On 21/09/16 11:53, Mel Beckman wrote: > This is a very comprehensive article, and worth handing out to techs. I have > one comment on Balder’s OTDR suggestion, and one on the article’s microscope > instructions. > > Although it certainly can’t hurt to run an OTDR test (except for extended > downtime), I fear hauling out the extra gear will prompt many techs to put > off fiber cleaning. In my experience, just doing the cleaning solves 99.9% of > the problem. Anything that an OTDR would pick up would likely severely impact > performance, while dirty connector will just increase the error rate. > > Also, the article didn’t mention eye safety when using a fiber microscope. > The example showed a USB digital video microscope, but many maintainer kits > in the field have much cheaper direct-view optical microscopes. Viewing an > energized fiber with a direct-view microscope can cause major eye damage. I > recommend all fiber kits throw out their optical scopes and substitute a USB > or WiFI scope (some of these can be used with a cell phone or tablet). > > -mel
Cool that this article got posted here (im not the author, but im the dude in the pictures). One reason we didn't bring up OTDR in the article is that OTDR-test only works on certain occasions. If you have problems with a circuit and decide to take it down to clean it up and inspect patches and ODFs you need to also disconnect the other side if you feel doing a OTDR-test. Launching light from a OTDR-instrument where you have a regular transceiver on the other side gives a potential risk of destroying it. Also if running the OTDR towards a TX will also skew up the results since there is already light in the fibre. We have however (both me and jörgen) done a few articles where we go through OTDR-stuff. https://www.sunet.se/blogg/sites-and-fibers-being-delivered/ https://www.sunet.se/blogg/first-test-on-real-fiber/ https://www.sunet.se/blogg/full-speed-ahead/ https://www.sunet.se/blogg/otdr-grundlaggande-om/ (use google translate on that one, i can get it translated if its of interest) -- hugge
