Campbell Scientific EC150 CO2 and H2O Open-Path Gas Analyzer and EC100 Electronics with Optional CSAT3A 3D Sonic Anemometer - Manual (Page 41)

EC150 CO
2
/H
2
O Open-Path Gas Analyzer
FIGURE 8-2. Replacing the desiccant/CO
2
scrubber bottles
8.6 Factory Recalibration
When the EC150 is manufactured, it goes through an extensive calibration
process, covering a wide range of temperatures, pressures, and gas
concentrations. All CO
2
calibration gases used in this process are mixtures of
CO
2
in ambient air that are traceable to the WMO Mole Fraction Scale
maintained by the Central Carbon Dioxide Laboratory and the Carbon Cycle
Greenhouse Gases Group of the Global Monitoring Division/National
Oceanographic and Atmospheric Administration in Boulder, CO, USA.
The long-term calibration stability of the EC150 is achieved by the use of high
quality optical and electrical components, a long lasting IR source, and a stable
MCT detector. The subtle, long-term aging effects are usually compensated by
the user with the field zero-and-span adjustments which bring the performance
of the analyzer within the original specifications. Proper handling and regular
maintenance of the instrument should make factory recalibration unnecessary
in most applications. If zero and span accessories and calibration standards are
not available, Campbell Scientific can provide two-point calibration upon
request (pn 27312).
However, if a user finds that signal strength outputs of greater than 0.75 cannot
be achieved after both cleaning the windows and a subsequent zero-and-span
procedure, contact Campbell Scientific. An application engineer will help
determine if the instrument should be returned to Campbell Scientific for a
factory recalibration.
For the CSAT3A, refer to the CSAT3 instruction manual for information on
recalibration.
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