EXFO OTDR 2 - Manual (Page 33)

Preparing Your OTDR for a Test
OTDR 25
Setting the IOR, RBS Coefficient, and Helix Factor
Thresholds values are saved with the measurement. It is possible to view
these thresholds values even if you open the file on another unit.
You can revert the IOR, RBS Coefficient, and Helix factor to their default
values.
To set the IOR, RBS, and helix factor parameters:
1. From the Main Menu, tap Test Configuration.
2. From the Apply to list, select Next acquisition.
3. From the Test Configuration window, go to the Link Definition tab.
I
MPORTANT
In the Apply to list, Next acquisition and Current file will be
displayed if an acquisition was made but was saved. The current
trace settings, as well as the future acquisitions, will be modified.