Abstract: A method and apparatus for determining the density of dry fibers, mainly in the form of fiber bundles. A sample of these dry fibers is weighed. The fiber bundles of these dry fibers are fed into the suction side of an air aspirator and opened into a combination of smaller fiber bundles and individual fibers as they exit from the pressure side of the aspirator. The combination of smaller fiber bundles and individual fibers passes through a chamber and is deposited onto a screen in the bottom of an enclosure. The enclosure is supported so that there is an open space under the screen, thereby allowing the air which is transporting the combination when the combination is deposited on the screen to pass through the screen and exit from the apparatus. The volume of the combination of smaller fiber bundles and individual fibers deposited on the screen in the enclosure is measured, and the density of the dry fibers is calculated using the measured weight and volume of the sample.