Smoothness And Porosity Tester (Bendtsen Type)

Roughness of paper or similar material is defined as the volume of air that forced by a specified pressure difference escapes in unit time by passing between the surface of the specimen and flat metal ring resting on a specimen and exerting a definite pressure on it. A sample is placed on a perfect plane glass plate, measuring head on the test piece a controlled and small air pressure pass through a flat metal ring and the specimen. The pressure difference read off on selected rotameter tube.