Campbell Scientific EC155 CO2 and H2O Closed-Path Gas Analyzer and EC100 Electronics with Optional CSAT3A 3D Sonic Anemometer - Manual (Page 26)

EC155 CO
2
and H
2
O Closed-Path Gas Analyzer
Unlike previous models of the CSAT3 3D sonic anemometer, the
CSAT3A sonic head and the EC155 gas analyzer head have
embedded calibration information. This means that any CSAT3A
and any EC155 may be used with any EC100.
d. Ground the EC100 by attaching a thick wire (e.g., 12 AWG) to the
grounding lug found on the bottom of the EC100 enclosure. The other end
of the wire should be connected to earth (chassis) ground (i.e., grounding
rod). For more details on grounding, see the CR3000 datalogger manual,
grounding section.
Grounding the EC100 and other electrical components in
the measurement system is critical. Proper grounding to
earth (chassis) will ensure the maximum ESD (electrostatic
discharge) protection and higher measurement accuracy.
e. Connect a communications signal cable to the EC100. Loosen the nut on
one of the cable entry seals (Cable 1 or Cable 2) on the bottom of the
EC100, remove the plastic plug (the plug can be stored in the mesh pocket
in the enclosure), insert the cable, and retighten the nut by hand. Refer to
the sections below on SDM, USB, RS-485, and analog communications
for information on required signal cable types and connections to the
EC100 panel.
1. SDM Communications: Use cable CABLE4CBL-L (pn 21972). “L”
denotes the length of the cable, which is customer-specified at time of
order. TABLE 6-1 below details which color of wire in the cable
should be connected to each terminal found on the SDM connector of
the EC100 panel.
TABLE 6-1. EC100 SDM output to a Campbell Scientific CR1000,
CR3000, or CR5000 Datalogger
EC100 Channel Description Color
SDM-C1 SDM Data Green
SDM-C2 SDM Clock White
SDM-C3 SDM Enable Red (or brown)
G Digital Ground Black
G Shield Clear
2. USB Communications: Use the EC100 USB cable (pn 26563) to
connect a PC to the on the bottom of the EC100 enclosure.
3. RS-485 Communications: Use cable CABLE3TP-L (pn 26987) for
lengths less than 500 ft. The connector on the EC100 panel labeled
RS-485 displays which terminals are for receiving and transmitting.
4. Analog Output: Use CABLE4CBL-L (pn 21972) or CABLE2TP-L
(26986-L). Once again, the customer specifies the length of this cable
at time of order. The connector labeled Analog Outputs on the EC100
panel indicates where each wire should be connected (CO
2
voltage
signal, H
2
O voltage signal, and two ground connections).
NOTE
CAUTION
16