Setting the span: Carbon dioxide

Note: Always set the zero before setting the span.

  1. Plumb the LI-8100A as shown in Figure 7‑3.
  2. Attach a tank containing a known concentration of CO2 to the LI-8100A air inlet. Use a flow splitter to vent the excess gas to the atmosphere. Vent the instrument outlet to the atmosphere to prevent pressurizing the analyzer. Turn on the pump and set flow from tank at 2 to 2.5 lpm.
  3. Figure 7‑3. Typical plumbing configuration for a CO2 span gas.
  4. Monitor CO2 concentration.
  5. When CO2 concentration is stable proceed to the next step. Allow 1-2 minutes for the CO2 concentrations to stabilize.
  6. Calibrate:

In the PC Software:

Configure the Data view to show CO2 (µmol/mol) and H2O (mol/mol).

Go to Utilities > Calibration, go to the Span tab, and enter the span gas concentration.

When the CO2 concentration is stable, click Span CO2.

In the App:

Go to Utilities > Calibration, then tap Perform: Span.

Under the CO2 tab, enter the span gas concentration.

When the CO2 reading is stable, tap Send Command.