A New Cotton Lustermeter for Yarns and Fibers'

Abstract

A single-answer, direct-reading instrument especially adapted for measuring luster of raw cotton and grey and mercerized yarns has been developed. It includes a special sample clamp, and a turret-top holder for the instrument. The sample is illuminated at 45° and measured at 0° and 45°. By means of a special circuit, the ratio of these two measurements may be read directly from an automatically indicating scale in terms of "per cent luster. Samples are easily and quickly prepared from .yarn skeins on special holders, and a similar but narrower holder is used for measuring combed fibers from pinches of blended raw stock samples. Results are related to goniophotometric measurements made for several conditions of illumination. Luster, sample preparation and holder, the instrument, calibration, and luster results for the USDA's Standardized Variety Series of cottons are discussed and summarized. The instrument is an adapta tion of a simplified all-purpose glossmeter under development by R. S. Hunter.