How to do automatic altitude calibration

Altitude measurement is based on air pressure. This is why weather changes affect the measurement and the absolute altitude value may be wrong at the beginning of an exercise. Using automatic calibration allows the Training Computer to use the preset calibration value
in the beginning of each exercise and thus ignore the effects of weather. This feature is especially useful if you frequently start your exercise at the same altitude. To calibrate altitude, see Altitude Calibration.

To enable automatic calibration for the beginning of an exercise
in Polar CS600/CS600X/RS800/RS800CX:

Select SettingsFeaturesAltitudeAutoCalibOn / Off.
'Altitude calibrated to xx m/ft' indicates that calibration was successful.

in Polar CS500
Select SettingsAltitude SETCalibrate and enter the desired altitude value → AutoCalibOn / Off.
If 'Altitude calibration failed' is displayed, re-calibrate the altitude manually. Altitude calibration fails if the difference between the calibrated value and real value is +/- 80 hPa; when the calibrated altitude value and the real value differ approximately 700 meters.
Disable automatic calibration if exercising at varying altitudes.
In a Polar ProTrainer 5 sport profile you can enter an automatic calibration value. When you start your exercise that uses a sport profile with a preset altitude value, the altitude measurement is always started at the altitude you defined for the sport profile regardless of the general elevation settings. For more details, see Polar ProTrainer Software Help.
You can change the altitude base line in the Polar ProTrainer 5 after the exercise. For more details, see 'Advanced Altitude Correction' in the Polar ProTrainer Software Help.