FFT Analyzer is an electrical measuring instrument for the purpose of the digital frequency analysis of low-frequency band using FFT technology and is a type of spectrum analyzer in a broad sense.

The spectrum analyzer in the sense of converting the time axis signal to the frequency spectrum can roughly be divided into the following two.

(1) The spectrum analyzer for high-frequency band using the super heterodyne system
(2) FFT analyzer for low-frequency band using the FFT technology (Instruments which describe in this FAQ)

Instrument (1) sweeps the frequency of the local oscillator to be mixed with the input signal to find the frequency spectrum. Instrument (2) simultaneously converts the time-axis data converted into the digital data by the A/D converter into spectral value of a certain frequency band. In recent days, high-frequency spectrum analyzer (1) which uses the FFT technology is on the market.

Recent FFT analyzer has not only frequency analysis function but also analysis function in the time-axis region and amplitude axis region and has character as a comprehensive digital signal processing measuring instrument for low-frequency signal. In addition, there is a 1/N octave analyzer is available as a spectrum analyzer in the low-frequency band as an application for analyzing acoustic vibration data.