Campbell Scientific ID-2000W Software - Manual (Page 47)

4-1
SECTION 4. FFT VIEW
ID-2000 makes no claims to be a full featured
frequency analysis product. However, it does
offer basic frequency analysis capabilities in the
form of Amplitude Spectrum and Power
Spectrum plots for those users that need to
periodically look at the frequency response of
their time-based data. These plots are
displayed in the FFT view.
The FFT view is very similar to the Plot view. It
can only be accessed from the Plot view by:
•
FFT toolbar button:
•
Selecting the View - Switch to FFT menu
item
The FFT view shares many common features
with the Plot View including cursor coordinates,
data tracking, zooming, statistics, copying a plot
to the Windows clipboard, and printing. For
information on these common features refer to
the chapter on Plot View.
For those of you not familiar with FFTs or
frequency analysis, an FFT is a complex
mathematical calculation performed on a set of
data points. The result of the calculation is a
set of values corresponding to the amplitude or
power of the signal at discrete frequency
ranges.
Figure 4-1 shows a Power Spectrum plot which
displays the amplitude the signal produced for
various frequency ranges. The tall bar in the
middle indicates that the largest amplitude was
concentrated at a single frequency range
corresponding to approximately 156Hz.
FIGURE 4-1. Power Spectrum Plot