Insertion Loss Testing Overview
7
Figure 4
Substitution Method
continued
• The test launch jumpers A and B are disconnected at Splice Bush-
ing A. Connector ends “X” and “Y” of the device under test are
connected to Splice Bushings A and B, respectively (see Figure 4).
The detector displays dB loss which represents optical power loss at
the “X” connection (due to misalignment, concentricity, angularity,
etc.) plus the loss at the “Y” connection, plus attenuation through
the length of fiber in the device under test.
