Oscilloscopes are vital instruments for scientists and engineers, used to analyze the repeating patterns of electrical signals in electronic devices. Because they’re built with high-grade, precision components, oscilloscopes can be quite costly. Choosing a top-quality pre-owned oscilloscope can be a smart way to get excellent performance at a much lower cost.

Before purchasing a used oscilloscope, consider these key questions to help you find the right one for your needs:

• What type of oscilloscope best suits my work?
• Which specific features do I require?
• Is the unit fully functional?
• Has it been accurately calibrated?
• What kind of warranty is provided?

By answering these, you can focus your search and identify the ideal second-hand oscilloscope. With that in mind, let’s explore the key factors to keep in mind when making your purchase.

What Is an Oscilloscope?

An oscilloscope’s main job is to measure voltage changes over time. It generates a visual graph of the waveform, enabling engineers and technicians to clearly see how an electrical signal behaves.

These instruments are indispensable for troubleshooting and developing electronic circuits. They can measure parameters such as frequency, time intervals, amplitude, signal rise time, distortion, and the proportion of a signal that is AC (alternating current) or DC (direct current). Oscilloscopes come in many forms, ranging from portable handheld devices to advanced benchtop models packed with high-end features.

At its most basic, an oscilloscope is made up of a display screen, a horizontal sweep system, and a vertical input amplifier. The horizontal sweep system generates a repeating electrical signal that moves from left to right across the screen at consistent intervals. The vertical input amplifier takes in the signal being measured and determines how high or low it appears on the display.

Working together, these two systems produce a visual graph showing signal voltage over time. This allows users to study the signal’s behavior, pinpoint issues, and develop effective solutions.

Benefits of Buying a Used Oscilloscope

When it comes to investing in an oscilloscope, many people assume that a brand-new model is the only way to go. In reality, that’s not always the most practical choice—especially if you’re working with a tighter budget. Pre-owned oscilloscopes offer a range of advantages that make them worth considering.

• Cost savings – Used models can be dramatically more affordable, sometimes costing up to 90% less than a new unit—an enormous benefit for anyone with limited funds.
• Warranty or return protection – Many reputable sellers offer warranties or return policies, giving you peace of mind with your purchase.
• Proven performance – A tested, working oscilloscope gives you the confidence that you’re getting a dependable tool.
• Eco-friendly choice – Opting for used equipment helps reduce electronic waste. With roughly 50 million tons of e-waste generated worldwide each year, buying second-hand is a small but meaningful way to help lower that number.

In short, buying a used oscilloscope delivers excellent value, proven reliability, and environmental benefits—all without stretching your budget.

Choosing the Right Display Type

When selecting an oscilloscope, one of the first decisions you’ll face is the type of display you prefer. Researching display options can quickly become overwhelming, with plenty of technical details to sort through. To make it simpler, oscilloscopes can generally be grouped into two main categories: analog displays and digital displays.

Analog Oscilloscopes

Analog oscilloscopes allow engineers and technicians to see the waveform of an electrical signal by plotting its amplitude over time, giving a clear view of its characteristics.

These devices work by directing an electron beam across a phosphor-coated screen at a speed determined by the signal’s frequency. When the beam strikes the screen, the phosphor glows, producing a bright spot.

By continuously sweeping the beam across the display at a steady rate—while adjusting the vertical position according to the input signal’s voltage—analog oscilloscopes create a real-time visual representation of the electrical signal.

While analog oscilloscopes may no longer represent cutting-edge technology, they’re still valued for their affordability and simplicity. Thanks to their straightforward operation and fast setup, many experienced engineers still choose analog scopes for certain tasks.

Digital Oscilloscopes

A digital storage oscilloscope (DSO) is an electronic test instrument that captures a signal’s waveform and converts it into a digital format for display on a screen. The core idea is straightforward: an incoming voltage signal, which changes over time, is fed into the oscilloscope’s input.

