CS IRGASON, Instruction Manual

Page: 58 / 74

Appendix A. Filter Bandwidth and Time Delay
A-2
The EC100 measures gas and wind data at 60 Hz, and 60-Hz data are down-
sampled to the datalogger scan rate through SDM communications (see Section
8 , EC100 Outputs
(p. 22)
). This process synchronizes EC100 gas and wind data
with other signals measured by the datalogger to within ±5 ms (plus or minus
one-half of the inverse of 60 Hz). Alternatively, when sending data to a non-
Campbell data acquisition system, the EC100 down-samples its USB and RS-
485 outputs to a user-selectable rate of 10, 25, or 50 Hz. Although the gas and
wind data from the EC100 remain synchronized, the user must consider the
down-sampled output interval when synchronizing the EC100 data with other
measurements in their system. These slower output intervals increase the
asynchronicity of EC100 data with other system measurements.
FIGURE A-1. Frequency and amplitude response of EC100 filter at
various bandwidths
1 10 70
Hertz
0.0001
0.001
0.01
0.1
1
10
N
o U
ni
ts
5 Hz
10 Hz
12.5 Hz
20 Hz
25 Hz
EC100 Bandwidths (Amplitude Responses)