Launch fibers are necessary for all OTDR measurements and mandatory for certification measurements. They make it possible to analyze the first connector along the optical path and minimize dead zones.
In multi-mode fibers, they are also responsible for the measurement conditions (i.e., the coupling conditions into the fiber being measured) always being identical. If a receive fiber is used, the last connector can also be analyzed.
The fiber type should always correspond to the fiber being measured; otherwise, this can lead to measurement errors. All common connector combinations are available. We offer different designs (e.g., small fiber rings or plastic cases). The patchcords can also be equipped with a special protective jacket or set up in a self-stretching manner.
The minimum length of the launch fiber largely depends on the pulse width used at the OTDR. Typically, 1,000 m of fiber are used for single-mode, and 100 m of fiber are used in a multi-mode environment. Practically speaking, it makes sense to use fibers of different lengths (e.g., 100 m and 120 m) when using both a launch and a receive fiber.
