Linear Variable Differential Transformers and Transducers (LVDTs)
Hoffmann-Krippner LVDT sensors amplify your ability to measure and monitor precise movements in equipment and industrial automation systems.
By converting an object’s linear movement into an electrical signal, LVDTs – or Linear Variable Differential Transformers, also known as Linear Variable Displacement Transducers – can measure movements as large as several inches in scale, down to millionths of an inch.

Depending on the application, LVDTs can be a critical component in maintaining high-performance functionality, enabling infinitesimally fine-tuned accuracy, and ensuring that industrial automation systems run seamlessly in a variety of settings and circumstances.

• Temperature ranges up to 125°C
• Protection class up to IP68
• Linearity tolerances from 0.25%
• External thread

Why use a Hoffmann-Krippner LVDT Sensor?
Extreme precision powers peak performance.

• Friction-Free Operation – With no mechanical contact between the LVDT’s core and coil assembly normally, no rubbing, dragging, or other source of friction will distort readings or affect performance. In turn, friction-free operation ensures accuracy in materials testing, vibration displacement measurements, high resolution dimensional gaging systems, and more.

• Infinite Resolution – The LVDT can measure any changes in core position. This infinite resolution capability is limited only by the noise in an LVDT signal conditioner and the output display’s resolution, giving an LVDT outstanding repeatability and allowing for very precise control schemes that can help increase operating efficiency, save energy or fuel, and more.

• Single Axis Sensitivity – In other words, an LVDT can usually function without adverse effect in applications involving misaligned or floating moving members, and in cases where the core does not travel in a precisely straight line. An LVDT responds to motion of the core along the coil’s axis but is generally insensitive to cross-axis motion of the core or to its radial position.

Dynamic response fuels fast, repeatable functionality.

• Fast Dynamic Response – The absence of friction during ordinary operation permits an LVDT to respond very fast to changes in core position, limited only by the inertial effects of the core’s slight mass.

• Null Point Repeatability – The location of an LVDT’s null point is extremely stable and repeatable, even over its very wide operating temperature range. This makes an LVDT perform well as a null position sensor in closed-loop control systems and high-performance servo balance instruments.

Unlimited mechanical life gives LVDTs the ultimate staying power, even in high-stress applications.

• Unlimited Mechanical Life – As no parts can rub together or wear out, LVDTs enjoy unlimited mechanical life (e.g., a Mean Time Between Failure exceeding a million hours), crucial for applications requiring high-reliability like aircraft, satellites and space vehicles, and nuclear installation; as well as many industrial process control and factory automation systems.

• Absolute Output – An LVDT can retain information even in the event of a power outage. As an absolute output device, the position data being sent from the LVDT will not be lost in the event of power loss. When the measuring system is restarted, the LVDT’s output value will be the same as it was before the power failure occurred.

Expert engineering and consultation electrifies performance potential.

• User experience – Our LVDTs are engineered with users in mind. The modern design is easy to calibrate, can connect to a wide variety of computer systems, customers can determine how data is displayed, and more.

• Extensive consultation – In addition to outstanding quality, reliability, accuracy, and life expectancy, Hoffmann-Krippner LVDTs come with extensive consultation. Our engineers offer a vast well of knowledge within the automation world. If clients have an LVDT application but can’t find a solution, we can help by designing and developing a custom LVDT sensor.

If you’d like to speak with one of our consultants to solicit input about your project or to inquire about our LVDTs, please send us a message here.

You can also skip right to our catalog of LVDT products here, or keep scrolling down to learn how and where our LVDT sensors can improve your applications.

Where to use our LVDT sensors: Areas of Application
Modern LVDTs are making inroads into new use-case scenarios, especially in rugged environments where other sensing equipment might fail. Hoffmann-Krippner LVDTs are perfect for harsh industrial environments subject to:

• High temperature and pressure ranges
• High acceleration and measuring cycles
• High vibration

The extreme precision of Hoffmann-Krippner LVDTs makes them perfect anywhere movement must be measured down to very small strokes, with measurements under one millimeter, including:

• Automation technology
• Testing facilities and applications
• Mechanical engineering
• Medical technology production lines.

Ready to start shopping? Skip right to our catalog of LVDT products here, or keep reading to learn how our LVDT sensors work.

How Does It Work?
The internal structure of an LVDT looks much like a transformer, consisting of a primary winding centered between a pair of two identically wound secondary windings. The two secondary windings are typically connected in “series opposing” (differential).

The LVDT’s primary winding, P, is energized by a constant-amplitude AC power source. The core couples the resulting magnetic flux to the adjacent secondary windings, S1 and S2. If the core is positioned midway between S1 and S2, equal flux is coupled to each secondary, so the voltages induced in each winding is equal. This is the null point, since the differential voltage output – i.e., the difference in voltage between S1 and S2 – is zero.

However, if the core moves closer to S1 than S2, more flux is coupled to S1 and less to S2, resulting in differential voltage. Through these very fine electrical changes, the displacement of the core – and hence of the object – can be measured with extreme precision.