© 2007 Delta-T Devices Ltd
3 Attach wind vane
1
Fully insert vane arm into hub.
2
Align vane with centre axis of sensor.
3
Use the hex 5/64” Allen key to tighten
the set screw at the top of the hub.
4 Install mast and
cross arm
The cross arm can be mounted on any
sturdy vertical (or horizontal) mast of
diameter: 42 to 52 mm (1
⅝
to 2 inches).
Make the ground sufficiently level, firm and
stable to secure your mast. If using the
M2-TRPD tripod mast use the optional guy
wire kit with ground stakes to further
stabilise it.
Install the mast securely and as vertical as
possible using a sprit level.
Shield the logger from direct sun by
mounting the cross arm East to West with
the logger away from the Equator.
If using a solar panel, ensure it is not
immediately below the RH and air
temperature sensor.
Bolt cross arm to the mast - using the U-bolts and box wrench, and make it horizontal.
5 Orient the wind vane
Find true north
It is best to set the wind direction sensor to
true north, not magnetic north.
Compass Method
: Get a compass and
the local angle of magnetic declination –
either from a map, local airport - or use an
online calculator e.g.
http://www.ngdc.noaa.gov/seg/geomag/jsp
Attach wind vane
South in the
northern
hemisphere
South in the
southern
hemisphere
A
B
Orient the cross arm East-West
/struts/calcDeclination
...and enter your latitude and longitude.
Magnetic declination (or variation) is the
angle between magnetic north and true
north.
It is positive when the angle measured is east of true north and negative when west.
So, if the declination is positive, true north is left of magnetic north.
+30°
MAGNETIC
NORTH
= 360M
TRUE
NORTH
=
= 270 M
TRUE
NORTH
= 0-(- 30)
= 30 M
-30°
N
S
E
W
N
S
E
W
+
-
PLUS
MINUS
Example : How to find true north given a compass
and the angle of magnetic declination
90
90
180
180
270
270
0-30
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