User Manual
15.5 FFT Function
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15
Chapter 15 Specifications
15.5 FFT Function
FFT channel mode 1ch FFT
2ch FFT
Frequency range 133 mHz to 8 MHz
Dynamic range 72dB (logical value) (with Model 8938 or 8947)
96dB (logical value) (with Model 8957 or 8960)
Number of sampling points 1000, 2000, 5000, 10000
Frequency resolution 1/400, 1/800, 1/2000, 1/4000
Antialiasing filter Automatic cutoff frequency selection linked to frequency range
(With Model 8957 High Resolution Unit, 8938 FFT Analog Unit, 8947 Charge Unit,
8960 Strain Unit)
Analysis channel setting Either one or two channels can be freely specified for FFT analysis (up to eight analyses
can be specified)
Analysis data Data to be subject to FFT analysis can be newly acquired or selected from data previ-
ously acquired with the Memory function.
Newly acquired: when measurement starts, the number of specified sampling points is
acquired, and calculation performed.
Memory waveform: applies calculations data prestored with the Memory function.
Data to be subject to FFT analysis can be newly acquired or selected from data previ-
ously acquired with the Memory function.
FFT analysis mode setting Storage waveform, Linear spectrum, RMS spectrum, Power spectrum, Power spectrum
density, Cross-power spectrum, Auto-correlation function, Histogram, Transfer func-
tion, Cross-correlation function, Impulse response, Coherence function, Octave analy-
sis, Phase spectrum, Power spectrum density (LPC)
Display format setting 1, 2, or 4 screen display, Nyquist display
When using memory waveforms as analysis data, memory waveform + FFT1 and mem-
ory waveform + FFT2 screens can be displayed.
(Calculation points can be specified by waveform scrolling.)
Windows Rectangular, Hann, Exponential, Hamming, Blackman, Blackman-Harris, Flat top
Display scale Linear scale, Log scale
Print function Applicable to the Memory function
Averaging function Timebase, simple averaging on frequency axis, exponential averaging on frequency ax-
is, peak hold on frequency axis
(settable from 2 to 10,000 counts)
Logging recording Prints measurement data as numerical values