Installation Manual

BEST PRACTICES
FS061
© Panduit Corp. 2018
For Technical Support: www.panduit.com/resources/install_maintain.asp
Page 7 of 12
Table 3 – Visual requirements for multimode PC polished connectors
a
Zone
Scratches (maximum
number of a given
dimension)
Defects
(maximum number of a given dimension)
A: core
0 μm to 65 μm
No limit ≤ 3 μm
None > 3 μm
4 ≤ 5 μm
None > 5 μm
B: cladding
65 μm to 115 μm
No limit ≤ 5 μm
None > 5 μm
No limit < 5μm
5 from 5 μm to 10 μm
None > 10 μm
C: adhesive
115 μm to 135 μm
No limit
No limit
D: contact
135 μm to 250 μm
No limit
No limit < 20 μm
5 from 20μm to 30μm
None > 30μm
a
For multiple-fibre rectangular-ferrule connectors only the requirements of Zone A and Zone B apply.
NOTE 1 There are no requirements for the area outside the contact. Cleaning loose debris beyond this region is
recommended good practice. This is of particular concern for multiple-fibre rectangular-ferrule connectors.
NOTE 2 For multiple-fibre rectangular-ferrule connectors, the criteria apply to all fibres in the array.
NOTE 3 The zone size for multimode fibres has been set at 65 μm to accommodate both 50 μm and 62,5 μm core size
fibres. This is done to simplify the grading process.
7.0 General Inspection Guidelines
Visual microscopic inspection of the connector end face is the best way to determine the quality of the
termination process and cleanliness of the connector. Connector end faces should be smooth,
scratch-free and should not display cracks. Several different contamination types and workmanship
flaws are shown in Figure 3 on the following page.
The proper magnification for viewing connectors is recommended to be 200x. At lower magnification,
typical of an eye loupe or portable magnifier, adequate resolution is not provided. At high
magnification, negligible defects at times look worse than they really are. Refer, for example, to
Figure 4, where the MTP* connector is magnified at 400x and shows oil or debris on the ferrule end.
Panduit has found that heightened levels of workmanship standards do not provide proportional
increases in interconnect performance. In general, if the defects aren’t observed at 200x
magnification, they do not significantly impact the optical performance of the connector. If
workmanship standards are adhered to with inspection at this magnification, connector performance
is relative to the cleanliness of the optical interface.
There is a tendency to be overly critical in connector end face inspection, especially at higher
magnification(400x). Typically, only defects over the fiber core are a problem. Chipping of the glass
around the outside of the cladding is not unusual and will have minimal effect on the ability of the
connector to couple light in the core. Likewise, scratches on the cladding area will not cause
significant loss problems.