Variohm Eurosensor has announced the availability of the Magnetopot non-contacting linear potentiometer, which provides position feedback from 8mm to 1,200mm in a low profile. Manufactured by Spectra Symbol, the Magnetopot is based upon a fully sealed membrane strip and a simple magnet. It is 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 available for compact, low-profile angle sensing. The Magnetopot is similar in concept to a traditional membrane-type potentiometer, but rather than using 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 relative position.
The thin IP65 membrane has a typical membrane thickness of less than 3.5mm - allowing the position sensor to be discretely installed with either the magnet or the membrane strip attached to the moving component. The standard linear Magnetopot is available in 11 travel range versions from 12.5mm to 1,000mm, 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 (5kohm to 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 66mm diameter 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. The non-contact technology is said to provide a long and maintenance-free working life.
