Chapter 3 ______________________________________________________ Installation of the Mast
VAISALA _______________________________________________________________________ 45
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Figure 32
SA20M Horizontal Obstruction (Top View)
Siting of the SA20M sensor also depends on the location of buried
electrical cables and electrical transformers. Site the SA20M sensor
away from emitters of electromagnetic interference, such as buried
electrical cables, and electrical transformers. SA20M will send a
message to the handheld terminal if the siting has been unsuccessful.
NOTE
SA20M can not be installed inside a closed-in structure. It must
always be installed outdoors facing magnetic north.
Present Weather Detection
Present Weather Detector PWD11A is installed on the sensor arm of
the mast. Avoid setting the system up near high brush or grass,
because foreign objects in the sample volume may cause sudden
changes in the scatter signal.
For the location of PWD11A the main requirements are:
1.
PWD11A should be sited in such a way that the measurements
will be representative of the surrounding weather conditions.
PWD11A should ideally be located in such a way that the site
has a minimum clearance of 100 m from all large buildings and
other constructions that generate heat and/or obstruct
precipitation droplets. The shade of trees should also be avoided
as trees may cause changes in the microclimate.
