The Altimeter profile should be selected when your outdoor activity involves changes in altitude (e.g. hiking in hilly terrain).
The Barometer profile should be selected when your outdoor activity does not involve changes in altitude (e.g. soccer, sailing, canoeing).
To get correct readings, you need to match the profile to your activity. You can either let Suunto Ambit2 decide a suitable profile for the activity, or choose a profile yourself.
You can define the profile as part of the sport mode settings in Movescount, or in your Suunto Ambit2.
To set the Alti & Baro profile:
To set the sea level pressure and altitude reference values:
You can access the Reference setting by keeping pressed when in Alti & baro mode.
You can also set your altitude during your exercise, see Setting altitude during exercise.