Heavy Duty AC-Operated
LVDT Position Sensors

The Macro Sensors SQ 1250 Series of heavy duty LVDTs were developed specifically to measure position or motion in mill-type hostile environments. These rugged and reliable contactless sensors, available in measuring ranges from ±0.50 inches to ±10.00 inches, have their electrical assembly totally encapsulated within a heavy duty aluminum housing, with their electrical connections made to screw-terminal style barrier strips. This complete encapsulation of SQ 1250 Series LVDTs allows them to withstand the high shock and vibration levels typically encountered in mill environments and permits them to meet the IEC IP-64 sealing standard against the intrusion of splashed water and other liquids.

SQ 1250 Series LVDTs are electrically and magnetically double shielded to maximize noise immunity and minimize their susceptibility to external AC magnetic fields developed by electric motors, transformers, etc. Because core shaft misalignment occurs often in mill applications, all SQ 1250 Series sensors incorporate Teflon™ bore liners to reduce friction and wear between the LVDT's core and its bore under such conditions, especially when measuring oscillatory motions.

SQ 1250 Series position sensors offer the high resolution, excellent repeatability, and low hysteresis associated with LVDT technology, as well as the highest sensitivity consistent with good linearity. The maximum linearity error for an SQ 1250 LVDT is ±0.25% of full range output, using a statistically best-fit straight line derived by the least squares method.

SQ 1250 Series LVDTs feature constant sum-of-the-secondaries output, so they can be used equally well with conventional differential input LVDT signal conditioners, or with ratiometric LVDT signal conditioners found in some industrial control systems.

Typical applications of SQ 1250 Series LVDTs are measuring roller gap position for hydraulic servo systems used to control primary metals rolling mills, sizing lumber to maximize yield in sawmills, maintaining proper calender roll position in paper mills, controlling steam valve opening in electric power plants, and measuring raker boom height in wastewater treatment plants.