OTDRs

   Its been a long time since I've posted anything. Time to get back to it. 

   I want to start concentrating on talking about optical test equipment. One of the more complex test sets is the OTDR -- Optical Time Domain Reflectometer (what a mouthfull!) -- a test instrument that will graph out the characteristics of an optical fiber to which it is connected. It is not difficult to use (these days, anyway), but it is difficult to truly understand what it is doing, how it operates, and how you can use this powerful tool to troubleshoot and maintain fiber. Hopefully I'll be able to make it all a bit more clear.
   I came across an old (1986 vintage) VHS video tape in my home office a while ago. It was a training video on an OTDR. I digitized it and created an MP4 video of the tape. Here is the YouTube link to this video on how to use a Laser Precision Corporation TD-9950 OTDR. This OTDR was produced in the late 1980s by Laser Precision in its Utica, NY, factory location. I was employed by LP from 1991 thru 2006 (through some name changes and consolidations... GN Nettest, NetTest, Anritsu...). We've come a long way since then as far as the technology in producing these instruments. But the specifications of the instrument and how to interpret the "trace" remains the same. 
   Watch this space. I will post a little booklet I started writing back in about 1992 called "Understanding OTDRs," That was version 1. I'm up to version 18 now as I've made many changes to keep up with changing technology and the improvements in the OTDRs specs and methods of use. I'll also post links to other educational sites that might help you understand the in-depth technology of fiber optics testing.