It needs a reference point in order to start measuring.
Absolute angle sensors.
Each code pattern forms a unique reference and is therefore an absolute position.
Absolute position sensors are very different from incremental sensors.
When you say incremental position sensor it implies a change in position.
With mechanical gearing of one disc to second disc it is possible to define position over multiple revolutions.
A position sensor may indicate absolute position location or relative position displacement in terms of linear travel rotational angle or three dimensional space.
Absolute versions of transmissive encoders incorporate multiple tracks light sources and sensors which completely define position within a revolution.
Common types of position sensors include.
For this a unique code pattern is assigned to each angle increment.
A position sensor is a sensor that facilitates measurement of mechanical position.
Absolute angle encoders and optical angle sensors as well as potentiometers the measurement of rotation angles in demanding applications often requires a technical adaptation of the angle sensor to the specific application environment.
Many engineers claim that they have been using absolute position sensors when all the while what they have been using are incremental sensors.
The posirot magnetic angle sensors of the pras prds series are based on a contact free and absolute measurement principle.