Electronics: Principles and
Applications
Eighth Edition
(Instrumentation Labs)
Charles A. Schuler
Lab 2
Introduction to the
Oscilloscope
McGraw-Hill
©2013 by The McGraw-Hill Companies, Inc. All rights reserved
Oscilloscope Basics
Triggering
Time/Division
Volts/Division
Vertical Position
Channel 1Power
inputOn/Off
Oscilloscope Settings
5 Div
4 Div
A typical display with correct settings:
Multiply 4 Div x Volts/Div to obtain
the peak-to-peak amplitude.
Multiply 5 Div x Time/Div to obtain
the period.
Oscilloscope Settings
BlankVolts/Division
display can beerror
caused
by:resolution)
no valid trigger,
(poor
Volts/Division
Vertical
Position
error
(overrange)
error
Time/Div
Trigger
error
(too
level
many
set
at
cycles
0 volts
displayed)
Time/Div
error
Trigger
(only
level
a
part
set
of
negative
positive
one
cycle
displayed)
position error, intensity (or brightness)
turned
off,
and other errors depending on oscilloscope model.
Oscilloscope Settings
When is ac coupling used?
ac
Here is ac ripple riding on a dc signal.
To see it better, choose ac coupling
and then decrease the Volts/Div setting
(this increases vertical sensitivity).
Oscilloscope Settings
If a waveform moves on the screen:
Check the trigger source, trigger
level, trigger mode, trigger slope,
and the trigger coupling.
An example of a common error:
the trigger source is set for Channel 2
but the input signal is fed to Channel 1.
Oscilloscope Quiz
The Volts/Div control is set at 100 mV/Div.
What is the peak-to-peak amplitude of this
signal?
800 mVP-P
Using the above, what is the RMS value
of this signal?
283 mV
The Time/Div control is set at 50 ms/Div. What is the period
of this signal?
250 ms
Using the above, what is the frequency of this signal?
4 Hz
Oscilloscope Quiz
0V
The Volts/Div control is set at 1V/Div. What
is the dc amplitude of this signal?
-3V
Using the above, what will be displayed if the
Volts/Div control is changed to 500 mV/Div?
Blank screen
Using the above, what will be displayed if the coupling is
changed to ac?
The waveform will move to the vertical center
What does ac coupling do to the dc component of a signal?
Removes it
Oscilloscope Quiz
What can cause the displayed waveform
to move on the screen?
No valid trigger