Campbell Scientific AP200 CO2/H2O Atmospheric Profile System - Manual (Page 81)

Appendix D. Output Tables
The AP200 program stores data in several output tables. Details are given for
each table.
IntAvg
The primary output table is IntAvg (Interval Average). A record is written to
this table at the end of every output interval (30 min). Space is allocated on the
memory card for 4,800 records (100 days at one record per 30 min). The CPU
has storage allocated for 480 records (10 days).
This table has a set of values for each level that includes CO2, H2O,
cell_tmpr, cell_press, NumSamples, and sample_flow. These values are
averages of all samples on that level after omitting data subsequent to the valve
switch for equilibration. For example, if all eight levels are used, the cycle
time is 2 min. In each 2-min cycle, the AP200 will spend 15 s on each level
(one to eight). For each level, the first 10 s are omitted and the remaining 5 s
are included in the averages. For this example, the number of samples in the
half-hour averaging interval will be 5 s x 2 samples/s x 15 cycles = 150
samples. This number will change if a different number of levels is used or if a
zero/span sequence is run during the averaging interval.
If fewer than eight levels are used (as determined by system configuration
variable LEVELS_USED), the unused levels will contain 0 or NAN.
Note: The columns for extra levels will be omitted if constant MaxLevels has
been set to a value less than 8.
See Section 5.4.2, Compile Switches, for details on setting program constants.
In addition to the level-specific data, several other parameters apply to all
levels. Some are similar to the level-specific data; they are averaged only
during the time end_omit = True. The rest of the parameters are averages that
include all data, regardless of end_omit.
At the end of the table are the average air temperatures for the optional
temperature profile. These data will be included only as specified by constant
N_AirTemps. See Section 5.4.2, Compile Switches, for details on setting
program constants.
The variables stored in IntAvg are listed below including notes on when
samples are included in the statistic and when the variable will be included in
the TABLE D-1.
TABLE D-1. Variables of the IntAvg Table
Name Units Statistic
When Used in
Calculation
When Included in
Table
TIMESTAMP TS always
RECORD RN always
D-1