| 释义 |
strength member have very low elongation at the expected tensile loads.The strength members in optical fibers commonly are of aramid fiber yarn, invented and marketed by Dupont as Kevlar®, while those in copper cables commonly are rods of fiberglass epoxy (FGE). As both aramid and fiberglass are dielectrics, they provide strength without contributing to issues of electromagnetic interference (EMI). Steel strength members were used historically, but are electrically conductive, which presents problems not only in terms of EMI, but also with respect to power surges such as those caused by lightening strikes.As steel and fiberglass, however, are more thermally stable than aramid fiber, they are preferred when extreme cold temperature performance is required. See also aramid, dielectric, EMI, FGE, and fiberglass. |