EXFO FastReporter 2 - Manual (Page 354)

Description of Event Types
344 FastReporter 2
Reflective Event
Reflective Event
Reflective events appear as spikes in the fiber trace. They are caused by an
abrupt discontinuity in the index of refraction.

Reflective events cause a significant portion of the energy initially
launched into the fiber to be reflected back toward the source.

Reflective events may indicate the presence of connectors,
mechanical splices, or even poor-quality fusion splices or cracks.

Normally, loss and reflectance values are specified for reflective
events.

When the reflective spike reaches the maximum level, its top may be
clipped due to the saturation of the detector. As a result, the dead zone
(minimum distance for making a detection or attenuation
measurement between this event and a second nearby) may be
increased.

If you set thresholds, the application indicates a reflective fault in the
events table, whenever a value exceeds reflectance or connector loss
thresholds.
Reflected
power (dB)
Distance
(km)
Reflective events
Clipped level