Manufactured by USA-based Spectra Symbol and available exclusively in the UK from Variohm-EuroSensor, the new MagnetoPot non-contact linear potentiometer is based on a fully sealed membrane strip and a simple magnet to provide position feedback from 8mm to 1200mm in a low-profile and robust design with exceptionally long life capability.
According to Variohm, the MagnetoPot is particularly suitable for hydraulic and pneumatic position sensing, as well as other medium-precision position feedback applications such as liquid level monitoring. A rotary version is also available for compact, low-profile angle sensing.
The MagnetoPot is similar in concept to a traditional membrane-type potentiometer but, rather than use a contacting wiper to connect the collector to the resistive element, it relies upon the interaction of a non-contacting external magnet and an encapsulated magnetic or ferromagnetic strip to determine the electrical output and, therefore, the relative position. The thin IP65 membrane has a typical membrane thickness of less than 3.5mm, which enables the sensor to be installed discretely with either the magnet or the membrane strip attached to the moving component.
Standard linear MagnetoPot devices are available in eleven travel versions from 12.5mm to 1000mm, with a choice of three-pin connection options including Crimplex solder tabs, male pins and a variety of connectors. The electrical specification includes a 10kohm resistance output over each linear position range (5-500kohm on request) with a linearity of +/-5 per cent. The positioning resolution is dependent upon the exterior magnet strength and its proximity to the MagnetoPot's magnetic strip. The rotary version is currently available with a diameter of 66mm and an active centre track diameter of 46mm.
The IP65 rating for the active area for both types of MagnetoPot allows for intense water spray, and the non-contact technology effectively yields an extremely long, maintenance-free working life.