|String Potentiometers are a versatile position measurement device that converts mechanical motion into an electrical signal that may be metered, recorded, or transmitted. Firstmark Controls string pots consist of a stainless steel displacement cable wound on a threaded drum that is directly coupled to a precision, long-life sensor. Operationally, the sensor is mounted in a fixed position and the extension cable, "string," is attached to a moving object. As movement occurs, the string extracts then later retracts under the power of an internal, engineered spring which also maintains tension on the draw wire throughout its stroke. The rotation of the sensor produces an electrical output proportional to the string's movement giving indication of positional translation.