9. Encircled flux

I have to issue a mea culpa on this one because it's something I should have put in last year's list. In October 2010 the TIA "back-adopted" the specifications for the encircled flux launch condition from the ISO. TIA-526-14-B Optical Power Loss Measurements of Installed Multimode Fiber Cable Plant is in complete harmony with the portion of IEC 61280-4-1 Edition 2 that specifies the launch condition for testing installed multimode fiber-optic cable.

We reported on that back-adoption earlier this year, then the proverbial fur began to fly. Not everyone is completely on board with the encircled flux launch condition, at least in part because of the current challenge to find field-deployable encircled-flux-compliant measurement equipment. (But you better believe those with such equipment want to be heard as well.) My current understanding (now there's a loaded expression) is that round-robin testing is taking place to ensure minimal variance among light sources. Meanwhile, as the author of one article pointed out earlier this year, those responsible for certifying installed fiber systems in the field can't wait until sometime next year or later to conduct their tests. It sure would help to have access to the flux capacitor (pictured above), so we could travel back and forth in time.