The magnetic declination is different in different places, the higher the geographical dimension, the greater the magnetic declination, but we can adjust compass magnetic declination to get the real accurate direction, you can do it by one compass which have a rotated bezel no need other tools, one prerequisite is you need know you local magnetic declination which you can check it from professional books.
Do not adjust compass declination is also okay for most people, because the declination is very small , it has not much influence on your short distance hiking. But for professional users or take a long distance hiking , It is necessary to know more about it! Here we will teach how to do it .
Adjust Declination Guide: First, we need to know the local magnetic declination, the declination eastward called “+”, westward called “-“, we can add or subtract the compass magnetic declination angle to confirm the true direction. You can adjust the compass bezel to revise declination angle by rotating the bezel toward left or right, turn compass bezel toward right if the local magnetic declination eastward, turn compass bezel toward left if the local magnetic declination westward, make the angle between the pointer and north and south scale tick mark is equal to the magnetic declination angle. After adjustment, we need read compass bezel scale north and south which are the true north and south; the pointer north and south is not real north and south, because it is have a small error.
For example: First, we put one compass on the table, so that the pointer north and the compass scale north coincidence, if the local magnetic declination is +6 °, we rotate the compass bezel 6 ° toward right, then the dial north mark ‘N’ is the real north.