Front page of European patent application EP 1 508 633 A1, filed by Sultex AG of Rüti, Switzerland, for a nozzle (jet) weaving machine. The abstract describes a machine in which weft is inserted by fluid from the weft side to the catch side along a path on the sley. A monitoring device on the catch side has two sensors for detecting the weft yarn, and exactly one of them is fixed on the sley. Fig. 1 is a side-view diagram of the machine showing the weft insertion path, reed and sensors.