Campbell IRGASON, Руководство по эксплуатации продукта

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7.1 Factory defaults
Table 7-1 (p. 20) shows the default value for each setting described in the following sections.
Table 7-1: Factory default settings
Bandwidth 20 Hz
SDM Address 1
Unprompted Output disabled
RS-485 baud rate 115200 bps
Unprompted Output Rate 10 Hz
Analog Output disabled
ECMon Update Rate 10 Hz
Temperature Sensor Auto-Select (IRGASON Temp Sensor)
Pressure Sensor EC100 Basic or EC100 Enhanced (depending on order)
Pressure Differential Enable Auto-Select (Disabled for IRGASON)
Heater Control Disabled
7.2 Bandwidth
The EC100 has a user-selectable low-pass filter to select the bandwidth (5, 10, 12.5, or 20 Hz).
Setting the bandwidth to a lower value will reduce noise. However, it must be set high enough to
retain the high-frequency fluctuations in CO
2
and H
2
O, or else the high frequency contributions
to the flux will be lost. The factory default bandwidth of the EC100 is 20 Hz, which is sufficient for
most flux applications. Lower bandwidth settings may be used for higher measurement heights,
which inherently have lower-frequency content. Refer to
Filter bandwidth and time delay (p. 58)
for more information on the digital filter options.
If a spectral analysis is being done to evaluate the experimental setup, the bandwidth should be
set to the Nyquist frequency, which is half the data logger sample rate (for SDM output) or half
the unprompted output rate (for USB and RS-485 output). This ensures that the data will not be
under-sampled and that higher-frequency variations will not be aliased to lower frequencies.
Note that if too small a bandwidth is selected, high-frequency fluxes may be under-measured.
IRGASON® Integrated CO
2
/H
2
O Open-Path Gas Analyzer and 3D Sonic Anemometer 20