Fluke DTX Series - Method B;A.1

DTX Series CableAnalyzer
Technical Reference Handbook
B-4
Method B/A.1
Method B/A.1 results account for the loss of two
connections plus the fiber in the link. This method is
suitable for testing premises fiber, where patch cords are
typically used at both ends of the link and connector loss
is a significant portion of the total loss. Method B is
defined in the ANSI/TIA/EIA-526-14A multimode
standard. Method A.1 is defined in the ANSI/TIA/EIA-526-
7 singlemode standard.
The Method B/A.1 reference connections shown in Figure
Figure B-2 cancel out the effects of one connection and
two reference patch cords in each fiber path. Note that
this method of achieving Method B/A.1 results includes
adapters in the reference connections. The adapters do
the following:
• The adapters let you use patch cords that match the
tester's connectors at one end, and match the
connectors in the link at the other end.
The standard Method B/A.1 reference connections
use just one patch cord for each fiber path. With
these connections, you can test only links with the
same connector style as the tester. To test links with
different connectors you would have to add
adapters after referencing. This would add the loss
of a connection not present in the link.
• The adapters reduce wear on the tester's connectors,
since it is not necessary to disconnect the patch cords
from the tester to connect to the link.
The test connections add two connections to each path,
plus the fiber in the link. Note the two short patch cords
used to connect the main tester’s to the link. The extra
cords ensure that the measured loss accounts for two
connections in the link, since one connection was
canceled out during referencing.
Loss results for Method B/A.1 therefore represent both
connections plus the fiber in the link. ANSI/TIA/EIA-526-
14A and 526-7 specify Methods B and A.1 for testing
multimode and singlemode premises fiber, where
connector loss is a significant portion of the total loss.
Note
For testing links with small form-factor (SFF)
connectors or different connector styles at each
end, use the alternate method described under
“The Alternate Method” on page B-8.
For testing links with the same SFF connectors at
both ends, you may use the modified Method
B/A.1 connections if you have the correct patch
cords. SFF patch cord kits are available from
Fluke Networks for this purpose.