Garmin GI 275 Installation Manual page 259

5.7.5.3 Fuel Quantity Calibration Procedure
Complete the following procedure using a calibrated fueling system:
1. Drain the fuel from the aircraft in accordance with the aircraft manufacturer's instructions.
2. Level the aircraft in accordance with the aircraft manufacturer's instructions.
3. Navigate to the Fuel page (Calibration/Test → Fuel).
4. Configure the fuel tank settings using Table 5-61.
5. Touch the Quantity Cal button.
6. Verify the Gauge Max Main and Gauge Max Aux settings are correct using Table 5-62.
7. Touch the Check gauge max button. A green checkmark will appear.
8. Touch the Drain fuel button if step 1 was completed. A green checkmark will appear.
9. Touch the Level aircraft button if step 2 was completed. A green checkmark will appear.
10. Touch the Num Points button and enter the number of calibration points to be performed. Refer to
Table 5-62 and Section 5.7.5.1 for guidance in determining the number of calibration points.
11. Touch the Select num points button. A green checkmark will appear.
12. Touch the Procedure button and select the procedure using Table 5-62.
13. Touch the Select procedure button. A green checkmark will appear.
14. When all steps are checked, the Begin button will be available. Touch it to begin.
15. Add the amount of unusable fuel determined from the aircraft manufacturer or other approved data
using a calibrated/verified fueling system.
16. Touch the corresponding button once the fuel has been added to check it off (refer to Figure 5-29).
17. Once the sensor readout has stabilized in the tenths place, touch the corresponding button to check
it off (refer to Figure 5-29).
a. It may be required to manually vibrate the area near the fuel sensor to prevent the float from
sticking and to improve the sensor response during each calibration point.
18. Touch the Calibrate button to set the first point with 0.0 GAL of usable fuel (i.e., tank only has the
required amount of unusable fuel).
19. If the Left & Right procedure was selected, repeat steps 15 through 18 for the other tank.
20. Fill the indicated tank with the specified amount of usable fuel using a calibrated fueling system.
a. The GI 275 will calculate an estimated amount of fuel to be added based on the number of
calibration points and the gauge max.
b. If more than the indicated amount of fuel was added, touch the Add Fuel Amount button and
enter the actual amount of fuel that was added. The GI 275 will automatically compensate for
the difference during the next calibration point for that tank.
21. Touch the corresponding button on the display once the fuel has been added to check it off.
22. Once the sensor readout has stabilized in the tenths place, touch the corresponding button.
23. Touch Calibrate to accept that value.
24. Repeat steps 20 through 23 for any other tanks included in the calibration and for each remaining
calibration point.
a. Touch the View ( ) tank status button at any point to view a graphical representation of the
process (refer to Figure 5-29).
b. Do not add more fuel than the maximum gauge range. The manual entry field will not allow
more fuel than the maximum to be entered.
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Rev. 11
GI 275 Part 23 AML STC Installation Manual
Page 5-81