little
dihedral can have a significant shift in fuel. Eventually this will effect the fuel level readings. Once you
establish level flight and the fuel has leveled out, it will take 32 to 128 seconds for an accurate fuel level
reading to be displayed on the FL-1, depending on the filter setting.
How your aircraft will react to different filter settings depends on your tank's shape, size, baffles,
baffle hole sizes, and probe placement. You may need to experiment with the filter setting to get the results
you like best. The filter setting has no effect on calibration or the response time during calibration.
Selecting the Proper Operating Mode: Selecting the Proper Operating Mode: Selecting the Proper Operating Mode: Selecting the Proper Operating Mode: Selecting the Proper Operating Mode:
If you have an FL-1CA Instrument (used with and Electronics International capacitive probe) set the
operating mode to “FL C” the “FLrH” mode will cause the instrument to read improperly.
If you have an FL-1RA-12 or -24 and a resistive fuel probe that decrease decrease decrease decrease decrease resistance as you add fuel, set
the operation mode to “FL r”.
If you have an FL-1RA-12 or -24 and a resistive fuel probe that increase increase increase increase increase resistance as you add fuel, set
the operation mode to “FLrH”.
Selecting the Resolution: Selecting the Resolution: Selecting the Resolution: Selecting the Resolution: Selecting the Resolution:
When displaying your fuel level in gallons, the resolution of the digital display may be set for one
gallon (shown as “GAL1”) or ½ gallon (shown as “GAL.5”). Fuel levels above 99 gallons will always show
in one gallon increments.
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