Bi-directional loss & ORL test procedure using a pair of two-way loss test sets

For standards compliant test procedures & equipment, please refer to Standards Center. For more background theory, please read on...


This method is the fastest and most accurate method for any link. The method of operation is a simplified version of Example 3:

  • bi-directional LTS is required at each end.
  • Each instrument is referenced to itself, which is best done just before the measurement. This greatly reduces the problem of source drift, battery life, etc.
  • The bi-directional dual wavelength measurement takes about the same time as a single direction, single wavelength measurement using previous generation instruments.
  • The averaged link loss results are displayed directly on both instruments. If dual wavelength LTS are used, both values are displayed. No operator calculation is required.
  • If the appropriate LTS is used, the return loss from each end is also automatically measured.
  • If the KITS™ program is used, the measurement is clicked directly into the user report

Light Source and Power Meter Procedure


Fiber Link to test Connectorised link
Optical Test Lead Patch Cord
Optical Bulkhead Through Adaptor Through adaptor
Optical Light Source, mandrel wrap if multimode Source, incl. mandrel wrap if multimode
opical testing meter Meter
system under test DUT Device Under Test (system being tested)

[instructions on use of the relative mode are in italics]



This application note assists in the following application areas...

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