EXFO FTB-2 - Manual (Page 81)

Setting Up Your FTB-2 and FTB-2 Pro
FTB-2 and FTB-2 Pro 71
Recalibrating the Touchscreen
4. Using the stylus (or any blunt pointing device), simply press the center
of the different targets that appear on the screen. Keep pressing until
the application displays OK to indicate that the new parameters have
been taken into account.
Note: If you want to stop the calibration process, stop pressing the screen. The
application will close automatically after a few seconds and you will return
to the System Settings window.
5. When you see the message indicating that the calibration is complete,
tap OK to return to the System Settings window.
New parameters taken into account
Percentage of completion