OLT-85/OLT-85P
79
13 A
PPENDIX
- R
EFERENCING
M
ETHODS
L
OOPBACK
AND
R
EMOTE
R
EFERENCING
13
A
PPENDIX
- R
EFERENCING
M
ETHODS
For a fiber loss measurement per length, connection, and splice,
the technician must indicate the fiber length, the number of
connections, and how many splices are present in the fiber
system under test.
There are four additional connections required to perform a test:
• A connection at the local device to the local reference jumper.
• A connection from the local reference jumper to the fiber
system under test.
• A connection from the fiber system under test to the remote
reference jumper.
• A connection from the remote reference jumper to the remote
device.
The reference method chosen (One, two or three jumper
reference) will determine how many of these connections are
included in the loss measurement and in the loss limit.
NOTE:
In the following procedures, test-reference jumper cables are
assumed to:
• be high-quality and in good condition
• be equal in length and relatively short
• have no end-face damage or debris
Disconnecting the connection at the transmitter of the OLT-85/
OLT-85P after a reference is performed invalidates the reference.
Since the connection at the receiver is not glass-to-glass, it can
be removed without affecting the reference. Any loss associated
with the test-reference jumper cables is negligible.
Loopback and Remote Referencing
NOTE:
The figures below display referencing methods (loopback/
remote) for single-mode fibers. The contents described apply
equally to measurements under multi-mode fibers.
Loopback Referencing
This mode is used to measure loss of a fiber loop or any optical
component connected to the loop. The internal laser source and
powermeter are locked.