Inside the DSO, an analog-to-digital converter (ADC) samples the signal at a rate much higher than the signal’s own frequency—often several megahertz. The oscilloscope uses a trigger event to capture a set of samples both before and after the trigger point, then plots voltage against time on the display.

The captured data is stored in memory, allowing the waveform to be recalled and analyzed later. DSOs can also perform mathematical functions—such as addition, subtraction, multiplication, and division—directly on the waveform data. This makes it easier to study the effects of these operations on the signal. Many digital scopes feature color displays for improved readability.

Overall, the advantages of a digital oscilloscope tend to outweigh its drawbacks.

Factors to Consider When Buying a Used Oscilloscope

We’ve covered the benefits of purchasing a used oscilloscope, how to choose the right display type, and the pros and cons of analog versus digital models.

Before making your final decision, there are still a few key specifications to review:

• Bandwidth – How wide a range of frequencies can the oscilloscope accurately measure?
• Sample rate – How many data points can it capture per second?
• Memory depth – How much waveform data can it store at once?
• Connectivity – What ports or interfaces are available for connecting to other devices or computers?
• Ease of use – Is the interface intuitive and quick to operate?

By considering these factors and doing a bit of homework in advance, you’ll be well-prepared to select the ideal used oscilloscope for your needs. Next, let’s take a closer look at each of these points.

Bandwidth

Bandwidth is one of the most critical specifications to check when choosing a used oscilloscope. It defines the frequency range the scope can accurately display—the higher the bandwidth, the higher the frequencies it can capture. When evaluating a second-hand unit, always verify the manufacturer’s original bandwidth rating.

Your required bandwidth will depend on your application. For instance, if you’re working with high-speed digital signals, you’ll need a high-bandwidth scope to capture all the rapid transients and fine details. On the other hand, if you’re using the oscilloscope for general troubleshooting or time-domain analysis, a lower bandwidth may be perfectly adequate. Always review the specifications for both high- and low-frequency performance before committing to a purchase.

Sample Rate

The sample rate indicates how many data points the oscilloscope records per second. A higher sample rate generally means better signal resolution. As a rule of thumb, your sample rate should be at least 2.5 times greater than the scope’s bandwidth. Keep in mind, though, that higher sample rates generate more data, which can slow down the scope’s processing.

Finding the right balance between resolution and speed is key. Some signals can be represented accurately at lower sample rates, while others—especially fast-transition digital signals—require a much higher rate to capture all the details. For example, a scope with a high sample rate is essential when testing circuits with sharp edge transitions, whereas slower, low-frequency signals can be analyzed effectively with a lower rate.

There are two primary sampling methods:

• Real-time sampling – The oscilloscope samples the signal at user-defined intervals. This approach works best for low-frequency or non-repetitive signals.
• Repetitive sampling – The oscilloscope takes samples at fixed intervals, ideal for high-frequency or periodic signals.

Some scopes let you set the sample rate manually, while others feature automatic sampling that adjusts to the detected signal. Both options have their pros and cons—so choose a scope that gives you the flexibility and control your work requires.

Memory Depth

Memory depth refers to the amount of waveform data an oscilloscope can store and display. The greater the memory depth, the more detail you can see, because it directly affects the signal’s resolution. Higher resolution means a clearer, more accurate view of the waveform.

An oscilloscope with limited memory may only capture a few seconds of data, which might not be enough to fully understand what’s happening in your signal. In contrast, a scope with deep memory can store hours—or even days—of data, allowing you to zoom in on any section for a close, high-resolution analysis.

Deep memory is especially valuable when troubleshooting intermittent problems that occur infrequently. A shallow memory might miss the event altogether, while a deeper memory lets you review exactly what happened before, during, and after the incident.

In short, deep memory depth allows you to capture more of the waveform, which is essential for analyzing complex or long-duration signals. Shallow memory can still be sufficient for simple, short measurements. Keep in mind that memory depth and sample rate are closely linked—higher sample rates generate more data, which requires more memory to store.

