(1) optical fiber splicing. Should follow the principle of optical fiber splice is: When the number of cores equal to the corresponding color beam tube fiber optic butt within the same, the core number is not the same, in order to meet a large number of cores, followed by a small number of cores. (2) fiber optic splice methods are: welding, active connections, mechanical connection of three. Most used in engineering welding method. With this welding method contact loss, return loss, and high reliability. (3) fiber optic splice processes and procedures:

① stripping cable and cable box fixed to follow. Be careful not to hurt the beam tube stripping lengths are about 1m, the ointment wiped clean with a tissue, penetrates the fiber optic cable connecting box, fixed wire must be pressed, not loose. Otherwise, it may cause the cable to break roll core.

② sub-fiber optical fiber through the heat shrink tubing. The different beam tube fiber of different colors separately, through the heat shrink tubing. Strip the coating of optical fiber is very fragile, use heat shrink tube, can protect fiber splices.

③ Open Furukawa S176 splicer power supply, the use of 42 kinds of preset programs are welded together, and timely in use and after use to remove welding machine in the dust, in particular fixture, each mirror and V-groove of dust and fiber is not broken . CATV fiber used with a conventional single-mode fiber and dispersion shifted single-mode fiber, the operating wavelength of 1310nm and 1550nm there are two kinds. So, before you want to select an appropriate fusion welding procedures and work according to the fiber wavelength system. As there are no special circumstances, generally use the automatic welding process.

④ production of the fiber end face. Fiber end production will directly affect the quality of the connection, so be sure to do qualified before welding end surface. Strippers with special coating stripped, and then clean cotton dipped in alcohol wipe several times on the bare fiber, the force should be moderate, then cut with precision fiber cleaver fiber of 0.25mm (outer coat) optical fiber, cut length of 8mm-16mm, for 0.9mm (outer coating) fiber cut length is only 16mm.

⑤ Place fiber. The fiber on the welding machine V-shaped grooves, carefully pressed on the optical fiber and optical fiber clamp plate, fiber position in the platen to be set according to the length of the fiber cut, off the windshield, you can automatically complete fusion, just 11 seconds.

⑥ out of the fiber with heat shrink tube furnace. Open the windscreen to remove the fiber from the welding machine, and then shrink tube on the bare fiber center, into the heating furnace. Heater may be used 20mm and 40mm miniature heat shrink tubing and heat shrink tubing 60mm general, 20mm heat shrink tubing required 40 seconds, 60mm heat shrink tubing is 85 seconds.

⑦ disc fiber fixing. The good fiber splice tray to the optical fiber housed disk, the disk fiber, the radius of the rim, the greater the curvature, the smaller the total loss of the line. So be sure to maintain a certain radius of where the laser transmission in the core, to avoid unnecessary losses.

⑧ seal and hang. Field continuation box must be sealed to prevent water. After the splice tray water, due to the optical fiber and optical fiber splices long-term immersion in water, it may appear first portion of the fiber attenuation increases. Wear a stainless steel hook and hung suspended line. At this point, fiber splicing is completed. 2, fiber testing fiber in the erection, welding after the completion of the work is to test the instrument used mainly OTDR tester, with Canadian EXFO's FTB-100B Portable Chinese color touch screen OTDR tester (Dynamic Range 32 / 31,37.5 / 35 , 40 / 38,45 / 43db), you can test the location of fiber break; full loss optical fiber link; understand the loss along the fiber length distribution; optical fiber splice connector loss points. To test accuracy, OTDR tester pulse size and width to the appropriate choice, given the factory in accordance with the refractive index n index value is set. In determining the point of failure, if the cable length is not known in advance, can be placed in the automatic OTDR, generally identify a fault point location, and then placed in the Advanced OTDR. The pulse width and choose a smaller size, but to correspond to the cable length, reduce blind spots and coordinates line up to coincidence, the more accurate the smaller the width, of course, the pulse small curve display appears after the noise, to be just right. Then increase access probe fiber plate, in order to prevent Vicinity has blind spots is not easy to find. Breakpoint on the judgment, if not break the connection box office, will continue near open box, connected to the exact distance OTDR tester, test the fault point distance test point, the use of standard cable on the meter it is easy to find fault . When troubleshooting use meter mark on Stranded Stranded cable has a rate problem that the length of the cable and the fiber length is not equal to the length of the fiber is approximately 1.005 times the length of the cable, using the above method may preclude successful many breakpoints and high loss points.