Fluke Versiv Series Technical Reference Handbook page 354

Versiv Series Cabling Certification Product Family
Technical Reference Handbook
Table 12. Settings for OTDR Tests (continued)
Select a fiber type that is correct for the type you will test.
Fiber Type
To see a different group of fiber types, tap MORE, then tap
a group. To make a custom fiber type, see Chapter 19.
IOR: The tester uses the index of refraction to calculate the
Fiber Type
optical length of the fiber. Optical length usually differs
Settings
slightly from the length of the fiber jackets in a link. This
occurs because fibers are often curved inside their jackets
and because there are small variations in the IOR of the
fibers.
Each fiber type includes a default value, which is the IOR
specified for the fiber by the manufacturer. To use a
different IOR, make a custom fiber type. See Chapter 19.
Backscatter: Backscatter is the backscatter coefficient. This
Fiber Type
is a measurement of the quantity of light that the fiber
Settings
(cont.) reflects back to the OTDR when the OTDR uses a 1 ns pulse.
The tester uses this value to calculate the reflectance of
events for OTDR tests and the overall ORL for the link. Each
fiber type includes a default value, which is the backscatter
coefficient specified for the fiber by the manufacturer. To
use a different backscatter value, make a custom fiber
type. See Chapter 19.
Select the correct test limit for the job. Generic limits, such
Test Limit
as General Fiber Optic and Document Only, let you do tests
when no industry-standard limit is applicable and you do
not want to make a custom limit. These limits are in the
Miscellaneous group. To see a different group of limits,
tap MORE, then tap the name of a group. To make a
custom test limit, see Chapter 19.
Some test limits use the measured length of the fiber to
calculate a limit for loss. See "OTDR Settings for Limits that
Calculate a Loss Limit" on page 319.
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If you use a length-based test limit, the IOR value
has an effect on the loss limit that the tester
calculates. See "OTDR Settings for Limits that
Calculate a Loss Limit" on page 319.
Note