Potentiometers and other sliding position sensors are electromechanical devices whose performance and operating life can be dramatically improved through lubrication. Each of these devices has a metal wiper that moves along a resistive element, to regulate current flow to a device or to indicate when pre-calibrated positions are reached. The tracks may be any of a variety of conductive materials: wound metal wire, conductive plastic or ceramic compositions. Lubricating these tracks helps prevent wear, attenuate electrical noise and extend operating life.
Wear prevention is the primary reason for potentiometer track lubrication. Most importantly, the lubricant film must be strong enough to prevent wear but thin enough throughout the operating range to prevent contact hydroplaning and resulting intermittencies. When working with small, delicate mechanisms with extremely low starting torque, oils may be required. However, greases, with their important stay-in-place advantage, have been the most successful potentiometer lubricants. Light, low shear greases, some approaching a semi-fluid state, can often be designed for even very low power applications.
There are a number of formulations on file but for a large amount of designs, one of the products detailed below should suffice…
A note about damping greases.
Although not intended as track lubricants, Nye’s damping greases are widely used on potentiometers and other rotary devices where shaft/bearing lubrication is needed to damp free motion and produce a ‘velvet feel.’ As there are a number of different viscosities to select from, this gives the opportunity to fine tune the ‘damping feel.’ See our page on Damping Grease for details.
|Product Name||Temp Range (°C)||Base Oil & Thickener||Base Oil Viscosity @ 40°C||Application & Product Notes|
|RHEOLUBE 716A||-54 to 150||Ester - Lithium Soap||18.5 cSt||Light viscosity ester-based grease fortified with special additives to reduce electrical noise & wear. Good wide-temp serviceability. Base fluid has excellent film strength for high-load applications. Use with caution around ester-vulnerable plastics. UV tracer|
|UNIFLOR 8511||-50 to 225||PFPE - PTFE||65 cSt||Medium viscosity, chemically resistant fluorinated grease with excellent thermo-oxidative stability & low-vapour characteristics. Capable of high temp applications or exposure to fuels or aggressive chemicals.|
Note: PFPE = Perfluoropolyether | PTFE = Polytetrafluoroethylene
The products mentioned above are the more popular from the range. If you do not find a product that fits your needs then please contact us as we have many more formulations on file for a variety of application types.