Campbell IRGASON, Руководство по эксплуатации продукта

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After an extended period of time in the field, the IRGASON gas analyzer may need to undergo
factory calibration again to ensure valid measurements. When recalibration is deemed necessary,
contact Campbell Scientific.
The IRGASON sonic anemometer also undergoes an initial factory calibration. Usually this
calibration remains valid unless a transducer fails or damage to the instrument leads to a change
in geometry. The sonic anemometer requires calibration when:
l
it develops a wind offset greater than the specification
l
it sets diagnostic flags under dry conditions with little to no wind and with no obstruction in
the ultrasonic paths
The wind offset is tested by creating a zero-wind environment. This is best done in a laboratory
setting with HVAC vents closed or covered to reduce air currents and by encircling the mounted
sensor with a large plastic bag (for example, an unused refuse bag), using caution not to block
the sonic paths. Once the IRGASON is connected to an EC100 and powered on, wind offsets may
be viewed by connecting the EC100 to a PC and using
ECMon to graph u
x
, u
y
, and u
z
wind
components (see ECMon (p. 24)). In this zero-wind environment, u
x
and u
y
should be less than ±
8 cm∙s
-1
(± 0.08 m∙s
-1
) and u
z
should be less than ± 4 cm∙s
-1
(± 0.04 m∙s
-1
). If recalibration is
deemed necessary, contact Campbell Scientific.
10. Data collection and data
processing
Data from the IRGASON is collected through the EC100 and then archived onto a data logger. A
common instrument configuration is to program a data logger to retrieve and collect raw data
from the IRGASON, to be used for post processing, for which various programs have been
developed.
More recently, programs have been developed that efficiently record and correctly process data
from instruments such as the IRGASON, as well as compile them with data from other,
complementary instruments. Campbell Scientific has developed a program, the
EasyFlux DL , that
both records and processes raw data from the IRGASON to provide useful measurements
immediately. An overview of both approaches is given in the sections below.
IRGASON® Integrated CO
2
/H
2
O Open-Path Gas Analyzer and 3D Sonic Anemometer 42