Abstract: A system (10) for automatically inspecting a stream of matter (12) for varying composition, comprising an emitting device (16) serving to emit a detection medium, which comprises electromagnetic radiation of a substantially constant intensity, to an irradiated zone (I) of the stream at which the medium penetrates a surface of the matter (12), the irradiated zone (I) extending continuously across substantially the width of the stream, the medium penetrating the surface being varied by the matter (12), a receiving device (32) for receiving the varied medium emanating from the matter (12) at a detection zone (D) substantially separate from the irradiated zone (I), and a detecting device (34) serving to generate detection data in dependence upon the varied medium, the arrangement being such that, in use of the system (10), at least the majority of the varied medium received at the receiving device (32) can be transflected medium.

Abstract: A system for automatically inspecting matter for varying composition comprises one or more detection stations through which one or more streams of matter are advanced and particular materials therein are detected through their diffusely reflected IR spectra, if any, and/or through their variation of an electromagnetic field by their metallic portions, if any. A row of light sources distributed across the overall width of one or more belt conveyors may cause desired portions of the stream to reflect light diffusely onto a part-toroidal mirror extending over that overall width, whence the light is reflected, by a rotating, polygonal mirror through optical filters dedicated to differing IR wavelengths, onto detectors the data output of which is utilized in controlling solenoid valves operating air jet nozzles which separate-out the desired portions.

Abstract: Apparatus for automatically inspecting a stream of matter comprises lamps which emit a detection medium, such as IR or visible light, to be active at the matter, a rotary polygonal mirror which receives from a multiplicity of detection zones at the matter detection medium which has been varied by variations in the matter, an optical detection device which receives the varied medium by reflection from the mirror, to detect a plurality of wavelengths of the varied medium substantially simultaneously, and to generate detection data in respect of that plurality of wavelengths substantially simultaneously and in dependence upon the variations in the medium, and a microprocessor which obtains the detection data from the device. The beams of the varied medium which are received at the device and emanate from the zones travel along respective paths from the matter to the mirror 9 which paths converge continuously with respect to each other from the matter to the mirror.