During slab rolling process in plate producing mills and hot-rolling mills, slabs’ width, length and camber are key factors that determine work conditions in a heating furnace and that can be used in rolling processes. This system measures the width & length, and camber while the slab is moving, and it especially makes it possible to measure the length and thickness profile of the hot charged slabs. With the information acquired about the slab, one can confirm the heating furnace charging conditions and can use it as the data for the process.