Fibre Testing

PLEASE NOTE

A new fibre testing standard was released in Australia on 15th May 2007. This page is currently being updated to reflect the changes. The text below relates directely to the standard as it stood before the 15th of May 2007

 

General

  • Multimode Fibre Backbone and Outlet Cabling should be tested at 850 nm and 1300 nm in both directions.
  • Singlemode Fibre Backbone and Outlet Cabling should be tested at 1310 nm and 1550 nm in both directions.
  • A length measurement of the fibre cable is required — may be obtained by the sheath marking on the cable (at present).
  • Gains in test results show fundamental problems in the test equipment and/or setup. Gains in some test results would in most cases invalidate all results.

Test Results

Fibre Test results should detail the following.

  • Distributors Identifier (name) A end (Closest to the CD)
  • Distributors Identifier (name) B end (Furtherest from the CD)
  • Cable Length
  • Core Count of Fibre Cables
  • Core number under Test
  • Wavelength of Test
  • Performance level of cable (OM1, OM2, OM3 or OS1)
  • Power meter test result should include
    • Zeroing methods
    • Zeroing reference
    • Channel loss
    • Test Method
    • Test personnel
    • Test Equipment used
    • Time and date of test
    • Site Location.

Light Budget Calculation

  • Cable Attenuation
    • 3.5 db/Km at 850 nm for Multimode Fibre Cables
    • 1.5 db/Km at 1300 nm for Multimode Fibre Cables
    • 1.0 db/Km at 1310 nm for Single mode Fibre Cables
    • 1.0 db/Km at 1550 nm for Single Mode Fibre Cables
  • Connectors .75dB (Mated Pair) at any wavelength.
  • Splices .3 dB at any wavelength.

Fibre Channel

  • OF300 is a fibre channel less than 300 metres long.
  • OF500 is a fibre channel less than 500 metres long.
  • OF2000 is a fibre channel less than 2000 metres long.
  • A fibre channel attenuation shall not exceed the components up the channel — Cable Attenuation + Connector attenuation + Splice attenuation.
  • A fibre channel attenuation shall not exceed the values detailed in the table below.
Channel Attenuation dB
Multimode Singlemode Channel
850 nm 1300 nm 1310 nm 1550 nm
OF-300 2.55 1.95 1.80 1.80
OF-500 3.25 2.25 2.00 2.00
OF-2000 8.5 4.50 3.50 3.50

Power Meter and Light Source Testing

Test Results Consistency

  • Use a Mandrel on the light source lead
  • Use the one patch cord referencing method if possible
  • Use single mode through adaptors for all tests
  • Clean Connectors before test
  • Zero/Reference out leads each time light source or power meter turned on
  • Zero/Reference out leads each time and retest whole cable when test results show a gain

OTDR

Test Results Consistency

  • Always use a launch Cable
  • Use a launch cable longer than the cable under test if possible
  • Clean Connectors before test
  • Use short pulse widths
  • Traces should include full Near-end connector reflection
  • Traces should include full Far-end connector reflection
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