Because of the existing difficult problem of on-line weighing of rolled-products all along, an on-line electron roller scale was developed for hot rolled strip by Baotou Iron and Steel (Group) Co.

The results showed that the quality of slabs cast under unsteady conditions is poorer than that cast under steady condition.

Based on those results,an integrated evaluation for slab quality is carried out,and some improvement measures for slab quality are put forward accordingly,which will provide a theoretical gist fo.

The basic theory of a new online weighing method is introduced in this paper:determining the volume of materials by image analisys,determining the density of materials employing Gamma rays,and then calculating the weight by the volume and the density.