Connectivity

Oscilloscope connectivity describes how the instrument interfaces with the device under test. The most common connection method is through probes, which link directly to the oscilloscope’s inputs. Common probe types include:

• Alligator clips – For quick, secure connections to wires or terminals.
• BNC probes – Standard coaxial connectors for general-purpose measurements.
• SMA probes – High-frequency connectors for RF and microwave applications.
• Current probes – Designed to measure current without breaking the circuit.

You’ll also need to connect the oscilloscope to a computer or other display device. Keep in mind that connectivity options can vary depending on the oscilloscope’s age and model. Common connection types include USB, RS-232, Ethernet, LAN, and WiFi.

• USB – The Universal Serial Bus (USB) is one of the most common connections. It’s compatible with nearly all computers and can transfer large amounts of data quickly.
• RS-232 – This serial connection is easy to use and widely available. While slower than USB, it’s sufficient for most general-purpose applications.
• Ethernet – Using a standard Ethernet cable, this connection links the oscilloscope to a network, allowing for remote monitoring and control.
• LAN (Local Area Network) – Similar to Ethernet but typically faster, LAN connections are often used in industrial environments where large amounts of oscilloscope data need to be transmitted to a computer.
• WiFi – Wireless connectivity is increasingly common on newer oscilloscopes, offering the convenience of a cable-free setup. Older models may lack WiFi, so check this feature when selecting a used unit.

Ease of Use

Ease of use is a key factor when selecting an oscilloscope.

If the oscilloscope is difficult to operate, its functionality is limited, and you may struggle to get accurate results. Complicated menus or settings can increase the chance of mistakes, leading to inaccurate measurements. Conversely, a user-friendly oscilloscope allows you to work more efficiently, produces more reliable results, and makes the overall experience less frustrating.

Older models may not support the latest software, which can make them harder to use and potentially affect measurement accuracy. When evaluating a scope, look for one with an intuitive, well-designed interface that is easy to navigate, even for complex tasks.

How to Test Your Used Oscilloscope

After purchasing a used oscilloscope, it’s important to verify that it works correctly. Here’s a step-by-step guide to setting up and testing your device:

1. Gather your equipment – You’ll need the oscilloscope, a probe, BNC cables, a ground lead, and the power cord.
2. Prepare the oscilloscope – Make sure the power is off and all cables are disconnected from the input channels.
3. Connect the ground lead – Attach it to the oscilloscope’s ground terminal.
4. Attach the probe – Connect it to Channel 1, matching the probe color to the channel color. Secure it firmly to ensure a good connection.
5. Connect BNC cables – Use one BNC cable to connect the trigger out port and another to Channel 2, again matching colors. Plug both cables into a splitter box or Y-cable connector.
6. Power on your device under test (DUT) – Turn on the DUT before powering up the oscilloscope.
7. Turn on the oscilloscope – Use the switch on the back panel to power it up.

Once the oscilloscope is set up, you’ll want to test its accuracy and functionality:

• Ensure all input and output connections are secure.
• Observe the startup screen to verify that all information is clear and legible.
• Apply a known signal source to generate a test waveform.
• Watch the waveform on the screen for any distortions or irregularities, such as missing portions or incorrect scaling.
• Compare the observed waveform to the oscilloscope’s specifications to confirm it is operating within acceptable tolerances.

By following these steps, you can be confident that your used oscilloscope is fully functional and ready for accurate measurements.

Common Mistakes People Make When Buying an Oscilloscope

• Choosing the wrong specifications – Oscilloscopes come in many shapes, sizes, and performance levels. It’s essential to pick a model that matches your specific needs. For instance, do you require a mixed-signal oscilloscope, or do you need a portable unit for field work? Answering these questions before purchasing can save you a lot of frustration later.
• Using the wrong probes – Probes are designed for specific applications, so using the wrong type can lead to poor measurements. For example, passive probes are generally not suitable for high-speed digital signals. Make sure your probes match the signals and tests you plan to perform.
• Skipping testing – Testing your used oscilloscope immediately after purchase is crucial. Failing to do so can result in inaccurate measurements, which could affect your work on critical applications.

