Linear Variable Displacement Transformer (LVDT) sensors are used in many different types of applications, from precision dimension gauging to monitoring of fault-line movement. Measuring displacement requires accurate readings with movements as small as a few millionths of an inch. Our sensors feature a unique design, removing physical contact across the sensing element, which leads to longer-lasting, friction-free operations. With quick response to changes, these LVDT transducers can respond and adjust accordingly when changes occur in the core position. These sensors are available with stroke ranges from ±0.01” to ±18.5” with free unguided, captive guided, spring return, air push return and precision gauging probe armatures and standard, miniature, submersible or subsea housings.
Precision gauging LVDT sensors are designed for precision displacement and position measurement for quality assurance in industrial environments. These sensors are constructed of stainless steel and utilize free unguided, captive guided or captive guided spring return armatures to meet the needs of the application.
Miniature LVDT sensors deliver a very high linear stroke range to body length ratio and can be used in environments where traditional LVDTs are too large. Extremely robust and capable of operating at temperatures up to 175°C in corrosive media such as saline, oil and brake fluid.
Long stroke LVDT sensors are designed for high performance and feature a captive guided armature inside the housing. Stroke ranges from ±0.01” to ±18.5”
The short stroke LVDT is most suited for applications where dynamic measurements are to be made. The body and probe are constructed from stainless steel, and the compact size makes it ideal for applications requiring limited space. Stroke ranges from ±0.01” to ±0.4”
Submersible LVDT transducers can operate under varying fluid environments and circumstances. These sensors have the ability to operate in many diverse conditions and are designed for displacement measurement applications while submerged in fresh water or most noncorrosive liquids and gases for prolonged periods.
Subsea LVDT transducers are specifically designed for use in seawater, as well as other very demanding environments, including in some corrosive liquids. Heavy duty construction makes these units suitable for the most rigorous applications, including 10 years submersible in seawater at a depth of 7500 ft.
LVDT mounting blocks offer a means of supporting our linear displacement transducers in your application. We suggest that at least 2 are used per transducer and for longer stroke units 3 or 4 mounting blocks.
Miniature LVDT sensors deliver a very high linear stroke range to body length ratio and can be used in environments where traditional LVDTs are too large. Our miniature displacement transducers are capable of operating at temperatures up to 175°C in corrosive media such as saline, oil and brake fluid. The near frictionless design enables sensors to operate over millions of cycles without wear or degradation in signal quality.
DIN-rail signal conditioners provide valuable complementary solutions for applications requiring high-level analog outputs in salutations where the LVDT may be exposed to conditions detrimental to internal signal conditioning or the required LVDT configuration will not accommodate internal amplifiers.
Custom LVDT Sensors
Not every sensor can be created equal. That’s why our team of sales and product engineers are available to work with you to find or develop a design to meet your application requirements. Provide us a few details and one of our representatives will be in touch.
Selecting the Right LVDT Sensors and Transducers
Finding the right LVDT sensors and transducers for your application requires understanding the specific needs and the requirements for the environment in which the sensor will be used. While standard options will normally work well, some applications require custom sensor solutions. These 5 considerations are designed to be at top-of-mind as you search for the right LVDT sensor for your application.
The first step to finding the right LVDT sensor is to determine what exactly you need it to do. What do you need it to measure? What performance capabilities must it have?
Before looking for an LVDT transducer, you should first:
- Determine the measuring range/scope that needs to be measured (the displacement from the null point)
- Determine the relationship between the LVDT and the part being measured
- Probe locates on part, but not attached
- Probe is attached, but cannot be removed from LVDT body
- Probe is attached and can be separated from LVDT body
- Select armature type needed
- Spring return (for applications measuring multiple targets)
- Captive guided (for applications requiring longer measurement ranges - ±0.5” to ±18.5”)
- Free unguided (for applications in which part moves parallel to LVDT body and requires frequent measurements)
- Identify engineering units required (inches, centimeters, millimeters, customer-specified)
- Accuracy of the sensor
- Thermal effect (how temperature affects the output)
- Total accuracy (static + thermal)
- Electrical output signal from the sensor
- AC/AC (mV/V or V/V sensitivity)
- Electrical termination
- Connector or integral cable
- Need for mating connectors and cable assemblies
- Connector/cable orientation (axial or radial)
- Wiring codes and pin-outs
- Type of power supply per output
- Signal conditioning
- DIN-rail mount
- Set-up (outputs with armature position)
The environment in which your LVDT transducer will be housed is a vital consideration. This can affect the way your LVDT sensor functions and its ability to adapt to the situation. Selecting an LVDT transducer that corresponds to the proper environment is essential.
Here are some environmental factors that should always been considered:
- Operating temperature range
- Compensated temperature range
- EMI/RFI conditions
- IP or NEMA rating requirements
- Hazardous environments; utilize a sensor that is:
- Intrinsically safe
- Indoor or outdoor use
- Exposure to the elements
- Dust, dirt, water, oils
- Temperature extremes
- Animals, critters, rodents, etc.
- Fresh water/salt water
- Case pressure
Certain applications may have specific requirements and needs. It’s important to recognize these needs so you can choose an LVDT transducer that can accommodate your application.
Special requirements may include:
- Calibrations requirements
- Special approvals/certifications
- Special labeling requirements
- Service frequency