OVERVIEW
• Spring loaded probe
• Air-extend option available
• 0.750" (19mm) O.D. size body
• Stroke lengths from ± 0.05 to ± 2 inches (±1.2mm to ±50mm)
• Non-Linearity better than ± 0.25% of FS
• Stainless steel housing sealed to IP68
• Applications: Laboratory R&D Materials Testing, Industrial Gauging Test Stands, Factory Automation
MADE IN THE USA
The HGSI GH-750-D/E/I series DC Spring Loaded DC Linear Variable Differential Transformer (LVDT) Position Sensors are used to monitor and track the linear motion or position of a target. These spring-loaded ruggedized sensors are ideal for use in industrial and laboratory applications including automotive R&D, motorsports, industrial, motion control, medical, military and aerospace.
The sensor shaft is spring loaded and guided by a pair of precision sleeve bearings. These hermetically sealed sensors are constructed entirely of stainless steel and are resistant to dust, water, temperature, shock, and vibration. For the air-extend option, the shaft is extended by introduction of a low pressure (10-30 psi), clean, dry air supply, with a regulated flow, through a 1/4 barbed fitting on the end of the unit. With the release of pressure, an internal spring returns the probe to its fully retracted position.
The amplifier electronics are contained within the housing, resulting in no need for an external signal conditioner. The output is pre-calibrated at the factory. GH-750-D
Options:
TECHNICAL SPECIFICATIONS
| GH-750-D | GH-750-E | GH-750-I | |
| Full Scale Output | ±10 VDC | 0 to 10 VDC | 4 to 20 mA. 2-wire loop |
| Input Power | ±15 VDC, ±25 mA | 24 VDC (from 15 to 26 VDC), 25 mA | 24 VDC (from 11 to 28 VDC) |
| Loop Resistance | NA | NA | 50Ω minimum |
Linearity Error: | ≤ ± 0.15% of FSO typical, ± 0.25% maximum |
Null Voltage: | 0.5% of FS |
Repeatability: | 0.01% of FS |
Hysteresis: | 0.01% of FS |
Bandwidth: | 3 Hz (mechanical) |
Operating Temperature: | -20 to +85°C (0 to +185°F) |
Thermal Coefficient: | < -0.02%/°C of FS (< -0.01%/°F of FS) |
Humidity: | 90% RH |
Housing: | Stainless steel |
Contact Tip: | AGD #9 hardened tool steel, chrome plated, #4-48 thread, interchangeable |
Mating Connector: | Amphenol PT06A-10-6S(SR) or equivalent |
Life Expectancy: | > 100 million cycles |
Shock Rating: | 1000g, 11 mS |
Vibration Rating:: | 20 g to 2 kHz |
IP Rating: | IEC IP68 |
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Integrated DC LVDT Gauging Probe with Built-In Electronics for Precision Linear Measurement
The GH-750-D/E/I Series DC Spring Loaded LVDT Linear Position Sensor from Harold G. Schaevitz Industries (HGSI) is a high-performance, rugged solution for precise linear displacement measurement in industrial, laboratory, and automation applications. Designed as a self-contained DC LVDT system, the GH-750 series integrates signal conditioning electronics directly within the sensor housing, eliminating the need for external signal conditioners and simplifying installation.
This spring-loaded LVDT sensor is ideal for applications requiring reliable, repeatable position feedback in harsh environments. Its robust stainless steel construction, hermetically sealed design, and precision mechanical components make it suitable for demanding conditions including exposure to dust, moisture, vibration, and temperature variation.
With stroke lengths ranging from 0.1 inches to 4.0 inches, the GH-750-D/E/I series provides flexible measurement solutions for both short-range precision sensing and larger displacement monitoring.
Integrated DC LVDT Technology
Unlike traditional AC LVDTs that require external signal conditioning, the GH-750-D/E/I series incorporates built-in electronics that provide a fully conditioned DC output signal. This integrated design significantly reduces system complexity and installation time while improving reliability by minimizing wiring and external components.
The GH-750 series is available in three output configurations:
GH-750-D: ±10 VDC output (bidirectional measurement)
GH-750-E: 0 to 10 VDC output (unidirectional measurement)
GH-750-I: 4 to 20 mA output (two-wire loop powered)
Each sensor is factory calibrated, ensuring consistent and accurate performance right out of the box. This eliminates the need for additional calibration steps during system integration.
