EXFO FTB -5240S/5240BP Optical Spectrum Analyzer for FTB 500 (NS-1434) - Manual (Page 400)

Managing Results
392 FTB-5240S/5240BP
Managing EDFA Test Results
4. Under Global analysis parameters, modify the following parameters
as needed:
³
Peak detection level (dBm): indicates the minimum power level
from where the peak can be considered as a signal.
³
RBW for OSNR (nm): indicates the resolution bandwidth for the
selected OSNR value. The resolution bandwidth of an OSA
determines its ability to deal with close optical channel spacing. It
is measured as the width of the response curve at half peak power
(i.e., 3 dB down) of the instrument to a monochromatic test signal.
The instrument’s RBW value is written below the graph on the right
(below wavelength offset).
³
Input wavelength offset (nm): indicates the offset value applied
on the input wavelength. You can use an offset to adjust your unit.
This does not replace a calibration performed at EXFO, but it can
help you achieve the specifications if you have determined that, for
example, your modules are used beyond the normal allowed.
Entering a value in THz is not possible. The wavelength offset
appears below the graph, on the right, next to the
arrow.