![Large Test Oscilloscope](http://www.edisontc.org/ui/files/2016/02/LargeTestOscilloscopes400.jpg)
A voltmeter will tell you a static measurement of a circuit at one point in time. These instruments can display the change of voltage over time on a screen. The device can also record the data over time, modern oscilloscopes can drop the data into a PC for further analysis.
Further reading:
How to use an oscilloscope
Oscilloscopes for radio amateurs ARRL
![Old oscilloscopes](http://www.edisontc.org/ui/files/2016/02/Oscilloscopes40s-500-1.jpg)
See our videos below to understand first how the screen works in an oscilloscope, and secondly where time measurement is found in the amplifier circuits.