MANUAL OPERATION-OPTICAL RETURN LOSS METER
KI23400/KI27400 UM-2
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44 -
ORL Meter Manual Operation
ORL is an instrument p/n option.
KI23400 Series instruments measure Optical Return Loss (ORL) using
the Optical Continuous Wave Reflectometer (OCWR) method. the
meter measures the accumulated reverse power at the point of
measurement.
This method is accurate and suitable for acceptance testing. However,
it cannot locate a reflection source, and has limited optical range.
The instrument ORL test
λ
are the emitter
λ
.
Optical return loss causes, effects and remedies are beyond the scope
of this manual. Please refer to our application notes.
It is common for in ORL test situations to use a relatively complex test
lead assembly, which can cause test errors due to both connector loss
and stray return losses. These can both be compensated if they are
stable.
Low Reflection Terminations
The instrument is delivered with a low loss termination, helpful for
performing ORL testing. The termination can be placed at the far end
of a test specimen, to help absorb far-end reflections.
For additional applications support to understand ORL in fiber
systems, please refer to the application notes on our web site.
ORL Meter Operation
No warmup is needed. Ensure all optical connectors are clean.
•
Connect the device under test to the Two-Way port.
•
Press button below [RETURN LOSS] to display ORL
measurement, ORL for all available
λ
will now be displayed
in dB RL.
•
Toggle
-
/
+
to change the test
λ
.
To improve accuracy, the ORL Zero Function feature or User
Calibration Mode (UCAL) feature may be used.
These offsets can be also set in Autotest mode.
ORL Zero Function
This compensates for stray (residual) reflections to allow testing of
weak reflection levels. Using this feature, the instrument can read
accurately up to 10 dB below the stray reflection level,
However, this feature causes increased noise, so when using this
feature, ORL test resolution is decreased as follows:
If the zeroed value is x dB, then
•
From x to (x+10) dB, resolution is limited to 0.1 dB.
•
From x to (x-10) dB, resolution is limited to 1 dB, which is
also the display range limit.
