Weft Sensor is used for weft detection on Rapier Looms. During the weft insertion the yarn is drawn from the thread guide of the sensor. This yarn movement is converted into electrical signal by piezo element inside the sensor. This electrical signal is amplified and evaluated along with flag position to detect broken weft and stop the machine. The weft sensor is available in 4-6-8 selectors also with "ANTI II" feature to prevent insertion of more than one yarn.