Fluke OF-500-01 OptiFiber, Technical Reference Handbook, Page: 126 / 278

OF-500 OptiFiber Certifying OTDR
Technical Reference Handbook
3-50
Diagnosing OTDR Test Failures
Tables 3-6 and 3-7 describes some typical causes of OTDR
test failures.
See also the table in Appendix C, which shows results from
a survey on common causes of fiber link failures.
Tip: If a trace shows multiple failing or unusual events, it's
usually best to start looking for faults at the nearest
event. Some faults can cause misleading events farther
down the cabling.
Table 3-6. Diagnosing OTDR Test Failures
-continued-
OVERALL LOSS fails
•
There is one or more dirty or damaged connections in the cabling. Check the OTDR trace or event table for
high-loss reflective events.
•
The wrong fiber type is selected on the OTDR tab in Setup.
•
A patch cord, launch fiber, or fiber segment has the wrong core size, backscatter coefficient, or mode field diameter. If
the patch cords and launch fiber are the correct type, check the OTDR trace for mismatched cable in the cabling.
•
The cabling has a bad fusion or mechanical splice or a sharp bend. Use the OTDR trace or event table to locate these
faults.
Note
OVERALL LOSS may show a WARNING if the first or last event is hidden.