34—A SONIC FINENESS TESTER FOR TEXTILE FIBRES

Abstract

A description is given of an instrument based on the well-known principle of measuring fibre diameter by means of air-flow. It differs from existing commercial instruments employing this principle in that it uses an alternating flow of air through the sample under test. Since there is no net flow of air, there is little change in the regain of the sample, which eliminates the need for spending time in conditioning the sample, and a further advantage is that an electrical output is available that has not the hysteresis or expense associated with static pressure transducers.