Simultaneous optical porosity measurement and detection of perforations in continuous material webs, especially paper webs, using powerful illumination sources which are moved transversely over the web

摘要

Method for detection of perforations in continuous material webs (1), especially paper webs, in which the webs are illuminated with transmission light using two spatially separate beam systems (7, 8) and position determination of the perforations and the porosity measurements are undertaken simultaneously during the same transverse movement (9) over the whole web width at different locations and at different or the same times. An Independent claim is made for device for optical porosity measurement and detection of perforations in continuous material webs, especially paper webs with disparate illumination light sources in the form or point or linear lasers or power LEDs.