Continuous measurement of geometry of optical fibre and coating - by measuring brightness profile of cross=section optically and recording in digital form

摘要

Continuous measurement of the geometry of optical fibres and their coating(s) involves passing the optical fibre through a measuring cell and irradiating it with a beam of light. The novelty is that the brightness profile produced by passing light through a length of the optical fibre is traced optically and recorded as digital brightness distribution over the cross-section of the optical fibre. Pref. the geometrical data found from the brightness distribution are used as input for regulation of the optical fibre dimensions. A beam of white light is used. After passing through the first measuring cell, the optical fibre is passed through a second cell, where it is irradiated from a direction shifted in the radial direction w.r.t. the first, pref. through an angle of 90 deg. . The measuring cell is filled with liquid, pref. volatile aromatics, esp. a mixt. of MEK, toluene and CS2. The brightness profile is recorded with a video camera connected to a processor, monitor and computer for digital evaluation or with a video camera conencted to a discriminator. USE/ADVANTAGE - The technique allows test during and after mfr. to detect flaws and the data can be used for on-line control during mfr.