User Manual

3.10 FFT Analysis Modes
89
Waveform Example
Power Spectrum Density PSD
Indicates the power spectrum density of the input signal with only the amplitude component
included. This is the power spectrum divided by the frequency resolution.
Not available with external sampling enabled.
Main uses:
To acquire a power spectrum with 1-Hz resolution for highly irregular waveforms such as white noise
See About the Functions "3.10.2 Analysis Mode Functions" (⇒ p. 102)
Axis Display Type Description
X axis
Linear
Frequency is displayed with equal spacing
Display Range: DC to the top of the frequency range
Log
Frequency is displayed logarithmically
Display Range: 1/400
th
to 1/4000
th
(depending on the number of analysis
points) to the top of the frequency range
Y axis
Lin-Mag
Analysis values are displayed linearly.
Log-Mag (logarithm)
Analysis values are displayed as dB values. (0 dB reference value: 1eu
2
/Hz)*
* eu: engineering units that are currently set are the standard (e.g., when the unit settings is volts, 0 dB = 1 V
2
/Hz)
Normal display
X axis: Log
Y axis: Lin-Mag
Normal display
X axis: Log
Y axis: Log-Mag