| 摘要 |
PURPOSE:To improve dielectric strength characteristics and to obtain an optical fiber cord adaptable to application in a monitor device and protection device of high voltage apparatus such as switches, voltage transformers or the like by providing a glass fiber layer as a reinforcing fiber layer between an optical fiber core and a jacket. CONSTITUTION:A primary covering 4 of a silicone resin and a secondary covering 5 of nylon or the like are applied on the outside circumference of a core 3 consisting of a core 1 and a clad 2, whereafter alkali-free glass fiber (Japanese Industrial Standards JIS R 3414 or the like) layer 6 is formed thereon as a reinforcing fiber layer. A jacket 7 is formed of PVC on the outside circumference of the layer 6. The insulation resistance of the layer 6 is made equal to the insulation resistance of the jacket 7 by the use of the alkali-free glass and the dielectric breakdown voltage of the optical fiber cord is improved. The cord is therefore usable safely for the monitor and protection devices for high voltage apparatus. |
