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在此处键入
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在此处键入
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12
Normal curve
A normal trace shows as above, the A mark is a start-peak and the B mark is a end-reflection-peak.
The tested trace is oblique, the total loss will become bigger with the increasing of the fiber length. The
total loss(dB) divides total length is the average loss(dB/km) of a fiber.
Curve with Jumper Connected
If there is additional reflection peak in a tested trace, this may be caused by a connection point or
some other reasons. Anyway, appearance of the reflection peak shows that the two connecting
surfaces of the connection are smooth. The smoother the connection surfaces are, the higher the
reflection peak is.
For an instance, if a broken optical line is under test, the OTDR trace will show a broken point. After a
maintenance of this line, use the OTDR test it again, we may see a reflection peak replacing the broken
point on the OTDR trace, this shows the maintenance is done.
Curve with Broken Point
If the tested trace is just like the figure shows above, this might be caused by several reasons like: a bad
connection between the connector and the lunching port, the optical pulse cannot be launched into
the optical fiber or a short distance broken point of the tested fiber from the initial connection and the
preset testing distance and pulse width is larger.
To fix this problem, we should:
1. Check the connection of the connector and the launching point