User manual

Acquire the Sign
al
Description Window
Rectangular
The frequency resolution when using the Rectangular (a.k.a. boxcar or none) window is very
good, the spec
tral leakage is high, and amplitude accuracy is poor.
Use the Rectangular window for measuring transients or bursts where the signal levels
before and after the event are nearly equal. Also, use this window for equal-amplitude sine
waves with fr
equencies that are very close together, and for broadband random noise with a
relatively slow varying spectrum. This window is the best type for measuring the frequency
spectrum of non-repetitive signals, and measuring frequency components near DC.
Hamming
The frequency resolution when using the Hamming window is good (slightly better than
Hanning), t
he spectral leakage is moderate, and amplitude accuracy is fair.
Use the Hamming window for measuring sine, periodic, and narrow band random noise. This
window works well on transients or bursts where the signal levels before and after the event
are signifi
cantly different.
Hanning
The freque
ncy resolution w hen using the Hanning (a.k.a. Hann) window is good, the spectral
leakage is low and amplitude accuracy is fair.
Use the Hanning window for measuring sine, periodic, and narrow band random noise. This
window wo
rks well on transients or bursts where the signal levels before and after the event
are significantly different.
Blackman
-Harris
The frequency resolution when using the Blackman-Harris window is poor, the spectral
leakage is very low and amplitude accuracy is good.
Use the B
lackman-Harris window for measuring predominantly single frequency waveforms to
look for higher order harmonics, or several moderately or widely spaced sinusoidal signals.
Flat-T
op
The frequency resolution when using a Flat-Top window is poor, the spectral leakage is
low and amplitude accuracy is very good.
Use the
Flat-Top window for making a ccurate amplitude measurements of moderately or
widely spaced sinusoidal signals.
86 MDO3000 Series Oscilloscopes User Manual