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KEY TEST PARAMETERS
Reference methods refer to the number of patch cables required to properly set a reference between the power meter and light
source used for testing (also referred to as “zeroing”).
Setting a reference involves recording a baseline optical power level (called a reference) between a power meter and light source
prior to taking measurements. The difference between this reference level and the link power measurement is called optical loss.
The most commonly used standard for defining reference methods is the EIA/TIA 526. This standard allow three methods:
1-jumper, 2-jumper, and 3-jumper.
To comply with industry recommendations, the 1-jumper reference method is preferred. This method eliminates mating sleeves
from the optical reference, thereby minimizing uncertainty in the measurement.
Technicians should always use the 1-jumper reference method whenever possible, unless there is a situation where using other
methods cannot be avoided.
Instructions in this manual assume the 1-jumper reference method.
REFERENCE METHOD
1-jumper reference method
Preferred by national and interna-
tional cabling standards
Setting a reference through one
patch cable eliminates mating
sleeves, thus minimizing uncertainty
in optical loss measurements
Additional “known good” test cable
is required to connect power meter
in to link under test
Can also be used to test links with
an interconnection on only one
end as long as the interconnection
matches the connector type on the
power meter detector port
2-jumper reference method
Most logical “looking” method, but is
not preferred because the additional
mating sleeve introduces unwanted
error in optical loss measurements
Typically used when 1-jumper
method does not work; e.g. when
the interconnections on the end of
the fiber link are not compatible with
the connector ports
3-jumper reference method
Typically used when the fiber under
test does not include
interconnections on the ends of the
fiber link
Examples:
Patch cables
Fiber on the spool
Complex optical fiber cable
assemblies
Channel testing (includes both the
installed fiber link and the station
cables in the test)
