Your Complete Guide to Buying a Used Oscilloscope That Works Like New

Oscilloscopes are essential tools scientists and engineers use to study the periodic behavior of electrical signals on electronic equipment. Since oscilloscopes contain costly high-quality components they can be relatively expensive to buy. Buying a premium used oscilloscope is an excellent option if you want to pick up a quality oscilloscope at a fraction of the price.

When purchasing a used oscilloscope, ask yourself these questions to ensure you get the best scope for your needs.

• What type of oscilloscope do I need?
• What functions do I need the oscilloscope to have?
• Is the device in good working condition?
• Is it properly calibrated?
• What warranty is available?

Answering these questions will narrow down your search for the perfect used oscilloscope. With that in mind, let’s disccuss some important factors to consider when buying a used oscilloscope.

When deciding what oscilloscope to buy, one of the first things to consider is what type of display you want. When researching oscilloscope display types, you will likely find an overwhelming amount of information that is difficult to understand. So let's break down the oscilloscope types into two categories: analog display and digital display.

Bandwidth is one of the most important factors when choosing a used oscilloscope. Bandwidth determines the frequency range that an oscilloscope can accurately reproduce. The higher the bandwidth, the higher the frequencies it can display. When buying a used oscilloscope, be sure to check what the specified bandwidth was at the time of manufacture.

It is important to consider the bandwidth requirements of your application. For example, working with high-speed digital signals, you will need an oscilloscope with high bandwidth to accurately capture all of the transient details.

A lower bandwidth may be sufficient if you use your oscilloscope for basic troubleshooting or time-domain analysis. Be sure to check the specs for both high and low-frequency performance before making your purchase.

The sample rate of an oscilloscope is the number of samples taken per second. The higher the sample rate, the higher the signal resolution. Sample rate should be at least 2.5 more than the bandwidth. However, increasing the sample rate also increases the amount of data the oscilloscope has to process, slowing down its performance.

It is important to find a balance between resolution and speed when setting the sample rate. Some signal details can be captured accurately with a lower sample rate, while others may require a higher rate to be represented correctly. Ultimately, it is up to you to decide what trade-offs you are willing to make to get the desired picture detail.

For example, if you are testing a digital circuit with a fast edge rate, you will need to use a scope with a high sample rate to capture all of the details accurately. On the other hand, if you are looking at a slow-moving signal, you can get by with a lower sample rate.

There are two main types of sampling: real-time sampling and repetitive sampling.

1. Real-time sampling. The oscilloscope samples the signal at regular intervals. The interval is set by the user and can be changed as needed. This type of sampling is best suited for signals that are not periodic or have a low frequency.
2. Repetitive sampling. The oscilloscope samples the signal at a fixed interval. This type of sampling is best suited for signals that are periodic or that have a very high frequency.

Some oscilloscopes allow the user to set the sample rate manually, while others have an auto-sampling feature that automatically sets the sample rate based on the measured signal. Both methods have advantages and disadvantages, so be sure to choose an oscilloscope that offers the features you need.

Memory depth is the amount of data an oscilloscope can store and display. The deeper the memory, the more information the scope will show you. This is important because it affects the resolution of the signal you’re viewing. The better the resolution, the more detail you will see in the signal.

A scope with shallow memory might only be able to store a few seconds’ worths of data, which might not be enough to really see what’s going on. But a scope with deep memory can keep hours’ or even days’ worth of data, letting you zoom in for a high-resolution view of whatever portion you’re interested in viewing.

Having a deeper memory can be helpful when you’re trying to track down an intermittent problem that only happens once in a while. Shallow memory might not capture the event at all, but deep memory will let you scroll back and look closely at what happened before and after the event.

A deep memory depth means that more of the waveform will be captured, while a shallow memory depth will only capture a small portion of the waveform. Deeper memory depths are useful for capturing complex waveforms, while shallower depths are sufficient for simple measurements.

Memory depth and sampling rate work hand in hand because the more samples you take per second, the more data you will have to store. As a result, scopes with higher sample rates will also have deeper memories.

Ease of use is important when purchasing an oscilloscope for several reasons.

1. If you have difficulty understanding how to operate the oscilloscope, it will limit its usefulness.
2. If you cannot quickly and easily navigate the oscilloscope’s menus and settings, you are likely to make errors that could lead to inaccurate measurements.
3. An oscilloscope that is difficult to use is likely to be frustrating to work with, leading to operator error and decreased productivity. By contrast, an oscilloscope that is easy to use will produce more accurate results and be more enjoyable to work with.
4. Older models may not be able to use current, up-to-date software, making them challenging to use. They may not be able to stay up-to-date with current software, which could affect their accuracy.

When considering ease of use, remember that a well-designed oscilloscope should be intuitive and straightforward.

• Not choosing the scope with the right specs for the job. Oscilloscopes come in a wide range of shapes, sizes, and specifications. It's essential that you select the scope with the proper specifications for your needs. For example, do you need a mixed signal oscilloscope? Do you need a portable scope to use in the field? Answering these questions before purchasing can save you many headaches in the future.
• Using wrong probes. Oscilloscope probes come in various types, each designed for specific applications. It's crucial to ensure you're using the proper probe for your needs. For example, passive probes are not recommended for high-speed digital applications.
• Not testing the device. As discussed above, testing your used oscilloscope is essential as soon as you buy it and before using it on critical applications. Not doing so could result in inaccurate measurements and data.

By avoiding these mistakes, you can be confident that you're getting a used oscilloscope that meets your needs and is in good working order.

Buying a good-quality used oscilloscope doesn't have to be complicated or stressful. By following the tips mentioned in this article, you can be confident that you're getting a scope that meets your needs and is in good working condition.

Some final tips to keep in mind:

• Consider the life expectancy of an oscilloscope. Since you are buying a used device, make sure to find out how old the scope is.
• If you plan on using your scope with modern software, ensure it is compatible with the new software.
• When buying online, always check the seller's reviews to ensure they are reputable.
• Ensure the seller has a good return policy in case the scope is not as described.
• Don’t expect spare parts to be readily available. Depending on the model's age, it may be challenging to find replacement parts.
• To be sure you're getting a quality scope, only buy from trusted manufacturers such as Keysight.

Buying a used oscilloscope can be a great way to save money. However, ensuring you're getting a quality scope that meets your needs is important. By keeping in mind the tips mentioned in this article, you can be confident you're getting an oscilloscope that will serve you well for years to come.

Keysight offers a wide range of high-quality, premium refurbished oscilloscopes backed by a 1-year warranty. You can rest easy knowing you're getting a quality product backed by a trusted manufacturer.

So don't wait; see our premium used equipment page and pick up a premium refurbished oscilloscope with some of the highest standards and specifications in the industry.

As we have looked at in this article, there are many benefits to buying a used oscilloscope. Purchasing a used oscilloscope is a great way to save money but not forgo quality.

When you purchase premium refurbished equipment from Keysight, you can have confidence knowing you are buying a brand you can trust. They come with a reliable warranty and are thoroughly tested, calibrated, and proven to work.

Keysight is a leading manufacturer of quality oscilloscopes, offering a wide range of models to meet your specific needs. We also have a large variety of premium used oscilloscopes at a fraction of the cost.

With a fast two-week delivery time* within the US and upgradable warranty, buying used is a wise investment if you're looking for quality and affordability. See Keysights Used Equipment for the widest selection of discounted, high-quality oscilloscopes.

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