Name: 
 

FO Test Self-Study: OTDRs


True/False
Indicate whether the statement is true or false.
 

 1. 
OTDR testing will give the same test results as a light source and power meter.
 

 2. 
Length measurements by the OTDR are longer than the actual cable because the fiber is longer than the cable itself by 1-2%.
 

 3. 
If a cable has a kink causing high loss, OTDR traces should show a non-reflective loss event similar to a fusion splice at the location of the kink.
 

 4. 
Reflections seen in traces from OTDRs comes from mismatches in the media being tested. (impedance in copper or indices of refraction in fiber)
 

Multiple Response
Identify one or more choices that best complete the statement or answer the question.
 

 5. 
OTDRs can measure _________, _________ and ___________. (3 correct answers)
 A.
Distance
 B.
Attenuation
 C.
Bandwidth
 D.
Reflectance
 

 6. 
OTDRs should always use launch cables to ___________.
 A.
Prevent errors caused by the launch pulse overloading the OTDR receiver
 B.
Avoid damaging the OTDR connector
 C.
Extend the range of the OTDR to longer distances
 D.
Allow the OTDR measure the initial connector on the cable plant
 

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 7. 
OTDRs utilize the ____________ in the fiber to make measurements.
A.
Bandwidth
B.
Backscatter
C.
Absorption
D.
Dispersion
 

 8. 
OTDRs measure the length of a cable. What information is needed to make this measurement accurately?
A.
Attenuation of the fiber
B.
Speed of the test signal in the cable
C.
Attenuation of the fiber
D.
Connection loss
 

 9. 
Multiple reflections in a cable may cause __________.
A.
Backscatter
B.
Ghosts
C.
Distance errors
D.
Loss
 

 10. 
A receive cable on the other end of the cable plant will allow the OTDR to ______________.
A.
Extend its range by the length of the cable
B.
Reduce the effects of reflectance
C.
Use a longer pulse width
D.
Measure the loss of the connector on that end
 

 11. 
OTDR connector or splice loss measurements are only accurate if you __________.
A.
Put index matching fluid on the connector
B.
Use reference quality connectors
C.
Have a matching launch cable
D.
Test both ways and average the reading
 

 12. 
Unless a mode conditioner is used, OTDRs will usually ________ the loss of a multimode cable plant compared to insertion loss testing.
A.
Overestimate
B.
Underestimate
C.
Equal
 

 13. 
The most important issue in testing properly with an OTDR is _______.
A.
Being properly trained and familiar with the instrument
B.
Using the proper adapters or launch cables
C.
Setting the range correctly
D.
Ensuring the batteries are at full charge
 



 
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