When an optical module is replaced after three to five years of use, the original margin of the link cannot be directly quoted. Aging lines need to be recalculated regularly. The method is not complicated: find the acceptance baseline, record each change, and compare the two, and the new margin will come out.

Retrieve the baseline: actual measured value minus ledger value

Use OTDR to retest the entire process, paying attention to the location and loss of each event point; at the same time, clean the end face on the equipment side and read the optical power, and put them side by side with the completion record. If the difference between the two readings exceeds 1 dB, first check for end surface contamination and bending. Do not rush to attribute it to fiber aging. For long paragraphs, it is recommended to read the two wavelengths separately and list the wavelength-related losses separately.

Each additional operation must be recorded

  • Add a weld: calculated as 0.1 dB, indicate the location
  • Change jumpers or add adapters: 0.3 to 0.5 dB per pair
  • Fiber rework and shaft diversion: check the bending radius and then retest for confirmation.
  • Change the equipment to run in a wide temperature cabinet: leave another 1 dB for the temperature item

Three destinations with less than 3 dB margin

The recalculation results generally point to three paths: if the loss is concentrated in individual joints or bending points, clean the process first and then retest; if the route becomes longer due to cutover, upgrade the module to one level, for example, switch toSFP 2.5G single mode dual fiber 80KM optical module; If the light collection is too high and reaches the overload point, add a fixed attenuator to push it back to the middle of the range. For lines with large operation and maintenance radius, such as tunnels and stations, it is recommended to build baselines when they are opened. You can refer toOptical fiber project for vehicle monitoring system in highway tunnel in a province, and then check back regularly.

The balance ledger does not need to be complicated: a table with one row for each segment, recording the baseline, changes and current balance. If you need field templates, please contact EB-LINK technical support at 0755-83179002.