EXFO FTB-7000 OTDR Series for FTB-500 - Manual (Page 174)

Analyzing Traces and Events
160 OTDR
Changing the Loss and Reflectance of Events
3. Position marker A as close as possible to the event, and submarker a
(to the left of marker A) as far as possible from marker A , without
including the preceding event.
The area between markers A and a must not include any significant
variation. For more information on positioning markers, see Using
Markers on page 187.
4. Position marker B after the end of the event, where the trace returns to
a regular loss inside the fiber, and submarker b (to the right of
marker B), as far as possible from marker B, without including the
following event.
The area between markers B and b must not include any significant
variation. For more information on positioning markers, see Using
Markers on page 187.
Event loss and reflectance are displayed, respectively, in the Loss and
Reflectance boxes.
Marker A Marker B
Loss and reflectance
values