ISO 6989:1981

Textile fibres — Determination of length and length distribution of staple fibres (by measurement of single fibres)

Specifies three methods for determination – method A: on a straightened fibre on a graduated rule, under a light tension applied with the aid of forceps and grease; – method B: measurement, using an opisometer, of the length of the image of fibre enlarged by projection on a screen; – method C: by use of a semi-mechanical device. – Intended to replace two existing International Standard, ISO 270 and ISO 1822.