Garmin CIRRUS PERSPECTIVE SR20 Line Maintenance Manual page 124

____________________________________________________________________
If any of the three measurements (Altitude, Vertical Speed, Power On Time)
are outside of their respective displayed limits, the displayed measurement
will appear in red, and the 'OK' button will be unavailable (grayed‐out). If
successful calibration is not achievable, clicking 'Cancel' will halt the program
and produce the following popup message:
14. After the 0 feet calibration is complete, the 'Set altitude to 11,000 ft' screen appears.
15. According to the on‐screen instructions, set the pressure control system to a pressure
altitude of 11,000 feet.
16. Allow the on‐screen altitude reading to stabilize, then click 'OK'.
17. After the 11,000 feet calibration is complete, the 'Set altitude to 30,000 ft' screen
appears.
18. According to the on‐screen instructions, set the pressure control system to a pressure
altitude of 30,000 feet.
19. Allow the on‐screen altitude reading to stabilize, then click 'OK'.
20. After the 30,000 feet calibration is complete, the 'Set altitude to 41,000 ft' screen
appears.
21. According to the on‐screen instructions, set the pressure control system to a pressure
altitude of 41,000 feet.
22. Allow the on‐screen altitude reading to stabilize, then click 'OK'.
23. After the altitude calibrations are complete, the 'Program Calibration to Unit?' screen
(Figure 5‐15) appears. Click 'OK' to program the new calibration to the GDC 74(X) unit.
Before the new calibration is written to the unit, the program stores the
current calibration to a file named CAL_(serial_num)_YYYYMMDD_
HHMMSS.txt that can be used to restore the original calibration back to the
unit if needed (refer to the "To Restore Original Calibration" section).
Page 5-78
Rev. E
NOTE
Figure 5‐14. Calibration Failed Screen
NOTE
Cirrus Perspective™ Line Maintenance Manual
190-00920-00