Garmin eTrex Summit Owner's Manual And Reference Manual page 42

Reference
Calibration
The eTrex Summit can try to
automatically calibrate the
altimeter using GPS altitude
readings. For optimum
performance of the Altimeter
you should perform the
calibration procedure
entering either the correct
elevation or barometric
pressure.
40
The eTrex Summit will calibrate the altimeter automati-
cally using GPS altitude. If you know the exact current
elevation or barometric pressure, you can calibrate the
altimeter manually.
Calibrating the Altimeter Manually:
1. With the 'MENU' Page displayed highlight 'CALI-
BRATE' and press ENTER.
2. Using the UP or DOWN button highlight 'ALTIM-
ETER' and press ENTER.
3. You will be asked 'DO YOU KNOW THE CORRECT
ELEVATION'? Using the UP or DOWN button select
'YES' or 'NO' and press ENTER.
4. If you selected 'YES'— the 'ENTER CORRECT
ELEVATION' Page will be displayed. Pressing the
DOWN button will move the highlight to the next
number in the elevation field. With the desired digit
selected, press ENTER to activate the drop down
number list. Using the UP or DOWN button select
the correct number then press ENTER. When all
numbers are entered correctly, highlight 'OK' and
press ENTER. A message "CALIBRATION COM-
PLETED SUCCESSFULLY' will be displayed, highlight
'OK' and press ENTER to end the calibration.
5. If you selected 'NO'—you will be asked 'DO YOU
KNOW THE CORRECT BAROMETRIC PRESSURE'.
Using the UP or DOWN button select 'YES' or 'NO'
and press ENTER.
6. If you selected 'YES'— the 'ENTER CORRECT
PRESSURE' Page will be displayed. Pressing the
DOWN button will move the highlight to the next
number in the pressure field. With the desired digit
selected, press ENTER to activate the drop down
number list. Using the UP or DOWN button select
the correct number then press ENTER. When all
numbers are entered correctly, highlight 'OK' and
press ENTER. A message "CALIBRATION COM-
PLETED SUCCESSFULLY' will be displayed, highlight
'OK' and press ENTER to end the calibration.
UA-1005.042