EXFO IQS-12004B DWDM Passive Component Test System for IQS-500 - Manual (Page 88)

Calibrating the DWDM Passive Component Test System
76 IQS-12004B
Calibrating the System
A nulling of the electrical offsets should be done:
³
At the initial installation after the system has reached a stable operating
temperature (approximately 30 minutes).
³
If there is a significant change in environmental conditions.
EXFO also recommends that a nulling be performed prior to the
wavelength response calibration and/or before the return loss calibration.
To perform a nulling:
1. Put protective caps on power meter detectors as well as on the input
and output of the WRM, as shown on the screen.
2. Click OK to perform the measurement.
OR