Sigma 900 MAX Refrigerated Sampler Instrument Manual

Page 69
8990options.fm Optional Device Installation
Section 5 Optional Device Installation
This section describes how to setup a rain gauge to the Sampler as well as
how to connect, program, calibrate, and maintain the optional water
quality probes:
5.1 Rain Gauge
An external “tipping bucket” rain gauge (Cat. No. 2149) can be connected to
the Rain Gauge connector of the sampler (Figure 21). The rain gauge
provides a dry contact closure to the sampler.
As rainfall collects in the 20 cm (8 in.) diameter funnel, it is directed into one
side of a “tipping bucket” assembly. As each bucket fills, it causes the bucket
assembly to tip and empty out into the bottom of the rain gauge. Each tip of
the bucket causes a single contact closure to the rain gauge and sends a
short 12 V dc pulse into pin C of the Rain Gauge connector. Each pulse (tip)
represents 0.025 cm (0.01 in.) of rain.
Figure 21 Rain Gauge Tipping Bucket
• Rain Gauge (section 5.1 on
page 69
• Dissolved Oxygen Probe
(section 5.4 on page 74)
• pH Probe
(section 5.2 on page 70)
• Conductivity Probe
(section 5.5 on page 76)
• ORP Probe
(section 5.3 on page 72)
Table 7 Rain Gauge Base Board Connections (J5)
Pin Signal Description
A +12 V dc source output
B not used
C +12 V dc pulse input
D not used
E not used
F not used