Optical Time-Domain Reflectometers (OTDRs)

OTDRs are used on outside plant cables to check the loss of each splice and locate any stress points that were caused during installation. OTDRs use the backscattered light of the fiber to indicate loss. With an installed cable plant the OTDR trace will show every connector splice, break, and anomaly in the fiber.

The OTDR Launch Box acts as a companion to OTDR test equipment. There are a few reasons to use a launch box (also know as a “launch cable” or “pulse suppressor”). One, the launch cable helps avoid problems with the dead zone, or the area close to the OTDR which causes an overload from the crosstalk between the instrument and the reflectance from the connector face of the OTDR. The long recovery time means the OTDR cannot make useful measurements near the instrument itself. The launch cable allows time for the OTDR trace to settle down after the test pulse is sent into the fiber so the beginning of the cable being tested can be analyzed.