Fiber optic cable inspection is an important step in ensuring the normal operation and transmission quality of fiber optic cable lines. It involves testing and evaluating various performance parameters of optical cables to ensure their integrity and reliability.

Fiber optic cable inspection usually includes the following aspects:

1. Appearance inspection: First, conduct an appearance inspection to check if the optical cable reel is deformed, if the protective plate is damaged, and if all the accompanying information is complete. After opening, check the outer skin of the optical cable for damage, whether the sealing of the cable end is intact, and whether the cable end markings are correct and obvious.

2. Retesting of optical cable length: Sample the length of the optical cable for retesting, and use an optical time-domain reflectometer (OTDR) to test the fiber length according to the refractive index coefficient specified by the manufacturer. At the same time, calculate the length of a single fiber optic cable based on the twisting coefficient indicated by the manufacturer to obtain the actual length of the cable.

3. Fiber optic cable single disc loss test: used to observe and determine whether the fiber optic cable is crushed, broken, or slightly cracked during cable formation or transportation. At the same time, it is also possible to observe whether the loss distribution of the fiber with length is uniform and whether there are defects in the fiber.

4. Observation of fiber optic backscatter signal curve: Use an OTDR tester to test the fiber optic backscatter signal curve to determine the attenuation and breakpoint position of the fiber optic. The curve should have a good linearity and no obvious steps, and there should be no abnormalities at the joints.

5. Insulation inspection of protective layer: Check the insulation of the optical cable protective layer to ensure good insulation of the optical cable to the ground. This is usually measured at the junction monitoring marker lead out line to measure the insulation of the metal sheath to ground.

In the process of fiber optic cable testing, it is also necessary to pay attention to maintaining consistency in testing conditions, such as the model of testing instruments, operating methods, and instrument parameter settings. At the same time, it is necessary to record in detail the remaining fiber optic cables and the cumulative length of each joint point position, as well as the total attenuation value of the relay section fiber optic cables, in order to deduct them when converting the length of the fault point routing.

The purpose of fiber optic cable inspection is to ensure the transmission quality and reliability of the fiber optic cable line, and to promptly detect and handle potential problems. By using scientific and standardized testing methods, the normal operation of optical cable lines can be ensured, meeting the needs of communication services.