Document #: GP-UM-PMD-1000-21
Page 7 of 122
Section 3. Feature Description:
3.1 Optical Features:
The PMDPro system has two bulkhead adapters on the front panel to accommodate the
optical input and output. The adapters are universal connector interfaces (UCI), which
feature a male-type adapter top piece that can be removed for direct access to the ferrule
end for routine cleaning and maintenance without removing the entire adapter from the
panel. This feature helps avoid high insertion loss, high return loss and measurement
instability caused by dirty or contaminated connectors. In addition, the PMDPro’s
universal interchangeable adapter allows the end user to switch to ST, SC, or FC
connectors without opening the instrument panel. Although the PMDPro is shipped with
a standard (typically FC/PC or FC/APC) fiber adapter, other interchangeable inserts are
available. For additional information on different input fiber adapter inserts, please
contact General Photonics.
External fiber connectors should be cleaned using industry standard cleaning methods
before connection to the PMDPro. If this procedure is followed before each connection,
the instrument’s internal connector ferrules should not need regular cleaning. However,
high insertion loss or measurement instability that does not improve after cleaning the
external connectors may indicate that the instrument’s internal connector ferrules require
cleaning.
Each connector ferrule is contained in a universal connector interface consisting of a
front piece that connects to the external fiber connector, and a base piece that is mounted
on the front panel of the instrument, as shown in Figure 2. To clean a connector ferrule,
first, make sure no external connector is connected to the universal connector interface.
Then, using a Phillips screwdriver, remove the two small screws connecting the front and
back parts of the adapter, and carefully pull the front flange straight out. (Note: never
remove the adapter base from the front panel). The ferrule end should now be exposed.
Clean the ferrule using standard cleaning procedures (compressed air or a fresh lint-free
tissue and alcohol), taking care to avoid scratching the ferrule surface. Finally, replace the
front flange (position it so that the key notch faces up, and the small alignment pin lines
up with the hole in the base piece, before pushing it in) and the screws. For frequent
measurements, we recommend that the user prepare a patch cord fiber to avoid wear on
the internal connector.
Figure 2 Diagram of universal connector interface
Hole for
alignment pin
Ferrule end
Remove screws
Front flange
Adapter base-
do not remove
