Calibrate 1, Calibrate 2
This function enters the fuel level sender calibration menu. The fuel level sender needs to be
calibrated before it can be used with this system. The calibration allows the system to learn the
shape of your tank as well as any errors your fuel level sender or installation has.
Note: You only need this function if you are using your FF-3 with physical fuel level
senders, there is no need for this function if you are using calculated fuel levels using the
fuel flow senders.
Performing the calibration procedure. Note: You start with an empty tank, you need a measuring
jug or fueling device that has calibration marks and you need enough fuel to fully fill the tank.
Regardless of your use of a fuel flow sender, you can install a fuel level sender into your fuel
tank. These level senders are inexpensive and are available as after market replacement fittings
from a car spares outlet. We recommend the senders available from VDO.
Be aware that some
makes of cheap level senders can prove troublesome, as the lever arms tend to be sticky.
This prevents the floats from floating on the surface of the fuel at all times. As a
consequence, this will lead to incorrect fuel level indication.
Once you have installed a fuel level sender into your tank, make sure the float can travel all the
way from empty to full position without hindrance of any kind.
The calibration procedure should be carried out with your aircraft in flight attitude. This means you
need to lift the tail if you have a tail-dragger or lift the nose wheel if you have a weightshift trike.
You start the calibration procedure with an empty tank.
We now start with the empty tank. Add five liters of fuel (our reserve quantity) using a suitable
measure. Make sure the measure is suitably accurate.
This is now the “level sender reading at 0 Lt” position. Move the highlight to this position and wait
until the sender reading has stabilized (You will see the sender reading at the top line). This could
take up to a minute so have patience.
ENSURE THAT THE FLOAT IS NOT SUBMERGED AND IS FLOATING ON TOP OF THE FUEL
LEVEL.
Should this number not react to changes of your level sender position, then you have a problem.
Please check your wiring according to the installation section of this manual.
You should expect the number to change in the region of at least 20 to 60 counts per calibration
position. If the number does not change with fuel level or only changes a very small amount –
check your installation. Something is not right !!!
The current level
sender reading
Level sender
readings at the
calibration
points
The six
calibration
points from
zero fuel level
to full tank
