C-2
Glossary of Terms
CO2 Abs. Absorption of photons in the optical bench due to CO
2
CO
2
Absorption. Absorption of photons in the optical bench due to CO
2
CO2 Dry. CO
2
corrected for water vapor dilution. Labeled Cdry in the data.
Units; μmol CO
2
mol
-1
air.
Comments. User entered information included in the data file header. Maximum
of 100 characters.
Compact Flash Card. Removable card used for additional/transportable data
storage
CrvFit.
2: Number of points used in the curve fit
3: A
4: Cx
CrvTime.
2: T
o
3: Dead band
4: Domain of the fit ( Stop time-Start time)
Date. Output in the format; 02/19/2004 14:26
Units; Month:day:year:hour:minute:second
DCdry/dt.
2: Slope at To (Exponential fit)
3: Slope of linear fit
4: Standard error (Exponential fit)
Dead Band. After a chamber closes there is a time interval before steady mixing is
established. The Deadband is a user entered estimate of what this interval is. Data
collected prior to the end of the Deadband interval are not used in the flux
computations, however, the data are stored in the raw file. The Deadband
requirement will change depending upon the chamber geometry, system flow rate
and collar and site characteristics (Fig. 4-2 Shows a time series of CO
2
vs time
across two observation cycles. This Figure illustrates Deadband, Obs. Length and
Obs. Delay). Generally we have found a Deadband between 10 and 60 seconds to
be adequate. However, there may be conditions where longer deadbands are
needed and the user can recompute the data with different deadbands in the "File
Viewer" software. Units; seconds.
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