La Crosse Technology WS-2306 Operation Manual page 17

For accurate results, the rain sensor should be securely mounted
onto a horizontal surface at least 1.0 metre above the ground and in
an open area away from trees or other coverings where rainfall may
be reduced causing inaccurate readings. Placing the gauge extremely
high is generally not a good idea as you may need to periodically
clear debris such as leaves, spider nests etc.
When securing into place, check that rain excess will not collect and
store at the base of the unit but can flow out between the base and
the mounting surface (test by pouring clean water).
Install the Rain gauge on a level platform that is stationary. If the
gauge isn't level it will read low, and if it isn't stationary wind may
cause it to read rain that isn't falling. Tip: Be sure not to screw the
rain sensor down too tightly as that will result in a low or inaccurate
reading. On the bottom of the sensor there are 4 holes that can be
used to screw the gauge down. First remove the cover. You have to
push in the tabs on the sides and then pull the cover off. There will
be a teeter-totter that has a metal bar for an axis. Pull the metal bar
out with pliers. The teeter-totter can then be removed giving you
access to the screw holes. You may also choose to mount with
25mm (1 inch) strips of silicone gel along the base. Be sure to leave
gaps for water to run out.
After mounting the rain sensor, connect the cable to the thermo-hygro
sensor at the corresponding socket so power supply can be received
and data can be transmitted to the base station. Be sure to leave a
small amount of cord below the thermo-hygro sensor as a "drip loop"
to prevent water from running into the ports of the sensor.
The rain sensor is now operable. For testing purposes, very slowly
pour a small amount of clean water into the rain sensor funnel. The
water will act as rainfall and will be received and displayed at the
base station after about 2 minutes delay i.e. when the reading interval
is reached (to clear this testing data on the base station, refer to the
section "MIN/MAX Mode" below).
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