Process for weighing the harvested crop stored in a tank on a harvesting machine

Known harvest weighing systems have problems associated with the disturbances from a moving harvester machine when attempting to weigh crops continuously. The invention relates to a process and harvester for weighing the harvested crop stored in at least one tank (9) supported by a frame (3) of a harvesting machine, said frame being mounted on a wheel set (2) by means of a lifting device (10) which is operable to move said frame upwardly and downwardly upon controlling a hydraulic system of said machine, said process comprising an acquisition procedure (C, D, E) wherein, upon controlling the hydraulic system for lowering and raising the frame (3) on a displacement course, the process providing for: determining at least one height position of the frame (3) on said course; measuring the lowering A1, B3 and the raising A2, B4 pressures in the hydraulic system at said position; calculating, from said measured pressures, a balancing pressure Pf, Pe for said frame; wherein said acquisition procedure is Performed before unloading the stored crop in order to calculate a loaded balancing pressure Pfand after said unloading in order to calculate an empty balancing pressure Pe, and the weight W of the stored crop is calculated from a pressure variation ∆P between said balancing pressures.