Method of excess fiber length estimating based on low subzero temperature climatic test

Method of optical cable lifetime prolongation

“…From the backscattering characteristics by known method [24][25][26] were calculated distributions of bending radius along the cable at the temperature -60 0 C at the first cycle and at the same temperature at the last cycle. Here attenuation coefficient for backscattering characteristics was calculated by approximating the regular sections of characteristics by linear function using the least squares method.…”

Problems of reliability of optical cables at low temperatures

“…The dependence of the helix pitch length from the fiber excess length can be expressed as [10][11][12] :…”

“…The lifetime of the optical fibers is determined by stress corrosion process and depends from the mechanical stress in the optical fiber [1][2][3][4][5][6][7] . Researches of deformations of optical cables at the low temperatures showed that residual radial deformations of optical cables loose tubes can be the cause [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] . Such deformations can be the cause of optical fibers stress at low negative temperatures and the cause of optical cables reliability decrease at fiber optical communication lines maintenance.…”

Optical Time-Domain Reflectometry Methods For Measurement Of Distribution Of Excess Optical Fiber Length In Fiber-Optic Cable Loose-Tubes

“…Параметры η(λ i ) и R C определяются либо экспериментально, либо рассчитываются [17]. В работах [18][19][20] предлагается для локализации в кабеле участков с повышенной кривизной ОВ сопоставлять результаты измерений характеристик обратного рассеяния ОВ, выполненные при положительной и низкой отрицательной температуре. Так в [20] предложен способ измерения распределений избыточной длины ОВ в модульной трубке на строительной длине ОК, заключаю-…”