Campbell Scientific EC155 CO2 and H2O Closed-Path Gas Analyzer and EC100 Electronics with Optional CSAT3A 3D Sonic Anemometer - Manual (Page 21)

EC155 CO
2
and H
2
O Closed-Path Gas Analyzer
FIGURE 6-3. Exploded view of mounting the EC100 enclosure
h. Remove the EC100 enclosure desiccant from the plastic bag and put it
back in the mesh pocket of the enclosure. Adhere the humidity indicator
card to the inside of the enclosure.
6.2 Plumbing
6.2.1 Flow
The EC155 has a small sample cell volume (5.9 cm 3 ) to give good frequency
response at a relatively low flow rate. The sample cell residence time is 50 ms
for a nominal 7 LPM flow. The CPEC200 pump module is designed to provide
this flow for the EC155, but other user-supplied pumps may be used. There is
no specific limitation to the flow rate that may be used with the EC155, but the
sample cell pressure must be considered.
6.2.2 Pressure
The EC155 is designed to be used near ambient pressure, but it will not be
damaged by operation under vacuum. The EC155 includes a differential
pressure sensor to measure the sample cell pressure relative to ambient
pressure, which has a range of ± 7 kPa. If the EC155 is operated less than
7 kPa from ambient pressure, the user must attach a separate, user-supplied
pressure sensor.
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