Automatic Weather Station with UT20/UT30 Tower
A-2
Figure A-2 Declination Angles
– True North to West of Magnetic North
For UT920/UT930-based weather stations, firstly determine the
declination angle. Use this value in conjunction with the magnetic
north bearing to set the wind sensor to true north as explained in
Section 2.3 of this manual.
NOTE
Declination angles for True North to the West of
Magnetic North are
subtracted
from 360
, therefore
True North reading is (360
– 15
= ) 345
for this
specific case.
MAGNETIC NORTH
COMPASS NEEDLE POINTS TO
MAGNETIC NORTH
TRUE NORTH (map bearing) 15
WEST OF MAGNETIC NORTH
Point the wind direction sensor to
TRUE NORTH (345
) bearing.
