What instrument is used for the visual inspection of fiber optic end-faces?

The instrument used for the visual inspection of fiber optic end-faces is the inspection scope. This device is designed specifically to allow technicians to closely examine the surfaces of fiber optic connectors and ferrules for cleanliness and damage. Visual inspection is a crucial step in fiber optic installation and maintenance because contaminants like dust, oil, or scratches can impede performance by causing loss of signal strength or reflection issues.

Using an inspection scope helps ensure that the connections are clean before they are mated, which is vital for maintaining optimal transmission quality in fiber optic networks. While the other instruments listed have important roles—such as measuring signal strength or analyzing the performance of the entire fiber link—they do not facilitate the direct visual examination of the fiber end-faces like an inspection scope does.