The classification of cotton is the process of describing the quality of cotton in terms of its grade, fiber length and micronaire. Before, touch and sight were used to make this classification. Micronaire determinations are made with a measurement of the air flow, which indicates the fineness of the fiber.
Classification is essential for cotton pricing systems, but additional testing is needed to have high-level quality control in the production of textiles. Therefore, an instrument was developed to measure almost all fiber properties. This instrument is known as the High Volume Instrument (HVI) and is manufactured by Zellweger Uster, Inc. Currently, its classification system consists of instrument measurements for length, resistance, length uniformity, micronaire, waste and fiber color. Since 1991, HVI has classified 100 percent of the United States' crops.