Campbell Scientific UT20 and UT30 Tower-based Weather Stations - Manual (Page 23)

UT20 and UT30 Tower-based Weather Stations
8. Check the UT20/UT30 for plumb using a level and adjust the leveling nuts
below the mounting feet on the J-bolts as required. When the tower is
plumb, use two wrenches to lock the leveling nuts on each J-bolt together.
Tighten the upper nuts to secure the base.
9. Removing the lower 3/8-inch bolt on the rear (south) leg allows the tower
to be hinged to the ground. If a ladder is available, it is easier to leave the
tower upright.
7.1.2.2 RFM18 Base Installation
1. Position the RFM18 on the surface where it will be installed. Make sure
the hinge direction is correct and mark the locations of the four mounting
holes. A drawing showing RFM18 dimensions and hole spacing is shown
in Appendix A. Install an appropriate anchor (user-supplied) for each
hole.
2. Attach the bottom section of the tower to the RFM18 base using one bolt
per leg (FIGURE 7-7). Position the base over the anchor holes. Secure
the base to the anchors with appropriate hardware (user-supplied). Check
the tower for plumb and shim the RFM18 if necessary before fully
tightening the bolts.
7.1.3 Guy Anchor Installation
There are two types of anchors for the tower guy wires: the UTEYE eye bolts
are poured in concrete; the UTDUK duckbill anchors are driven into the soil.
7.1.3.1 UTEYE Eyebolt Guy Anchor
1. Dig a hole 24 inches square by 24 inches deep at each anchor location
(Section 7.1.1, Base and Guy Anchor Layout).
2. Optional  construct a concrete form out of 2-inch x 4-inch lumber, 24
inches square (inside dimensions) for each hole. Center the forms over the
holes and level them using a carpenter’s level and stakes.
3. Fill the holes with concrete and install the eyebolts as shown in FIGURE
7-8.
7.1.3.2 UTDUK Duckbill Guy Anchor
1. Locate the three anchor locations (Section 7.1.1, Base and Guy Anchor
Layout). It is important that the anchors be driven at the same angle as the
guy wires (FIGURE 7-9). Insert the steel drive bar into the anchor body
and drive the anchor into the ground using a fence post driver or
sledgehammer until only the top half of the loop remains above the
ground.
2. Attach a high-lift jack to the loop and jack the anchor up about 6 inches to
rotate the anchor into the load-lock position.
Failure to install and lock the anchor at the correct angle
will result in the anchor cable cutting through the soil
until the angles equalize, causing slack in the guy wires.
WARNING
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