By avoiding these common mistakes, you can ensure that your used oscilloscope meets your needs and is in reliable working condition.

Final Tips on Buying Used Oscilloscopes

Purchasing a high-quality used oscilloscope doesn’t have to be complicated or stressful. By following the guidelines outlined in this article, you can feel confident that you’re getting a scope that fits your needs and works reliably.

Here are some final tips to keep in mind:

• Check the scope’s age – Since you’re buying a used device, find out how long it’s been in service and consider its expected lifespan.
• Ensure software compatibility – If you plan to use the oscilloscope with modern software, make sure the device supports it.
• Buy from reputable sellers – When purchasing online, check reviews and ratings to confirm the seller is trustworthy.
• Review the return policy – A good return policy provides peace of mind if the oscilloscope isn’t as described.
• Spare parts may be limited – Older models can be difficult to repair due to scarce replacement parts, so factor this into your decision.
• Stick with trusted brands – Purchasing from well-known manufacturers, such as JMBom, increases the likelihood of getting a reliable, long-lasting scope.

By keeping these tips in mind, you’ll be well-equipped to find a used oscilloscope that delivers both performance and value.

Buy a JMBom Premium Refurbished Oscilloscope for a Fraction of the Price

Purchasing a used oscilloscope is a smart way to save money—but it’s important to ensure you’re getting a high-quality device that meets your needs. By following the tips in this guide, you can feel confident that your oscilloscope will deliver reliable performance for years to come.

JMBom offers a wide selection of premium refurbished oscilloscopes, all backed by a 1-year warranty. With a trusted manufacturer like JMBom, you can be sure you’re investing in a reliable, high-performance product.

Don’t wait—visit our premium used equipment page today and find a refurbished oscilloscope that combines top-tier standards, advanced specifications, and exceptional value.

Frequently Ask Questions

What is an oscilloscope and what does it do?

An oscilloscope is a device used to measure and visualize electrical signals over time. Its display shows voltage on the vertical (y) axis, time on the horizontal (x) axis, and sometimes signal intensity as brightness (z-axis). The waveform display helps users analyze signal patterns.

Is an oscilloscope just a voltmeter?

An oscilloscope can be thought of as a visual voltmeter with a timing function. It not only measures voltage but also shows how the voltage changes over time. Essentially, it’s an electronic tool used to analyze waveforms and pulses on its screen.

Who uses an oscilloscope?

Oscilloscopes are commonly used by electronics technicians, engineers, and other professionals to troubleshoot circuits, validate designs, and analyze electrical systems. They are widely used in industries such as telecommunications, automotive, aerospace, and manufacturing.

Is a multimeter the same as an oscilloscope?

A multimeter provides a single numeric measurement of voltage, current, or resistance at a given moment. An oscilloscope, on the other hand, shows a dynamic, graphical representation of a signal over time, capturing changes and patterns that a multimeter cannot.

Do oscilloscopes measure current or voltage?

Oscilloscopes are primarily used to measure voltage over time. However, they can also be set up to measure current with the proper configuration. There are simple methods to measure current using an oscilloscope, which you can learn more about in related guides or videos.

Are oscilloscopes AC or DC?

Most oscilloscopes offer options for AC, DC, and ground (GND) coupling, and sometimes additional modes. When set to AC coupling, a capacitor is placed between the input amplifier and the probe, allowing only AC signals to pass while blocking DC signals.

Do I need a multimeter if I have an oscilloscope?

Some oscilloscopes, like the Fluke 120B ScopeMeter, include a built-in multimeter, providing both numerical readings and graphical waveforms. In many situations, such devices can replace a separate multimeter.

Do electricians use oscilloscopes?

Yes. Oscilloscopes are used by a variety of professionals and hobbyists, including:

• Electronics Engineers – For designing and testing circuits.
• Electrical Technicians – For diagnosing, troubleshooting, and maintaining electrical systems.

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