How to Read an OTDR Trace - from Corning Cable Systems

www.fiberoptics...
www.fiberoptics...
An optical time-domain reflectometer (OTDR) is an optoelectronic instrument used to characterize an optical fiber. An OTDR injects a series of optical pulses into the fiber under test. It also extracts, from the same end of the fiber, light that is scattered (Rayleigh backscatter) or reflected back from points along the fiber. (This is equivalent to the way that an electronic time-domain reflectometer measures reflections caused by changes in the impedance of the cable under test.) The strength of the return pulses is measured and integrated as a function of time, and is plotted as a function of fiber length.
An OTDR may be used for estimating the fiber's length and overall attenuation, including splice and mated-connector losses. It may also be used to locate faults, such as breaks, and to measure optical return loss. To measure the attenuation of multiple fibers, it is advisable to test from each end and then average the results, however this considerable extra work is contrary to the common claim that testing can be performed from only one end of the fiber.
In addition to required specialized optics and electronics, OTDRs have significant computing ability and a graphical display, so they may provide significant test automation. However, proper instrument operation and interpretation of an OTDR trace still requires special technical training and experience.
OTDRs are commonly used to characterize the loss and length of fibers as they go from initial manufacture, through to cabling, warehousing while wound on a drum, installation and then splicing. The last application of installation testing is more challenging, since this can be over extremely long distances, or multiple splices spaced at short distances, or fibers with different optical characteristics joined together. OTDR test results are often carefully stored in case of later fiber failure or warranty claims. Fiber failures can be very expensive, both in terms of the direct cost of repair, and consequential loss of service.
OTDRs are also commonly used for fault finding on installed systems. In this case, reference to the installation OTDR trace is very useful, to determine where changes have occurred. Use of an OTDR for fault finding may require an experienced operator who is able to correctly judge the appropriate instrument settings to locate a problem accurately. This is particularly so in cases involving long distance, closely spaced splices or connectors, or PONs.
OTDRs are available with a variety of fiber types and wavelengths, to match common applications. In general, OTDR testing at longer wavelengths, such as 1550 nm or 1625 nm, can be used to identify fiber attenuation caused by fiber problems, as opposed to the more common splice or connector losses.
The optical dynamic range of an OTDR is limited by a combination of optical pulse output power, optical pulse width, input sensitivity, and signal integration time. Higher optical pulse output power, and better input sensitivity, combine directly to improve measuring range, and are usually fixed features of a particular instrument. However optical pulse width and signal integration time are user adjustable, and require trade-offs which make them application specific.

[@cowboyhmc]

Very down to earth and basic video on OTDR usage. Very usable Information. Thank you.

[@deaameliap7864]

You know, there is so many people need this in my country lol

[@GigisCreation]

amazing ! wow this is interesting , love learning new things, thanks for the knowledge.. stay safe

[@naymyo5257]

Do u have DAC cable taste ? i want to use in my factory , some time faulty cable make my server line down . please help

[@wbi007]

Hmm, at 1:47 he did clean the patchcord (or launch reel wich ever you prefer) but he did not clean the coupler. Just a small note :D

[@wbi007]

And I olso noticed he gets some reflection on his coupler. 'the peaks' you see on the graph. If the logic is the same as in Europe, blue connectors means they are 0dgrees. Green connectors wich are 9degrees tend to have less reflection.

[@midrees987]

jAZAKALLAH

[@zantaclawz9292]

@@wbi007 correct

[@AkhFarouk]

Do we need the launch cord or not?

[@GigisCreation]

wow, very interesting, very informative.. thanks for sharing.

[@khamisihussein8777]

really helpful, very good video. thank you so much bro

[@mehdiachouri]

really helpful, very good video. thank you

[@kowthamkarthick6735]

😎

[@ramialluhaiby5177]

which pulse width should i choose according to the distance in OTDR can i find any table show this formula

[@cowboyhmc]

Start with a Higher pulse width to get a base. Then shoot again using a Lower pulse width to "enhance" the trace (show more Detailed issues)

[@vijaykumar84masala]

Can u help me with the chain tw2100e otdr using

[@engmohamedhaji8191]

good lecture for OTDR so i hope next so on. but i have one question. When do I need to use a tail cord (receive cable)?

[@cowboyhmc]

Use a receive cable when you need to test the Final, or End connector at the far end of the trace.

[@johnose1306]

Good morning sir please I need more clearing on the reflection and attuantion thanks

[@kareemkadhum1994]

thanks for this lectures

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[@mannypadayachee6818]

Thanks Corning. Please teach the South African Fibre Engineers about fibre testing. These engineers cannot read fibre events .

[@rajeshwaritelecompvtltd7291]

Well explained. 👍

[@k50159]

Thank you so much

[@vijayasanthip6343]

I want pls expected loss

[@khamisihussein8777]

really hepful

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👍

[@EdCorona-dr8kt]

Nice

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