Operation Manual

Using the OTDR Module
Looking at OTDR Test Results
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7
Table 7-4.
• Overall loss cannot be measured, either because no backscatter was detected or the fiber is too short
for attenuation to be measured.
• The fiber is too short for the tester to detect events after the first deadzone.
• There is a bad connector or broken fiber within a few meters of the tester.
• There are bad connections on the fiber.
• The launch or receive fiber is too short.
• There is a problem with the launch fiber or patch cord.
• The pulse width is too long.
• The wrong fiber type is connected.
• A multimode fiber is connected, but the connection is dirty.
OTDR Measurement Details (cont.)
-continued-
Detail Description
Warnings Cannot measure overall loss:
Fiber detected on other OTDR port:
There is a fi
ber connected to the unused OTDR port. Reflections from the fiber can affect measurements
on the port being used. Remove the fiber.
A singlemode fiber is connected to the multimode OTDR port: