| 摘要 |
A method of measuring the twist imparted to an optical fiber comprises the steps of advancing the optical fiber in a predetermined direction and at a predetermined velocity, imparting to the optical fiber, during the step of advancing, a twist about its axis, measuring the diameter of the optical fiber (210) during the step of advancing, to generate a time-based signal indicating the diameter, and processing this signal to find a value indicating the imparted twist. The step of processing comprises the principal steps of transforming in the frequency domain (240) the signal relating to the measurement of the diameter, calculating the power spectrum (250) of the signal thus obtained, distinguishing in this power spectrum the signal peaks correlated with the imparted twist (270), determining the maximum frequency (280) associated with these signal peaks, and dividing the value of this maximum frequency by the value of the velocity of advance of the fiber to find the value indicating the imparted twist (290).
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