82
OLT-85/OLT-85P
13 A
PPENDIX
- R
EFERENCING
M
ETHODS
L
OOPBACK
AND
R
EMOTE
R
EFERENCING
Fig. 31 Two jumper reference - unidirectional
Fig. 32 Two jumper reference - bidirectional (switching source and
powermeter mode)
The losses (Δ) at Δ
Conn. 1
, Δ
Conn. 2
and Δ
Conn. 4
are referenced out,
so the loss measurement is as follows:
Measured loss = Δ
FiberUnderTest
+ Δ
Conn. 3
This reference removes any loss at the connection between the
transmitter of the instrument in source mode and a reference
test jumper plus the loss at one connection plus a second
C1
C4
TX
RX
S
P
C2
C1
C4
C1
C4
TX
RX
RX
TX
S
P
P
S
C2
C2
C1
Connection 1
C4
Connection 4
C2
Connection 2
TX
Laser source output (Transmitter)
RX
Powermeter input (Receiver)
S
Source device
P
Powermeter device