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Fluke Networks CertiFiber Pro Users Manual User Manual

Page 318

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Versiv Cabling Certification Product Family
Technical Reference Handbook

296

Table 15.

The event is a dirty, scratched, cracked,
misaligned, or unseated connector.
Misaligned or unseated connectors can also
cause large reflections that produce ghosts.
Clean and inspect the connection, then do
the test again.

A good connector has a sharp bend or
crack within its dead zone. The tester can
possibly show a sharp bend as a break,
especially at longer wavelengths or in
Manual OTDR mode with smaller
resolution settings.

The event is a crack in the fiber. Use a visual
fault locator to find the fault.

The event is a bad fusion or mechanical splice or a sharp bend.

The event is a connection between mismatched fibers (different
backscatter coefficients, core sizes, numerical apertures, or other
parameters). The top example could be caused by a larger core (on the
left) connected to a smaller core. Do an OTDR test from the other direction
and look for a reflective event that has a gain.

The launch cord has PC or UPC connectors, but the link has APC
connectors.

Causes of OTDR Test Failures (continued)

GPU33.EPS

The trace shows a large reflective event with
high loss (top) or excessive tailing (bottom). The
tester can possibly show it as the End event,
though it occurs before the end of the link.