BAK - Disamat 801 Hot Air Welding Machine. BAK - Disamat 801 The welding machine for â¦more
The different grades of the Risser sign give a measure of bone maturity and thus of the skeletal growth to be expected. In Europe, a scale ranging from Risser 0 to Risser 5 defines the grades from beginning ossification to complete fusion of the apophysis to the iliac bone. In the USA, 4 grades are defined.
RMS and Ra are based on different methods of calculating the roughness. Both are done with a profilometer, but the profilometer calculates the roughness differently for Ra and RMS. Ra is the arithmetic average of surface heights measured across a surface. Simply average the height across the microscopic peaks and valleys. Ra and RMS are both representations of surface roughness, but each is calculated differently. Ra is calculated as the Roughness Average of a surfaces measured microscopic peaks and valleys.