The draw-wire displacement sensor is also called a draw-wire sensor, a draw-wire electronic ruler, or a draw-wire encoder. The draw-wire displacement sensor is a sophisticated structural construction of a linear displacement sensor. It fully combines the advantages of an angle sensor and a linear displacement sensor to become a sensor with a small installation size, compact structure, large measuring stroke, and high accuracy. The stroke ranges from hundreds of millimeters to tens of meters. A draw-wire sensor (also called a string pot, cable extension transducer）is a linear position sensor that measures the displacement or velocity of a moving object. It works by converting the linear motion of a flexible measuring wire into a rotary motion, which is then translated into an electrical signal.