The Theoretic Research Of Fiber Drop Sensor

The optical fiber drop sensor is a type of the liquid-testing sensors based on the relationship between the dripping process and the characters of the liquid to be tested. It is potentially useful testing systems of physical and chemical characters of liquid samples by analyzing the variety of the light intensity, termed as the fingerprint drop trace, shortly FDT.The fingerprint drop trace could be acquired by theoretic analysis. At first, the theory of relationship between liquid character and drop shape formation is discussed. The information of the drop shape has been acquired when the drop is dripping, and the profile curve of the drop also can be acquired. A theoretic model can be set base on the precondition that take the drop head as a concave mirror. Finally, using the theory of optic field in the plastic fiber and the Fresnel law of reflection, the fingerprint drop trace can be approximately work out. At last, the formation and infection factor of rainbow peak and vibration peak are discussed.The fingerprint drop trace can by acquired through theory analysis, it has insrructive signification for experiment, it also very help for liquid differentiation.