Appendix Optical Cable
W
dBm
RANGE
HOLD
REF
660
780
820
850 nm
X
X
Fig. A.1 Arrange of the switch for optical meter setting
[2] Measure the optical cable ( Standard length: 1 to 2 m )
A
A
Î
B Standard measurement level
( A Translate
，
B Receive )
B
Î
A Standard measurement level
( A Receive
，
B Translate )
B
Optic
a
l
me
te
r
Standard optical cable
Optic
a
l
me
te
r
[3] Measurement of optical cable of measurement target
Op
ti
c
a
l
meter
Op
ti
c
a
l
meter
A
Standard optical
cable
B
Repeater adapter
Optical cable of
measurement target
Receive side
Transmission side
A
Op
ti
c
a
l
meter
Op
ti
c
a
l
meter
A
Standard optical
cable
B
Repeater adapter
Optical cable of
measurement target
Receive side
Transmission side
1)
A
Î
B measurement target level
2)
B
Î
A measurement target level
( loss level of repeater adapter ---
≤
2 dBm)
[4] Judgment of measurement result
1)
A
Î
B loss of target optical cable =
(A
Î
B Standard measurement level)–(A
Î
B Target measurement level)
2)
B
Î
A loss of target optical cable =
(B
Î
A Standard measurement level)–(B
Î
A Target measurement level)
It is judged that it is good if the loss of each target optical cable is within 12dBm.
But, the loss of the optical cable is the rate of 12dBm/km. Confirm whether it is the loss level which
corresponded with the distance, too.
[5] S
imple method
A standard optical cable to use with the process 1) is measured as less than 1m.
In the process 3), A standard cable isn't connected, and it is measured only with the target optical cable.
It is judged if a loss is within 12dBm.
A - 4
