RM3 SERIES BACKREFLECTION METER
USER’S MANUAL
Loss Before the DUT
When a DUT is connected to the RM meter, the loss from connectors before the DUT affects the backreflection reading. Because the light is going out from the RM meter and then returning, it goes through the connectors twice, so the effect of the loss is doubled. If the loss is close to 0.15 dB, its effect is compensated automatically by the meter. If the loss differs substantially from 0.15 dB, follow the measurement procedures described at the end of the Measuring Backreflection section.
Reflections Before the DUT
When a device is connected to the RM meter, the reflections from the connectors affect the backreflection reading. The front panel FC/PC connections must have backreflection levels lower than
Reflections After the DUT
When making a backreflection measurement, the fiber after the DUT must be terminated to eliminate the reflections from the end of the fiber (see the Termination Techniques section). For greatest accuracy when making very low backreflection measurements, terminate near the DUT to eliminate reflections from the fiber itself.
Front Panel Connectors
Follow the maintenance procedure described in the Maintaining the Meter section, to ensure that the internal pigtail connectors are clean and properly connected to the front panel mating sleeve.
Ensure that the loss and backreflection of all the connectors are low and stable, complying with the connector specifications.
To confirm proper operation of the RM meter, terminate the internal cable while using the
Long Cables (for single mode model only, except 980 nm model)
Terminate the cables near the devices or connectors being tested in order to eliminate backreflections from the fiber.
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