User`s guide

RIGOL

User’s Guide for DS1000E, DS1000D Series

2-11

1. Using the FFT

The FFT (Fast Fourier Transform) process converts a time-domain signal into its

frequency components mathematically. The horizontal axis shows the frequency and

the vertical axis shows the amplitude dBVrms or Vrms. FFT function can not only to

help you find crossfire problem and analog waveform distortion caused by nonlinear

amplifier, but also can adjust the analog filter.

FFT waveforms are useful in the following applications:

 Measuring harmonic content and distortion in systems

 Characterizing noise in DC power supplies

 Analyzing vibration

Press MATH→Operate→FFT, to display FFT menu.

Figure 2- 17 Table 2- 6 The FFT menu

Settings

Comments

Operate

A+B

A-B

A x B

FFT

Add source A to source B

Subtract source B from source A

Multiply source B by source A

Fast Fourier Transform

Source

CH1

CH2

Define CH1 or CH2 as FFT source

Window

Rectangle

Hanning

Hamming

Blackman

Select window for FFT

Display

Split

Full screen

Display FFT waveform on half screen

Display FFT waveform on full screen

Scale

Vrms

dBVrms

Set “Vrms ” as vertical unit

Set “dBVrms ” as vertical unit