Campbell Scientific EC155 CO2 and H2O Closed-Path Gas Analyzer and EC100 Electronics with Optional CSAT3A 3D Sonic Anemometer - Manual (Page 12)

EC155 CO
2
and H
2
O Closed-Path Gas Analyzer
• CAUTION:
o Grounding the EC100 measurement electronics is critical. Proper
grounding to earth (chassis) will ensure maximum ESD
(electrostatic discharge) protection and improve measurement
accuracy.
o Do not connect or disconnect the gas analyzer or sonic connectors
while the EC100 is powered.
o The SDM, USB, and RS-485 output options include EC155
diagnostic data. Be aware that the absence of diagnostic data in
the analog output option could make troubleshooting difficult and
may lead to the user not being aware of potential problems with
the instrumentation (see Section 8, EC100 Outputs).
o Resting the analyzer on its side during the zero-and-span
procedure may result in measurement inaccuracy.
o When cleaning the gas-analyzer window, make sure the alcohol
and any residual water completely evaporate before proceeding
with the zero-and-span procedure (see Section 9.3, Cleaning
Analyzer Windows).
3. Initial Inspection
Upon receipt of your equipment, inspect the packaging and contents for
damage. File damage claims with the shipping company.
4. Overview
The EC155 is a closed-path, mid-infrared absorption analyzer that measures
molar mixing ratios of carbon dioxide and water vapor, along with sample cell
temperature and pressure. It has been designed specifically for eddy
covariance flux measurements and may be used in conjunction with the
CSAT3A 3D sonic anemometer head. The analyzer has a rugged, aerodynamic
design with low power requirements, making it suitable for field applications.
The EC155 gas analyzer connects directly to the EC100 electronics, which
computes real-time CO
2
and H
2
O molar mixing ratios of the air inside the
sample cell of the analyzer. A CSAT3A sonic anemometer head may also be
connected to the EC100.
The EC155 has been designed specifically to address issues of aerodynamics,
power consumption, performance during precipitation events, ambient air
density fluctuations, temporal synchronicity, and system integration. Its unique
design enables it to operate with only 4.8 W power; it has minimal spatial
displacement from the sample volume of a CSAT3A sonic anemometer; the
EC100 electronics synchronize data from the EC155 and CSAT3A; and the
analyzer is easily integrated into the CPEC200 closed-path eddy covariance
system, a turn-key system containing data acquisition and control
instrumentation, a sample pump, and optional zero-and-span valve module.
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