How to Measure Voltage with an Oscilloscope
Oscilloscopes help you visualize your electrical signal. At their core, oscilloscopes display a plot of voltage vs. time for one or more signals. This voltage vs. time graph is often called a “waveform.” This waveform is displayed by connecting a particular signal on the device under test (DUT) to the oscilloscope using a probe. The probe tip is connected to the signal and the grounding clip is connected to a reliable grounding point. Measuring the voltage with your oscilloscope provides basic information about the signal, however oscilloscopes often offer many more advanced tools to further analyze your signal. Understanding how to measure voltage with an oscilloscope is the first step to uncovering the powerful measurement capability your oscilloscope offers.
Getting Started: Oscilloscope Voltage Measurement
Step 1: Turn on your oscilloscope and push the “Default Setup” front panel key.
Step 2: Plug in a probe to Channel 1. Don’t worry too much about the type of probe at this point, but if you have one with a clip or other mechanism that prevents you from having to hold it to a wire, it’ll make your life easier. Below is a basic passive probe that’s great for getting started!
Step 3: Find a reliable grounding point and connect the ground clip to it.
Step 7: The most basic way to calculate voltage is to count the number of divisions from top to bottom of the signal and multiply this by the vertical scale (volts/division). Note that the divisions are also labeled in volts on the Y-axis so you can easily calculate the voltage of your signal using these labels.