Self-cleaning porosimeter

摘要

A high-speed dynamic porosimeter including a device for removing accumulated debris is disclosed. The porosimeter has an apertured surface, preferably curved, across which a web whose porosity is to be measured is drawn while suction is applied to the apertures. A pressure transducer monitors the pressure in a sensor line or chamber, which pressure varies as a function of the porosity of the web. A scraper blade scrapes debris from the apertured surface from time to time. Preferably, vacuum suction is also applied to a slot at the upstream side of the apertured surface to ensure a good seal between the web and the surface.