1-5
IM AQ7280-01EN
Features
1
2
3
4
5
6
7
8
Index
1.2 Optical Pulse Measurement
The AQ7280 applies an incident optical pulse to the connected optical fiber cable and measures
the power level of the reflected light from the different sections of the optical fiber cable such as its
connections, bent sections, and the open end of the fiber. The AQ7280 uses the measured power
level to determine the distance to the different points (splices, breaks, etc.) of the optical fiber cable
and the loss and other phenomena that occur at those points. For details on how to view optical pulse
waveforms, see section 1.3.
Reflection point
Optical fiber cable being measured
Optical pulse output
Reflected light
Do not bend the optical fiber cable.
OTDR/Light source port
(optical port 1)
or
OTDR port (optical port 2)
AQ7280
Mode
• Simple Mode
In optical pulse measurement, there are measurement conditions related to measurement
resolution—such distance range and pulse width—and analysis conditions related to the
optical fiber cable—such as index of refraction and backscatter. These conditions must be set
according to the item being measured or analyzed. The AQ7280 can perform an optical pulse
measurement immediately before the actual measurement, calculate the distance, splice loss,
and the like beforehand, determine the suitable range from these values, and perform the actual
measurement.
• Detail Mode
If the distance to the measurement target or the optical fiber cable characteristics are known or
if you want to measure or analyze a specific event in detail, you can set the values individually
as necessary. If you set the measurement conditions—such as the distance range and pulse
width—to Auto, the AQ7280 will determine the suitable range and perform the measurement like
in Simple Mode, described above.
• PON Mode
If the optical fiber cables to be measured are connected to a PON (passive optical network)
system, optical splitters that divide the optical fiber cables into the PON system is installed. The
measurement and analysis conditions will vary depending on the installation conditions of the
optical splitters. In PON mode, the AQ7280 determines the suitable measurement and analysis
conditions based on the number of optical splitter stages, route information, and distance range
to set the optimal values. These values can be changed if necessary.
Averaged Measurement
Averaged measurement is effective when you want to detect reflections, splice loss, and other faint
events that are generated from connections or splice points but are buried in noise. The AQ7280
derives the measured data by averaging the specified number of optical pulse measurements or by
averaging optical pulse measurements over the specified duration. During averaged measurement,
you cannot change the measurement conditions. You can stop an averaged measurement before it
completes.