METHOD AND DEVICE FOR MEASURING STRESS-STRAIN CHARACTERISTIC OF OPTICAL FIBER

摘要

PURPOSE:To evaluate accurately stress-strain characteristics by obtaining elongation in accordance with a ratio of peripheral speeds of both capstans which is obtained when rotative velocities of both capstans are so controlled that the length of a sample fiber between both capstans is constant. CONSTITUTION:In case of measurement of stress-strain characteristics of an optical fiber 1, variance of the angle of an arm supporting a dancer roll 6 at the time when it is rotated around a fulcrum P is detected by a potentiometer, and elongation of the optical fiber 1 is detected and is fed back to a control part of a servo motor which drives a capstan 5. The rotative velocity of the capstan 5 is controlled automatically by this feedback to keep always the length of the optical fiber 1 between points B and C constant. Consequently, the extent of elongation of the optical fiber 2 is obtained on a basis of a ratio of peripheral speeds of capstans 4 and 5 in this state, and stress-strain characteristics are evaluated accurately.