User Manual

3.10 FFT Analysis Modes
86
Waveform Example
Linear Spectrum LIN
The linear spectrum plots the input signal frequency. It can be displayed as a Nyquist plot.
Main uses:
• To inspect the peak frequency contents of a waveform
• To inspect signal amplitudes at each frequency
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
Nyquist display
The real-number component of analysis values are displayed linearly.
Y axis
Lin-Mag
Analysis values are displayed linearly.
Log-Mag
Analysis values are displayed as dB values. (0 dB reference value: 1eu)*
Lin-Real
The real-number component of analysis values are displayed.
Lin-Imag
The imaginary component of analysis values are displayed.
Nyquist display
The imaginary component of analysis values are displayed.
* eu: engineering units that are currently set are the standard (e.g., when the unit settings is volts, 0 dB = 1 V)
Normal display
X axis: Log
Y axis: Lin-Mag
Normal display
X axis: Log
Y axis: Log-Mag
Normal display
X axis: Log
Y axis: Lin-Real
Normal display
X axis: Log
Y axis: Lin-Imag
Nyquist display