EXFO FTB-7000 OTDR Series for FTB-500 - Manual (Page 210)

Analyzing the Results Manually
196 OTDR
Getting Reflectance
Getting Reflectance
Reflectance is the ratio of reflected light to input light.
Note: When performing reflectance measurements on recalled traces from
non-EXFO test equipment that were saved in Telcordia (Bellcore) format,
the results displayed could be less accurate than with EXFO file format.
To get reflectance:
1. From the main window, go to the Graph tab and press the Measure
button
2. In the Measurements section, press the Refl. button. Markers a, A and
B appear on the graph.
3. Zoom in and position marker A on the linear area preceding the event
to be measured. For more information, see Using Zoom Controls on
page 137 and Using Markers on page 187.
4. Position submarker a at the beginning of the linear area preceding the
event to be measured.
5. Position marker B at the peak of the reflective event to be measured.
Note: Using this procedure, you can measure the reflectance of all the events in a
merged reflective fault event.
Note: For non-reflective events, ∗∗∗∗∗ will be displayed.