Start with Tier 1 optical loss testing, then move to Tier 2 advanced diagnostics if problems persist. You begin troubleshooting by calibrating your power meter. This step ensures accurate measurement of. 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. Therefore. To determine the power budget and power margin needed for fiber-optic connections, you need to understand how signal loss, attenuation, and dispersion affect transmission. Fiber loss, or attenuation, refers to the reduction in optical power as light travels through a fiber optic cable. While some loss is expected, excessive or unexpected loss can lead to poor performance, network. The Fiber-optic Cable dB Loss Budget calculator computes the transmission loss budget (allowance) in dB over a distance of fiber optic cable based on the length of the cable (L), type of cable (FT), number of connectors (C), the dB loss per connector (CL), the number of splices (S), and the dB loss. Fiber loss can be also called fiber optic attenuation or attenuation loss, which measures the amount of light loss between input and output. Factors causing fiber loss are various, such as intrinsic material absorption, bending, connector loss, etc.