阐述了通过测量投影到观察屏幕上的高放大图像来确定圆形和近圆形横截面纤维平均直径的程序。该方法适用于所有圆形或近圆形横截面的纤维。它可以应用于所有加工阶段的羊毛纤维，以及一些人造纤维，例如聚酰胺、聚酯和玻璃，以及数量有限的聚丙烯酸和再生纤维素型纤维。该方法不适用于嵌入乳胶或沥青中的纱线和纤维。该标准主要基于ISO 137。

Sets out a procedure for determining the mean diameter of fibres of circular and near-circular cross-section by measuring highly magnified images projected onto a viewing screen. The method is applicable to all fibres of circular or near-circular cross-section. It may be applied to wool fibres taken from all stages of processing, as well as to some man-made fibres, e.g. polyamides, polyesters and glass, and to a limited number of polyacrylic and regenerated cellulose type fibres. The method is not applicable to yarn and fibre embedded in latex or bitumen. This Standard was largely based on ISO 137.