Subminiature Differential Variable Reluctance Transducer

The Subminiature DVRT is a larger version of our Microminiature DVRT. It features an outside body diameter of 4.76mm. Three stroke lengths of 8, 24, and 38mm are available from stock. Custom stroke lengths, smaller body length to stroke ratios, hermetic packaging, and high temperature options (up to 175 deg. C) are also available. The Subminiature DVRT features a resolution of 0.16 microns (-3dB @ 1KHz); high resolution and super resolution devices (down to 10 nanometers over ±200 microns of stroke) are also available.

A DVRT consists of two coils which measure the linear movement of a ferrite core. The core position is detected by measuring the coils' differential reluctance, using a sinewave excitation and synchronous demodulator. This differential method provides a sensitive measure of core position, while canceling out temperature effects. The transducers' coils and flex circuit leads are sealed in vacuum pumped epoxy, within the stainless steel case, providing outstanding environmental resistance. The flex circuit is covered by a polyurethane sheath for strain relief. The DVRT has been successfully employed in harsh applications, including immersion in saline and pressurized oil.

Several attachment options are available from stock: threaded body, threaded core, spring tips, mounting blocks, and a gauging option.

MicroStrain, Inc., 294 N. Winooski Ave., Burlington, VT 05401-3680. Tel: 802-862-6629; Fax: 802-863-4093.