To measure Return Loss,
some means of isolating the connector part of the reflected signal is required:
a mandrel wrap, index matching gel, or Optical Time Domain Reflectometer (OTDR).
- A mandrel wrap is impossible to use with thick cables – Early instruments relied on using a mandrel wrap to choke off further reflections. This referencing works well enough for thin, single-fiber jumpers, but thicker multi-fiber cables cannot be mandrel wrapped tightly enough to be effective.
- Gel is difficult with many connector types – Index matching gel works for simple cables, but it’s difficult for complex connectors such as MTP/MPO male or Lemo. Plus, this method is messy and requires cleaning time.
- Today, OTDR is the universally preferred method to measure Return Loss – Any sort of cable/connector can be accurately measured using an OTDR, provided the device under test is not too short (~0.5um).
READ THE BLOG: How to Accurately Measure IL/RL
Additional resources from the FOC team include:
- Category Resource FOC Test Page
- Glossary, Acronyms, Military Specifications for Connectors: http://bit.ly/2a2EFn8
- Q&A Resource: email technical questions to AskFOC@focenter.com
Have questions about this FOC Tip?
Contact FOC with questions at: (800) 473-4237 / 508-992-6464 or email: FiberOpticCenter@focenter.com and we will respond ASAP.