For each connector, we usually figure 0. 3 dB loss for most adhesive/polish or fusion splice-on connectors. 75 max per EIA/TIA 568)To be able to judge whether a fiber optic cable plant is good, one does a insertion loss test with a light source and power meter and compares that to an estimate of what is a reasonable loss for that cable plant. The estimate, called a "loss budget" is calculated using typical component losses for. Fiber optic loss is the reduction of signal strength through a link. It comes from fiber attenuation, connectors, splices, splitters, bends, and engineering reserves. Why is wavelength important? Different wavelengths experience different attenuation levels. 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.