EXFO FTB-5600 Distributed PMD Analyzer - Manual (Page 44)

Setting up and Operating your Distributed PMD Analyzer
38 FTB-5600
Performing an Acquisition
The sensitivity of the measurement allows you to increase the PMD
measurement range. A greater sensitivity increases the number of averages
and will take longer to be achieved.
To improve the dynamic range for your acquisition, consider the following:
³
For less than 13 dB, put the sensitivity to low. This means an acquisition
of about 15 minutes with three resolutions.
³
Setting the sensitivity to medium will improve the dynamic range and
means an acquisition of about 30 minutes with three resolutions.
³
Setting the sensitivity to high will give you the optimal dynamic range
and means an acquisition of about 1 hour with three resolutions.
Note: You can obtain the dynamic range of the trace by subtracting the
backscatter level at the fiber end from the injection level accepted range
value.
Sensitivity
Number of
Averages
Electronic
Sensitivity
Low 500 Low APD gain
Medium 1000 High APD gain
High 2000 High APD gain
Difference between
injection and OTDR
trace level where
the PMD curve ends