bisci chapter 6 Flashcards
A gain splice on an OTDR trace indicates a fiber mismatch, in which one fiber has a higher backscattering coefficient. (T/F)
True
What optical fiber testing supplements the OLTS?
Optical time domain reflectometer
What structured cabling components are tested in the permanent link test?
Up to 90m of horizontal cable,
Cross-connect or patch panel connection,
Consolidation point,
Telecommunication outlet
How many individual RL tests are done on a 4-pair cable?
8
What is the optical fiber equipment link power budget (system gains) when the transmitter has a power output of -17 dBm and the receiver sensitivity is -32 dBm?
15 dBm
What is the maximum number of cable terminal points that may be used in a channel?
4
The permanent link excludes both the cable portion of the field test instrument and the connection to the the field test instrument. (T/F)
true
What is the maximum dB loss of mated pair connectors?
0.75db
What is the function of a mandrel wrap?
To configure a mode filter
What structured cabling components are tested in the channel test?
Up to 90 m of horizontal cable,
Cross-connect or patch panel connection,
Cross-connect jumper or patch cable,
2nd cross-connect or patch cable,
Equipment cable,
Consolidation point,
Telecommunication outlet,
Work area cable
*PASS indicates that the result is better than the specified test limit but is within the accuracy margin for the test equipment and should not be questioned because of the accuracy of the instrument.
false
What is the maximum dB loss of a fusion splice?
0.3 dB
Using 300 meters of OM2 fiber with 5 mated connectors and 1 splice, what will the maximum channel attenuation of this system with a 3.5 dB/km loss?
300 meter of OM2 fiber → 1.05 dB,
5 mated connectors → 3.75, 1 splice → 0.3 dB,
Total maximum allowable attenuation for the system → 5.1 dB
Select the following conditions in which a reflective break is observed.
Unconnected fiber,
Broken or bad connector,
Broken Fiber
A multimode fiber link 6468 ft. long, operating at 850 nm, has 2 fusion splices and 2 mated connectors. What is the maximum allowable attenuation of this link with an attenuation of 3.5 dB/km?
Fiber attenuation @ 850 nm → 6.9 dB,
2 splices → 0.6 dB,
2 mated connectors → 1.5 dB,
Maximum allowable attenuation → 9.0 dB
Installers can negatively effect attenuation with severe cable bends, poorly installed connectors, and even the presence of dirt on a connector’s end face.
True
What is the function of the launch jumper when testing a fiber with an OTDR?
To be able to measure the beginning and the end points of the fiber.
What 2 durations are included in the dead zone
Duration of the reflection and the recovery time for the sensor to re-adjust to its maximum sensitivity.
High order modes should be dissipated in the light source’s test jumper prior to a connection to the optical fiber to be test. Therefore, necessitating the creation of a mode filter on the test jumper that is connected to the light source.
True
description for Propagation Delay
Propagation delay → Is the time required for a signal to travel form one end of the transmission path to the other end
description for Delay skew.
Delay skew → Is the difference in signal delay between any 2 pairs within the same cable sheath.
Select 4 cable installation procedures that will have significant impact on RL?
Impedance mismatch,
Improper termination practices,
Incorrect or substandard components,
CP too close to the TR
When a fiber is cut or broken, the end may shatter such that the angle at which the light is hitting the end, may not reflect at all. When this happens, the trace will suddenly fall into the noise level.
True
What length pulse width would an OTDR be set to, when testing for breaks on OSP fiber?
Long
The NVP setting of the cable tester will not affect the accuracy of the cable length test
False
Identify all the tests required to certify a Category 5e permanent link.
Wire Map,
Insertion ,
Length,
Next loss, measured from the local end,
Next loss, measured from the far end,
Power sum near-end crosstalk, measured from the local end,
Power sum near-end crosstalk loss, measured from the far end,
Attenuation-to-crosstalk ratio far end,
Power sum attenuation-to-crosstalk ratio far end,
Return loss, measured at the local end,
Return loss, measured at the far end,
Propagation delay,
Delay skew
When determining the NVP of a given length of cable, what tools are required to verify accuracy?
Tape measure,
Cable sheath markings
How much power does 0 dBm represent?
1 milliwatt
BASED ON TRADE KNOWLEDGE: Which optional cable test provides an indication of bandwidth?
ACR
At what stage of the test is the power meter set to zero using the one jumper method?
