Datasheet

24
Notes for using FFT
 Use the default dB scale for details of multiple frequencies, even if they have very different
amplitudes. Use the Vrms scale to compare frequencies.
 DC component or offset can cause incorrect magnitude values of FFT waveform. To minimize
the DC component, choose AC Coupling on the source signal.
 To reduce random noise and aliased components in repetitive or single-shot events, set the
oscilloscope acquisition mode to average.
What is Nyquist frequency?
The Nyquist frequency is the highest frequency that any real-time digitizing oscilloscope can
acquire without aliasing. This frequency is half of the sample rate. Frequencies above the Nyquist
frequency will be under sampled, which causes aliasing. So pay more attention to the relation
between the frequency being sampled and measured.
Use Vertical Position and Scale Knobs
1. The Vertical Position knob is used to adjust the vertical positions of the waveforms.
The analytic resolution of this control knob changes with the vertical division.
2. The Vertical Scale knob is used to regulate the vertical resolution of the wave forms. The
sensitivity of the vertical division steps as 1-2-5.
The vertical position and vertical resolution is displayed at the left bottom corner of the screen
(see Figure 0-1).
Figure 0-1 Information about Vertical Position
How to Set the Horizontal System
The HORIZONTAL CONTROLS includes the Horizontal HOR button and such knobs as