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Evaluating the reliability of optical connectors
6-4 Observation of the tip shape
Fig.9 shows the results of observations made on the shape of the ferrule tip before and
after the High Temperature Storage Test (Damp Heat). After 2000 hours at 85°C and 85
percent relative humidity, the surface of the ferrule tip showed signs of pitting and was
rougher than before testing. This roughness did not appear on the surface of the tip after
the Temperature Cycling Test, leading to the conclusion that the roughness was caused
by humidity. Fig.10 shows a three-dimensional computer graphics rendition of the shape
of the tip. After 2000 hours at 85°C and 85 percent relative humidity, the ferrule tip
exhibited flattening distortion. However, pistoning measurements with the Ferrule Tip
Condition Surveyor measured the position of the apex of the tip from the sphericity of the
ferrule tip, and, using that position as a standard, calculated the amount of pistoning.
Accordingly, if the position of the tip section differs from these measurements, the
amount of pistoning could be greater than that calculated.
(a) Initial period
(b) After testing
Fig.9 Ferrule tip observation (85°C, 85%rh, 2000 h)
(Initial period) (-40 /85°C, 500 cycles) (85°C, 85%rh, 2000 h)
Fig.10 Three-dimensional shape of the ferrule tip
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Espec Technology Report No20