User manual

6 To Make Measurements RIGOL
DS2000A User’s Guide
6-5
Table 6-1 Window Functions
Window Characteristics
Waveforms Suitable for
Measurement
Rectangle
The best frequency
resolution;
the poorest amplitude
resolution;
similar to the situation
when no window is
multiplied.
Transient or short pulse, the signal
levels before and after the
multiplication are basically the same;
Sine waveforms with the same
amplitude and rather similar
frequencies;
Wide band random noise with
relatively slowly changing waveform
spectrum.
Hanning Better frequency
resolution;
poorer amplitude
resolution.
Sine, periodic and narrow band
random noise.
Hamming A little bit better
frequency resolution
than Hanning
Transient or short pulse, the signal
levels
before and after the
multiplication are rather different.
Blackman The best amplitude
resolution;
the poorest frequency
resolution
Single frequency signal, search for
higher order harmonics.
3. Set the Display Mode
Press Display to select “Split” (default) or “Full Screen” display mode.
Split: the source channel and the FFT operation results are displayed separately.
The time domain and frequency domain signals are displayed clearly.
Full Screen: the source channel and the FFT operation results are displayed in
the same window to view the frequency spectrum more clearly and to perform
more precise measurement.
Note: In FFT mode and when MATH is the active channel, you can also press
HORIZONTAL SCALE
to switch between “Split” and “Full Screen”.
4. Set the Vertical Scale
In FFT measurement, the unit of the horizontal axis changes from time to
frequency. Use HORIZONTAL SCALE
and HORIZONTAL POSITION