Fluke Versiv Series Technical Reference Handbook page 473

Table 17. Event Types in the Event Table (continued)
Gainer
(continued)
An apparent gain in the
strength of the returned
signal. A gainer shows as a
negative value of loss.
Page 501 shows OTDR
traces with gainers.
No Fiber
The tester does not see a
fiber connected to the
OTDR port.
Chapter 12: The OptiFiber Pro HDR OTDR Module
If you do the OTDR test from the other end,
the gainer event will show a loss. If you save
the result with the same ID as the result from
the other direction, the tester automatically
calculates bi-directional averages of loss
measurements and includes the averaged
values in the test record. The averaged loss is
more accurate than the loss measured in one
direction. See "Averaged Bi-Directional
Results" on page 478.
Gainers at launch events can occur when the
launch cord does not have the same properties
as the fiber under test. In this situation, you
can get more reliable results if you do a bi-
directional test. Use a tail cord that has the
same properties as the launch cord and use
Launch + Tail compensation.
No fiber is connected to the OTDR port, the
fiber is broken or cracked near the port, the
port has very high loss, or the fiber is too
short.
Connect a fiber to the port or to the launch
cord. If a fiber is connected:
 Make sure the connection is tight and there
are no breaks or cracks in the fiber near the
port.
 Clean and inspect the port connector.
 Do a Manual OTDR test with a narrow pulse
width.
HDR OTDR Results
-continued-
437