Fiber optic inspection microscopes are used to inspect connectors to confirm proper polishing and find faults like scratches, polishing defects and dirt. They can be used both to check the quality of the termination procedure and diagnose problems. A well made connector will have a smooth , polished, scratch free finish and the fiber will not show any signs of cracks, chips or areas where the fiber is either protruding from the end of the ferrule or pulling back into it.
The magnification for viewing connectors can be 30 to 400 power but it is best to use a medium magnification. The best microscopes allow you to inspect the connector from several angles, either by tilting the connector or having angle illumination to get the best picture of what's going on. Check to make sure the microscope has an easy-to-use adapter to attach the connectors of interest to the microscope.
Video readout microscopes are now available that allow easier viewing of the endface of the connector and some even have software that analyzes the finish. While they are much more expensive than normal optical microscopes, they will make inspection easier and greatly increase productivity.
And remember to check that no power is present in the cable before you look at it in a microscope - to protect your eyes! The microscope will concentrate any power in the fiber and focus it into your eye with potentially hazardous results. Some microscopes have filters which remove infrared light from sources to be safe.
December 20, 2011