Campbell Scientific EC150 CO2 and H2O Open-Path Gas Analyzer and EC100 Electronics with Optional CSAT3A 3D Sonic Anemometer - Manual (Page 61)

Appendix B. Filter Bandwidth and Time
Delay
The EC100 measures CO
2
and H
2
O from the EC150 gas analyzer head. It will
also measure wind velocity and sonic temperature if the optional CSAT3A
sonic head is being used. EC100 measurements occur at 100z and then a user-
selectable, low-pass filter is applied. The available filter bandwidths are 5, 10,
12.5, 20, and 25 Hz.
FIGURE B-1 shows the amplitude response of these filters. The EC100 filters
provide a flat pass band, a steep transition from pass band to stop band, and a
well-attenuated stop band. FIGURE B-2 compares the EC100 10-Hz filter to a
50-ms moving average filter with approximately the same bandwidth.
FIGURE B-1. Amplitude response of EC100 filter at various bandwidths
B-1