ARG100 Tipping Bucket Rain Gauge
3
3.4 Levelling
If the rain gauge is tilted by more than a few degrees, the bucket mechanism
may be thrown out of balance, significantly affecting its calibration.
Furthermore, during wind-driven rain the response of a gauge with a tilted
funnel collector will vary with wind direction.
Where a concrete slab is used, add sand underneath the slab to level the gauge.
If the gauge is mounted on a concrete base using Anchorbolts, add packing
material under the base before tightening the bolts. Use the internal bubble to
check that the base of the gauge (with the funnel removed) is level; as an
additional check, place a spirit level across the rim of the assembled ARG100.
4. Wiring
The rain gauge is supplied with custom cable length at the time of order. For
most applications the ARG100 may be connected directly to a pulse counting
input on the datalogger as shown in Figure 4-1. For a long cable, a significant
capacitance can exist between the conductors, which discharges across the reed
switch as it closes. As well as shortening the life of the switch, a voltage
transient may be induced in any other wires which run close to the rain gauge
cable each time the gauge tips. A 100
:
resistor is fitted inside the gauge to
protect the switch from arcing and prevent transients.
Figure 4-1 Wiring Diagram from ARG100
4.1 Wiring to a Pulse Channel
When Short cut software is used to generate the datalogger
program, the sensor should be wired to the channels shown on the
wiring diagram created by Short Cut.
The ARG100 is typically wired to a datalogger’s pulse channel (see Table 4-1).
Black
Clear
Yellow
(Shield)
ARG100
P
G or
Pulse
Port
Control
Port
C
+5V
No
Physical
connection
Note
