Measuring and testing continuous elongated textile material

摘要

A device for determining hairiness of thread-like element comprises a light source (111) and first light detecting means (113) comprising a plurality of position resolving detector elements. The light source and the detecting means are placed in a manner that the thread-like element is illuminated by light emitted from the light source and that a proportion of light emitted from the thread-like element upon illumination by the light source the thread-like element casts a shadow on the first detecting means. The device further comprises signal evaluation means for evaluating a time-dependent signal produced by the first detecting means, carrying out the following steps:
€¢ evaluating a total hair protrusion signal indicative of how far hairs protrude from the thread-like element,
€¢ evaluating a total hair length signal indicative of the total length of the protruding hairs and being proportional to the total shadow signal, and
€¢ evaluating a time dependent hairiness signal based on the total hair protrusion signal and on the total hair length signal.