SUUNTO AMBIT2 S User Guide - Manual (Page 56)

If the calibration is successful, the text CALIBRATION SUCCESSFUL is
displayed. If the calibration does not succeed, the text CALIBRATION
FAILED is displayed. To retry the calibration, press [Start Stop].
9.2 Setting declination value
To ensure correct compass readings, set an accurate declination
value.
Paper maps point to true north. Compasses, however, point to
magnetic north – a region above the Earth where the Earth’s
magnetic fields pull. Because magnetic North and true North are
not at the same location, you must set the declination on your
compass. The angle in between magnetic and true north is your
declination.
56