OTDR Launch Cable is nothing more than a simplex fiber patchcord. It consists of a single fiber, much longer than standard fiber optic patchcords used in networks. Usually these lengths range from 100m to even 5000m. One of the most important features of a launch cable are high quality connectors that have a direct impact on the measurement results. Connectors are selected depending on the needs. One must match the connector on the meter, while the other must match the connector of the measured network.. The fiber optic type, used in the launch cable should match the type of the fiber that was used to build the network. This is quite important, because otherwise errors will appear that result from different fiber structure or material differences that were used to make them.
Without the launch cable it would not be possible to measure the initial section of the measured route and the connector at its beginning. The pulse length is selected according to the length of the measured network. The longer the network is, the longer the impulse should be. With the extension of the measuring pulse, the dead zone section increases. The longer the dead zone is, the longer the launch cable should be used to eliminate this zone.