Campbell Scientific AP200 CO2/H2O Atmospheric Profile System - Manual (Page 54)

AP200 CO
2
/H
2
O Atmospheric Profile System
If seq_ACTIVE is True, then set STOPsequence = True to stop the sequence
and then verify that seq_ACTIVE changes to False.
Set valve_number to Zero (9). Look at the LEDs on the valve module to
confirm the selected valve is now active.
The CO2_SPAN_PPM variable displays the concentration in the CO
2
span
tank.
Check the value of diag_AP200. If it is not zero, a problem in the AP200
system should be resolved before continuing (see Appendix B, AP200
Diagnostics).
Wait for the values of CO
2
and H
2
O to stabilize. Normally, this takes one or
two minutes.
Record the value of CO
2
. This is the measured CO
2
concentration in ppm. If
the zero cylinder is selected, the value should be close to zero. If the CO
2
span
tank is selected, it should be close to the value of CO2_SPAN_PPM.
Record the value of H
2
O. This is the measured H
2
O concentration in ppt. The
value should be close to zero for either cylinder.
Set valve_number to CO
2
span (10) and repeat the previous steps.
Press <Esc> to return to the Manual Zero/Span menu.
6.2.2 Do CO
2
and H
2
O Zero
At the Manual Zero/Span menu, select <Do Zero (CO2&H2O)>. This menu
guides the user through the steps to flow the zero gas and to send the command
to zero the IRGA.
If seq_ACTIVE is True, then set STOPsequence = True to stop the
sequence. Then verify seq_ACTIVE changes to False.
Set valve_number to Zero (9). Look at the LEDs on the valve module to
confirm the Zero valve is now active.
Check the value of diag_AP200. If it is not zero, a problem in the AP200
system should be resolved before continuing (see Appendix B, AP200
Diagnostics).
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