Envelope Analysis for Diagnostics of Local Faults in Rolling Element Bearings

Envelope Detection or Amplitude Demodulation is the technique of extracting the modulating signal from an amplitude-modulated signal. The result is the time history of the modulating signal. This signal may be studied/interpreted as it is in the time domain or it may be subjected to a subsequent frequency analysis. Envelope Analysis is the FFT (Fast Fourier Transform) frequency spectrum of the modulating signal.