1-12
IM AQ7280-01EN
4-point Method
The AQ7280 uses the following four points to perform the measurement: the measurement start
point
1
, the splice loss start point
2
, the splice loss end point Y2, and the measurement end point
3
. At position
2
, the level difference between the approximated line
2
–
1
and the approximated
line Y2–
3
is calculated as the splice loss. The splice loss changes greatly depending on the
position of
2
. Set the correct position for
2
. The splice loss value changes depending on the
approximation method that you have specified. This can only be used when Marker Mode is set to
Marker.
Y2
b (dB)
e (dB)
c (km)
f (km)
Approximated line
Y2 -
3
2
1
3
Splice loss :
Return loss :
b
c
b/c
dB
km
dB/km
a dB
e
f
e/f
dB
km
dB/km
–
–
a (dB)
5-point Method
The AQ7280 uses the following five points to perform the measurement: the near-end point (n), a
point (N) that is used to calculate the near-end side's approximated line, a point (E) where splice
loss is detected, a point (F) that is used to calculate the far-end side's approximated line, and the
far-end point (f). At position E, the level difference between the approximated line n–N and the
approximated line F–f is calculated as the splice loss. The splice loss changes greatly depending
on the position of E. Set the correct position for E. The splice loss value changes depending on the
approximation method that you have specified. This can only be used when Marker Mode is set to
Line.
n
N
f
F
a (dB)
b (dB)
c (km)
e (dB)
f (km)
E
Approximated
line F - f
Approximated
line n - N
Splice loss :
Return loss :
b
c
b/c
dB
km
dB/km
a dB
e
n-E
E-f
f
e/f
dB
km
dB/km
6-point Method
The AQ7280 measures using the 6-point method when there are two adjacent splice loss events.
The AQ7280 uses the following six points to perform the measurement: the first splice loss start
point
1
, start point Y1 used to calculate the approximated line, end point Y3 used to calculate
the approximated line, the second splice loss start point
2
, the second splice loss end point Y2,
and the measurement end point
3
. At the position of marker
2
, the level difference between the
approximated line Y1–Y3 and the approximated line Y2–
3
is calculated as the splice loss.
Y2
Y1
Y3
a (dB)
b (dB)
c (km)
e (dB)
f (km)
Approximated
line Y1 -
Approximated
line Y1 - Y3
1
2
3
3
Splice loss :
Return loss :
b
c
b/c
dB
km
dB/km
a dB
e
f
e/f
dB
km
dB/km
–
–
1.4 Optical Pulse Analysis