Use an LSPM or OLTS to reveal if the loss is on a single fiber or on all the fibers in a cable. This can be especially helpful for identifying bad splices when using splice-on pigtails since they are near the end of the link. Primarily used for Tier 1 certification and acceptance testing and the most accurate tool for measuring loss, a light source and power meter (LSPM) or Optical Loss Test. 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. The three standard methods for testing fiber optic cabling are a visible light source, power meter and light source, and optical time domain reflectometer (OTDR). Since fiber optic transmissions typically operate in the infrared spectrum (invisible to the naked eye), visible light sources such as visual fault finders or visible fault locators can be used to. A Visual Fault Locator which can be also called visual fault identifier (VFI), fiber fault locator, fiber fault detector, etc., is a visible red laser light designed to inject visible red light energy into an optical fiber. Look for dirt, scratches, or damage on the connectors.
