METHOD FOR DESIGNING CONDITION OF PROOF TEST OF OPTICAL FIBER, METHOD FOR CALCULATING INFORMATION ON MECHANICAL STRENGTH, AND PROGRAM THEREFOR

PROBLEM TO BE SOLVED: To provide a method for designing a proper condition of a proof test for screening an optical fiber, and a method for calculating information on mechanical strength such as more appropriate breaking strength probability.SOLUTION: A method for designing a condition of a proof test of an optical fiber, includes, from a condition of the proof test of an optical fiber in which success of the proof test is confirmed, using a formula specifying a successful condition of the proof test to design the condition of the proof test of the new optical fiber. Moreover, a method for calculating information on mechanical strength, includes: applying a tensile test to the optical fiber screened on the condition, and calculating a predetermined parameter so that an accumulated hazard function of an equation (21) is fitted to a high-strength part of a graph of breaking strength/accumulated hazard indicating the result, and an accumulated hazard function of an equation (22) is fitted to a low-strength part thereof (S21); and then using n at S11, at S13, a market load (requirement specification) , and a predetermined parameter at S21 and also using Bat S12 as a B value, to calculate breaking strength probability in a market time t(S22).