1-11
IM AQ7280-01EN
Features
1
2
3
4
5
6
7
8
Index
Dead Zone
An area where the influence of a large event such as a connector’s connection point makes it
impossible to recognize other events that exist in that area is a dead zone. There are the following
types of dead zones.
• Event Dead Zone
An area where adjacent reflections cannot be separated. This is the area represented by the
pulse width between the two points on the waveform at the level that is 1.5 dB below the peak
value.
• Attenuation Dead Zone
An area where, because there is a large reflection, the surrounding splice losses cannot be
measured.
Event dead zone
Attenuation dead zone
1.5 dB
Near-end Dead Zone Prevention
In sections where near-end reflection is detected, loss and reflections that occur at connections
cannot be detected. If you are measuring a short distance, connect a launch fiber cable to move
events that are hidden in the near-end reflection the distance of the launch fiber cable.
Do not bend the optical fiber cable.
Optical fiber cable being measured
Launch fiber cable
Event generation point
Small reflection that was hidden
within a large reflection
AQ7280
Splice Loss
The AQ7280 measures the distance and the loss between the specified points.
2-point Method
The AQ7280 measures the distance and the loss between two points. If reflection is detected
between the two points, the return loss is also measured. The splice loss value changes depending
on the approximation method that you have specified. This can be used when Marker Mode is set
to Marker or Line.
Splice loss a (dB)
(Total loss)
d (km)
(n when Marker Mode is set to Line)
(E when Marker Mode
is set to Line)
2
1
Splice loss :
Return loss :
–
–
20
20
1
dB
km
dB/km
Splice loss
1.4 Optical Pulse Analysis
