VeEX FX150, User Manual

Page: 100 / 128

OTDR Series e-Manual, RevE00 Page 100 of 128
8.2.7 ORL Measurement
ORL is the total amount of light being reflected back towards the transmitter or source. This
includes all backscatter and all reflections.
To calculate ORL:
1. Select the trace for measurement (if multiple traces are displayed on screen). The trace to
be measured can be selected using the green arrow in the trace overview window.
2. Select ORL from the drop-down list.
3. Place marker A at the beginning of the fiber under test and marker B at the end of the fiber
span under measurement (just before end reflection, if available). Moving marker B beyond
the end will not change the span ORL; moving marker B to less than the end will result in a
change in ORL.
The bottom of the screen displays:
•
Distance to A cursor
•
Distance to B cursor
•
Distance between markers A-B
•
Loss between the markers A-B (dB)
•
Optical Return Loss (ORL), dB