WHAT ARE VISUAL FAULT LOCATORS?

Many of the problems in connection of fiber optic networks are related to making proper connections. Since the light used in systems is invisible infrared light (IR) beyond the range of the human eye, one cannot see the system transmitter light.

 

By injecting the light from a visible source, such as a LED, laser or incandescent bulb, one can visually trace the fiber from transmitter to receiver to ensure correct orientation and check continuity besides. The simple instruments that inject visible light are called fiber tracers or visual fault locators.

 

Continuity testing is useful to test a few fibers in a cable before installation or to determine if a terminated cable has been damaged.To test for continuity, attach the fiber to the fiber optic tracer or VFL. If light is visible at the far end, the fiber is not damaged.

 

One of the best uses for these devices is to trace fibers for identification or to determine correct connections. To trace fibers using the fiber optic tracer or VFL, connect the fiber to the output connector of the unit. The light output will be visible to the eye at the other end of the fiber. This allows finding particular fibers in multifiber cables easily for proper connections during installation.