EXFO FTB-500 (Window XP) - Manual (Page 119)

Using the Optional Built-In Power Meter and VFL
FTB-500 109
Accessing the Built-In Power Meter
Below is a description of the Power Meter buttons and functions.
Selected wavelength
To switch between available
power meter wavelengths
To access reference mode
Measured power or loss
Fail values appear in red (when option is
selected.)
To switch between dB, dBm
and W as measurement
units
Reference value (when in
reference mode)
To store a reading to the
Measurements window
Pass/Fail status icon (displayed
only when option is selected.)
To activate VFL and
changes VFL mode
To perform an offset
nulling