User Manual

1. Click
to show Function menu, choose "Math". Check "FFT". The user interface is
switched into Three View mode.
2. Set "Channel", "Window", "Format", "Scale", "Frequency Base".
3. You can drag anywhere in FFT window to move the signal up and down and side to side.
15.1. To select the FFT window
There are four FFT windows. Each one has trade-offs between frequency resolution and magnitude
accuracy.
Type
Characteristics
Window
Hamming
Better solution for magnitude
than Rectangle, and good for
frequency as well. It has slightly
better frequency resolution than
Hanning.
Recommend to use for:
Hamming
 Sine, periodic and narrow
band random noise.
 Transients or bursts where the
signal levels before and after
the event are significantly
different
Rectangle
Best solution for frequency,
worst for magnitude.
Best type for measuring the
frequency spectrum of non
repetitive signals and measuring
frequency components near DC.
Recommend to use for:
 Transients or bursts, the
signal level before and after
the event are nearly equal.
 Equal-amplitude sine waves
with frequencies those are
very close.
 Broadband random noise with
a relatively slow varying
spectrum
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