DETERMINATION OF CHARACTERISTICS OF MATERIAL

摘要

A system for automatically inspecting matter for varying composition comprises 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 light 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 overall width, whence the light is reflected, by a rotating, polygonal mirror 108 through optical filters dedicated to differing IR wavelengths, onto detectors (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 which extends over that overall width generate an electromagnetic field through the 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 control the solenoid valves operating the nozzles 116 to separate-out the metallic portions.