A measurement system for measuring the coefficient of friction on a conveyor belt, slidable in a direction of movement (x), the system comprising: a metallic disk suitable for being floatingly placed on said conveyor belt, said disk having a bottom surface, at least one rounded element, having a contact surface that rests on said conveyor belt, protruding below the bottom surface; a pair of abutment elements arranged to keep the disk fixed relative to the direction of movement (x) of the conveyor belt; and a pair of load cells, operatively associated with the abutment elements and the disk, arranged to measure a thrust force exerted by the disk on each load cell due to the relative sliding of the conveyor belt with respect to the disk; wherein said at least one rounded element is one of the following: a) a plurality of rounded elements shaped and projecting such that, regardless of the relative orientation of the disk with respect to the conveyor belt, at least one rounded element extends along a direction of extension (d) that is not parallel to the direction of movement (x) of the conveyor belt, and wherein the rounded elements have an elongated shape, the direction of extension (d) corresponding with the direction along which said elongation extends, b) a single annular rounded element, arranged concentrically with respect to the disk, c) a plurality of lobe-shaped rounded elements that protrude from the bottom surface of the disk. a metallic disk suitable for being floatingly placed on said conveyor belt, said disk having a bottom surface, at least one rounded element, having a contact surface that rests on said conveyor belt, protruding below the bottom surface; a pair of abutment elements arranged to keep the disk fixed relative to the direction of movement (x) of the conveyor belt; and a pair of load cells, operatively associated with the abutment elements and the disk, arranged to measure a thrust force exerted by the disk on each load cell due to the relative sliding of the conveyor belt with respect to the disk; wherein said at least one rounded element is one of the following: a) a plurality of rounded elements shaped and projecting such that, regardless of the relative orientation of the disk with respect to the conveyor belt, at least one rounded element extends along a direction of extension (d) that is not parallel to the direction of movement (x) of the conveyor belt, and wherein the rounded elements have an elongated shape, the direction of extension (d) corresponding with the direction along which said elongation extends, b) a single annular rounded element, arranged concentrically with respect to the disk, c) a plurality of lobe-shaped rounded elements that protrude from the bottom surface of the disk. a) a plurality of rounded elements shaped and projecting such that, regardless of the relative orientation of the disk with respect to the conveyor belt, at least one rounded element extends along a direction of extension (d) that is not parallel to the direction of movement (x) of the conveyor belt, and wherein the rounded elements have an elongated shape, the direction of extension (d) corresponding with the direction along which said elongation extends, b) a single annular rounded element, arranged concentrically with respect to the disk, c) a plurality of lobe-shaped rounded elements that protrude from the bottom surface of the disk.