... mesh, 12-18 mesh, 12-20 mesh, 16-20 mesh, 16-30 mesh, 20-40 mesh, 30-50 mesh, 30-60 mesh, 40-60 mesh, 40-70 mesh, 70-140 mesh ... appointed detecting equipments made by the national designated factory. With years of development, the center has improved methods for test and research, which ...