The measurement principle of Linear Potentiometers is based on a potential divider. The Linear Potentiometer provides inside a sliding contact (also called potential divider) which is running on a resistance track. This sliding contact is mostly fitted with a piston rod (combined with a piston rod), which is fixed to the measuring object. Depending on the wiper position, the resistance inside the circuit is changing and therefore also proportional the voltage drops. As resistance changes proportionally to the actual traversed path by the sliding contact, the distance can be determined by the change in voltage.