IMPROVED DETECTOR AND DETECTION METHOD FOR CONTAMINANTS IN TEXTILE MATERIALS BASED ON AN ABSORPTION MEASUREMENT OF LIGHT

摘要

A detector and method for detecting contaminants in a measurement object aredescribedwhere there is compensation for changes in cross-sectional area of themeasurement object.Such methods and detectors are suited to detect foreign fibers in yarn sliversin a spinningmill.The detector comprises a measurement chamber (31), preferably spherical inshape with ahighly reflecting inner surface. A tube (34) allows an elongate measurementobject such as asliver to pass through the chamber (31). Absorption of light by themeasurement objectand/or any contaminant is measured through a transparent window (33).Light escaping through the ends 35, 36 of tube 34 can be compensated byaddition ofadditional light sources (41, 44) or additional photodetectors (51, 54) insideor outside themeasurement chamber (31).