The Advantage of Tier-2 Testing for Fibre Optic Cabling

04/12/2017

The Advantage of Tier-2 Testing for Fibre Optic Cabling

When installing or maintaining a network, an OTDR (Optical Time Domain Reflectometer) is used to perform Tier-2 certification for fibre optic cabling.

The primary advantage of a Tier-2 test is that it provides information about each connection, splice and cable segment in the link and offers a graphical representation of the components and their performance.

An OTDR is unrivalled for troubleshooting because it creates a visual representation of the link allowing the operator to see the contribution of each component to the link’s total loss. Previously OTDRs were only used for troubleshooting in LANs because of their cost and complex operation. Today OTDRs are very easy to use and the costs have come down to a point where it is practical to use them for initial “turn-up” testing.

When certifying new cabling with an OTDR a snapshot is created, documenting the location and performance of every component at the time of installation. Should an issue arise later, a current OTDR test can be compared with the initial test to immediately identify what has changed in the cabling and the location of that fault.

An OTDR performs different measurements during a test. An OTDR classifies everything it “sees” as one of two categories of event - attenuation/non-reflective events or reflective events.

Attenuation events are those where power is lost going through the event and none is reflected back to the OTDR. Events that fall into this category are fusion splices, micro bends, macro bends and the fibre optic cable itself.

Reflective events are those where power is lost going through the event, and power is reflected back to the OTDR. Events that fall into this category are connections/bulkheads, mechanical splices, breaks in the fibre and the end of the fibre optic cable.

An OTDR will provide a number of very different looking traces when testing the same fibre depending on the OTDR’s wavelength, acquisition time and pulse width settings for each test. Ultimately, obtaining the perfect, single OTDR trace for a given cable is a matter of compromise that boils down to resolution (sharpness) versus dynamic range (max loss that can be measured). In some cases, there is no single setting that provides a perfect trace, so a cable may be tested with different settings providing two or more reports to capture every event.

Recent articles

  • Installers overestimate cable certifier usage 05/12/2017

    Data cable installers are overestimating their usage requirements for cable certifiers, says IDEAL Networks, suggesting that this may be generating extra costs for contractors and installation companies.

    Read more
  • The Advantage of Tier-2 Testing for Fibre Optic Cabling 04/12/2017

    When installing or maintaining a network, an OTDR (Optical Time Domain Reflectometer) is used to perform Tier-2 certification for fibre optic cabling.

    Read more
  • New Software Update for IDEAL AnyWARE™ App 01/12/2017

    We are pleased to announce that the IDEAL AnyWARE™ app has been updated for Android users and is now available to download on Google Play.

    Read more
  • How Can a Cable Fail a Certification Test Yet Still Pass Data? 29/11/2017

    A common question that comes up with certification is “how can a cable fail a certification test yet still pass data”? To answer this question, it is necessary to understand the differences between the performance requirements for various data speeds and cabling performance categories.

    Read more
  • New IDEAL FT-45™ for simpler, more reliable cable terminations 17/10/2017

    To make assembly and termination of CAT5e and CAT6 modular plugs simpler and more successful, the IDEAL FT-45 Feed-Thru Modular Plugs and Crimp Tool are now available in Europe. The ‘next generation’ modular plugs and crimp tool perfectly complement IDEAL Networks data cable testers, for a complete end-to-end solution.

    Read more