Episode 122: Using an oscilloscope

Students learn to use an oscilloscope to measure voltages.

Lesson Summary

• Demonstration and/or student experiment (30 minutes)
• Student questions: Understanding the CRO (20 minutes)

Demonstration and/or student experiment: Learning to use a CRO

Bear in mind that most students (and teachers?) find oscilloscopes daunting at first. If they are not already familiar with them then try to use the simplest ones available (single beam, non-storage). Whatever you use, be prepared to spend a lot of time helping them with settings and familiarising them with the adjustments.

It may help if you start by demonstrating the experiment first, and then allow your students time to repeat it for themselves. The most important ideas to get across are:

• Used normally, an oscilloscope plots a graph of voltage (y-axis) against time (x-axis).
• The scales on the x- and y- axes can be adjusted using the timebase (time per division) and voltage gain controls (voltage per division). (Check what these are called on the oscilloscopes you use.)

Episode 122-1: The cathode ray oscilloscope (Word, 32 KB)

There are two main aims here:

• Familiarity with the oscilloscope so that they can get a stable trace and adjust settings.
• Taking measurements of voltage and time from the screen.

Student questions: Understanding the CRO

Questions on use of the oscilloscope.

Episode 122-2: Questions on use of the oscilloscope (Word, 26 KB)