Moving paper path characteristic detecting device for production control in paper making, has outlet window sealed into front plate of housing to direct infrared light from infrared emitter to paper path

摘要

An infrared illuminator (22) with an infrared emitter (26) radiates the infrared light to a paper path (20) with a light receiver (30). A detector (28) determines the light reflected by the paper path. The infrared emitter is arranged in a housing (38) having a front plate (40) turned to the paper path. An outlet window (48) is sealed into the front plate to direct the infrared light to the paper path.