基于渐变热压塑料光纤和干涉膜的液位和温度同步测量方法研究

Research on the liquid level and temperature measurement based on gradient hot-pressed plastic optical fiber and interference film

摘要:

为了消除液位测量过程中，环境温度漂移的影响，本文提出了一种渐变热压塑料光纤和PE干涉膜复合结构传感器。基于液位改变引起渐变热压光纤中透射光强的正比变化，采用透射光强解调液位高度；同时通过塑料光纤间固化PE薄膜构建F-P干涉仪，用于感测环境温度的影响；最后借助同时解调某一干涉峰的峰位波长和透射光强，实现液位和温度的同步测量，进而消除液位测量过程中环境温度的交叉影响。实验结果证明，在0-65 mm液位范围内，液位感测灵敏度可达0.552 %/mm。该传感器具有成本低、易于批量生产、强的鲁棒性，尤其可通过增加串联热压光纤段数目，按需增大液位测量范围等优点，可广泛用于石油储运、化工、智能制造等领域。

Abstract:

In order to eliminate the influence of ambient temperature drift during liquid level measurement, a composite sensor with PE interference film and gradient hot-pressed plastic optical fiber is presented, which can be used for simultaneous measurement of two parameters of liquid level and temperature. Based on the direct ratio of transmitted light intensity to liquid level, the liquid level is demodulated by transmitted light intensity, and the F-P interferometer is constructed by curing PE film between plastic optical fibers, it can be used to detect the change of ambient temperature, and can realize the simultaneous measurement of liquid level and temperature by demodulating the peak wavelength and transmitted light intensity of an interference peak at the same time, so as to eliminate the cross-influence of ambient temperature in the process of liquid level measurement. The experimental results show that the sensitivity of liquid level is 0.552 %/mm in the range of 0-65 mm. In particular, the measuring range of liquid level can be increased by increasing the number of hot-pressed fiber. the sensor has the advantages of low cost, easy batch production and strong robustness. It can be widely used in petroleum storage and transportation, chemical industry, intelligent manufacturing and other fields.