OTDR Fiber Optic Test Results

[Dobber1978]

I have two sets of test results for our single mode fiber optic line, one done at 1310nm and one at 1550nm, I was under the impression that I should get a little higher losses at 1550nm but this was incorrect as the OTDR was showing much higher losses at 1310nm,

Can anyone explain?

Thanks
Jeff

 

[robertjo24]

Average loss of Single-mode fiber is listed as:
1310 nm 0.4 dB/km
1550 nm 0.3 dB/km

Dispersion-Shifted fiber will have even lower loss at the 1550nm end.

 

[Dobber1978]

That explains it, guess I should look at those specs a little closer, I was getting about an extra 2db for a 16km run.

Thanks

 

[robertjo24]

Also,

If there is a big disparity between the losses at 1310 and 1550, it could indiacate a tight bend/pinch point.