Fiber training.txt

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Fiber training.txt
2013-04-25 01:43:30
Fiber Training

Fiber Training Questions for Testing Cables
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    • author "me"
    • tags ""
    • description "Test equipment"
    • fileName "Fiber training"
    • freezingBlueDBID -1.0
    • Power Meter
    • Measures loss directly in dB
    • Detector sensitivity is dependent on wavelength
    • Use before using microscope
  1. Optical Power Testing
    • Most basic test
    • Basic measuring parameter
  2. 0dBm
    • 1milwat (1mW) optical power
    • 3dB loss = 1/2 power
    • 3dB gain = 2X power
    • 10 dB = 10X
    • 20 dB = 100X
  3. 0dB
    • No loss
    • Power measured is = to reference value
    • Reference value for loss measurement
  4. Zero loss reference
    Pretest measurement with reference test cable only
  5. M.M. loss measurement depends on
    • Wavelength
    • Coupled mode power distribution
    • Stability
  6. Insertion loss testing
    • The loud a link will experience in actual operations
    • Fiber and connector
  7. Reference cables
    • Must be compatible with fiber and connector type
    • High quality known good lore loss cable
  8. OTDR
    • Verifies splices, finds faults, verifies cable length long distance
    • Uses back scatter
  9. Scratches on core
  10. Meter calibration
    Will not affect loss readings
  11. Dirty connectors
    Can cause a gainer during insertion loss testing
  12. 1550nm
    Most sensitive to stress and bending loss SINGLE MODE
  13. Length of OTDR pulse
    Will not increase the likelihood of seeing a gainer
  14. FOTP-171
    Only test one connector, most common for single cables or patch cords
  15. OFSTP 7/14
    Required for all installed cable plants
  16. Only way for OTDR to give actual splice or connector loss
    Cable measured in both directions and average the results
  17. 1% more fiber than Cable
    To reduce stress during istallation
  18. Pulse Suppressor
    Reduces the effect of the "dead zone"
  19. Ghosts
    Cause by multiple reflections in a short cable
  20. Different Backscatter on either side of splice
    Different loss measurements when testing in different directions
  21. Visual Fault Locator
    used to find faults to close for the OTDR
  22. Makes testing easier
  23. Polarization mode dispersion
    caused by varying speeds of planes of polarization
  24. Bit Error Rate or Signal noise ration
    • Optical power/link is basied
    • dependent on power
  25. First Test
    • Determine if connection and/or polarity is correct
    • Ensure everything is on
  26. Accidental Dig ups
    Most common cause of outside premise failure
  27. Broken or dirty connector
    Most common cause of premise failure
  28. HFC (hybrid fiber coax)
    power levels as high as +20dbm
  29. OCWR
    Used on patch cords
  30. Two methods for finding backscatter
    OTDR and OCWR