Fiber U Free Self Study Programs

Reading An OTDR Trace - MiniCourse 


MiniCourse: Reading An OTDR  Trace
Level: Basic/ Intermediate

Fiber Optic MiniCourse: Reading An OTDR Trace

Fiber U MiniCourses are courses on a specific topic that you can take in about an hour or less. They are based on questions people ask FOA all the time, so the topics are recommended by our readers.

Level: Intermediate

Intended For:
This course is intended for anyone involved in fiber optics who wants to understand the information in an OTDR trace.
Technicians testing fiber optic  cable plants
Users of fiber optic communications networks
Contractors and techs who install, operate and maintain them.

Objectives: From this self-study program you should learn:
The information included in an OTDR trace
How those events are generated
How those events are interpreted

You will need a basic understanding of OTDRs and fiber optics, e.g. training and a FOA CFOT certification or at least a familiarity with fiber optic technology.
For preparation, see the Fiber U Basic Fiber Optics self-study program or the printed FOA textbook FOA Reference Guide To Fiber Optics.
Fiber U has a course on OTDR Testing that is excellent preparation for this MiniCourse

Fiber U Certificate of Completion
When you finish, you can take an online test on this course to qualify for a "Fiber U Certificate of Completion." The test cost for a Fiber U MiniCourse is $10US.

One of the questions most often missed on the FOA CFOT and CFOS/T Testing Specialist exams is identification of the events on an OTDR trace. This course shows you what each part of an OTDR trace is and what information can be gained from it.

Below is a schematic representation of an OTDR trace showing the elements of the trace, the events the trace can show and the information you can get from the trace.

For this lesson you can point to 9 the elements of an OTDR trace and learn more about them by clicking on that part of the image. When you click on a element of the trace, it will take you to a page discussing that part of the trace and the information it can provide.

trace map dB Scale distance scale launch cable connection splice gainer receive cable end of cable

You will find information on all these 9 elements and events on the trace above.

  • dB Scale
  • Distance Scale
  • Dead Zone
  • Launch Cable
  • Receive Cable
  • Connection
  • Splice
  • Gainer
  • End of Cable

Click on the elements of the OTDR trace on the diagram above to learn more about them.

When finished, you can take a quiz (Test Your Knowledge) to complete the course.

Test Your Comprehension
See if you can identify each item on the list above in the trace.  Here are the answers.

Fiber U Certificate of  Completion
Optional. When you finish all the assignments you can take an online test on this course to qualify for a "Fiber U Certificate of Completion." The test cost is $10US. If you are taking this course linked from another Fiber U Course, it will be included in that course's Certificate of Completion. If you are taking this course as part of an online course from an instructor, they will give you directions.

Go here to take the Fiber U "Reading An OTDR Trace" Certificate of Completion test. Here are detail directions if this is your first time taking a
Fiber U Certificate of Completion exam.

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.

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