User Manual

26
FAQs Tips
Why do I need to use
a launch and receive
cable?
A launch cable allows the OTDR to settle
down after the initial pulse and provides
a reference cable for testing the first
connector on the ber under test. A receive
cable provides a reference cable for testing
the last connector of the ber under test.
What is the purpose of
the Live Mode?
With a launch cable, the Live or “real-time”
mode may be used to quickly view many
short ber links. It can also be used to
quickly “trace” short ber link bers.
What is the advantage
of the Expert Auto
Mode?
User is able to select a single l and have the
OTDR set the other test parameters.
Can I save traces for
viewing later?
Yes. There is a dedicated Save key. In the
Main Menu “File Tab”, set up the location/
folder (Internal, CF, or USB) to save the le,
the le naming format and ber number.
The ber number will increment after each
trace is saved.
Test in feet or meters?
If you know your ber distances in feet, it
may be benecial to measure distances to
events/faults in feet.
Fiber loss specifications are given in
dB/km. Therefore it is often benecial to
measure bers in meters/kilometers when
loss results are required.
Expert OTDR Setup
RANGE: Length
• Too Short: you will not capture the
entire ber length
• Too Long: trace will be squashed to left
side of Screen
• Good Range: 1.5 to 2 times length of
actual ber
PULSE WIDTH:
• Too Narrow: trace disappears into noise
oor before end of ber is reached
• Too Wide: events can not be resolved
• Good Pulse Width: Events can be seen
and trace is smooth
AVERAGES:
• Too Few: Trace is noisy, trace oor is
too high
• Too Many: Trace is smooth but wastes
time
• Good Number of Averages: smooth
trace