EXFO IQS-12004B DWDM Passive Component Test System for IQS-500 - Manual (Page 100)

Interpreting the DWDM Passive Component Test System Results
88 IQS-12004B
Optimizing Performance
IL/PDL Errors
There are numerous possible sources of errors for the insertion loss
measurement. Some of them are inherent to system and test procedures,
while others are related to operation and fiber handling. Understanding
these sources of error will help you to optimize the accuracy of your loss
measurements.
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Environmental stability
To ensure optimum results, it is important to respect the
recommended 30-minute warmup period before performing any
calibration, reference, or null measurement.
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Source power stability
The IQS-9401 has an internal detector that is always measuring the
optical power at the output of the WRM. This reference power is used
along with the calibrated coupling ratio of the output coupler to correct
variations in the source power. Therefore the effect of any instabilities
in the source output power have been minimized.
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Connector repeatability
It is well known that connector repeatability is a significant source of
error when testing the IL of any connectorized component. There is no
practical way of completely eliminating these errors. However, if all
connectors are of good quality and adequately cleaned, the errors are
minimized. Where it is important to measure the IL of the device
alone, you should use fusion splices on the launch side of the DUT.