EXFO FTB-500 (Window XP) - Manual (Page 121)

Using the Optional Built-In Power Meter and VFL
FTB-500 111
Setting Thresholds and Correction Factors
Setting Thresholds and Correction Factors
You can define thresholds to specify acceptable power or loss values for
each wavelength. Thresholds are usually supplied by system
manufacturers and depend on the system deployed.
A power measurement (in dBm) will be considered as “Fail” when its
value is lower than the defined absolute power threshold.
A loss measurement (in dB) will be considered as “Fail” when its value
is greater than the insertion loss threshold.
When the measurement status is “Pass”:

The value is displayed in black and the symbol appears next to
it, both in the Instrument View tab and on the Measurements list.

In reports, the value is displayed in black and the Status column
shows a check mark.
When the measurement status is “Fail”:

The value is displayed in red and the symbol appears next to it,
both in the Instrument View tab and on the Measurements list.

In reports, the value is displayed in black and the Status column
shows an X.
You must select the pass/fail status feature for the application to take
into account the defined thresholds and display the appropriate status
icons. By default, this feature is not selected.