Method and apparatus for measuring the diameter of rod- or bar-shaped products in the tobacco processing industry

摘要

The invention relates to a device for measuring the diameter of filter tows (2) with a porous peripheral surface by means of a pneumatic testing system (19 to 23 and 119 to 123 respectively), which maintains constant the pressure of the test air directed against the tow within a tow measuring nozzle (1) and comprises measuring means (14) which record the volume of test air flowing through, which varies as a function of fluctuations in the diameter of the tow. In the same manner, the porosity of the wrapping material (29) is separately measured and taken into account in determining the diameter of the tow. <IMAGE>