Abstract: A conveyor system (10) for transporting a transportable material (M) by means of a fluid for transporting the transportable material (M) between a first conveying line portion (11) and a second conveying line portion (12), said conveying line portions (11, 12) comprising a plurality of pipes forming a continuous conveying line (13), said system (10) comprising: a conveyor device (1) in fluid connection to one of said first or said conveying line portions (11, 12) operative to provide negative air pressure or vacuum through said conveying line (13); a material feeder device (2); wherein the conveyor device (1) comprises at least one material level sensor (1a, 1b), wherein the at least one material level sensor (1a, 1b) is used to monitor one or more material level(s) inside the conveyor device (1) and via one or more material level sensor lines (3) giving at least one material level signal (1aa, 1bb) to a controller (4) and from the controller (4) via a control signal line (5) transmit a control signal (5a)