Non-Contact Positional Sensing

By Paul Fears | 26 April 2023

Sensor applications using magnets is not new, although the application scope continues to evolve with developments and advances in magnetic materials and magnetising technology.  In this specific sensing project, the magnets are used for non-contact position sensing, which is, perhaps, one of the unique ways in which magnets are meeting the changing demands of the sensor industry.

Sensor Magnets
Magnet assemblies for a sensor application

Coordinate Measuring Machines

In order for the head of a Coordinate Measuring Machine (CMM) to return home, a simple looking, but highly accurate magnetic assembly, is used to give repeatable and non-contact position information.

The magnets are tuned to provide a consistent magnetic field, from part to part, and the dimensional and positional accuracy of the assembly needs a x20 magnification visual check during build to ensure the optimum performance.  In addition to the assembly accuracy, a magnetic screw is used to bias the field by a variable amount to ensure magnetic repeatability.

These magnetic assemblies are also used to hold lightweight probe heads.

Sensor Magnets
Magnet assemblies for a sensor application

Repeatedly Accurate Presentation

This type of small magnetic assembly is one of the range of volume parts focused on consistent lean manufacturing activity and automation designed and manufactured by Bunting.  In addition, following Bunting’s announcement that all online magnets [sold through the e-Magnets UK website] are carbon neutral, the customer for this part enquired about the sustainability of this magnetic component.

This led to a more in-depth study of the CO2e impact of the whole product and not just the magnet.  This study is ongoing, developing a sustainability programme for the product, which is anticipated to support other internal sustainability activities.

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Magnet and Magnet Assembly Design

Bunting designs and manufactures a wide range of magnets and magnetic assemblies for sensor applications.  For further information please contact us via:

Phone:  +44 (0) 1442 875081


Via the Bunting-Berkhamsted website for specialist magnets, magnetic assemblies and magnetising equipment

Via Bunting-eMagnets for online purchase of Magnets and Magnetic Technology

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