Campbell Scientific EC150 CO2 and H2O Open-Path Gas Analyzer and EC100 Electronics with Optional CSAT3A 3D Sonic Anemometer - Manual (Page 38)

EC150 CO
2
/H
2
O Open-Path Gas Analyzer
8. Maintenance and Troubleshooting
EC150 operation requires six maintenance tasks:
• Routine site maintenance
• Wick maintenance
• Analyzer window cleaning
• Zero and span
• Replacing the analyzer desiccant/scrubber bottles
• Factory recalibration
8.1 Routine Site Maintenance
The following items should be examined periodically:
• Check the humidity indicator card in the EC100 enclosure. If the highest
dot has turned pink, replace the desiccant bags. Replacement desiccant
bags may be purchased as pn 6714.
• Make sure the Power and Gas LED status lights on the EC100 panel are
green. If not, check the individual diagnostic bits for the specific fault.
See TABLE 8-2, Diagnostic Flags of Sonic Status LED, and Section 8.7.3,
LED Status Lights, for more information.
8.2 Gas Analyzer Wicks
The windows of the EC150 gas analyzer are polished and slanted at an angle to
prevent water from collecting on their surfaces. However, due to increased
surface tension at the interface with the snout, water can pool at the edges and
partially block the optical path and attenuate the signal. To minimize the
occurrence of such events and the resulting data loss, consider using the wicks
listed in TABLE 8-1. The weave of the wicking fabric promotes capillary
action that wicks the water away from the edge of the windows. The seam and
the straight edge of the wicks are permeated with a rubberized compound to
prevent them from shifting during operation.
Proper installation of the wicks is critical. They should not block or encroach
on the optical path. Before installation, record signal strengths for both H
2
O
and CO
2
. Following installation, repeat testing of signal strength and check
that these values are unchanged.
TABLE 8-1. Rain Wick Replacement Parts
Wick
Campbell Scientific, Inc.
Part Number
Campbell Scientific, Inc.
Description
Bottom wick 28652 Fab EC150/IRGASON rain
wick bottom
Top wick 28653 Fab EC150/IRGASON rain
wick top
The top wick has a short seam which must be aligned with the short side of the
top snout. The angled edge of the wick must closely follow the edge of the
window without encroaching on the optical path. See FIGURE 8-1 for
guidance on proper positioning of the wick.
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