Using An Oscilloscope


What is an oscilloscope used for?         The oscilloscope is the most powerful instrument in our arsenal of electronic instruments.  It is widely used for measurement of time-varying signals.  Any time you have a signal that varies with time - slowly or quickly - you can use an oscilloscope to measure it - to look at it, and to find any unexpected features in it.

        The features you see in a signal when you use an oscilloscope to look at a signal are features you cannot see otherwise.  In this lesson you will learn about oscilloscopes and you should keep this goal in mind as you proceed through the lesson.

Given a time varying signal that you need information about,
Be able to use an oscilloscope to portray the signal as a function of time.
Be able to measure signal parameters with an oscilloscope.

What does an oscilloscope look like?

        Note the following features of the oscillscope


How do you use an oscilloscope?
Showing a Simple Signal on the Scope

        To get familiar with the scope, you can show a sine signal on the scope.  We're going to ask that you show a signal with the following characteristics


What will the signal look like?

        The oscilloscope has an illuminated dot that moves across the screen.  With no signal, it would look like the following.

When a sinusoidal signal is applied, then the vertical position is proportional to the voltage at any instant.  If you applied a low frequency sine signal, you would get a track like the one below.

        If you have a sinusoidal signal that repeats every half millisecond - a frequency of 2kHz - you would get a picture like this one.  It would appear to be stationary on the oscilloscope screen, but it really isn't.  It's just that it repeats so frequently that you see it as a constant image.


Measuring A Simple Signal

        Here's the connections for a simple signal measurement.  The oscilloscope is being used to display the voltage output from a signal generator.  You should do that also.

        Now you need to set the oscilloscope so that it can display the signal.  If you're lucky the oscillscope will have an autoscale button.  If not:         Triggering the oscilloscope can be frustrating if you don't understand the process.
Some Simple Oscilloscope Experiments

        Being able to use an oscilloscope is an important skill for anyone who takes electrical measurements.  In this section we'll present a few things you can do with oscillscopes to get better acquainted with them.

        The first thing to do is to become acquainted with the oscilloscope you have and to learn its capabilities and limitations.  Here are some things to do.
 

        Now, you have used several of the standard test signals to learn your way about when using a scope.  Still, it's nice to have a real signal.  Here are two alternatives. Let's talk about the connections you need to make to the headphone jack.

        There are a lot of other things that might be possible for you to do.
The End

        That's it for this lesson on using the oscilloscope.  Don't let that stop you from trying other measurements with your oscillscope.  Experiment, and learn the other things your oscilloscope can do.