The loss of connectors on a patchcord or short cable is given by FOTP-171 and the loss of an installed cable plant is measured by OFSTP-14 (MM) or OFSTP-7 (SM. ) In order to establish a typical loss for connectors, it is necessary to test all connectors in a standardized fashion. 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. designed for diverse fiber optic applications. It is caused by factors such as misalignment, air gaps, and imperfections in the connector components.