Laite paperiradan pinnan topografian määrittämiseksi

The invention concerns an arrangement for determination of the surface topography of a paper web. The arrangement includes a laser light source 1, which is installed fixed above the paper web; alignment optics 2 which are arranged to align the laser beam essentially perpendicular to the surface of the paper in a small light spot; a deflector 3 which is arranged to deflect the beam of laser source 1 with an essentially large sweep rate linearly and essentially in the cross direction of the web and/or in the direction of the web with a predetermined sweep interval; a detector 4, which represents a two-dimensional position-sensitive detector, like a CCD camera, and which is arranged to detect the light beam scattered from the paper's surface in an oblique direction relative to the paper web so that the alignment optics and detector's optical axes form an angle alpha relative to each other to form a topographic image of the surface based on sweep; imaging optics 5, which are arranged in front of the detector to magnify the image of the light spot on the detector; and measurement electronics 6 for the detector, laser source and deflector control and for processing of the measurement results.