EXFO FTB-500 (Window XP) - Manual (Page 136)

Using the Optional Built-In Power Meter and VFL
126 FTB-500
Identifying Fiber Faults Visually with the VFL
To activate the VFL and inspect a fiber:
1. Clean the connectors properly.
2. Connect the fiber under test to the VFL port.
3. If necessary, from Toolbox, on the Main Menu, tap Optical Power
Meter and VFL.
4. Select the Instrument View tab.
5. Tap ON/Blink/OFF to change the VFL state.
6. Without looking directly into the beam, examine the fiber. If the fiber is
defective, you will see light coming through its rubber jacket or on the
side of the ferrule.