For measuring porosity, air permeability or air resistance of paper and paper products by determining the time necessary for a certain volume of air to flow through the inserted sample, under a uniform pressure.
With Electronic self starting timer as an optional accessory, for automatic measuring of either 25, 50, 100, 150, 200 or 300cm3 air to pass through the test specimen. The timer starts automatically when the zero slit of the graduated ruler pass an optional read fork and stops automatically as soon as the predetermined volume of air has been passed through the sample.