A root crop harvester is provided, including a feed conveyor device for conveying conveyable material consisting of harvested crop and additional materials in a feed conveying direction. The root crop harvester also includes a separating device having at least one separating element for separating the additional materials from the harvested crop. The separating device has a conveyable material sensor, which is coupled to a first EDP evaluation unit and, during operation, is directed toward the conveyable material, and which is intended for recording conveyable material data. The conveyable material sensor may be directed toward the feed conveyor device during operation. In addition, the conveyable material sensor may be an optical conveyable material sensor.