The attenuation measurement determines the power loss in an assembled fiber optic cable. The main focus is to determine the loss at the connector transitions. Loss values that are too high will exceed the attenuation budget of a fiber optic network, rendering it impossible to operate. To analyze the attenuation values, power meters with a measuring accuracy of ± 0.05 dBm are used in accordance with the IEC 61300-3-4 Standard.
The IEC 61300-3-3 Standard generally differentiates between two methods:
- Method B (Attenuation at the individual connector)
- Method C (Total attenuation of the test object)
Typical attenuation values:
- 20 dB/km for SM fibers at 1550 nm
- 35 dB/km for SM fibers at 1310 nm
- 7 dB/km for MM fibers (G50) at 1300 nm
- 5 dB/km for MM fibers (G50) at 850 nm
- 10 dB/km for PCF at 660 nm
- 230 dB/km for POF at 660 nm
- 05 dB for a fusion splice
- 3 dB for a mechanical splice
- 5 dB for a connector pair
- Splitter/check points: variable (e.g. 1:32 Splitter ≈ 17dB)
