8
Testing Fibers with MFT and MFI
Prior to testing, make sure the plunger is oriented correctly for the type of ber to
be tested.
• Power On the MFI identier by pressing the Power button . Alternatively the
MFI may be activated by pulling down the trigger. An audible tone generator will
“beep” when the unit is energized.
• Gently insert the ber to be tested into the ber groove located at the top of the
MFI’s head.
• Pull down and hold the trigger to depress the ber being tested against the
optical assembly.
• The MFI will start looking for Fiber ID bursts when the plunger has closed and the
ber is in the appropriate position.
Once the trigger is completely retracted, the MFI will discriminate transmitted
optical signals as follows:
–If the ber under test is active, the MFI display will show ber number if signal
is detected. Both arrows will alternately ash, and an audible tone will
beep every 3 seconds.
–When no signal is present, the MFI will illuminate the “No Signal” indicator
and show “ - - -” (no ber) on the display.
Additional Information for Ribbon Fibers Testing
Ribbon ber is typically comprised of 4, 8, or 12 bers with a 250 µm coating
attached together. The MFI will test ribbon bers, however, the user should be
aware of some limitations.
Warning: Can not be used on live ber network!
• The MFI will not isolate a specic ber from the group in a ribbon. If the ribbon
under test is carrying more than one MFT data burst signal, the MFI will not
function properly.
• Ribbon identication on bers 5,6,7,or 8 is the best since they are more
centrally located.
