Pölynkeräys- ja analysointilaitteisto sekä menetelmä kuitumateriaalista irtoavien hiukkasten koon ja massan määrittämiseksi

The invention relates to a dust collecting and analysing apparatus for deter mining the size and mass of particles detaching from fibrous material, such as paper or board webs or sheets. The apparatus comprises means (1) for controllably detaching dust from the surface of the material (11) being examined and means (14, 8) for leading the detached material (12) into a virtual impactor (15), where the detached dust is separated into fine material and coarse material, which are led to a fine material measuring apparatus (2) and a coarse material measuring apparatus (3), respectively, and the results obtained from the measuring apparatuses are combined in an analyser (5). The invention also comprises a method for determining the size and mass of particles detaching from fibrous material, such as paper or board webs or sheets.