App note from Bourns on linear motion potentiometers and how they can be used to detect position by voltage division ratio. Link here (PDF)
The elements of the LMPs are manufactured with conductive plastic (CP) for extended wear capabilities. Unlike Trimmers, which are “set and forget,” these devices are designed to monitor position and are thereby designed to have a very high cycle life capability. LMPs are ideal for converting a mechanical linear motion displacement into a proportional voltage output when used as a sensor.