ISO 1136:1976

Wool — Determination of mean diameter of fibres — Air permeability method

The air permeability test method is based on the Kozeny equation. Weighed fibres (test specimen) are introduced in a measuring chamber with known volume. Air is passed through this test specimen. A scale indicating variations in permeability of air may be calibrated in appropriate absolute units of rate of flow or pressure difference and a table or graph is provided for conversion of the observed reading into values of mean diameter of the measured wool fibres.