Lü Tao, Yang Suping
School of Mathematics and Physics, China University of Geosciences, Wuhan, China.
Appl Opt. 2007 Jun 20;46(18):3682-7. doi: 10.1364/ao.46.003682.
An optical fiber liquid-level sensor based on an extrinsic Fabry-Perot (FP) cavity is proposed and demonstrated. The FP cavity consists of the end of the single-mode optical fiber and the elastic silicon layer. Liquid pressures act on the mechanical construction to change the cavity length, resulting in differential phase shifts that may be observed as variations of the output signal intensity. Self-compensated steps have been taken to obtain high accuracy and long-term stability in realistic circumstances. Experimental results indicate that accuracy of 2 mm over a full scale of 3.5 m (water) is obtained under ambient temperature 10-38 degrees C. The sensor can be used to measure liquid levels continuously and accurately in explosive and flammable environments.
提出并演示了一种基于外腔法布里-珀罗（FP）腔的光纤液位传感器。FP腔由单模光纤的末端和弹性硅层组成。液体压力作用于机械结构以改变腔长，从而导致差分相移，可将其观测为输出信号强度的变化。已采取自补偿措施以在实际情况下获得高精度和长期稳定性。实验结果表明，在环境温度10 - 38摄氏度下，在3.5米（水）的满量程范围内可获得2毫米的精度。该传感器可用于在易爆易燃环境中连续且准确地测量液位。
