A position sensor is a sensor that detects an object's position. A position sensor may indicate the absolute position of the object (its location) or its relative position (displacement) in terms of linear travel, rotational angle or three-dimensional space. Common types of position sensors include the following:
Capacitive displacement sensor Eddy-current sensor Hall effect sensor Inductive sensor Laser Doppler vibrometer (optical) Linear variable differential transformer (LVDT) Photodiode array Piezo-electric transducer (piezo-electric) Position encoders: Absolute encoder Incremental encoder Linear encoder Rotary encoder Potentiometer Proximity sensor (optical) String potentiometer (also known as a string potentiometer, string encoder or cable position transducer) Ultrasonic sensor
See also List of length, distance, or range measuring devices Positioning system
Literature David S. Nyce: Linear Position Sensors: Theory and Application, New Jersey, John Wiley & Sons Inc. (2004)