Apparatus and method for measuring permeability of a moving web.

摘要

The permeability of a moving web (3), for example, of perforated cigarette tipping paper, is monitored by inducing a fluid flow across the web to a head (100), measuring (20) the pressure drop across the web, independently measuring (10) the volumetric glow rate, and calculating (120) the permeability in CORESTA units. This method is embodied in apparatus which sequentially measures the instantaneous permeability of successive areas on the web (3) to provide direct indication (130) of the instantaneous CORESTA permeability.