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APPENDIX C: ALTERNATE TEST METHOD B
Setting a fiber optic reference establishes the zero loss power and zero length distance for all future measurements. Setting a reference also
removes additional losses due to reference patch cords and adapters that should not be included in the measurement. Therefore properly
setting a reference is necessary for obtaining accurate results.
Alternate Test Method B
When a fiber optic link under test uses the same non-SC style connectors at each end of the link the reference measurement and
certification measurement test method needs to be altered to ensure accurate results while accommodating the non-SC style connectors.
This alternate method requires the following additional equipment:
(4) SC Adapters
(3) Duplex SC Fiber Optic Reference Cords
(2) Duplex SC to (non-SC) Fiber Optic Reference Cords (Short Length)
The purpose of alternate test method B.1 is to accommodate non-SC style connectors while producing Test Method B results.
Caution
Establish a fiber optic reference only after the SCT Primary and Secondary units and the SCT-MMA/SMA fiber optic adapters
have been on for five minutes. Allow additional time for the adapter to reach ambient temperature if the adapters have been
stored above or below ambient temperature.
Caution
The reference measurement is invalidated if the reference patch cord is disconnected from the SCT_MMA/SMA fiber optic
adapter. Disconnecting and re-connecting a reference patch cord will alter the optical characteristics resulting in a different
reference loss power.
Duplex SC - SC style fiber
optic reference cord
Duplex SC - SC style fiber
optic reference cord
Short SC - SC style patch
cords
Do not disconnect the reference cords from the output
connectors. Disconnecting the reference cords
from the output connectors will invalidate the reference
setting.
Caution
Figure 9 Alternate Method B Reference Setting