EXFO FastReporter 2 - Manual (Page 149)

Working with OTDR Files
Post Processing Software 139
Managing Markers
Various options of the Manual Measurement table are described below.
Option Description
4 points
event loss
In the 4 points event loss, four markers (a, A, b, and B) are visible. This
least square approximation method is used to fit a straight line to the
backscatter data within the two regions defined by markers a, A and b,
B, that is over the regions to the left and to the right of the event
bordered by markers A and B, respectively.
A-B LSA loss This loss of event bordered by the markers A and B is obtained by fitting
a straight line to the backscatter data between these two markers.
2 points
section
attenuation
In the 2 points section attenuation, two markers (A and B) are visible.
This measurement gives the reduction in Rayleigh backscatter level as
a function of distance (always expressed in dB/km to follow the
standards of the fiber-optic industry) between two selected points.
Only those two points are used to perform the calculation and there is
no averaging.
A-B LSA
attenuation
This LSA attenuation is obtained by fitting a straight line between two
points in the backscatter data between markers A and B.
A-B ORL This displays the ORL between markers A and B.
3 points
reflectance
In the 3 points reflectance, three markers (a, A, and B) are visible. This
measurement displays the reflectance pointed by marker a, A, and B.
3 points
maximum
reflectance
This measurement displays maximum reflectance for the selected
event.