Correct Curve: A is dead zone, B is reflection peak of testing end
Appearance: No Fresnel Reflection, curve slope and attenuation is normal, cannot specify fiber length
Problem: Fiber end face is dirty or fiber quality is bad
Solution: Clean fiber end face or reform end face
Appearance: Curve appears obvious arched, attenuation is serious larger or smaller, no Fresnel Reflection
Problem: Wrong measurement range
Solution: Increase measurement range
Appearance: 'A small peak ' on the curve with constant curve slope
Problem: a) Fiber quality (crack)
b) Secondary reflection produce reflection at anterior face
Solution: Change measuring range, pulse width, reform end face , then re-test. If small peak disappears,reason b), otherwise, reason a)
Appearance: Obvious increase at the point of fiber connector, splicing, coupler
Problem: Diameter does not match
Solution: Test attenuation and connector loss must two-way test, and take the average
Appearance: 1310nm curve: smooth, attenuation slope and index is normal
1550nm curve: attenuation slope is bad, index is seriously high
Problem: Bending radius is too small
Solution: Increase rest length of fiber tube