The oscilloscope transforms the collected analog data into a digital form after they are
gathered in the following three different modes, such as sampling, peak value detection and
averaging values.
The oscilloscope takes samples from the signal at a equal time interval to reconstruct the
waveform in this mode, by which the analog signal can be expressed correctly in most
cases, yet, the rapid changes cannot be collected between two sampling time intervals,
causing the confusion and loss the narrow pulse in the signal probably.
The oscilloscope takes samples from the maximum and minimum of signals in each
sampling interval and shows the waveform with the sampled data in this mode, thus, by
which the oscilloscope may collect the possibly lost narrow pulse in the sampling mode but
the noise is obvious.
The oscilloscope collects several waveforms and average over them, and displays the
averaged waveform in this mode, by which the random noise can be reduced.
When a new waveform is displayed, the previous waveform shown on the screen does not
disappear immediately only to be displayed for a period of time, that is, the duration time, by
setting which, the waveform can be displayed more continuously and thus a display similar
to that shown
by the analog oscilloscope can be achieved.
The oscilloscope updates the waveform sampling points by scrolling display through a
screen from left to right in this mode, which is only applicable to the primary time base setting
of above 50ms.
5.15. Selecting AC-coupling
After a reset, the Oscilloscope is dc-coupled so that ac and dc voltages appear on the screen, Use ac-coupling when you
wish to observe a small ac signal that rides on a dc signal.
To select ac-coupling, do the following:
1.) Press MENU key and the function menu appears at the right side of the screen.
2.) Press MENU ▲ or MENU ▼ key to select the CH SETUP. Four items selectable are visible at the bottom of the
screen.
3.) Press the F1 key and jump to AC. The bottom left side of the screen displays the ac-coupling icon.
Now, you can see a screen that looks like the following figure 14.
Figure 14: AC-Coupling
-80-
To Next Page
Loading...
