LI-COR LI7200RS, Instruction Manual

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Section 7. Software Reference
In most cases you will never need to manually edit these values. If, for some
reason, the instrument calibration becomes unstable (e.g., you accidentally zeroed
or spanned the instrument with the wrong gas), you can manually enter a value of
1 for each of these parameters (and zero for Span 2 values), and click
Apply
. This
will return the instrument to a more normal state, after which you can perform
zero and span calibrations again. Alternatively, if you have performed at least one
previous (successful) calibration, you can restore those values using the
History
tab.
History Tab
The
History
tab displays a list of previous calibration backup files generated during
a zero and/or span calibration of the instrument (when used with the same com-
puter used to connect to the instrument). You can click on any previous calibration
in the list to view the details; you can also restore the values from a previous cal-
ibration by choosing a file in the list and clicking the Restore button. Click
Delete
to permanently remove calibration files from the list stored on the computer.
Changing Sensor Heads
Sensor heads are freely interchangeable between LI-7550 Analyzer Interface Units.
However, the LI-7550 must have the correct calibration coefficients and current
zero and span information for the attached sensor head. This can be done by hand,
or "automatically".
By Hand
1 Attach the new sensor head to the LI-7550
2
Connect the instrument to a computer and establish communications.
3
Enter the calibration coefficients from the Calibration Certificate under the Coefficients tab.
4 Zero and span the instrument.
Automatic
Acquire a calibration file for your instrument. You can get it from the LI-COR sup-
port site (www.licor.com/env/support) under calibration information, or you can
save it from the LI-7550 (
Config Files > Save Configuration
). The file has a *.7x
extension. To move a sensor head to another LI-7550:
7-24 LI-7200RS Enclosed CO₂/H₂O Analyzer