OTDR Testing

OTDRs are powerful test instruments for fiber optic cable plants, if one understands how to properly set the instrument up for the test and interpret the results. When used by a skillful operator, OTDRs can locate faults, measure cable length and verify splice loss. Within limits, they can also measure the loss of a cable plant. About the only fiber optic parameters they don't measure is optical power at the transmitter or receiver.

OTDRs are almost always used on OSP cables to verify the loss of each splice and pinpoint stress areas caused by installation. They are also widely used as OSP troubleshooting tools since they can locate problems in the cables. Most ODTRs lack the distance resolution for use on the shorter cables typical of premises networks.

In order to use an OTDR properly, it's necessary to understand how it works, how to set the instrument up properly and how to analyze traces. Most OTDRs offer an "auto testing" option. Using that option without understanding the OTDR and manually checking its work often leads to problems. Let's look at how an OTDR works and see how it can help testing and troubleshooting. (Read more about the OTDR)

December 21, 2011

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