When it heats the production manner and the device null hole equipped optical fiber basic material of measuring method and the device, and the hole equipped optical

摘要

PROBLEM TO BE SOLVED: To provide a method and device for measuring a diameter of a void in an optical fiber having voids without damaging the optical fiber, capable of increasing productivity, and further having a wide application range, and capable of precisely measuring the diameter of the void of the optical fiber.;SOLUTION: When passing the optical fiber 22 having voids obtained by heating and melting an optical fiber base material having voids for drawing between a pair of electrode plates 14A, 14B disposed opposingly, capacitance is measured, and the void diameter of the optical fiber 22 having voids is calculated using a correlation relationship between the capacitance obtained in advance by an actual measurement and the void diameter, based on the measurement value.;COPYRIGHT: (C)2010,JPO&INPIT