Campbell Scientific EC155 CO2 and H2O Closed-Path Gas Analyzer and EC100 Electronics with Optional CSAT3A 3D Sonic Anemometer - Manual (Page 62)

Appendix C. EC155 Sample Cell and Intake Maintenance
3. Plug the hole in the inlet with your finger. The pump will pull a
vacuum on its internal filter/buffer volume, the pump tube, analyzer,
and intake tube.
4. After approximately one minute, unplug the hole.
During these steps, ambient air will rush in and blow dust from
the inner walls of the intake tube, which is likely be deposited on
the analyzer windows. For this reason, Campbell Scientific
recommends performing the dust blowout prior to cleaning
windows.
5. Repeat this procedure as needed.
When the windows no longer become dirty (CO
2
and H
2
O signal levels do not
change) this indicates no more dust is being removed from the intake tube.
C.2.2 Solvent Flush
If the intake tube has other contamination, such as salt deposits, it may be
flushed with water or alcohol, but be careful to keep the solvent out of the
pressure sensor passages (see earlier note on cleaning the sample cell).
Following the steps in the following procedure, will help keep the pressure
sensor passages clear.
1. Power the system down.
2. Remove the sensor head from the sample cell.
3. Close the lid of the sample cell assembly.
4. Position sample cell assembly upside down. This allows the solvent
to flow away from the pressure sensor passage.
5. Tilt slightly so that the intake is higher than the sample cell.
6. Remove the intake filter.
7. Fill a syringe with solvent (generally, tap water will be sufficient) and
press it against the hole in the end of the intake tube.
8. Depress the plunger to let the solvent flow through the intake tube.
The waste solvent will collect in the lid of the sample cell assembly.
9. Fill the syringe with air and push the air through the intake tube to
force most of the solvent out of the tube.
10. Dump the solvent out of the sample cell assembly and wipe the
assembly dry.
11. Clean the analyzer windows and the sample cell as described in
Section 9.3, Cleaning Analyzer Windows, and C.1, Cleaning Sample
Cell, in the section above.
This procedure is likely to leave some of the solvent in the system.
Make sure it is completely dry before attempting a zero/span.
NOTE
NOTE
C-2