ACES Int'l
Secrets & Tips
for Fiber Optics
Welcome to ACES Int'l Secrets & Tips for Fiber Optics. ACES Int'l is pleased to present what we believe to be the most in-depth and enlightening articles we can publish involving the field of Fiber Optics. ACES Int'l would, however, like to gratefully thank Noyes (A Division of Alcoa Fujikura Ltd.), for the rights to use its Application Note for this installment of ACES Int'l Secrets & Tips for Fiber Optics.
The articles presented in this section do not necessarily reflect the views or opinions of ACES International Incorporated, nor is
ACES Int'l Inc. responsible for any claims resulting from the use or dissemination of these articles (Note: We have to print the above disclaimer statement for legal reasons).
The Mandrel Wrap
How To Meet TIA/EIA 568-B Requirements For
Measuring Insertion Loss on Multimode Optical Fiber Links
by Roger Boettcher
The new TIA/EIA-B North American Standard on Commercial Building Telecommunications Cabling requires that insertion loss measurements of multimode optical fiber links be performed using a filtered LED or equivalent light source. This article of Secrets & Tips for Fiber Optics will take you through that new requirement Step by Step and, in the process, clear up some confusion on one or two points.
Figure 1 is a commercially made Mandrel Wrap Mode Filter. This relatively inexpensive plastic Mandrel Wrap Mode Filter can be used in place of an LED or other type Light Source with internal "beam optics" specified in TIA/EIA-B.3. The "controlled launch" LED Light Source with internal "beam optics" specified in TIA/EIA-B.3 costs about $500 more than the overfilled LED Light Source you are probably using right now and this newer "controlled launch" LED Light Source can only be used to test one multimode fiber type instead of two (as with most current overfilled Light sources on the market today).
Figure 1- Mandrel Wrap Mode Filter (50 µm)
Virtually all field-portable LED Light Sources, as well as multimode Fiber Test adapters used with premises cable test sets are used with overfilled Light Sources. So before you whip out your check book to buy two new "controlled launch" LED Light Sources, you might want to invest in a couple of the inexpensive plastic Mandrel Wrap Mode Filters (both 50 and 62.5 µm are available).