Fuente: Wipo "precision farming" The present invention is an apparatus and method for measuring flow rate of materials, for example the flow rate of agricultural products. The apparatus includes an x-ray generator positioned near flowing materials, a converter for converting the x-ray radiation which passes through the flowing materials into visible light, a camera for capturing images of the visible light, and a processor for processing the images to determine the flow rate. The invention may also include an image intensifier to intensify the images before being converted by the camera. The method directs x-rays through flowing material, converts the x-rays to visible light, records the intensity of the visible light and derives the flow rate from the intensity measures.