Section 4
Calibration
4-5
Figure 4-3. Calibration dialog box in PC communications software.
The calibration dialog box allows you to define a calibration action to be
performed for CO
2
and/or H
2
O. You then flow the appropriate gas(es)
through the appropriate cell(s), wait for the readings to stabilize, and then
press DoCO2 (f2) or DoH2O (f3) to execute the calibration action. For
the next 4 or 5 seconds, the LI-7000 will average the readings it is taking,
then perform the requested action.
There are three major choices for calibration actions:
1. Make cell A read...
2. Make cell B match cell A
3. Make cell B read...
The “Make cell A read...” option is designed to correct the drift with time
that occurs while in Reference Estimation Mode (REM). (This action is
not available from the front panel unless you are in REM.) You perform
this procedure while temporarily flowing a known concentration through
cell A. Any concentration will work, even 0.
