Fast Fourier Transform for varying period (Order analysis)

1. How many periods do I need for FFT?
2. What does FFT analysis show?
3. What is Fast Fourier Transform FFT used for?
4. What are the limitations of FFT?

How many periods do I need for FFT?

Number of periods of signal required when doing an FFT: 1

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What does FFT analysis show?

In a complex signal, the FFT helps the engineer to determine the frequencies that are being excited and the amplitude at each frequency. Additionally, it highlights the changes at the frequency and amplitude and the harmonic excitation in a frequency range.

What is Fast Fourier Transform FFT used for?

It converts a signal into individual spectral components and thereby provides frequency information about the signal. FFTs are used for fault analysis, quality control, and condition monitoring of machines or systems.

What are the limitations of FFT?

A disadvantage associated with the FFT is the restricted range of waveform data that can be transformed and the need to apply a window weighting function (to be defined) to the waveform to compensate for spectral leakage (also to be defined). An alternative to the FFT is the discrete Fourier transform (DFT).