Linear potentiometers

Displacement encoders

Displacement encoders are used to measure a distance to an object. They consist of sensors and are based on different operating principles. There are also different types of displacement encoders.

Types of displacement encoders

In pneumatics, a distinction is made between linear and rotary displacement encoders. Linear displacement encoders are used to detect positions and measure distances. The measurement works either without making contact or with a contacting sensor. Rotary displacement encoders, on the other hand, are usually encoders, shaft encoders or potentiometers. A difference is made here between absolute and incremental measuring systems. With absolute measuring systems, the user can read the position value immediately after switching on the application. With incremental measuring systems, on the other hand, a homing run must first be carried out after switch-on in order to obtain the zero position. The position is then recorded by a cyclic signal.

Operating principles of displacement encoders

Displacement encoders are subject to different operating principles. Inductive systems work completely contactlessly and have a measuring range of up to approx. 50 mm. The output signal is not binary, but is fed back as an analogue value. The functional principle of magnetostriction is also contactless measurement. Operation of magnetostrictive systems is wear-free and absolute. They are widely used in industry as they cover a measuring range of up to approx. 8000 mm.

Linear potentiometers are part of contacting systems. These work by dividing the voltage and have a conductive resistance path with a slider travelling over it, thus enabling the position to be detected. Magnetically encoded displacement measurement, which can be used up to approx. 50 metres, is also contact-based.

In addition, there are optoelectronic displacement encoders and optical distance sensors. They measure the distance to an object by using a light beam generated by a light-emitting diode or laser diode and are therefore contactless measuring devices.

Festo displacement encoders

Festo displacement encoders are available in analogue and digital versions, are suitable for measuring and positioning and have a wide range of applications in pneumatics. Displacement encoder MME-MTS-TLF is based on the magnetostrictive measuring principle, is completely contactless and impresses with its high travel speed. Displacement encoder MLO-POT-LWG is a push rod potentiometer with absolute measurement, has a long service life and is characterised by a high resolution. Our displacement encoder MLO-POT-TLF is a conductive plastic potentiometer that guarantees a high travel speed with a long service life.