Spring-Loaded Probe Design
The GH-750 series features a spring-loaded probe shaft designed to maintain continuous contact with the measured surface. The shaft is guided by a pair of precision sleeve bearings, ensuring smooth and repeatable motion throughout the measurement range.
This design provides several key advantages:
Consistent probe contact during measurement cycles
Simplified installation without complex mechanical linkages
Improved repeatability in dynamic or automated systems
The spring-loaded mechanism ensures reliable engagement with the target, making the sensor well suited for applications such as gauging, inspection, and material testing.
Optional Air-Extend Functionality
For applications requiring controlled probe engagement, the GH-750 series is also available with an optional air-extend configuration (GHRA models).
In this configuration:
Low-pressure clean, dry air (10–30 psi) extends the probe
An internal spring retracts the probe when air pressure is removed
This feature is particularly useful in automated systems where the probe must retract between measurement cycles to avoid interference with moving components or to reduce wear.
Measurement Performance and Accuracy
The GH-750-D/E/I series delivers excellent measurement performance suitable for precision applications:
Linearity: ≤ ±0.15% typical, ±0.25% maximum of full-scale output
Repeatability: 0.01% of full scale
Hysteresis: 0.01% of full scale
Resolution: 13-bit
These characteristics ensure consistent, high-quality measurement data across repeated cycles, making the sensor ideal for critical applications such as industrial gauging and automated inspection systems.
The sensor also provides a fast response with:
Bandwidth: 125 Hz (electrical output)
This allows for accurate tracking of dynamic motion in real-time measurement applications.
Non-Contact Sensing for Long Life
At the core of the GH-750 series is LVDT technology, which uses a non-contact electromagnetic measurement principle. Unlike potentiometric sensors, there is no physical contact between internal sensing elements.
This results in:
No wear-related degradation of signal quality
Extremely long operational life (>100 million cycles)
Stable output over time
Minimal maintenance requirements
This makes the GH-750 series particularly well suited for high-cycle and continuous-use applications.
Rugged Industrial Construction
The GH-750-D/E/I series is engineered for durability in demanding environments:
Stainless steel housing
Hermetically sealed internal components
IEC IP68 environmental rating
The sensor is designed to withstand:
Shock up to 1000g
Vibration up to 20g
High humidity (up to 90% RH)
Wide temperature ranges from –20°C to +85°C (0°F to +185°F)
This robust construction ensures reliable operation in industrial, automotive, aerospace, and laboratory environments.
Flexible Mounting and Mechanical Design
The GH-750 series is designed for easy mechanical integration:
1/2"-20 threaded mounting
Compact cylindrical housing
Axial (GH-750) and radial (GHR-750) connector options
Interchangeable AGD #9 contact tip
The interchangeable contact tip allows users to adapt the sensor to different measurement surfaces and geometries, increasing its versatility across applications.
Electrical Integration and Output Options
With integrated electronics, the GH-750 series simplifies electrical integration. Depending on the model, power requirements include:
±15 VDC for ±10 V output
24 VDC supply for 0–10 V output
2-wire loop-powered 4–20 mA configuration
The availability of multiple output formats allows seamless integration into:
PLC systems
Data acquisition systems
Industrial control systems
Test and measurement equipment
The 4–20 mA option is particularly useful for long-distance signal transmission and noise-resistant environments.
Typical Applications
The GH-750-D/E/I series is widely used in applications requiring accurate and reliable linear position measurement, including:
Industrial gauging systems
Laboratory R&D and materials testing
Factory automation and process control
Automotive and motorsports testing
Aerospace and military systems
Its combination of accuracy, durability, and ease of integration makes it a versatile solution across industries.
Summary
The GH-750-D/E/I Series DC Spring Loaded LVDT Position Sensor provides a complete, high-performance solution for linear position measurement. By integrating signal conditioning electronics within the sensor housing, it simplifies installation while delivering precise, repeatable measurements.
With its spring-loaded probe design, optional air-actuation capability, rugged stainless steel construction, and multiple output options, the GH-750 series is engineered to perform reliably in demanding industrial and laboratory environments.
For applications requiring accurate, long-life, and low-maintenance position sensing, the GH-750-D/E/I series delivers a proven and dependable solution.