This sampler is used to measure bed-load of coarse sand and fine gravel in rivers and other water- courses. The streamlined sampler is mounted in a frame and consists of a mouth followed by a basket of fine wire meshing (width of the mesh 300 mu). The sharp decrease of the velocity in the wide sampling chambers causes the sediment material to settle there. A tail fin mounted on the frame keeps the sampler in up-stream direction. The results of the measurements are influenced by the shape of the bed (ridges, dunes, flat beds, etc.). For a successful measurement knowledge of the relief of the bed is essential. The sampler can be discharged on board using the sample trough.