PAPER MACHINE OPTICAL MONITORING DEVICE AND METHOD

摘要

The present invention relates to an apparatus for measuring an optical property of a sheet material. The apparatus is comprised of a receiver for receiving a sheet material which has a fluorescent constituent, an optical system for directing light from a light source to a photometric sensor along a light path which includes the receiver; and a filter for controlling the light path so that the photometric sensor supplies respectively a first signal substantially exclusive of any fluorescent contribution and a second signal inclusive of a fluorescent contribution.