METHOD OF MEASURING THE VELOCITY AND/OR LENGTH OF ENDLESS WEBS OF TEXTILE MATERIAL AND APPARATUS FOR CARRYING OUT THE METHOD

摘要

PCT No. PCT/DE88/00143 Sec. 371 Date Jan. 16, 1989 Sec. 102(e) Date Jan. 16, 1989 PCT Filed Mar. 15, 1988 PCT Pub. No. WO88/07208 PCT Pub. Date Sep. 22, 1988.A method and an apparatus for measuring the velocity and/or length of endless webs of textile goods are described. The textile web is irradiated with a light beam of which one deflects a first portion prior to impinging on the surface of the textile web and one directs the deflected light beam to evaluation means. The light beams reflected from the surface of the textile web are directed through a convex lens and are also directed to the evaluation means so that the corresponding light beams are superimposed. The velocity and/or the length of the web of textile goods are determined from the frequency of the interference formed by the superposition of the light beams.