The IEC 61300-3-35 standard focuses on observing and classifying debris, scratches, and defects during visual inspection of fiber end faces. Connector interferometry equipment employs cameras, mirrors, phased light, and intricate analysis to provide a comprehensive 3D assessment o a ferrule's end-face. This geometry determines the degree of physical contact when wo connectors are mated. Digital ferrule scopes are commonly used in production and by field installers to inspect ferrule surface quality and comply with. The best answer to the question “what should be inspected and cleaned?” is everything—every optical end-face connector should be inspected, and every optical end-face connector that fails should be cleaned. If an optical end-face connector passes the specified pass/fail criteria, do not clean it. These include many connector styles, including the well-known SC, LC, S T, FC, the less common SN, E2000, MU, D4, LEMO, as well as military-style “pin-and-socket” connectors, and others.
