DETERMINATION OF CHARACTERISTICS OF MATERIAL

摘要

A system for automatically inspecting matter for varying composition compris es one or more detection stations (131) 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 lig ht sources (105) distributed across the overall width of one or more belt conveyors (104) may cause desired portions (125) of the stream to reflect light diffusely onto a part-toroidal mirror (107) extending over that overal l width, whence the light is reflected, by a rotating, polygonal mirror (108) through optical filters dedicated to differing IR wavelengths, onto detector s (120) the data output of which is utilised in controlling solenoid valves operating air jet nozzles (116) which separate-out the desired portions. Alternatively or additionally, an oscillator (137) and an antenna (138) whic h extends over that overall width generate an electromagnetic field through th e belt (104) and sensing coils (139) sense variations therein produced by metallic portions of the stream passing through the detection station (131) and the detection data produced by the sensing coils (139) is used to contro l the solenoid valves operating the nozzles (116) to separate-out the metallic portions.