对射式螺旋形光纤液位传感器的设计与实现

Design and realization ofan opposite-type spiral optical-fiber liquid-level sensor

介绍了一种将对射和螺旋两种结构结合在一起的光纤液位传感器。该传感器以两根侧发光光纤为基础,其中一根作为发射光纤,另一根作为接收光纤,当液面变化引起外部介质折射率发生变化时,发射光纤中光功率的损耗量会发生变化,耦合进入接收光纤的光功率会随之变化,通过检测此变化量即可获知液面高度信息。相对于直接使用两根直侧发光光纤对射的结构而言,螺旋结构的引入会提高光功率相对变化量,从而使其获得更好的性能。实验结果表明,该传感器能够实现液位的连续测量,并具有较好的重复性能。

An optical-fiber liquid-level sensor which combines two structures, opposite-type and spiral-type is present. The sensor is based on two side-glowing optical fibers, one as a launching fiber and the other as a receiving fiber. When refractive index of external media varies with liquid-level, light leakage of the launching fiber changes and then light in- tensity coupled into the receiving fiber will change. So the liquid-level can be obtained by this change. Compared with a sensor using two side-glowing optical fibers directly, spiral structure introduction can increase relative variation and then imorove its performance. The experimental results indicated feasibility and excellent repeatability of the sensor.