DETERIORATION INSPECTING DEVICE AND METHOD OF PAPER SHEET

PROBLEM TO BE SOLVED: To determine the quality deterioration of a paper sheet that does not accompany surface staining of the paper sheet. SOLUTION: The deterioration inspecting device 91 of the paper sheet 5, for determining whether the paper sheet 5 has deteriorated, is equipped with first and second clamps 71 and 72, a tensile machine 73, a displacement measuring instrument 74 and a deterioration determining processor 4. The paper sheet 5 is held between the first and second clamps 71 and 72, and the first length in the tensile direction of the paper sheet 5 is measured, in a state that first tensile force is applied to the paper sheet 5 by the tensile machine 73; furthermore, the second length in the tensile direction of the paper sheet 5 is measured, in a state where second tensile force larger than the first tensile force is applied to the paper sheet 5. The deterioration determining processor 4 determines whether the paper sheet 5 is deteriorating, on the basis of the difference between the first and second lengths of the paper sheet 5. COPYRIGHT: (C)2009,JPO&INPIT