METHOD AND APPARATUS FOR DETECTING STRAND INHOMOGENEITY OF MATERIAL STRAND OF TOBACCO PROCESSING INDUSTRY

摘要

PROBLEM TO BE SOLVED: To examine various items of a strand quality in a material strand of a tobacco processing industry in which an object is disposed and detect strand inhomogeneities of, especially, the inserted object and a foreign substance.SOLUTION: An object 72 is inserted in a material strand 71 at a predetermined object position. After the insertion of the object 72, the material strand 71 is transferred in a direction of a longitudinal axis so as to pass through at least two strand measuring instruments 30 and 40 that are driven at different frequencies and, for evaluating measurement signals, the material strand 71 is divided into an object zone including one or a plurality of predetermined object positions and an empty zone without including the predetermined object position. The measurement signals of the strand measuring instruments 30 and 40 in the object zone and the empty zone are evaluated by different evaluation methods respectively. Strand inhomogeneities 72, 73 and 74 are detected by using an object algorithm 85a in the object zone and by using at least one empty-zone algorithm 85b and 85c in the empty zone.