A coherent optical method based on heterodyne detection of back-scattered laser light for continuous measurement of paper surface roughness and the corresponding instrument is presented. Results of laboratory and online pilot plant tests well correlate with those of conventional off-line air-leakage /Bekk, PPS/ methods. An industrial prototype probe is installed above the last free running section of paper path on a supercalander.
|Number of pages||4|
|Publication status||Published - Dec 1 1986|
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