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
Содержание MR8827
Страница 19: ...14 Operation Precautions ...
Страница 81: ...76 Start and Stop Measurement ...
Страница 111: ...106 Manage Files ...
Страница 125: ...120 Miscellaneous Printing Functions ...
Страница 143: ...138 View Block Waveforms ...
Страница 191: ...186 Setting Output Waveform Parameters ...
Страница 291: ...286 FFT Analysis Modes Measurable Ranges With Octave Analysis 1 1 OCT 1 3 OCT ...
Страница 292: ...287 FFT Analysis Modes 1 1 OCT 1 3 OCT 13 FFT Function ...
Страница 293: ...288 FFT Analysis Modes 1 1 OCT 1 3 OCT ...
Страница 295: ...290 FFT Analysis Modes ...
Страница 309: ...304 Editor Command Details ...
Страница 387: ...382 Module Specifications ...
Страница 405: ...400 Dispose of the Instrument Lithium Battery Removal ...
Страница 431: ...A26 FFT Definitions ...
Страница 436: ......