Campbell Scientific IRGASON Integrated CO2/H2O Open-Path Gas Analyzer and 3D Sonic Anemometer - Manual (Page 40)

IRGASON ® Integrated CO
2
/H
2
O Open-Path Gas Analyzer and 3D Sonic Anemometer
FIGURE 9-4. The zero-and-span shroud mounted on the zero-and-
span stand. The top tube is the gas intake, the black cable is the
temperature thermistor, and the short bottom tube is the gas
exhaust.
4. Disconnect the IRGASON temperature sensor from the EC100 and
connect the shroud temperature sensor in its place.
5. Connect the EC100 to a PC with the EC100 USB cable (pn 26563).
6. Resume power to the EC100. Wait for all the Gas and Power LED status
lights on the EC100 panel to turn green.
7. Launch ECMon, select the appropriate USB port, and click Connect. The
main screen should now be reporting real-time CO
2
and H
2
O
concentrations. Click Zero/Span. A graph will appear in the lower half
of the zero-and-span window showing measured CO
2
and H
2
O
concentrations (see FIGURE 9-5).
8. Connect a gas tank of known CO
2
concentration to a pressure regulator,
then to a flow controller, and finally to the intake of the shroud.
Optimally, the concentration of span CO
2
should be near the concentration
of CO
2
being measured in the field. Begin with both the pressure regulator
and flow controller turned off. Then use the pressure regulator to slowly
increase pressure to the recommended setting for the flow controller. Next
set the flow between 0.4 and 0.6 l/min. Watch the ECMon zero-and-span
graph for the CO
2
measurement readings to stabilize (5 to 10 minutes).
Once stable, write down the reported CO
2
concentration.
Intake
Thermistor Cable
Exhaust
30