Amount of air expressed in cubic feet per minute, that can be drawn through a 2"x 2"x 1" foam sample at 5-inch water pressure differential Air Flow is measured by a test (ASTM D3574)
Amount of air expressed in cubic feet per minute, that can be drawn through a 2" x 2" x 1" FPF sample at 5-inch water pressure differential
a method of measuring the Mean Fibre Diameter of a sample of wool in which a test specimen (a measured mass of the scoured, dried and carded sample), after exposure to a conditioning atmosphere, is compressed to a fixed volume and a current of air is passed through it The rate of flow is then adjusted so that the pressure drop across the sample equals a predetermined value The rate of flow is an indicator of the mean fibre diameter of the wool in the sample The instrument is calibrated to international standard wool tops of known fineness