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CHAPTER 8: Testing Twisted-Pair Cable
8.2.5 N
OISE
Noise is defined as unwanted signals on the segment. Because of the
construction of UTP cable, it acts as an antenna to electromagnetic and
radio-frequency signals (refer to Figure 8-12). Examples of noise producers
are fluorescent lights, electric motors, power lines, signals caused by voice
lines sharing the same pathway as a data line, elevators, and industrial-type
equipment.
Figure 8-12. Noise.
The IEEE 802.3 standard for 10BASE-T includes an impulse noise
specification. If you have selected 10BASE-T as the cable test standard
when performing a noise test, the 802.3 requirements are used for
pass/fail criteria. For all other selected cable test standards, noise will
be measured but will not be judged as pass or fail.
out
in
UV light fixture
Noise
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