Choosing the Right Signal Conditioner for Your LVDT

Written by transtek_admin on 10/24/2023

Often, an LVDT installation will require a signal conditioner to convert, process or enhance the generated signals by the sensor. There are lots to choose from on the market, and they are offered with lots of features and options. As a result, we are often asked by customers how to determine which signal conditioner is best for their needs.

What Purpose does the Signal Conditioner Serve?

Before we get into selection, let’s take a minute to review why you would need a signal conditioner. The most popular reason is compatibility. LVDTs are AC devices. They operate off AC, and output AC. However, most other system components require a DC analog signal. If the manufacturer is doing their own electronics, and designs the system with considerations to compensate for this, a conditioner might not be required.

Conditioners are also used for other functional requirements such as signal amplification, filtering/noise reduction, or linearization in cases where the signal isn’t perfectly linear. They are also needed in certain circumstances for offset and span adjustment, or to provide electrical isolation in situations where electrical interference could cause a safety issue.

What Selection Considerations Need to be Made?

The answer relies on a few factors. The first is to understand what type of output is required. This usually depends on the application. While the it’s typically 0-5 volts or 0-10 volts, in reality, it could be anything. So you must first determine the output you need, and identify options that match your requirements.

Frequency/Phase Angle – You then need to look at the reference frequency your LVDT is set up for, and the phase angle it has. For example, most LVDTs that we manufacture are set for 7 kHz. While the signal conditioner doesn’t need to match this exactly, it should come close. Phase angle is a bit more forgiving. The exact number isn’t as critical, it’s more of a binary situation where you determine if it’s less than OR greater than say 10 degrees.

Isolations and Grounding – If your LVDT is operating in a noisy environment, filtering capabilities become an important option. Similarly, you might require isolation from electrical interference or ground loops, so you’ll need a unit that can handle those conditions.

Environmental Considerations – And let’s not forget about LVDTs used in extreme environments. If you are using a ruggedized LVDT in hash conditions such as high humidity, extreme temperatures, or corrosive atmospheres, you’ll need to be sure your conditioner can withstand these threats or that it can be located in a benign environment.

What Happens if You Choose the Wrong Signal Conditioner?

If you select the wrong one, your system will melt down, leading to the complete destruction of the entire space-time continuum, thus ending humanity as we know it. OK. That’s not the case at all. In fact, almost any signal conditioner would work, however determining the correct one will bring better accuracy, and alleviate performance issues. If you get it wrong, you’re not likely to cause the LVDT fail, but a mis-specked signal conditioner could change how the unit operates, and alter sensitivity or linearity. This is not ideal, especially when considering that LVDTs are widely celebrated for their incredible accuracy. You wouldn’t want to blow it by selecting the wrong signal conditioner.

In summary, you’ll need to make your signal conditioner selection based primarily on output, frequency and phase angle. For more demanding applications, consider additional requirements and features as we mentioned earlier. The better you match your needs to the selected unit, the more reliable and accurate your measurements and performance will be. And all of humanity will be grateful that you got it right.

Need Help Determining Which Signal Conditioner is best for your LVTD?

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Posted Under: LVTDs

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