Screening machines principle of working. Backscatter X-ray. Backscatter X-ray is an advanced X-ray imaging technology. Vibrating Screen,Vibrating screen machine,Sand screening Vibrating screen is a kind of sieving equipment of international advanced level. It is widely used for grading and screening materials in many fields.This series of screening machine is a successful example of the combination of probability theory and engineering practice. Its new design concept, unique structure and screening principle have achieved the perfect screening effect of the probability screen and have a wide application prospect.