Two new models of ac-ac LVDTs have been developed to work in extreme pressures and temperatures. To handle high pressures, the transducer housing is perforated to equalize pressure inside and outside. Because holes in the housing expose the coils inside, fluids must be electrically nonconductive and chemically benign. Of course, many hydraulic oils meet this requirement. Special internal materials let the LVDT handle high temperatures.
The LVDTs are rated to 35,000 psi, operate at temperatures up to 450˚F, and feature ±0.25% nonlinearity and a ±0.01%/degree/F temperature coefficient of sensitivity The high sensitivity output offers infinite resolution in a variety of strokes. The LVDTs come in 3/8 or ¾-in. OD bodies with signal conditioners for dc-dc or 4-to-20-mA operation.
Trans-Tek Inc., 10 Industrial Dr., Ellington, CT 06029, (800) 828-3964,