Fluke OF-500-01 OptiFiber, Technical Reference Handbook, Page: 127 / 278

Using the OTDR
Diagnosing OTDR Test Failures
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3
Table 3-6. Diagnosing OTDR Test Failures (cont.)
LARGEST EVENT fails
•
The event is a dirty or damaged connector. Check the OTDR trace or event table for high-loss reflective events.
•
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 event is a bad fusion or mechanical splice or a sharp bend. Use the OTDR trace or event table to locate these faults.
FIBER LENGTH fails, a known length of cabling measures too long or too short, or the distance to an event is wrong.
•
The fiber is broken or there is an open connection where the trace shows the fiber end.
•
The wrong fiber type is selected on the Cable tab in Setup.
•
The index of refraction needs adjustment. Change n on the Cable tab in Setup.
•
The wrong test limit is selected on the OTDR tab in Setup.
An event shows a FAIL result, but the event does not exceed any limit.
The segment before the event exceeds a limit. To see results for the segment,
C
View Details from the EVENT TABLE
or the OTDR SUMMARY screen.