Garmin G3X Installation Manual page 748

32.4.25.3 Input Configuration Items Requiring Calibration
Fuel Quantity Calibration – The G3X has two fuel calibration curves, the standard 'in-flight' or normal
flight attitude calibration curve and an optional 'on-ground' or ground/taxi attitude calibration curve. The
ground/taxi calibration curve can be used for aircraft that have a significantly different attitude when on the
ground, such as tailwheel aircraft. If no calibration data is entered for the ground/taxi curve, the normal
flight calibration curve will be used when the aircraft is in flight and on the ground. The calibration curve
being used to display fuel quantity switches automatically and is determined by GPS groundspeed,
indicated airspeed, and height above ground.
Softkeys on the calibration page are used to switch between the normal flight and the ground/taxi
calibration curves. Since the ground/taxi attitude calibration is optional and only available when the
normal flight attitude calibration data has been entered, the 'GROUND' softkey is greyed out (unavailable)
until calibration points are entered for the normal flight attitude curve.
To perform the Fuel Quantity calibration:
1. Press the Calibrate button to display the Calibration Page.
2. Orient the aircraft appropriately for the calibration curve (normal flight or ground/taxi) being
performed.
3. Drain all usable fuel from the tank and calibrate at 0.0 gallons.
4. Put a known quantity of fuel (e.g. 5.0 gallons) into the empty fuel tank and enter that same amount
into the Actual Fuel Quantity field.
5. Note the resulting sensor value displayed in the Sensor Value field (the sensor value should change
with each added amount of fuel), wait at least 2 minutes for the reading to stabilize.
6. Press the Calibrate button.
7. Repeat this process until the fuel tank is full.
The user determines the best interval values of fuel to most accurately calibrate the full range of the tank.
190-01115-01 G3X/G3X Touch Install Manual - GDU 45X/46X Config and Post Install Checkout
Rev. AA Page 32-153