Reference Procedure (Fot-20A And Fot-30A) - EXFO FOT-10A Manuel D'instructions

Power reading
If the received signal is too low to be measured, a dashed line is displayed. If the
received signal is too high to be measured, the display flashes.

3.5 Reference Procedure (FOT-20A and FOT-30A)

When the FOT is in reference mode, the reference value is subtracted from the
power received so that the value displayed only refers to the loss created by the fiber
under test.
To store a reference value,
1. If necessary, calibrate the FOT.
2. Connect the light source to the FOT as shown below.
EXFO
Light source
3. Power on the light source and activate the first wavelength.
4. Press d B m / W to select absolute mode.
5. Press s e l e c t to match the FOT and source wavelengths.
6. Press r e f to access reference mode.
7. Press and hold r e f until the display reads
appears in small digits.
The reference value just stored applies only to measurements taken at the current
wavelength. If you are using a dual-wavelength source, select the second wavelength
and repeat steps 4 to 7.
FOT-10A, FOT-20A, & FOT-30A
Bulkhead connector
Test jumper
0.00 dB
nm
Power meter wavelength
dBm
Test jumper
EXFO
FOT
Reference value (in dBm)
dBm
dB
and the new reference value
Connector
adapter
5