Fluke OF-500 OptiFiber, Техническое справочное руководство

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Using the OTDR
Looking at OTDR Test Results
3
3-35
Table 3-4. Event Types (cont.)
Event Possible Causes and Solutions
GAINER
An apparent gain in the
strength of the returned
signal.
Caused by a splice between two fibers with different backscatter coefficients, numerical
apertures, core diameters, or mode field diameters.
Check the fiber type on either side of the splice. Replace fiber if necessary. Matching fibers
may have different tolerances, which can cause gainers at a splice. In these cases, the splice
is good and does not require rework.
Tip: If you test the fiber from the other end, the gainer event will show a loss. Adding this
loss to the event’s gain provides the true loss of the event.
OUT OF RANGE
The tester did not find an
end event.
This can occur in Manual mode when the selected range is too short.
In Auto mode, OUT OF RANGE can occur when the cabling is much longer than the
module's range. Rarely, very bad connections along the cabling can cause the OTDR to
select a range that is too short.
For Manual mode, select a higher range on the OTDR tab in Setup.
For Auto mode, compare the expected cabling length to the module's test range. If the
length is within range, try testing in Manual mode with the maximum range setting.
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