Kipp & Zonen LAS, Instruction Manual

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24
120
o
Guys
Steel enclosure
T/RH sensor on 2-sided arm
Mast and
base plate
Net radiation sensor
Solar panel
Earth nails
Figure 13: 4 m mast seen from above, showing the orientation of the sensors, enclosure, arms and guys.
The last sensors that have to be installed are the soil heat flux plates. Place them at the same side of
the mast where the net radiation sensor is mounted, preferably at a spot that is not disturbed by
footsteps. Remember that the measurements should be representative for a large area! Do not
position the plates directly beneath the net radiation sensor, as they may disturb the net radiation
measurements. Depending on the soil type and the presence of vegetation the plates are buried at a
depth of about 0.03 m (bare soil conditions) or just beneath the surface at 0.003 m (fully covered soil).
In the latter case the amount of ‘missing’ flux is as small as possible. Note that plates at depths of 10
cm can underestimate the soil heat flux by more than 50%! Prevent that the plates are measuring in
air gaps or cracks (i.e. avoid air gaps between the soil and the plates)! When using more than 1 plate,
burry them at the same depth. It is safest to install plates at depth’s of > 3 cm from the side, to prevent
disturbance of the covering soil layer!
3.2.4.3 Mounting enclosure, solar panel and connecting wires
Once the mast (plus arms and sensors) is erected and levelled, the stainless steel enclosure plus the
solar panel can be fixed on the mast. The solar panel should be facing south (on Northern
hemisphere) or north (on Southern hemisphere) to have maximum insolation over the year. The solar
panel is partly fixed on the mast and partly on the ground using 2 earth nails such that it is tilted to
have maximum efficiency. Use the extendable legs of the solar panel to get the desired tilt angle.
Once the tilt angle is set, use the 2 earth nails to fix the legs on the ground.
The enclosure is best mounted opposite of the solar panel. All cables (signal, antenna and power)
enter the enclosure at the bottom through the cable ducts. Connect all sensor cables to the data
logger (via the over voltage protection, see Figure 15) according to the connection plan (see
APPENDIX 9 – CONNECTION PLAN) and the antenna cable to the RF modem via the adapter and
lightning arrestor). Finally, the power cable of the solar panel can be connected to the solar controller.
Ensure correct polarity (brown is + and blue is - )!!!