EXFO IQS-12004B DWDM Passive Component Test System for IQS-500 - Manual (Page 94)

Calibrating the DWDM Passive Component Test System
82 IQS-12004B
Performing Reference Measurements
Performing Reference Measurements
Once the calibration is complete, you will have to perform an Insertion
Loss/PDL reference as well as a Return Loss Zero reference. Normally, the
application brings you to this step automatically. If necessary, you can go
directly to the Reference step. For information on accessing a step, see
Accessing a Specific Test Step on page 34.
Note: The IQS-12004B DWDM Passive Component Test System test system
automatically prompts you to perform a reference measurement (see
procedure below) at start-up. However, to obtain good results, EXFO
recommends to also perform a reference measurement when the test
system is used non-stop during a long period of time or when there are
important variations in environmental conditions.
IL/PDL Reference Measurement
An IL/PDL reference is performed to compensate for any loss or spectral
non-uniformity of the launch fiber connection to the WRM output port.
During this step, a complete sweep on the first channel is performed.
Note: An IL/PDL reference measurement is required each time the system is
turned on, and is recommended whenever there is a significant change in
environmental conditions.