Non-Contact DVRT®
Non-Contact DVRT®
Differential Variable Reluctance Transducer
Ideal for difficult sensing applications, the Non-Contact DVRT® is designed to measure the displacement and proximity of a metal target without physical contact. The measurement is unaffected by interposed nonmetallic, non-conductive materials, such as polymers and biomaterials. The stainless shell of the device houses two coils; one for sensing and the other for temperature compensation. The coils and Teflon® cable are mounted on a stable PEEK substrate. This assembly is potted into the stainless housing using high-grade, vacuum-pumped epoxy and includes integral strain relief. This packaging allows the sensor to be used in applications requiring long-term immersion in water and saline solutions.
MicroStrain’s desktop consoles and in-line signal conditioners provide the Non-Contact DVRT® with plug and play housing, power, analog output, LCD display, RS-232 output and software. Custom ranges are available on request.
Sensor Design
Two coils within the Non-Contact DVRT® housing form its sensing and compensation elements. When the face of the transducer is brought into close proximity to a ferrous or highly conductive ‘target’ material, the reluctance of the sense coil is changed, while the compensation coil acts as a reference.
The coils are driven by a high-frequency sine wave excitation and their differential reluctance is measured using a synchronous demodulator. Differencing the two coils’ outputs provides a sensitive measure of the position signal, while cancelling out variations caused by temperature.
Ferrous targets change the sense coils’ reluctance by altering the magnetic circuit’s permeability; conductive targets (such as aluminum operate by the interaction of eddy currents induced in the target’s skin with the field around the sense coil.
- miniature control elements for automotive and robotic systems
- process control for production-line monitoring
- dimensional gauging for quality control applications
- measuring strain and deflection in materials science and civil structures
- linear/angular positioning of optical components
- miniature force, torque, acceleration sensors
- measuring strain, micromotion and deformation in bone and tissue
- available with sub-micron resolution and long stroke range
- operating temperature to 175 °C
- frequency response up to 20 kHz with DEMOD-DC
- frequency response up to 8 kHz with DEMOD-DVRT
- lightweight core will not influence frequency response
- stainless steel and high-performance polymer design suitable for extremely harsh environments
- waterproof, suitable for short term submersion in corrosive media such as brake fluid and hot saline
- frictionless design suitable for high duty-cycle applications
- easily customized to suit specific applications
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Electrical Specifications (Obtained using DEMOD-DVRT® and DVRT® with 800 Hz low pass filter at constant temperature)
Mechanical Specifications
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General Documentation
FAQ's
Mechanical Prints
Support Electronics
- System chart - system illustration showing items needed for system specification.
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NC-DVRT-1.5-SK1 |
Online Price: $640.00 Part Number: 6127-0331 |
Displacement Sensor Comparison