| 摘要 |
The present invention concerns a procedure and a means for observing streaks in the machine direction in paper or in its coating, on a web (1) in continuous motion, a measuring box (2) being moved reciprocatingly across the paper web, from a light source (A) therewithin light being conducted against the paper web (1) in the form of separate light beams (5) spaced uniformly in the direction across the web, whereafter the intensities of the transmission beams from the paper or of the reflected beams from the coating are measured each separately by means of a detector (7) placed in the path of each light beam (5), the deviation of intensity found by the detector being automatically recorded in time and in space, whereafter the deviations of intensity coming later in succession from other detectors (7) are superimposed in time, whereby when similar intensity deviations come from the majority of the different detectors, the deviation must have been caused by a streak in the machine direction across which the equivalent number of light beams (5) has passed. |
