EXFO FTB -5240S/5240BP Optical Spectrum Analyzer for FTB 500 (NS-1434) - Manual (Page 292)

Managing Results
284 FTB-5240S/5240BP
Managing WDM Test Results
³
Noise (dBm): indicates the level of the noise for the selected channel
(according to the current calculation method, in dBm).
³
BW 3.00 dB (nm): indicates bandwidth measured by taking the width
of a signal at 50 % linear power of the peak or -3 dB from the peak.
³
BW x dB (nm): indicates bandwidth measured by taking the width of a
signal at x dB from the peak.
A small red marker ( ) will point down at the peak in the Graph tab when
you select a row in the Results tab. The red marker will move accordingly
to indicate the corresponding peak on the graph, with a focus on the
selected channel.