Q: why some customers need launch cable box?

A--Optical time domain reflectometer (OTDR) is a necessary fiber optic testing tool which use light backscattering technologies to analyze the optical fiber performance. It can test the light loss and locate the breaks, splices and connectors in fiber optic network. However, OTDR has "dead zone" which can affect the testing result if proper measure is not taken. To overcome the limitation of OTDR dead zone, OTDR launch box is being used.

Q:How can OTDR launch box minimize the effect of OTDR dead zone during fiber optic testing?

A--The dead zone of OTDR, caused by high return level of reflection and affected by the pulse width, might extend hundred meters from the OTDR. Full length of optical fiber is suggested to use before the optical fiber under test. Thus, the receiver of the OTDR can have enough time to settle. OTDR launch box, which is actually a long spool of optical fiber inserted between the fiber under test and OTDR, can ensure that the OTDR dead zone happens in the OTDR launch box (shown in the following picture). Then, the fiber optic link under test won't be largely affected by the OTDR dead zone.

Q:Which OTDR Launch Box Fit Your Applications?

A--The selection of OTDR launch box is like selecting fiber patch cable. You should basically consider about the fiber type, connector type. Another important factor should be considered is the length of optical fiber of OTDR launch box as above mentions. The optical fiber of OTDR launch box should be longer than the dead zone. Thus, most of fiber OTDR launch box can support hundreds or thousands meters. Usually customers choose 0.5km，1km and 2km Launch cable Box.