Campbell Scientific AVW200-series Vibrating Wire Interfaces - Manual (Page 43)

AVW200-series 2-Channel Vibrating Wire Spectrum Analyzer Modules
FIGURE 5-9. Graphs for Evaluating Spectral Analysis of a Sensor
Check the manufacturer’s specification for the sensors frequency
and excitation range before picking the begin/end frequencies and
excitation voltage.
In FIGURE 5-9, the bottom graph shows the raw time series data recorded
from a vibrating wire sensor after the sensor has been excited with the
frequency swept voltage signal and the top graph shows the spectrum after the
AVW200 has applied the FFT. In addition to the wire’s resonant frequency,
the spectrum shows the response amplitude, noise amplitude, and noise
frequency. The AVW200 computes the signal-to-noise ratio diagnostic by
dividing the response amplitude by the noise amplitude. The AVW200
computes the decay ratio diagnostic from the time-series ending amplitude
divided by the beginning amplitude.
Read more! More comprehensive information about the Spectrum and
Time-Series graphs are provided in Appendix F.
6. The results of the poll may be saved by clicking the Save Last Results tab
at the bottom of the window.
NOTE
Response
Amplitude Noise Amplitude
Resonant Frequency Noise Frequency
Beginning Amplitude
Ending Amplitude
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