The iso dis 11801 standard section 71 general specs

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The ISO DIS 11801 standard, Section 7.1 General specs for 100 ohm and 120 ohm balanced cable lists three different minimum bend radii. Minimum for pulling during installation is 8x cable diameter, min installed radius is 6x for riser cable, 4x for horizontal. For fiber optic cables not in tension, the minimum bend radius is 10 x diameter; cables loaded in tension may not be bent at less than 20 x diameter. SP-2840A states that no f/o cable will be bent on a radius less than 3.0 cm (1.18-in). Some manufacturers recommendations differ from the above, so it is worth checking the spec sheet for the cable you plan to use. ------------------------------ Subject: 20.0 Fiber Optic Cable 20.1 Multimode (MM) Fiber Step index or graded index fiber. In North America the most common size is 62.5/125; in Europe, 50/125 is often used. These numbers represent the diameter of the core (62.5) and diameter of the cladding (125) in microns. Multimode fiber is typically used in applications such as local area networks, at distances less than 2 km. 20.2 Single Mode (SM) Fiber Single mode fiber has a very small core. Typical values are 5-10 microns. Single mode fiber has a much higher capacity and allows longer distances than multimode fiber. Typically used for wide area networks such as telephone company switch to switch connections and cable TV (CATV). 20.3 Loose Buffer The fiber is contained in a plastic tube for protection. To give better waterproofing protection to the fiber, the space between the tubes is sometimes gel-filled. Typical applications are outside installations. One drawback of loose buffer construction is a larger bending radius. Gel-filled cable requires the installer to spend time cleaning and drying the individual cables, and cleaning up the site afterwards. 20.4 Tight Buffer Buffer layers of plastic and yarn material are applied over the fiber. Results in a smaller cable diameter with a smaller bending radius. Typical applications are patch cords and local area network connections. At least one mfr. produces this type of cable for inside/outside use. 20.5 Ribbon Cable Typically 12 coated fibers are bonded together to form a ribbon. There are higher density ribbons (x100) which have the advantage of being mass-terminated into array connectors. A disadvantage is that they are often harder, and require special tools to terminate and splice. 20.6 Fiber Connectors There are a lot of different types of connectors, but the ones commonly found in LAN/MAN/WAN installations are: FSD - Fixed Shroud Device, such as the FDDI MIC dual-fiber connector. SC - A push-pull connector. The international standard. The SC connectors are recommended in SP-2840A. The SC connector has the advantage (over ST) of being duplexed into a single connector clip with both transmit/receive fibers. SMA - Threaded connector, not much used anymore because of losses that change with each disconnection and reconnection.
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  • Spring '12
  • BryanJensen
  • Twisted pair

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