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., insertion loss), low return loss, or high reflectance will impair an application (i. A high return loss is a good thing and usually results in low insertion loss. Contractors often install, terminate, and certify cabling without knowing the client's specific requirements. Losses can be introduced by various means such as intrinsic material absorption, scattering, bending, connector loss and more.