13.9 FFT Analysis Modes
250
Octave Analysis
Octave analysis consists of frequency analysis of the signal passed through a constant-width band-pass filter.
The power spectrum displays the power level in each subband after dividing the spectrum into fixed-width
segments (subbands), while octave analysis scales the spectrum logarithmically and displays each octave
(subband) as a bar graph.
The center frequency of the octave bands and filter characteristics are determined according to IEC61260
standards. With this instrument, 1/1- and 1/3-octave analyses are calculated using power spectrum Analysis
results.
1/1 Octave Analysis: 6 subbands
1/3 Octave Analysis: 16 subbands
The octave analysis results of this unit are displayed based on the oscillation level as a reference. Therefore,
when only sine waves are input, the value doubles (3.01 dB) versus the overall value. To directly read by
energy base, adjust the level by the setting scaling in advance.
See:
"8.5 Converting Input Values (Scaling Function)" (
1/1 Octave
X axis: Log
Y axis: Log-Mag
Filter: Sharp
1/3 Octave
X axis: Log
Y axis: Log-Mag
Filter: Normal
1/3 Octave
X axis: Log
Y axis: Log-Mag
Filter: Sharp
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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