Sensor system for sensing a weft thread (4, 5) that is being inserted in the weft insertion direction, in at least a first zone; the sensor system comprising: a plurality of light emitters comprising at least a first and a second light emitter (110, 120) configured for emitting light (L1, L2) in the first zone where the weft thread (4, 5) needs to be detected; wherein the first light emitter and the second light emitter are located at a distance from each other, seen in the weft insertion direction; one or more light receivers comprising a first light receiver configured for receiving light from the first and the second light emitter (110, 120) which has been reflected by the weft thread in the first zone; wherein the first light receiver is located, seen in the weft insertion direction, between the first light emitter and the second light emitter; characterized in that the second light emitter is further configured for emitting light in a second zone where the weft thread needs to be detected, the second zone is located downstream of the first zone, seen in the weft insertion direction; wherein the plurality of light emitters comprises a third light emitter configured for emitting light in the second zone; wherein the second light emitter and the third light emitter are located at a distance from each other, seen in the weft insertion direction; wherein the one or more light receivers comprise a second light receiver configured for receiving light from the second and the third light emitter (120, 130) which has been reflected by the weft thread in the second zone; wherein the second light receiver is located, seen in the weft insertion direction, between the second light emitter and the third light emitter. a plurality of light emitters comprising at least a first and a second light emitter (110, 120) configured for emitting light (L1, L2) in the first zone where the weft thread (4, 5) needs to be detected; wherein the first light emitter and the second light emitter are located at a distance from each other, seen in the weft insertion direction; one or more light receivers comprising a first light receiver configured for receiving light from the first and the second light emitter (110, 120) which has been reflected by the weft thread in the first zone; wherein the first light receiver is located, seen in the weft insertion direction, between the first light emitter and the second light emitter; characterized in that the second light emitter is further configured for emitting light in a second zone where the weft thread needs to be detected, the second zone is located downstream of the first zone, seen in the weft insertion direction; wherein the plurality of light emitters comprises a third light emitter configured for emitting light in the second zone; wherein the second light emitter and the third light emitter are located at a distance from each other, seen in the weft insertion direction; wherein the one or more light receivers comprise a second light receiver configured for receiving light from the second and the third light emitter (120, 130) which has been reflected by the weft thread in the second zone; wherein the second light receiver is located, seen in the weft insertion direction, between the second light emitter and the third light emitter.