Magnetostrictive linear transducers are immune to noise

Paul Boughton

Gefran's MK4-S and IK4-S magnetostrictive linear position transducers now feature increased performance and higher immunity to electromagnetic noise thanks to an improved electronic design. The RS422-SSI interfaced transducers, available in IP67-sealed profile (MK-4) and open-rod (IK-4) versions, benefit from contactless technology for extremely long life and low maintenance. Stroke lengths are form 50mm to 4m with positioning resolution to 2um.

The new design includes an 'internal linearisation' feature that provides a four-fold improvement in the standard linearity of 0.02 per cent of full scale by introducing a linearity compensation factor. The new electronics are also more resistant to power surges and fully conform to EMI CE compatibility standards with an overall noise reduction that improves communication reliability. Furthermore, the maximum working temperature range has been raised to +90 degrees C for applications in more arduous conditions, and the current input has been halved to just 50mA.

Gera says the IK4-S rod version has also undergone some mechanical design improvements over the older IK-2 version that it replaces; for example, a new cylindrical head design offers straightforward integration for in-cylinder use. For both versions, connector and flying lead options are available.

The SSI interface versions offer high levels of convenience for control systems and the durability of the technology suits some of the most demanding applications in electrical and hydraulic servo systems. Other interfacing versions available include analogue, digital, Profibus and Canopen.

All versions can be used with up to four measurement cursors on a single sensor for complete application flexibility. For MK-profile versions the cursor may be fixed or moving to aid installation and the IK-rod versions can include different magnet geometries to accommodate applications from in-cylinder use to level control.

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