User Manual

110
Figure 7-17 Sample Spectrum View Setting Screen 1
 Spectrum Bins: It allows you to set the number of frequency bins into which
the spectrum is divided.
 Window function: It allows you to select one of the standard window functions
to reduce the impact of running on a time-limited waveform.
Table 7-3 Window Function Table
Window
Main peak
width
(bins @ -
3dB)
Highest
side
lobe
(dB)
Side lobe
roll-off
(dB/octave)
Description
Rectangle
0.89
-13.2
6
No fading; maximal
sharpness; used for short
transients
Blackman
1.68
-58
18
Often used for audio work
Blackman-
Harris
1.90
-92
6
Used for general purpose
Flattop
2.94
-44
6
Negligible pass-band ripple;
mainly used for calibration
Gauss
1.33 to
1.79
-42 to -69
6
Gives minimal time and
frequency errors
Hann
1.20 to
1.86
-23 to -47
12 to 30
Used for audio and vibration
work