OTDR Launch Cables Demo

OTDR Launch Cables are designed to be used in conjunction with an OTDR to measure complete link loss of a fiber. They are also known as pulse suppressor cables, launch cords, launch leads, receive cables or fiber rings.

OTDR launch cable Video

An OTDR launch cable, which connects the OTDR to the link-under-test, discloses the insertion loss and reflectance of the near-end connection. A receive cable, which is connected to the far-end of the link, exposes the insertion loss and reflectance of the far-end connection.

A fiber ring serves as both a launch cable and a receive cable. Specialized Products Company stocks AFL Fiber Rings and FiberXP OTDR Launch Cables. It is recommended that the OTDR launch cable be longer than the dead zone. The shorter 150 meter lengths are ideal for premises fiber network test applications.

We also carry single mode OTDR launch cables of 500 meters and 1000 meters for broadband, long-haul fiber network test applications. Launch cables are offered in a variety of connector styles including SC, ST, LC, FC and MTRJ.

FAQ

How to Generate a Baseline Trace Using Fiber Rings
Use the fiber ring as a launch cable. Connect the fiber ring between an OTDR and the fiber link under test. In this configuration, the loss of the near-end connection can be measured.
Use the fiber ring as a receive cable. Connect the fiber ring to the far-end connector of your fiber link under test. In this configuration, the loss of the far-end connection can be measured.
By using fiber rings as both launch and receive cables, as shown in the diagram at the right, total insertion loss of the fiber link under test can be measured.

What length of launch cable should I use in testing single mode and multi mode fiber?

The length of launch cable used can very depending on the measurement needs. But there are some general rules to follow. The cable should be longer than either of the following specifications, Event Dead Zone or Loss Dead Zone and the pulse length being used. The better of the two to select is Loss Dead Zone as this will meet both. This would meet the minimum length recommendation. Now with that said you may find that the launch cable may need to actually be longer because of the pulse length being used. Another item to watch is that the launch cable is not a small integer length of the cable being tested, i.e. test cable / launch cable = 1, 2, or 3. This is because of Ghosting.

Here are some recommendations.

Multi Mode and Single Mode: The jumper cable needs to be at least 4 to 5 times the length of the pulse width you will be using, 10 times is better. This applies for both a launch cable and a terminating cable. (Terminating cable allows you to see the true loss of the end connector. Because to see the loss of this connector you need to see beyond it.)

OTDR Launch Cable Application