From the main menu, select Setup > Altimeter.

Barometer Mode

Sets the barometer mode. The Variable Elevation option allows the barometer to measure changes in elevation while you are moving. The Fixed Elevation option assumes the device is stationary at a fixed elevation. The barometric pressure should change only due to weather.

Plot Type

Allows you to view elevation changes over a period of time or distance, barometric pressure over a period of time, or ambient pressure changes over a period of time.

Auto Calibration

Automatically calibrates the altimeter each time an activity is started. The device continues to automatically calibrate the altimeter as long as the device receives GPS signals and the Continuous calibration option is turned on.

Calibrate Altimeter

Allows you to calibrate the barometric altimeter when you know the correct elevation or the correct barometric pressure (Calibrating the Barometric Altimeter).