In order to test “insertion loss” or the direct loss of a fiber optic cable or cable plant using a light source and power meter (LSPM in most international standards or optical loss test set – OLTS – in many articles), one must make an initial measurement to determine the. In order to test “insertion loss” or the direct loss of a fiber optic cable or cable plant using a light source and power meter (LSPM in most international standards or optical loss test set – OLTS – in many articles), one must make an initial measurement to determine the. In order to test “insertion loss” or the direct loss of a fiber optic cable or cable plant using a light source and power meter (LSPM in most international standards or optical loss test set – OLTS – in many articles), one must make an initial measurement to determine the “0 dB” reference point. Various measurement techniques are used in fiber optic deployments—one of them is the Optical Loss Test Set (OLTS). It calculates the optical signal loss between two points by comparing transmitted and received power levels. But what exactly is being measured, and why is this value so critical for. In optical communication, every fraction of a decibel can decide whether a link runs flawlessly or fails under load. One of the most important parameters is insertion loss (IL) — the amount of optical power lost when light travels through a component, connector, or fiber link. Engineers consider. This virtual hands-on page will take you through the steps involved in the process. If you have your own equipment, do the experiments suggested. The use of verified reference grade test cords is mandatory. For clarity, mode filters and the necessary presence of.