This guide walks you through 7 proven, step-by-step methods to confidently use an OTDR to test fiber optic splices, read and interpret results, and make smart decisions about when to re-splice and when to sign off. An Optical Power Meter and Laser Light Source will be used to measure power loss on each completed ring or distribution span to verify continuity between fibers (no fibers incorrectly spliced. Fiber optic sources, including test equipment, are generally too low in power to cause any eye damage, but it's still a good idea to check connectors with a power meter before looking into it. Some telco DWDM and CATV systems have very high power and they could be harmful, so better safe than. Fiber Optic Testing Testing is used to evaluate the performance of fiber optic components, cable plants and systems. As the components like fiber, connectors, splices, LED or laser sources, detectors and receivers are being developed, testing confirms their performance specifications and helps. Whether you're commissioning a new installation or diagnosing mysterious signal loss, an Optical Time Domain Reflectometer (OTDR) gives you a precise, visual map of every splice, bend, and break across the entire fiber run. Key tests include: Effective fiber testing utilizes advanced tools such as Optical.