13.9 FFT Analysis Modes
242
Waveform Example
LPC (Power Spectrum Density )
When the spectrum shape is complex and hard to comprehend with either linear or power spectra, a
rough spectrum structure can be obtained.Main uses:
To obtain a spectral envelope using statistical methods
See:
About the Functions
"13.9.2 Analysis Mode Functions" (
Axis
Display Type
Description
X axis
Linear
Frequency is displayed with equal spacing
Log
Frequency display of logarithm interval
Y axis
Lin-Mag
The analysis data is 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)
X axis: Log
Y axis: Lin-Mag
X axis: Log
Y axis: Log-Mag
• Always specify the order (from 2 to 64). Higher orders can expose finer spectral details.
• Amplitude values provided by LPC are not always the same as the power spectrum density.
• If an error occurs during analysis, no waveform is displayed.
• Noise-like phenomena can strongly affect the spectrum shape.
• Not available with external sampling enabled.
Summary of Contents for 8847
Page 1: ...MEMORY HiCORDER Instruction Manual 8847 December 2010 Revised edition 4 8847A981 04 10 12H ...
Page 2: ......
Page 18: ...Operating Precautions 8 ...
Page 26: ...1 4 Basic Key Operations 16 ...
Page 74: ...4 4 Waveform Observation 64 ...
Page 98: ...5 5 Managing Files 88 ...
Page 110: ...6 6 Miscellaneous Printing Functions 100 ...
Page 126: ...7 8 Seeing Block Waveforms 116 ...
Page 160: ...8 10 Making Detailed Settings for Input Modules 150 ...
Page 198: ...10 6 Numerical Calculation Type and Description 188 ...
Page 296: ...15 7 Controlling the Instrument with Command Communications LAN USB 286 ...
Page 304: ...16 2 External I O 294 ...
Page 362: ...Appendix 5 FFT Definitions A28 ...
Page 368: ...Index Index 6 ...
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