In this recent video, Tom Warren of Alliance Corp., a manufacturer of fiber-optic cables for the wireless telecom industry, demonstrates how to conduct continuity testing on fiber-optic cabling with duplex LC connectors using a visual fault locator (VFL).
Continuity testing is recommended to ensure that the fiber-end to fiber-end continuity exists (i.e. that there are no breaks in the fiber) and to and make sure port connections and fiber mapping is correct. Alliance recommends that any telecommunications contractor installing fiber-optic cable at a wireless site conduct a continuity test on cabling before installing it. The company also recommends conducting continuity tests once the fiber-optic cable is installed to make sure the correct ports are matched.
See also: Fiber-optic testing: Keeping it simple in the field