Davis Instruments 7852, Installation Manual

Page: 8 / 16

Extending Cable Runs
8
As you reattach the cone, make sure to run the cable to the cable slot in the base, or the
cone will not fit snugly against the base.
10.Place the debris screen, points down, into the cone. The screen prevents large bits of
debris from blocking the funnel hole.
11.To prevent fraying or cutting of the cable where it is exposed to weather, it is impor-
tant that you secure it so it doesn’t whip about in the wind.
Use cable clips or weather resistant cable ties to secure the cable. Place clips or ties
approximately every 3 to 5 feet (1 to 1.6 m). Do not use metal staples or a staple gun
to secure cables. Metal staples—especially when installed with a staple gun—have a
tendency to cut the cables.
Extending Cable Runs
If the cable length supplied with the rain collector is not long enough for your purposes,
you may extend it. The maximum length of cable is 900 feet (270 m). Note that this
length represents the total length from the rain collector to the console, including any
length of cable from the junction box to the console. To extend the cable, purchase stan-
dard 4-Conductor Extension Cables from Davis and connect them to the existing rain col-
lector cable.
Adjusting the Rain Collector II
The Rain Collector II is calibrated at the factory so the
bucket tips (and records rainfall) for each 0.01" (or 0.2
mm if the metric adapter has been fitted) of rain. To adjust
the calibration slightly, use a 3/16" (or 5 mm) wrench to
rotate the adjustment screws which are located underneath
the bucket (see “Rain Collector Internal Components” on
page 2). The adjustment guide embossed in the platform
shows how far you must rotate both screws in turn to
effect a 1% and a 2% change. Moving the screws in the
positive (+) direction causes the bucket to tip more times
(i.e. give a larger count) for a given amount of water.
Note: Modify both adjustment screws by the same amount.
To check the accuracy of the rain collector, compare the Davis Rain Collector with a tube
type rain gauge. Use a rain gauge with an aperture of at least 4 inches. Any smaller and
the readings obtained may not be accurate. Place the tube type rain gauge directly next to
the Davis rain collector. Compare the totals on three storms. Based on this, develop an
average for how far off the reading are. Adjust the screws to fine tune the reading for the
next three storms if necessary.
Note: Do not compare rainfall readings to reading obtained from television, radio, newspapers, or neighbors
readings. Such readings are not located in your specific environment and therefore are not an accurate
measurement of the weather readings taking place in your surroundings. The rain collector is carefully
tested at the factory to conform to the specifications listed in the back of this manual.
Adjustment Guide