The Edge 500 calculates elevation data using a barometric altimeter. Once the device is properly calibrated, the standard area of accuracy will be +/- 50 feet. To ensure that elevation data is accurate at the beginning of an activity you have the ability to calibrate the elevation manually.
To calibrate the elevation manually:
The elevation will be calibrated from this manually set elevation.
The barometric altimeter is not temperature compensated. Temperature changes in the device will affect the barometric pressure sensor and altimeter readings.