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The Fiber Optic Association, Inc.

Quickstart

Fiber Optic Testing

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QuickStart Guide:
Cable Plant And Patchcord Testing

FOA "Quickstart Guides" are short, simple guides to basic fiber optic tests. All are written in the same straightforward format: what equipment do you need, what are the procedures for testing, options in implementing the test, measurement errors and documenting the results.  References to FOA "1 Page Standards" are provided to allow printing out the directions.

Other FOA Quickstart Guides are linked at right >

Optical Power In Fiber Optic Communications Systems  


OTDR Testing  


 Fiber Optic Testing

This is your "QuickStart" guide to testing fiber optic cable plants, patchcords and communications equipment with a fiber optic light source and power meter. We'll give you the basic information you need and provide some printable references. Just go to the topics below to find the information you need. Links to videos and more comprehensive information will be provided in each section.




Get started - choose your topic:

Testing A Fiber Optic Cable Plant


Testing Patchcords






Testing A Fiber Optic Cable Plant


This test will measure the loss of an installed fiber optic cable plant, singlemode or multimode, including the loss of all fiber, splices and connectors. The method shown is on the FOA "1 Page Standard" FOA1 which you may print or download and insert in your documentation.


Equipment Needed To Perform This Test

Test equipment needed for fiber optic cable plant test

1.    Test source (#1) appropriate for the fiber being tested (Multimode: 850 and/or 1300nm LED, singlemode, 1310 and/or 1550 nm laser)

2.    Optical power meter (#2) calibrated at the same wavelengths as the source output.

3.    Launch and receive reference cables (#3) of the same fiber type and size as the cable plant and have connectors compatible to those on the cable plant. They should be tested per FOA-2 to ensure they are in good condition.

4.    Mating adapters compatible to connectors (#4)

5.    Cleaning supplies


Test Procedure

Fiber optic cable plant test

1.    Turn on equipment and allow time to warm-up

2.    Attach launch cable to source. This should remain connected to source for the duration of the test.

3.    Clean all connectors and mating adapters.

4.    Set “0 dB” reference using method shown below. Meter may be set to read “0 dB.”

5.    Attach source/ref cable and meter/ref cable to the cable plant under test and make loss measurement.



Options For “0 dB Reference” - Set Before Testing

3 ways to set reference for fiber optic cable plant testing

1.    Use the “1 Cable Reference” if connectors are the same on the test equipment as the cable plant and reference cables or may be adapted using hybrid adapters.

2.    Use the “2 Cable Reference” if connectors are not the same  on the test equipment as the cable plant but can be mated to each other with adapters and hybrid reference cables are being used.

3.    Use the “3 Cable Reference” if connectors are plug/jack styles and reference cables are both ended in either plugs or jacks.


What Test Results Should You Expect?
The results of your test can be estimated by calculating a loss budget for the cable under test. It takes just a minute (or you can use the FOA iPhone/iPod/iPad app.)


Reducing Measurement Uncertainty


Reducing Measurement Uncertainty
1.    Clean all connectors regularly before and while testing.

2.    Use modal control on launch cable, e.g. small loop on SM fiber or mandrel wrap on MM fiber.

3.    Check “0 dB Reference” periodically during testing.

4.    4. Periodically check reference cables per FOA-2 to verify their condition.



Documentation

Record the following data to document your tests and keep copies for future reference:

1.    Date of the test

2.    Cable being tested and fiber identification

3.    Operator

4.    Test equipment used

5.    Reference method

6.    Test wavelength

7.    Measured loss.



 Learn More

Also see the FOA YouTube Video on loss testing
  



Testing Patchcords

This test will measure the loss of a fiber optic cable, singlemode or multimode, including connectors on each end individually - one at a time. For short cables, e.g. patchcords, with negligible fiber loss, the measured loss may be considered the loss of the connector mated to the reference connector. Reversing the cable tests the connector on the other end of the cable. The method shown is on the FOA "1 Page Standard" FOA2 which you may print or download and insert in your documentation. Patchcords may also be tested both ends at once using the cable plant test method shown above.


Equipment Needed To Perform This Test

Test equipment needed for fiber optic cable plant test

1.    Test source (#1) appropriate for the fiber being tested (Multimode: 850 and/or 1300nm LED, singlemode, 1310 and/or 1550 nm laser)

2.    Optical power meter (#2) calibrated at the same wavelengths as the source output with adapters to mate to connector type on cable.

3.    Launch reference cable (#3) that is the same fiber type and size as the cable plant and have connectors compatible to those on the cable.

4.    Mating adapters compatible to connectors (#4)

5.    Cleaning supplies


Test Procedure

Testing fiber optic patchcords - single ended


1.    Turn on equipment and allow time to warm-up

2.    Attach launch cable to source. This should remain connected to source for the duration of the test.

3.    Clean all connectors and mating adapters.

4.    Set “0 dB” reference using method shown above. Meter may be set to read “0 dB.”

5.    Attach source reference cable and to the cable under test and make loss measurement.

6.    Reverse cable and test again. This tests the connector on the other end of the cable.


Options For Testing With Different Connector Types Or Double-Ended

If the connector(s) on the cables to test are “plug and jack” type and/or are not compatible to the optical power meter for testing and/or reference, you cannot test single-ended. Use the Fiber Optic Cable Plant or FOA "1 Page Standard" FOA1 method with a 2 or 3 Cable Reference as appropriate. Results will include loss of connectors on both ends.


Reducing Measurement Uncertainty

1.    Clean all connectors regularly before and while testing.

2.    Use modal control on launch cable, e.g. small loop on singlemode fiber or mandrel wrap on multimode fiber.

3.    Check “0 dB Reference” periodically during testing.


Documentation
Record the following data to document your tests and keep copies for future reference:

1.    Date of the test

2.    Cable being tested and fiber identification

3.    Operator

4.    Test equipment used

5.    Reference method

6.    Test wavelength

7.    Measured loss.


 Learn More

Also see the FOA YouTube Video on loss testing  


Learn More


Also see the FOA YouTube Video on optical power testing  




References

FOA Standards
FOA "1 Page Standard" FOA1 (cable plant testing)
FOA "1 Page Standard" FOA2 (patchcord testing)


Online FOA Reference

FOA Reference Guide to Fiber Optics( general)
, Basics/Testing, Test Section 


Reference Textbooks

FOA Reference Guide to Fiber Optics, Chapter 8

FOA Reference Guide to Outside Plant Fiber Optics, Chapter 8
 


Videos

FOA YouTube Videos
, with individual links as appropriate


This information is provided by The Fiber Optic Association, Inc. as a benefit to those interested in teaching, designing, manufacturing, selling, installing or using fiber optic communications systems or networks. It is intended to be used as an overview and/or basic guidelines and in no way should be considered to be complete or comprehensive. These guidelines are strictly the opinion of the FOA and the reader is expected to use them as a basis for learning, as a reference and for creating their own documentation, project specifications, etc. Those working with fiber optics in the classroom, laboratory or field should follow all safety rules carefully. The FOA assumes no liability for the use of any of this material.


 

Table of Contents: The FOA Reference Guide To Fiber Optics

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