
255
FFT Analysis Condition Settings
13.3.8
Emphasize Analysis Results (Phase Spectra Only)
By specifying a setting factor (rate) to be applied to the input signal, the display of data that exceeds the
resulting threshold can be emphasized. This feature is useful for viewing waveforms that may otherwise
be obscured by noise.
The reliability of phase spectrum values is poor when discrete Fourier transform values are extremely
small. For example, in the case of a pure sine wave, almost all phase values at frequencies other than
the input frequency result from calculation errors. By treating the maximum value of the power (or cross-
power) spectrum of the input signal,
P
max
, as a reference value, data that exceeds that value multiplied by
rate
R can be displayed with emphasis.
Emphasis
Display
10log
P
max
[dB]
10log
RP
max
[dB]
Power Spectrum
Phase spectrum
Procedure
Press the
STATUS
key to open the Status screen, and then select the
[Status]
sheet.
1
Enable the highlighting function.
Move the cursor to
[Highlight (phase)]
.
Off
Emphasis display disabled.
(Default setting)
On
Emphasis display enabled.
1
2
3
Attenuation Rate and Value
Attenuation value: A [dB]
Attenuation rate: R
−A = 10log
10
R
1 × 10
−6
≤
R
≤
1
0
≤
A
≤
60
2
Set the attenuation rate or attenuation value.
To set an attenuation rate
Move the cursor to
[Attenuation rate]
.
Enter the attenuation rate.
Refer to “8.1.3 Alphanumeric Input” (p. 143).
To set an attenuation value
[dB]
Move the cursor to
[
(db)]
.
Enter the attenuation value.
Refer to “8.1.3 Alphanumeric Input” (p. 143).
13
FFT
Function
Summary of Contents for MR8827
Page 19: ...14 Operation Precautions ...
Page 81: ...76 Start and Stop Measurement ...
Page 111: ...106 Manage Files ...
Page 125: ...120 Miscellaneous Printing Functions ...
Page 143: ...138 View Block Waveforms ...
Page 191: ...186 Setting Output Waveform Parameters ...
Page 291: ...286 FFT Analysis Modes Measurable Ranges With Octave Analysis 1 1 OCT 1 3 OCT ...
Page 292: ...287 FFT Analysis Modes 1 1 OCT 1 3 OCT 13 FFT Function ...
Page 293: ...288 FFT Analysis Modes 1 1 OCT 1 3 OCT ...
Page 295: ...290 FFT Analysis Modes ...
Page 309: ...304 Editor Command Details ...
Page 387: ...382 Module Specifications ...
Page 405: ...400 Dispose of the Instrument Lithium Battery Removal ...
Page 431: ...A26 FFT Definitions ...
Page 436: ......