Agilent Technologies 54622A User Manual page 118

MegaZoom Concepts and Oscilloscope Operation
Acquisition Modes
Average Mode
Averaging lets you average multiple triggers together to reduce noise and
increase resolution. Averaging of multiple triggers requires a stable trigger. The
number of triggers being averaged is displayed in the # Avgs softkey.
• Turn the Entry knob to set the number of averages (# Avgs) that best
eliminates the noise from the displayed waveform.
The number of averages can be set from 1 to 16384 in powers-of-2
increments. The higher the number of averages you set, the more noise
reduction and resolution will be accomplished.
# Avgs
1
4
16
64
256
Smoothing
The term smoothing is an oversampling technique used when the digitizer
sampling rate (200 MSa/s) is faster than the rate at which samples are being
stored into acquisition memory. For example, if the oscilloscope is sampling at
200 MSa/s, yet storing the samples at 1 MSa/s, it needs to store only 1 out of
every 200 samples. When smoothing is used, the slower the sweep speed, the
greater the number of samples that are averaged together for each display point.
This tends to reduce random noise on the input signal, which produces a
smoother trace on the screen.
4- 18
Bits of resolution
8
9
10
11
12