PeakTech Peak Tech 1265 Bedienungsanleitung Seite 111

Hamming
Hanning
Blackman
Fig. 20, 21, 22 and 23 show four kinds of window function referring to sine wave of 1 KHz under the selection
of four different windows for FFT:
This is a very good window for resolving frequencies that
are very close to the same value with somewhat
improved amplitude accuracy over the rectangle window.
It has a slightly better frequency resolution than the
Hanning.
Use Hamming for measuring sine, periodic and narrow
band random noise. This window works on transients or
bursts where the signal levels before and after the event
are significantly different.
This is a very good window for measuring amplitude
accuracy but less so for resolving frequencies.
Use Hanning for measuring sine, periodic and narrow
band random noise. This window works on transients or
bursts where the signal levels before and after the event
are significantly different.
This is the best window for measuring the amplitude of
frequencies but worst at resolving frequencies.
Use Blackman-Harris for measuring predominantly
single frequency waveforms to look for higher order
harmonics.
Fig. 20 Rectangle window
-110-