公开(公告)号：US09625382B2

公开(公告)日：2017-04-18

申请号：US14439259

申请日：2013-10-30

Applicant: VALMET AUTOMATION OY

Inventor： Markku Mäntylä

IPC: G01N21/55 ,  G01N21/57 ,  G01N21/47 ,  G01N21/86 ,  G01N21/89 ,  G01N33/34

CPC classification number: G01N21/57 ,  G01N21/47 ,  G01N21/86 ,  G01N21/8901 ,  G01N33/346 ,  G01N2201/06113 ,  G01N2201/062 ,  G01N2201/069 ,  G01N2201/12

Abstract: An apparatus of measuring a small scale property of a sheet, the apparatus includes: a first light source for illuminating the sheet moving with respect to the illumination; a detector for forming a total intensity of reflection of the light illuminating the moving sheet by each detection; a detected dimension of the reflection on the sheet in the direction of the movement being limited the same as or shorter than a lowest acceptable spatial resolution of the measurement; a duration of each detection being equal to or shorter than the lowest acceptable spatial resolution divided by a speed of the moving sheet; and a processing unit for forming information about a small scale variation of gloss of the sheet on the basis of the detections by the detector.