One method of testing fiber optic cable is a visual inspection for continuity. A visual inspection probe, an essential tool for people working with optical components or systems, is a portable video microscope used to inspect fiber optic terminations for cleanliness or damage. It’s used to make sure the fibers are not broken by tracing a fiber from one end to the other. 

This tool is like an oversized pen-type flashlight with a lightbulb or LED source. It’s very simple to use. Just attach the tracer to the cable and then check the other end of the fiber to see if the light is transmitted. If there’s no light, there is a bad connection or section of cable.

It can also be used to check hard-to-reach connectors that are installed on the back of patch panels or inside hardware devices, saving you the need to access the back side of the panels or to disassemble hardware devices before inspecting fiber optic terminations. The probe is inserted through the bulkhead adapters.

Visual inspection probes also enable you to inspect connector endfaces for debris or damage, the leading causes of transmission failure, prior to mating them.
 
For example, the 400x power probe and 3.5-inch display of the Visual Inspection Probe make it easy to view small particles that may exist on connectors. Using adapter tips, you can inspect patch cords, pigtails, and cable assemblies as well. 

A visual inspection probe provides a fast and effective way to install, troubleshoot, or maintain fiber optic patch panels.