Fluke DSX-8000 - How to Compensate for Launch and Tail Cords; Methods of Launch Compensation

Chapter 11: The OptiFiber Pro OTDR Module
About Launch and Tail Cords
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 To help make sure the tester can find the Tail event
when you do tests on fibers with APC connectors,
use a tail cord that is terminated with a non-APC
connector at the far end.
Notes
Do not use hybrid patch cords to connect the launch
or tail cords to the cabling under test. Use launch
and tail cords with the correct connectors to connect
directly to the cabling under test. This gives the best
measurement of the first and last connectors in the
link. Launch and tail cords with different types of
connectors are available from Fluke Networks.
The style of the case for your launch/tail cords can be
different from the cords shown in this manual.
How To Compensate for Launch and Tail Cords
The launch compensation function lets you specify the lengths of
the launch and tail cords. The OTDR can then remove the losses,
lengths, and attenuation coefficients of the launch and tail cords
from overall OTDR results. It does not remove the losses of the
connections at the launch and tail cords.
Launch compensation also gives a more accurate ORL (optical
return loss) measurement if you entered the correct backscatter
coefficient for the fiber you will test.
Methods of Launch Compensation
The tester has four methods of compensation:
 Launch Only: Does an OTDR test to find the end of the launch
cord.
 Launch + Tail: Does an OTDR test to find the ends of the
launch cord and tail cords.