Automatic Weather Station with UT20/UT30 Tower
2-2
2.2 Fitting the Mast Assembly and Lightning Rod
Attach the mast assembly to the top tower section by sliding it into the hole in the
central boss until the weld on the assembly is just above the top of the boss.
Tighten the setscrews to achieve maximum security.
Fit the lightning rod assembly to the mast as shown in Figures 2-1 and 2-6 below,
using the special clamp supplied.
Figure 2-1 Attaching the Lightning Spike
2.3 Fitting Equipment to the Top Tower Section
Some sensors will have to be fitted to the top tower section while it is on the
ground. The pyranometer is fitted and levelled
before
the tower top section is
attached to the rest of the tower assembly, while windvanes will need to be
attached to the top section
after
it is fitted to the rest of the tower structure, but
before the tower is raised. Exact details are given below.
2.3.1 Fitting the Pyranometer to the Top Mast Assembly
It is essential that pyranometers are fitted, aligned and levelled as accurately as
possible, following the advice given below, in order to reduce the likelihood of
measurement errors. This section gives details of mounting the pyranometer to the
top mast assembly. This is the recommended mounting position for the
pyranometer as it minimises any shading effects, but you may wish to mount it
elsewhere on the tower structure to facilitate maintenance – see further comments
below.
To ensure correct levelling of these sensors, it is recommended that, before fitting
to the main tower, you place the top tower section on a level piece of ground in an
upright position and in the same relative position it will be when fitted to the tower
in its ‘working’ position (see Figure 2-2). Use a spirit level to ensure that the
section is perfectly level before fitting the sensors. You may need to pack the legs
to achieve this.
You may also need a stepladder to reach the highest part of this section. If so,
ensure that there is room to properly position the ladder for safe working. It is
strongly recommended that there is a second person to hold and stabilise the
stepladder while in use.
Clamp
– a similar clamp is also
used for clamping the enclosure
earthing cable to the tower
– see
Fig. 2-13
Lightning Spike
Tower Mast Assembly
Tri-Clamp
011E Mounting
Arm
