EXFO FTB -5240S/5240BP Optical Spectrum Analyzer - Manual (Page 199)

Setting Up the Instrument in Spectral Transmittance Mode
OSA 193
Setting Up Spectral Transmittance Analysis Parameters

Channel distance (GHz or nm): indicates distance between the
channels. The value of channel distance will be set depending on
the selection made for the channel definition option. The channel
distance box will be enabled only when the channel center
wavelength option is set to custom.

Channel range (GHz or nm): indicates the limit inside which the
power values will be considered in the channel. Integrated power
is calculated on channel width.

Bandwidth 1 at (dB): Set the power level used, relative to the
channel peak power, to compute the bandwidth.

Bandwidth 2 at (dB): Set the power level used, relative to the
channel peak power, to compute the bandwidth.

Input wavelength offset (nm): indicates the offset value applied on
the input wavelength. This does not replace a calibration
performed at EXFO, but it can help you temporarily sharpen the
specifications if you have determined that, for example, your
modules are used beyond the normal allowed use. Entering a
value in THz is not possible. When an offset is applied, it is
indicated at the bottom of the graph (
).

Input power offset (dB): indicates the offset value applied on the
input power. 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 use. When an offset is applied, it is indicated at the
bottom of the graph (P
).
To edit the power offset value as a tap percentage, press the Edit %
button.