Hioki MR8827, Instruction Manual

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FFT Analysis Modes
Cross-Correlation Function
Shows the correlation of two points on tow input signals at time differential t. Output is displayed
as a function of differential time t.
Main uses:
To determine the phase shift of two signals per unit of time
To determine the speed and distance of time lag between two signals
About the Functions, refer to “13.9.2 Analysis Mode Functions” (p. 289).
Axis Display type Description
X axis Linear
Time display
The center ( t = 0) is the reference. To the right is lag time (+ t), and to the left is
lead time (- t)
Y axis Lin-Mag
+1 to −1 is displayed in dimensionless units.
At time differential t , this value is +1 when the correlation of input and output
signals is the closest, and 0 when correlation is the least. −1 indicates
completely reversed polarity.
Waveform Example
X axis: Linear
Y axis: Lin-Mag
This instrument provides a circular cross-correlation function.
Analysis results are normalized to the maximum value.
1/1 Octave, 1/3 Octave
Analyze spectrums such as noise using fixed rate spectrum filters of 1/1 octave band or 1/3 octave
band.
Main uses:
To analyze noise frequency
About the Functions, refer to “13.9.2 Analysis Mode Functions” (p. 289), “Octave Filter Characteristics” (p. A24)
Axis Display type Description
X axis Log Displays the center frequency of each band.
Y axis
Lin-Mag Displays octave analysis values linearly.
Log-Mag(logarithm) Displays octave analysis values as dB values. (0 dB reference value: 1eu)*
* eu: engineering units that are currently set are the standard (e.g., when the unit settings is volts, 0 dB = 1 V)