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What's the difference between a multimeter and an oscilloscope?

Multimeters and Oscilloscopes are essential for making, testing & measuring, but which one is right for your project? Common questions we get about these tools range from, “When do you use a multimeter or an oscilloscope or vice versa?” and “Do I need a multimeter if I already have an oscilloscope?” to “Is there a difference between multimeters and oscilloscopes?”

Although multimeters and oscilloscopes are often confused, their displays, measurement recordings and uses vary greatly. To fully understand the differences between them, you first need to understand what these electrical measurement tools are.

What is a multimeter?

A multimeter is an analog or digital instrument that measures and tests multiple electrical parameters such as voltage (volts or V), current (amps or A), resistance (Ω or ohms) of batteries, motors, resistors, wires and more. Also known as a multitester, a multimeter has four major parts:

  • Display
  • Selection dial
  • Jacks
  • Buttons

Depending on if a multimeter is analog or digital, the display will vary. Analog displays have a multi-level scale that displays readings for voltage, current and resistance. Digital display readouts usually have four digits, icons for battery life and high voltage readings, and the capability to display a negative symbol all on a large LCD screen.

The selection dial allows you to select which type of electrical parameter you’d like to measure. Measurement options are divided by each electrical parameter, DC or AC and range options for improved accuracy.

Jacks are where test leads are inserted. Multimeters use test leads to record measurements.

Buttons are only on digital multimeters. They control the power of the device, backlight and other functions depending on model type.

Analog Multimeters

Analog multimeter example
Pictured - Velleman AVM360: Analog Multimeter

Analog multimeters are cheaper than their digital counterparts and are recommended for measuring current. These multimeters can be difficult to read due to the needle and scale output. Viewing angle and movement of the device can also impact the output. Analog multimeters are generally more fragile than digital multimeters and require manual calibration.

Digital Multimeters

Digital multimeter example
Pictured - Velleman DVM850BL: Digital Multimeter with Hold Function

Digital Multimeters are usually preferred over analog multimeters due to their ease of use, accuracy and durability. Newer digital multimeters have ascended from only measuring voltage, current and resistance to being capable of reading temperature and displaying minor graphs of results.

What is an oscilloscope?

Oscilloscopes, as known as o-scopes or scopes, measure and display time-varying voltage signals. They produce visual representations such as graphs, wavelengths and grids based on time (x-axis) and voltage (y-axis). Along with having both digital and analog options, most modern scopes are either standalone or PC-based.

Standalone oscilloscope example
Pictured - Velleman HPS140I: Handheld Pocket Oscilloscope with Probe

Standalone scopes can either be digital or analog and can range from portable, handheld devices to large, bulky pieces of equipment. Digital handheld scopes are lightweight and are mostly used in the field. Most standalone oscilloscopes have three major parts:

  • Display
  • Ports
  • Buttons

Displays on both analog and digital standalone scopes are similar. Oscilloscopes display a graph where time is the horizontal axis and voltage is the vertical axis.

Scopes range from handheld to bench top, but most have the same two or three ports:

  • Probe
  • Power / USB connection (for digital scopes)

Mainly found on digital scopes, buttons are used to navigate an oscilloscopes functions and graphs.

PC-based oscilloscope example
Pictured - Velleman PCSU200: USB PC Oscilloscope and Signal Generator

PC-based oscilloscopes use software to relay and display data on your computer. These scopes have ports for probes and PC connections but no built-in display. They are mainly found in labs but are portable enough to use with a laptop.

Analog Oscilloscopes

Analog oscilloscopes usually have a higher bandwidth and use cathode ray tubes for their displays compared to digital scopes, but have smaller sample rates and memory. Much like analog multimeters, analog oscilloscopes are nostalgic but can still compete with their digital brothers in accuracy and performance. These oscilloscopes aren’t produced nearly as much as their digital counterparts anymore making them hard-to-find and sometimes a more expensive tool.

Digital Oscilloscopes

Digital oscilloscope example
Pictured - Velleman HPS140MK2: Handheld Pocket Oscilloscope

Oscilloscopes have come a long way since the creation of their analog forefathers. Today’s digital oscilloscopes can storage large amounts of waveform data to view at a later time or even directly upload to a computer. Digital Oscilloscopes are more user-friendly, require less setup and are incredibly good at measuring with high sample rates.

Differences between a multimeter and an oscilloscope

As you can see, multimeters and oscilloscopes are two completely different instruments that are easily confused. Simply put, a multimeter shows a snapshot of electrical parameter readings while oscilloscopes show a movie.

Key Differences

  1. Multimeters measure multiple electrical parameters such as voltage, current and resistance individually while oscilloscopes measure voltage over time.
  2. An oscilloscope displays a waveform of its voltage readings while a multimeter outputs a single measurement.

Multimeter vs oscilloscope - uses and applications

Multimeter applications Test and accurately check the voltage, current and resistance of common batteries, car batteries, light bulbs, electrical outlets, fuses, wires and cords
Oscilloscope applications Test for malfunctioning electronic equipment for unexpected voltage & possible faulty components, measuring time between events, looking at signal shapes and measuring the amplitude and frequency of a signal

Popular Velleman Multimeters

Popular Velleman Oscilloscopes

Summary

Although multimeters and oscilloscopes are similar pieces of equipment, their uses vary. Most basic projects and tests will require a multimeter but not an oscilloscope. Need to see if that AA battery in your desk still works? Use a multimeter. Need to look for anomalies such as spikes, noise or distortion? Use an oscilloscope. As your knowledge of electricity grows and the complexity of your projects increase, investing in an oscilloscope is great to further understand voltage. If you have any questions about either of these tools, leave us a comment below.

What multimeter and oscilloscope do you use? Join the conversation and tweet us at @VellemanStore.