Determining the length of an APC launch fiber

Problem

In case of APC, the only valid method for launch compensation is Manual Entry.

In order to do so, one must know the precise length of the launch and/or receive fiber.

Solution

It is highly recommended to measure the length of launch and receive fiber at the beginning of each shift, and to do so with the same OTDR as the one used during this test cycle.

Step 1: create or select a test that has Singlemode set as Fiber Type.

Step 2: make sure Launch Compensation is set to the Off position before starting the test.