fiber

[elsayed1976]

hi iam an engineer in egyptian electricity co. i work in the control center which we use fiber NT. i meet a problem when we test the fiber cabel that some time we found the attenuation at 1550nm is larger than the attenuation at 1310nm at the same distance and condition and it is not normal can i get the reason for it and how to reach to the normal state..............
thanks alot.. ELSAYED

 

[robertjo24]

Two things that I know of that could cause this:

Dirty fiber connectors- clean the ends of the fiber connectors with isopropyl alcohol and a lint free cloth.

Tight bends- single mode fiber is very sensitive to tight bend radiuses, check all you jumpers and cable runs and look for tight bends or pinch points.

Are you measuring attenuation with an OTDR or an optical meter? If you are using an OTDR, measure the distance to the attenuation anomaly and check the cable at that point.