A measuring roller for a device for measuring a fiber composite (2), in particular on a draw frame, a carding engine or a comber, is made of a material of low thermal expansion (3) and has a surface coating (4). The measuring roller (1) features a shell surface (5) for clamping a fiber composite (6) along with a rotary axis (7). The shell surface (5) features a structure forming an air buffer, made of grooves (8), boreholes (9), and/or spherical projections (18).