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Subminiature Gauging DVRT® Diff erential Variable Reluctance Transducer

displacement transducer - 27212 How it works Electrical Specifi cations

Core position is detected by measuring the coils’ diff erential reluctance, using a sinewave excitation and synchronous demodulator. This diff erential detection method provides a very sensitive measure of core position while cancelling out temperature eff ects.The transducers’ coils and fl ex circuit leads are sealed in vacuum-pumped epoxy, within the stainless-steel case. This provides outstanding environmental resistance. The DVRT® has been successfully employed in harsh applications, including immersion in saline and pressurized oil.

(obtained using MicroStrain’s DEMOD-DVRT)

Linear Stroke Lengths4, 8, 24, 38 mm (standard resolution)6 mm (high resolution) 500 µm or less (nano resolution)Accuracy*± 1.0 % using straight line± 0.1 % using polynomialSensitivity1 volt/mm typical (for 8 mm stroke) Signal to noise(using DEMOD-DVRT)4200 to 1 (with fi lter 3 dB down at 800 Hz, standard resolution), 466 to 1 (unfi ltered)Resolution(0.025% of full scale for standard version)1.0 µm for 4 mm stroke2.0 µm for 8 mm stroke 6.0 µm for 24 mm stroke 9.5 µm for 38 mm stroke 0.6 µm for high resolution version 10 nm for nano resolutionFrequency response800 Hz standard, 20 KHz optional Temperature coeffi cient off set 0.002% / ËšC (typical)span 0.030% / ËšC (typical)Hysteresis*± 1 micron Repeatability*± 1 micron* at constant temperature

Mechanical Specifi cations

Overall body length30.5 mm for 4 mm stroke50.5 mm for 8 mm stroke 127 mm for 24 mm stroke 183 mm for 38 mm strokeOutside diameter6.0 mm (smooth body) Housing 400 stainless steel; smooth body or /-24 UNF threadCore materialstainless steel Bearing materialruby and stainless steel Standard core tip4.76 mm stainless steel ball Leadouts45 cm multistrand, shielded, stainless steel reinforced tefl on insulated cableConnectorkeyed 4 pin Lemo Operating temperature-55 to 175 ËšC

U.S. Patent No. 4,813,435 and Patents Pending MicroStrain Inc. 310 Hurricane Lane, Unit 4 Williston, VT 05495 USA www.microstrain.com ph: 800-449-3878 fax : 802-863-4093 sales@microstrain.com
Copyright © 2007 MicroStrain Inc. DVRT is a trademark of MicroStrain Inc. Specifi cations are subject to change without notice.Updated May 4, 2007

Patents Pending