Fast Fourier Transforms with Rigol Oscilloscopes
FFT (Fast Fourier Transform) is a process which converts a time-domain signal into its frequency domain equivalent. Common applications for usage of FFT waveforms are :
● Measuring harmonic content and distortion in systems
● Characterizing noise in DC power supplies
● Analyzing vibration
How to obtain a waveform's FFT?
For this demonstration an FFT will be generated for the square wave being sensed on Channel 1 as seen below:
Press the “MATH” button, a menu will appear on the side, select FFT and set the source to Channel 1
A fast fourier transform of the current signal on Channel 1 will appear in violet color below the square wave.
How to save a waveform's FFT?
To save an FFT to the scope or a USB drive, the FFT must be saved as a reference wave “REF” as in the following procedure: Press the “REF” button. When the side menu appears, set the source to be the FFT. Then use the “Save” option in the menu to save locally or externally.
How to Import / Export an FFT?
Press the “REF” button, reference wave side menu will appear . To save the waveform, select save.
To save the FFT waveform to a USB drive press the “Location” buttonThe Location now switches to “External” as in the figure below:
Upon selecting “Save” select the file to save the waveform to and exit upon completion.