Campbell Scientific AP200 CO2/H2O Atmospheric Profile System - Manual (Page 53)

AP200 CO
2
/H
2
O Atmospheric Profile System
After these variables are set, the valve sequence must be restarted to make the
changes effective. See Section 5.5, Starting and Stopping the Sequence, for
detail on starting and stopping the sequence. The program will then set its
timing variables as appropriate for the options selected (see Appendix F, Valve
Sequence Timing, for details).
6.2 Manual Zero and Span
This section describes how to perform a manual zero and span of the IRGA.
This procedure assumes the use of a keyboard display, but the process is
similar when using LoggerNet.
The AP200 keyboard menus are designed to guide the user step by step
through the manual zero/span process. Each line in a menu is either a submenu
or it displays or edits a public variable. At the top-level AP200 menu, select
Manual Zero/Span.
The Manual Zero/Span menu has four submenus that should be visited in the
order listed.
After the steps on the four submenus are completed, there are three lines to
restart the valve switching sequence. The following section provides details on
this procedure.
6.2.1 Check Zero and CO
2
Span
At the Manual Zero/Span menu, select <Check Span, Zero>. This menu
guides the user through the steps to flow the CO
2
span and zero gases to assess
the current state of the IRGA.
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