38
ORL-85/ORL-85P
6 R
ETURN
L
OSS
O
PERATION
G
ENERAL
INFORMATION
6
R
ETURN
L
OSS
O
PERATION
General information
In the
Return Loss
mode the light source (two to four lasers) and
the receiver of the ORL-85 are activated. The wavelengths of the
Power Meter unit are locked to the wavelengths of the source
and can be selected independently.
In the Return Loss mode a signal is sent to the Device Under Test
(DUT) from the internal laser source. The power level reflected
from the DUT is measured and compared to the transmitted
signal. The result of the return loss is displayed at the ORL-85.
The accuracy of the return loss measurement depends highly on
the quality of the optical connection at the ORL-85.
J
Take care to keep the test connection very clean.
In the case the display does not show
HIGH dB
with the port
open:
1.
Clean the test connection (see
2.
To store the internal noise in
Return Loss
mode as reference
value, normalize the instrument (see
Normalization
To ensure a high measurement accuracy, it is required to
normalize the unit from time to time. This is done with the port
open, i.e. no Device Under Test is connected.
Normalizing the unit
NOTE:
To normalize for high return loss measurements, connect a
mandrel wrap to the test port (> 55 dB) instead of using an open
test port.
I
The instrument is in
Return Loss
mode.
1.
Disconnect DUT from test port.
2.
Unmount test adapter from test port, clean fiber surface of
test port and mount test adapter.
3.
Close the dust cap, or connect a mandrel wrap.
4.
To turn on the selected lasers, tap the
[
Laser On/Off
]
field or
press the center key within the arrow keys.
