Appendix 5 FFT Definitions
A
25
Appendi
x
The following example shows input sine waves of 1050 and 1150 Hz analyzed
with different window functions. Because the frequencies in this example are
close to one another, a rectangular window with a narrow main lobe is able to
separate and display both frequencies, but a Hann window with a wide main lobe
displays the two as a single spectral component.
Flat top window
Time-Domain Waveform
Spectrum
Analysis Using a Rectangular Window
Analysis Using a Hann Window
N-1
0
Am
p
litu
d
e
0
0
2
4
6
8
10
-80
-60
-40
-20
0
Frequency (1/W)
Gai
n
[
d
B
]
100
500 1000
5000 10000
-100
-50
0
Frequency [Hz]
A
m
pl
it
ud
e [
d
B
]
100
500 1000
5000 10000
-100
-50
0
Frequency [Hz]
Amp
lit
ude [dB
]
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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